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CUMR-T-81-007 C3
TREMIE CONCRETE FOR BRIDGE PIERS AND
OTHER MASSIVE UNDERWATER PLACEMENTS
Washington, D.C, 20590
Document is available to the public throughthe National Technical Information Service,Springfield, Virginia 221 61
Report No. FIIWA/RD-81/I53, !LOAN COPY ONLY
*4' Sea Grant College ProgramUniversity of CaliforniaU voila, CA 92093
FOREWORD
This report describes a laboratory and field investigation ofconcrete that is placed underwater by tremie. It will be ofinterest to bridge engineers and to other engineers concernedwith hydraulic structures placed in rivers and along the coast.Technically, it presents recommended guidelines and specifi-cations to cover all aspects of a field construction project,such as mixture design, placement procedures, flow patterns, andtemperature development.
The report presents the results of the study partially funded bythe Federal Highway Administration, Office of Research, Washing-ton, D.C., under Contract DOT-FH-11-9402. This final reportcovers the entire study, which was initially sponsored andfunded by NOAA, National Sea Grant College Program, Departmentof Commerce, under a grant to the California Sea Grant CollegeProgram, f04-7-158-44121, and by the California State ResourceAgency, Project Number R/E-14.
Sufficient copies of the report are being distributed to providea minumum of one copy to each FHWA regional office, one copy toeach FHWA division office, and one copy to each State highwayagency. Direct distribution is being made to the division offices.Additional copies of the report for the public are available fromthe National Technical Information Service ANTIS!, Department ofCommerce, 5285 Port Royal Road, Springfield, Virginia 22161.
Charles F. Sc eyDirector, Office of ResearchFederal Highway Administration
NOT ICE
This document is disseminated under the sponsorship of theDepartment of Transportation in the interest of informationexchange. The United States Government assumes no liabilityfor its contents or use thereof. The contents of this reportreflect the views of the contractor, who is responsible forthe accuracy of the data presented herein. The contents donot necessarily reflect the official policy t>f the Departmentof Transportation. This report does not constitute a standard,specification, or regulation.
The United States Government does not endorse products ormanufacturers. Trade or manufacturers' names appear hereinonly because they are considered essential to the object ofthis document.
Technical Report Ooctteentotion Page
3. Recipient's Carol og Ho.2. Government Accession Ho.1. Report Ho.
FHWA/RD-81/153d. Tiri ~ and Subti tlo
S, Report Date
September 1981TREMIE CONCRETE FOR BRIDGE PIERS AND OTHER MASSIVEUNDERWATER PLACEMENTS
d. Per Oneing OrgOnieatiOn Cede
fi. Performing Orgonisotion Repor ~ Ho.
Ben C. Gerwick, Jr., Terence C. Holland, andG. Juri. Komendant
T-CSGCP-004
10. Work Unit Ho. T R Al S!
FCP 34HO-0049. Performing Organisation Home and AddressDepartment of Civil EngineeringUniversity of CaliforniaBerkeley, Calif. 94720
ll. Controct ar Grant Ho.
DOT-FH-11-940213. Type of Report and P ~ riod Covered
Sponsoring Agency Home ond AddressOffices of Research and DevelopmentFederal Highway AdministrationU ~ S. Department of TransportationWashington, D. C. 20590
Final Re ortSponsoring Agency Cods
N/0720
Supplementary Hotes
FHWA contract mana er: T. J. Pasko HRS-22
16. Distrihunon StatementNo restrictions. This document is available to the public through the NationalTechnical Information Service, Spring-field, Virginia 22161.
17. Key Wordstremie concrete; portland cement;underwater concrete; pozzolans;heat development in concrete;bridge pier construction,'concrete mixture design. 21 ~ Ho. of Pegrs 22. Price20. Security Classif. ef this poge!19. Security Clossif. of this report!
Unclassified
fore DOT F 1100.1 <a-22!
Unclassified 203
Reproduction of cotnpleted pooe authorised
lb. "h'"o" This study reviewed the placement of mass concrete under water using atremie. Areas investigated included a! Mixture design of tremie concrete includingthe use of pozzolanic replacement of portions of the cement; b! Flow patterns andflow related characteristics of tremie-placed concrete; c! Heat development and asso-ciated cracking problems for tremie concrete; d! Prediction of temperatures in mas-sive tremie concrete placements; and e! Quality of tremie-placed concrete. Addi-tionally, the tremie placement of a massive cofferdam seal for a pier of a ma]orbridge and the tremie placement of a deep cutoff wall through an existing earthfilldam are examined.A recommended practice and a guide specification for massive tremie placementsare provided. These items cover basic principles of tremie placement, concrete mate-rials and mixture design, temperature considerations, placement equipment, preplace-ment planning, placement procedures, and postplacement evaluation.
Item 812 continued!This work is a result of research sponsored, in part, by NOAA, National SeaGrant College Program, Department of Commerce; under a grant to the California SeaGrant College Program,-404-7-158-44121, and. by the California State Resources Agency,Project Number R/E � 14.
TABLE OF CONTENTS
~Pa e
1
1.1
1.2 3 33
4 612
' ~ ~ ~
evaluated.1 ~ 3
and
1.4
2.1
2.223
23
23
23
302.3 30
30
32
3737
55
57
57
2.3.3
2.3.4
2.3.5
2 ~ 3.6
2.3.7 ~ ~ 0 4 ~ i ~ ~
61
623 ~ 1
3.262
62
62
62
62
63
63
INTRODUCTION......... ~
CHAPTER 1. SMALL-SCALE LABORATORY COMPARISONS OFSELECTED TREMIE CONCRETE MIXTURES.
Objectives.Background.
1.2.1 Workability of tremie concrete.1.2.2 Description of tests performed.1.2.3 Description of concrete mixturesObservations and discussion1.3.1 Slump, unit weight, air content,
temperature tests1.3.2 Tremie flow test.1.3.3 Time of setting test.1.3.4 Bleeding test1.3.5 Segregation susceptibility tests.1.3.6 Temperature development test.1.3.7 Compressive strength test1.3.8 Splitting tensile strength test1.3.9 Slump loss test1.3.10 Overall performanceSummary I t i ~ ~ ~ ~ ~ i ~ ~ ~ o ~ ~
CHAPTER 2. LARGE-SCALE LABORATORY TESTS OF TREMIECONCRETE PLACEMENT
Obj ectiveBackground.2.2.1 Description of the test procedure2.2.2 Description of concrete mixtures evaluated.2.2.3 Flow of tremie concreteObservations and discussion2.3.1 Direct observations of concrete flow.2.3.2 Flow during placement as determined by
soundingsSurface profiles and surface appearanceDistribution of concrete colorsConcrete density.Flow around reinforcing steelLaitance formation. ~
2. 4 SummaryI
CHAPTER 3. TREMIE CONCRETE PLACEMENT, I-205COLUMBIA RIVER BRIDGE.
ObjectiveBackground.3.2.1 Description of the bridge3.2.2 Geometry of Pier 123.2.3 Temperature predictions3.2.4 Tremie concrete mixture3.2.5 Placement technique
12
1515
15
15
15
19
19
19
19
22
~Pa e
3.3 6363
76
7982
82
temperatures.
3.4
87
4.1
4.2
4.3
4.4
106
5.1
5.2
106
106
106
106
106
106
106
106
108
ill
5.3
~ ~
5.4
117
6.1
6.2
6.3
~ t ~ ~ ~
6.4
TABLE OF CONTENTS, Continued
Observations and discussion .3.3.1 Measured temperatures3.3.2 Measured versus predicted3.3.3 Concrete flow patterns,3.3.4 Concrete quality.Summa ry ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ r ~
CHAPTER 4 ~ TREMIE CONCRETE CUTOFF WALLrWOLF CREEK DAM
Objective I e ~ t ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~Background.4.2.1 Description of the dam.4.2.2 Description of problem.4.2.3 Repair proceduresObservations and discussion .4.3.1 Quality of tremie concrete.4.3.2 Tremie starting leakage4.3.3 Tremie joint leakage.4.3.4 Tremie centering.4.3.5 Concrete placement rate4.3.6 Tremie removal rate4.3.7 Breaks in placing4.3.8 Water temperature during placement.4.3.9 Concrete mixture.
4.3.10 Observation of placements4.3.11 Core and placement logs4.3.12 Tremie resistance to flow4.3.13 Potential for concrete segregation.S ummary
CHAPTER 5. TEMPERATURE PREDICTIONS FOR TREMIE CONCRETE.
ObjectiveBackground.5.2.1 Need for finite element analysis5.2.2 Finite element program selected5.2.3 Cracking predictions.Observations and discussion5.3.1 General description Program TEMP5.3.2 User options and variables.5.3.3 Example of Progra~ TEMP usageSummary
CHAPTER 6. FLOW PREDICTIONS FOR TREM!E CONCRETE
Ob j ectiveBackground.6.2.1 Literature review . ~6.2.2 Dutch investigationObservations and discussion6.3.1 Square placement model.6.3.2 Advancing slope placement model6.3.3' Summary of Dutch placement models6.3.4 Dutch hydrostatic balance model6.3.5 Example placement calculations.S ummary
87
87
87
87
87
90
90
90
93
93
93
93
96
96
96
96
96
96103
103
117
117
117
118
118
118120
122
122
122
122
TABLE OF CONTENTS, Concluded
~PeCHAPTER 7. CONCLUSXONS AND RECOMMENDATIONS. . . . , . . . i , ~ . . . . 127
works o i ~ ~ ~ ~
APPENDIX A: CONCRETE MIXTURE PROPORTIONSMIXTURE EVALUATZON TESTS. . . , , . . . . . . . . . , . . . 141
B'. CONCRETE MATERIALS - MIXTURE EVALUATION TESTS . . . , . . . 143
144
D: DETAXLED DATA " MIXTURE EVALUATION TESTS, . . . . . . ~ . . 146E: SOUNDZNG DATA - LABORATORY PLACEMENT TESTS. . . . . . . , ~ 149F: SURFACE PROFILE DATA � LABORATORY PLACEMENT TESTS . ~ . . . 151Gl COLOR LAYER DATA - LABORATORY PLACEMENT TESTS . . . . . . . 153He TEMPERATURE INSTRUMENTATION PLAN � PIER 12!
I 205 BRXDGE ~ ~ ~ s ~ ~ ~ ~ ~ ~ ~ e ~ ~ ~ ~ s ~ ~ ~ a 1 5 5I ~ DATA RECORDING AND REDUCTION - TEMPERATURES ZN
PIER 12 SEAL CONCRETE . . . . , . . o . ~ . ~ . . . . . , ~ 165J ~
~ ~ ~ 167
Kl LISTING OF PROGRAM TEMP . . . . . . . . . . . . . o . ~ 172Ll USER INSTRUCTIONS - PROGRAM TEMP ~
182
M: INTERFACE INSTRUCTIONS - PROGRAMS TEMP AND DETECT . . . . . 187
~ ~ I 189
7.1 Specific conclusions.7.2 General conclusions7.3 Recommended practice.7. 4 Guide specif ica t ion7.5 Recommendations for further
REFERENCES, ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ I ~
C: SUMMARIZED DATA - MIXTURE EVALUATION TESTS.
PREDICTED VERSUS MEASURED TEMPERATURES - PZER 12,I-205 BRIDGE.
Nl SAMPLE OUTPUT - PROGRAMS TEMP AND DETECT.
127129
~ 130~ l34
137
139
LIST OF ILJUSIRATEONS
Title
Schematic of compacting factor apparatus
Schematic of segregation susceptibility apparatus.
~Pa eFi ure No.
Concrete sample after performance of segregationsusceptibility test.
Schematic of tremie flow test apparatus.
Tremie flow test apparatus
Tremie flow test being performed
Schematic of flow trough apparatus
Partially assembled tremie placement box . . . ~
10
24
Tremie placement box completely assembled and readyfor placement.
10
2712
28
14
15
3316
Sounding locations in tremie placement box17
Tremie concrete profiles during placement, Test l.
Tremie concrete profiles during placement, Test 2.
3418
3519
Tremie concrete profiles during placement, Test 3.
Tremie concrete profiles during placement, Test 4.
20
21 36
22 Tremie concrete profiles during placement, Test 5. 36
Centerline and right edge surface profiles, Test 1
Centerline and right edge surface profiles, Test 2
23 38
38
Centerline and right edge surface profiles, Test 325 39
Centerline and right edge surface profiles, Test 4
Centerline and right edge surface profiles, Test 5
26 39
27 40
Concrete surface, Test 1
Close-up of concrete surface, Test
28 41
1 4 ~ ~29 41
30 Concrete surface, Test 2
Concrete surface, Test 3
42
31
Details of tremie hopper and pipe during a placement
Schematic of tremie placement box.
Overall view of placement operation.
Taking sounding during break in. concrete placement
Coring pattern for large-scale laboratory placements
Tremie-placed concrete at completion of coring program
Observed and postulated flow of concrete near tremie pipe.
LIST OF ILLUSTRATIONS, Continued
Title
Concrete surface, Test 4
Concrete surface, Test 5
Color distribution, Test 1
Fi ure No. ~Pa e
4332
4433
34
45Color distribution, Test 235
Color distribution, Test 3 4636
Color distribution, Test 4 4637
38 Color distribution, Test 5
Cross section, Test 2.
Cross section, Test 2.
4839
4940
41 Cross section, Test 3. 50
Cross section, Test 3.
Cross section, Test 4.
Cross section, Test 4.
Cross section, Test 4.
Reinforcing steel placement.
Concrete laitance! flow around reinforcing steel,T es't 1 e ~ ~ ~ ~ ~ ~ ~ s ~ + ~ ~ i ~ ~ ~ ~ ~ ~
Concrete flow around reinforcing steel, Test 5
42 51
5243
44 53
45 54
47
59
48 60
49 Overall view of site during placement of tremieconcrete for Pier 12 of I-205 Bridge 64
50 View inside cofferdam during tremie concreteplacement.
Details of tremie placement equipment.
Tremie system being moved to new location.
6651
52 67
53 Steel end plate and rubber washer being tied to endtremie pipe. 68
69
Manual recording of temperatures in seal concrete. 70
Location of selected temperature instruments56 73
57 Temperature history, instrument No. 8 ~ ~ ~ 74
58 Temperature history, instrument No. 11 74
59 24
29
times, long
Tempera ture history, instrument No.
Temperature history, instrument No.75
6075
61 Tremie concrete profiles at variousaxis of seal 80
V1
General instrumentation plan, Pier 12, I-205 Bridge.
LIST OF ILLUSTRATIONS, Continued
TitleFi ure No.~Pa e
Tremie concrete profiles at various times, longaxis of seal 4 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
6280
Tremie concrete profiles at various times, shortaxis of seal
63
Tremie concrete profiles at various times, shortaxis of seal
6481
Mounding on surface of seal.6583
6683Low area in surface of seal.
67 Core locations, Pier 12. 84
6885Section of core taken from tremie concrete
Water flowing from core hole in tremie seal.
Schematic of tremie-placed cutoff wall
Casing handling machine.
Breather tube in tremie hopper
Tremie support scheme. . . . . , . . . . . ~
Secondary element excavation device.
Cores taken from primary element
Pine sphere inside tremie at beginning of placement.
Position of pine sphere upon leaving tremie,
Fins added to tremie pipe to insure proper centering
6985
7088
8971
7289
7391
7492
92
7694
7794
78
Primary element at completion of tremie placement.7997
80 Key for Figures 81 through 84.
Analysis of element P-611.
Analysis of element P-985.
Analysis of element P-1001
98
81
82100
83101
84 Analysis of element S-576. 102~ ~ ~ ~ ~
85104
86107
87 109
88 112
89112
90113
91 113
92114
V11
Tremie geometry and derivation of resistance to flow
Geometry used by program TEMP.
Typical finite-element grids generated by program TEMP
Predicted versus measured temperatures, centerline
Predicted versus measured temperatures, outside edge
Predicted versus measured temperatures, off centerline
Predicted versus measured temperatures, outside edge
Section through seal showing locations of nodes.
LIST OP ILLUSTRATIONS, Concluded
Title ~Pa e93
95 Section through seal showing horizontal temperaturegradientsi ~ ~ ~ I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 116
96 Section through seal showing vertical temperaturegradients. 116
Dutch failure model.97119
98 Dutch square placement model
Placement curves derived from Dutch square placementmodel.
Dutch advancing slope placement model.
Geometry and notation for example spacing calculations
Geometry and notation of advancing slope technique
119
99
121
100121
101
102124
Horizontal variation in predicted temperatures . . . . . . 115
Vertical variation in predicted temperatures . . . . . . . 115
LIST OF TABLES
~Pa e
5
Table No. Ti. tie
Summary of test program
Summary of concrete mixtures tested
Summary of mixture evaluation test data
13
14
16Rankings, tremie flow tests
16Rankings, time of setting tests
Rankings, bleeding tests
Rankings, segregation susceptibility tests.
Rankings, temperature development tests
Rankings, compressive strength tests.
Rankings, splitting tensile strength tests.
Rankings, slump loss tests.
Overall concrete performance.
17
17
18
18
10 20
20
12 21
Characteristics of concrete mixtures used in laboratoryplacements.
1331
5614
6415
6516
7117
7218
77
20 Predicted versus measured temperatures at variouselevations.
7821 Summary of concrete production for Pier 12.
Tremie concrete placement rates22 95
9723 Tremie concrete mixture, Wolf Creek Dam
Tremie resistance to flow measurements. 10424
11025 Variables used in example problem
Heat functions used for temperature predictions
Calculated flow distances
11026
12527
Representative concrete unit weights.
Temperatures predicted using the Garison Method
Tremie concrete mixture, Pier 12, I-205 Bridge.
Maximum temperatures recorded in Pier 12 seal concrete.
Maximum temperatures grouped by instrument location
Temperature gradients in outer portions of seal concrete.
Introduction
When major structures are built in s river,harbor, or coastal area, the underwater por-tions of the structure usually require place-ment of underwater concrete. In some casesplacement of underwater concrete is the onlypracticable means of construction, while inother cases, it resy be the most economical orexpeditious mesne,
In recent years, the device most frequentlyused for placing underwater concrete has beenthe tremie. A tremie is simply a pipe langenough to reach from above water to che loca-tion of concrete deposition. A hopper isusually attached to the COp of the tremie COreceive concrete being supplied by bucket,pump, or conveyor. In most cases, the lowerend of the tremie ie init'islly capped to excludewater. Once the tremie is filled with concrete,it is raised slightly, the end seal is broken,and the concrete flows out embedding the endof the tremie in s mo~nd of concrete, Intheory, subsequent concrete flows into thismound and is never exposed directly to thewater. See Chapter 2 regarding this flawtheory.!
One critical element af a successful tremieplacement is maintaining the embedment of themouth of the tremie at all times in the freshconcrete . If this embedment is lost, water willenter the pipe and any concrete added at thehopper will fall through water resulting insevere segregation of aggregates and the wash-ing out of cement and other fine particles,Such a segregated material ie unfic for eithera structural or nonstructural application.*
In bridge construction tremie concrete hss longbeen used ta seal cofferdams so that they may bedewatered and the piers constructed in the dry,In such cases, the tremie concrete serves ss atemporary seal and as s mass concrete base.Tremie concrete has also been used to plug thebottom of caiseone co insure full bearing overthe surface area.
More recently, tremie concrete has been usedfar the structure itself rather than just as aseal. In this application, the trcmie concreteis reinforced with pre-placed reinforcing steel.This structural use has been applied to drydocks, pump houses' snd especially to the piersof major over-water bridges, including theseveral Chesapeake Bsy Bridges, several ColumbiaRiver Bridges, and major crossings over SanFrancisco Bay.
Among the largest tremie concrete placements arethe east anchorages of the two Delaware Memorial
+ For more inforsurtion on the tremie techniquesee references 1 through 5.
Bridges quantities approached 30,000 yd3�3,000 m3! each! and the repair and recon-struction of the stilling basin for Tarbela Damin Pakistan total placement of almost 57,000 yd3�3,000 m3!
Among the deepest tremie placeraents are those ofthe Verrazano-Harrows Bridge l70 fc! �2 m!and the Wolf Greek Dsm cutoff wall �80 ft! 85 m! which is described in Chapter 4. Evendeeper plscements have been made in mine shafts.
Although tremie concrete has proven itself onmany projects, there have been s significantnumber of unsatisfactory placements whichnecessitated removal and reconstruction. Seriousdelays, large cast over-runs, and major claimshave resulted .
In light of the problems which have occurredduring tremie placements, the ConstructionEngineering snd Management Group at the Univer-sity of California, Berkeley, has undertaken amajor study of the tremie placement process.This study has two main objectives, The firstis to establish criteria for mixture design andplacement procedures which will minimize thenumber of unsatisfactory events, The secondobjective is to facilitate snd encourage thewider use of structural tremie concrete byinsuring greater reliability . Achieving thesetwo objectives will permit significant savingsin costs and time on major underwater constructionprojects.
The work covered by this report consists of threeinterrelated areas of investigation The first'area considers tremie concrete mixture designand tremie concrete flow after leaving thetremie pipe . The second area considers tempera-ture development in massive tremie placemants.The third area of investigation involved a pro-ject which, although not a mass underwaterplacement, offered a unique opportunity toexamine a tremie placement at extreme depths�80 ft SS m!! and which used s mixture suit-able for maes plscemente. The work performedin each af these three areas of investigationis described in Chapters 1 through 6. Chapter 7contains conclusions and recorrnendatione relat-ing to all areas snd identifies areas requiringadditional study. Additionally, Chapter 7contains a recommended practice snd a guidespecification for massive tremie placements .
The work described in this report was jointlyfinanced by the Federal Highway Administration FHWA! snd the University of California SeaGrant Program. This diversity of fundingrepresents the diversity of applications forthe results of the work. The reconmrendationepresented apply to sll massive underwater con-crete placements whether for s bridge pier fora major highway or for a footing for an off-shore terminal.
Much of the work described in this report wasconnected with the construction ef the tremie
concrete seal for Pier 12 of the I-205 Bridgeover the Columbia River near Portland, Oregon Anadditional task covered by the FlgfA grant forthis research project was to provide logisticalsupport, through the State of Oregon HighwayDepartment, to.three other groups of investiga-tors working at the Pier 12 site . These in-vestigations were aimed at determining thequality of the concrete in the seal by non-destructive methods. The specific investiga-tions were as follows;
a. Lawrence Livermore Laboratory: Cross-Borehole Electromagnetic Examination; FHWAPurchase Order 47-3-0069, Task F.
b . Ensco, Inc.: Short Pulse Radar Investiga-tion and High Enexgy Sparker System Investiga-tion; DOT contracts DOT-FH-11-9120 and DOT-FH-11-9422.
c. Ho!osonics~ Inc.: Through Tx'ansmissionAcoustic Surveys for Evaluation of Tremie Con-crete: MX contract DOT-FH-11-926g, Task D.
The support received from Mr. Allan Harwood,Project Engineer for the State ef Oregon,1-205 Bridge Project, and from Mr. Joe Turner,Resident Engineer, Cox'ps of Engineers, WolfCreek Dam Remedial Work, is gratefully acknow-ledged,
CHAPTER 1
1,2 Back round.
SHALL-SCALE LABORATORY COHPARISONS OFSELECTED TREHIE CONCRETE NIXTURKS
1.l Ob'ectives. The objectives of this portionof the project were to define the character-istics of a concrece mixture necessary forsuccessful placement by cremie snd to evaluateseveral nan-traditional concrete mixcures whichappeared to have potential for use in tremieplscements. To accomplish these objectives, avariety of concrete mixtures meeting generalguidelines for placement by tremie was comparedto a reference tremie mixture using s series ofstandard and non-standsrd laboratory tests.
1.2.1 Workabiiic of tremie concrete. Thereare two concrete characteristics generallyregarded as critical for a successful tremieplacement. The concrece must flow readily andit must be cohesive. In this case, coheaion isthought of as that property which prevents theconcrete fram segregating as well as preventsthe cement fram being washed out of the con-crete due to contact with mater. In practice,flowability and cohesiveness are usuallyachieved by adding extra cement, maintaining alow water-cement ratio and a high percentage offine aggregate, snd by having s high slump.
Unfortunately for the concrete technologist,these two desired characteristics are neithereasily defined nor easily measured. These twaterms may be replaced by the more general term"workability" which is casssonly used to de-scribe essentially the same characteristics farconcrete which is placed in the dry. Althoughit will be shown that workabi'ity is na easierta measure than flowability or cohesiveness,there is certainly s great deal of previouswork to draw upon,
An excellent definition for workability, whichincludes the characteristics required far tre-mie placement, was presented by Powers ref. 6!, "Qorkability is that property of splastic concrete mixture which determines theease with which it csn be placed, and thedegree co which it resists segregation. Itembodies the combined effect of mobility andcohesiveness."
This definition is certainly not controversial.The difficulty arises in determining what pro-perties of s fresh concrete determine its work-ability. Fallowing is s brief sampling fromthe literature.
1, Powers ref. 6! listed three factors asdefining workability:
a! The quantity of cement-water paste includ-ing admixtures, if any! per unit volume ofconcrete.
b! The consistency of the paste - which isdependent on the relative proportions and thekinds af material of which it is composed.
c! The gradation and type of the aggregate.
2. Herschel ref. 7! listed four character-istics which he thought defined the workabilityof a concrete mixture, These were "harshness,segregation, shear resistance and stickiness."His paper included tests for each of theseitems as well as examples af the use of thetests to evaluate a variety of concrete mix-tures.
3, Tattersall ref. B! in an exhaustive studylists five factors affecting the workability ofconcrete:
a! the time elapsed since mixing:
b! che properti.ss of the aggregate, in par-ticular, particle shape and sixe distribution,porosity, snd surface texture;
c! the properties of the cement, to an extentthat is less important in practice than theproperties of the aggregate;
d ! the presence af admixtures;
e! the relative proportions of the mix con-stituents.
Tattersall cakes a rheological approach tomeasuring workability and argues that any ofthe cosxsonly used tests for workability measureonly one aspect while measurement of more thanone is required. He writes that "at least twaconstants are needed ta characterise the work-ability of fresh concrete, and the two con-stants are dimens ionally di f ferent. "
Tattersall concedes chat development of apractical test to determine these two constantsis same time away.
Presentation of theories of the factors com-prising workability could ga on for some length.Tattersall alone lists l43 references. Asufficient sample has been presented toestablish that there is s wide variscy of con-cepts concerning workability for which anequally large variety of tests have been pro-posed.
Based upon the work of the authors di.scussedabove and others!, the following conclusionswere drawn for the present work;
1. There is no single test which will providedefinitive data on the workability of sconcrere mixture. Any attempt to develop ssingle test for use with tremis concrete wouldprobably be facile.
2. The ease beneficial approach would be toapply s series of standard tests each measur-ing some characceristic of potencial tremiecancrstes! and non � standard tests designedspecially to re late to crsmie placement! to areference concrete mixture snd the other mix-tures of interesc. Behavior of the variousmixtures in relation to the reference mixturecauld then be assessed.
3. The objective of the testing would be todetermine the significant characteristicsrequired of tremie concrete, while simultaneous-ly evaluating the selected mixtures, ratherthan to develop a single recommended concretemixture,
Mich these conclusions in mind, s number ofstandard tests were reviewed to determine theirsuitability for use in this project. Severalof the more coaaaon tests i. e., Powers ' Remold-ing Test! were eliminated prior ta beginningactual laboratory work due to their incompati-bility with concretes in the desired slumprange. The tests which were selected are describedin the next section.
1.2.2. Descri tion of teats erformed. A sum-mary of the test program is presented in Tablel. The basic test plan was co subject each ofthe concrete mixtures to the selected teststhree times. To insure objectivity, no mixturewas tested more than once on a given day.
2. Unit weight.
Standard: ASTM C-138 CRD-C 7!.Frequency: One test per batch.Data Reported: Unit weight, lb/ft3 kg/m3!.
3, Air content presaure method! .
Scandard: ASTM C-231 CRD-C 41!.Frequency: Initially, two tests per fourbatches. Later, two tests per three batches.Dsts Reported.' Air content, percent.
4. Bleed ing.
Standard: ASTM C-232 CRD-C 9!.
Frequency. One rest per day.Data reported: Total bleed water accumulationat 160 minutes + 10 min! after completi.on ofmixing� ml; bleed water as percentage of avail-able mixing water.
5. Compressive Strength.
Due to capacity limitations in the laboratorymixing equipment, each dsy's test of a particu-lar concrete mixture required that multiplebatches af concrete be produced. Initially,four batches �.8 ft each �.05 m !! wererequired. Later, after two tests had beendropped from the test program, the number ofbatches required was reduced to three. Table 1also shows which testa were performed on eachbatch of concrete.
Par each of the batches of concrete produced,the Sump, unit Weight, air COntent two Ofevery three batches!, snd temperature of theconcrete were determined iaaaediately aftercampletian of mixing. If these variables werewithin the correct range for the mixture beingtested, the batch was accepted ss being repre-sentative of that mixture.
All concrete was batched snd mixed in accordancewith ASTN G 192* CRD-C 10!++. As fsr as waspossible, all tests throughout the test programwere performed by che same individual to elim-inate any operator induced variations.
A description of each of the tests in the pro-gram follows:
1. Slump test.
Standard: AS'TM C-143 CRD-C 5!Prequency: One test per batch.Data reported' .Slump, in. cm!.
* ASTM test designations are from the AnnualBook of ASTM Standards ref. 9!.
ae CRD-C test designations sre from the Corps ofEngineers Handbook for Concrete and Cmaent re f. 10! .
Standard: ASTM C-39 CRD-C 4!.Frequency: Three cylinders � x 12 in. �5.2 x30.5 cm!! were prepared from each batch.Remarks: Specimens were cured in accordance withASTM C-192 CRD-C 10! and capped in accordancewith ASTM C-617 CRD-C 29! using a sulfurmortar, Testing was accomplished at 7, 28, and90 days. Gf the three cylinders made fram aparticular batch, one was tested st each ageData Reported: Compressive strength, lb/in. MPa!.
6. Splitting Tensile Strength.
Standard: ASTM C-496 CRD-C 77!.Frequency: One cylinder � x 6 in, �,6 x 15.2cm!! wss prepared from each batch.Remarks: Specimens were cured in accordance withASTM C-192 CRD-C 10!, Testing was done at28 days.Data Reported: Splitting tensile strength,lb/in.2 MPs!.
7. Time of Setting.
Standard '. ASTM CW03 CRD-C 86!.Frequency: One teat per day.Data Reported: Time af initial and final setting,minn te s.
8. Relative Temperature Development.
Standard: MonePrequency: Two cylinders � x 12 in. �5.2 x30.5 cm!! per day.Remarks: Disposable metal cylinder molds werefilled with concrete using the same proceduresss the compressive strength cylinders, Eachmold contained a chermaeauple tied st the mid-point. Care wss taken during the concreteplacement ca insure that the thermocouple wasnac disturbed. Sech cylinder was wrapped in sfiberglass insulation blanket and placed in aconstant temperature room. Concrete tempera-rures were recorded using a strip chart re-corder and s digisl thermometer.
TABLE 1 � SUMMARY OF TEST PROGRAM+
Batch 3**Batch 2**Batch 1**FrequencyTest and Standard
YesYesYes1 per batch
1 per batch YesYesYes
Yes2 per day NoYes
Yes1 per day
No1 per day Yes No
YesYes No
Slump LossNonstandard
Yes1 series per day
NA2 per day Abandoned-no data reported!
NACompacting FactorBritish Standard
Yes2 per day YesNo
Yes2 per day YesNoTremie Flow
Nonstandard
Flow TroughNonstandard
*3 batches 1 day's test of a particular mixture3 days' tests complete test of a mixture
*"l.8 ft �.05 m !3 3
OASTM test designations from Reference 9ttCRD-C test designations from Reference 10
SlumpASTM C-143~CRD-C 5th
Un i t We igh tASTM C-138CRD-C 7
Air ContentASTM C-231
CRD-C 41
Bleed.ingASTM C-232CRD-C 9
CompressiveStrengthASTM C-39
CRD-C 4
Splitting TensileStrengthASTM C-496
CRD-C 77
Time of SettingASTM C-403CRD-C 86
TemperatureDevelopmentNonstandard
SegregationSusceptibilityNonstandard
9 cylinders per day� x 12 in. �5.2 x 30.5 cm!!
3 cylinders per day� x 6 in. �.6 x 15.2 cm!!
2 cylinders per day� x 12 in. �5.2 x 30.5 cm!!
2 per day Abandoned-no data reported!
3 cylinders 3 cylinders 3 cylinders
1 cylinder 1 cylinder 1 cylinder
Date Reported: Maximum temperature increaseabove mixing temperarure, degrees F degreesC!; time to achieve naximvm temperature increase,hours.
Weight of concrete, large disc: BWeight of coarse aggregate, large disc: BaWeight of concrete, small disc: AWeight of coarse aggregate, small disc: As
9. Slump Loss.
Standard: none.Preqvency: One series of tests per day.Remarks: Approximately 0.5 ft3 �.01 m3! ofconcrete was set aside from the first batch.At specified times after mixing, a slvmp testin accordance with ASTM C-143 CRD-C 7! vasperformed. Concrete used in the test wss re-turned to the storage psn. The concxeee in thepsn was rexxixed by hand prior to each test.Data Reported: Slump, inches cm!; slump asa percentage of initial slump st T 15, 30,60, 90, and 120 minutes after completion ofmixing.
10. Ccxspacting Pactor.
Standard: British Standard 1881:1952 ref. 11!.This is nat s standard test in the United States.Frequency: Two tests per day.Remsx'ks: Figure 1 shove tbe basic apparatus.Concrete is placed into the top hopper and theflap is released alloving the concrete to dxopinto the lower hopper. The lower flap is thenreleased allowing the concrete co drop intothe cylinder. The concrete in the cylinder isthen etrvck off snd the cylinder is weighed.The cylinder is then refilled and thoroughlycompacted, The ratio of the weight of thepartially compacted drapped! cylinder to theweight of the thoroughly compacted cylinder istermed the compacting factor. More informa-tion on this test msy be found in the reportof ACI Cosmittee 211 ref, 11! or in the varkof Mather ref. 12!.Data Reporeed. Hone, this test vss abandonedafter initial experimentation showed that itdoes not discriminate well msong high slumpconcretes ef the nature of the mixtures beingtested.
11. Segregation Susceptibility
Standard: None.Frequency; Tvo tests per dsy.Remarks: This test wss a modification of thatpresented by Hughes ref. 13! snd later revisedby Ritchie ref. 14!. In the present case,the caspscting factor apparatus vss modified tobe used on this test by fabricating a cone sndtva wooden discs, The modified apparatus isshown in Figure 2, The test begins similarlyta the compacting factor eeet by dropping con-crete into che bottom hopper. Then the con-crete ie dropped onto the cone which caused itto scatter onto two discs. Ths cohesion of theconcrete controls the degree of scatter. Pig-ure 3 shave a sample af concrete after beingdropped on the cone.
The weight of concrete on ehe small and largediscs was determined. Then the concrete oneach disc wss wee sieved on s 1/4 in. �.64 cm!screen to obtain ehe coarse aggregate vhich wasoven dried snd weighed. Thus the follovingfoux weights vere known:
Hughes used the above data to define ehsStability Factor as folIaws:
SF Aa/A!/ Ba/B!
Riechie used ehe same data to define theCohesion Index as follovs:
CI B/A
Data Reported; Stability Pactor; CohesionIndex,
12. Tremie Plow.
Standard: Hone.Frequency: Two tears per dsy.Remarks: This test wss designed to simulateconcrete flov through a eremie pipe. Theapparatus is shown in Pigures 4 and 5. Approx-imately 0.20 fc3 �.006 m3! of concrete wasplaced into the tube in three layers. Eachlayer was rodded 25 times ca produce s uniformdensity fram test to test. After the concretewas in place, the tube wss lifted until ehemouth of the tube vss 4.5 in. 11.4 cm! abovethe bottom af che pail allowing the concretein the tube to flow into the pail Figure 6!.
Af ter the flaw stopped, the distance from thetop of the tube to che tap of the concrete inthe tube vae determined.Data Reported: Plov of concrete, in. cm!.
13. Flow Trough.
Standard: None.Frequency: Two tests per day.Remarks: This test wae intended eo provide ~qualitative measure of the ability of a con-crete to resist washing out of the cement vhenfloving inta water, The appsrstve is shown inFigure 7. Approximateiy 0. 1 fe �.003 m3! afconcrete wss placed into the tx'ough above theslide gate When the gate was lifted, the con-cxete wss intended to flaw into the vater anda qualitative estimate of cmsent washout wasto have been made.Data Reported: Hone, this test wss abandonedafter initial testing showed that no usefuldata wss being obtained.
1.2.3. Descri tion of concrete mixturesevaluated. The first step in the selectionof mixtures to test was the development ofthe standard or reference mixture. The mixtureselected wss based upon recosssendaeians fromthe literature and upon the senior author' spersonal experience on ~ number of major tremi ~placemente. The basic elements of the referencemixture were:
Cement: 7 1/2 sacks/yd3 �05 lb/yd !�18 kg/m3! Water-cement ratio: < 0.45.
Fine aggregate: 45K by weight of taealaggregate.
IO in�5,4 cm!
UPPERHOPPER II in
�7.9 cm!
8 in�0.3 cm!
�5.4 cm!
LOWERHOPPER 9 in
�2.9cm!
Sn I2.7 cm! 8 In
20.3 cm6in I5.2 cm!
CYL!NOER
12 in�0.5 cm!
Figure 1. Schematic of compacting factor apparatus.
UPPERHOPPER
LOWERHOPPER
m!
Figure 2. Schematic of segregation susceptibility apparatus.
CONK9in �2.9cm! DIAMETK5in�27cm! TALL
UPPER18in Dl A MK
LOWER DISC30 in �6.2 cm!DIAMETE R
+ I2.7 cm!
IO in
COMPACTINGFACTORA PPARATUS
Figure 3. Concrete sample after performance of segregation susceptabllity test.
LIFTING HANDLES
SUPPORT COLLAR-CLAMPED TO PAILAT THREE LOCATIONS
METAL PAILIl.5 in �9.2cm!INSIDE DIAMETER
MOUTH OF TUBEIN RAISED POSITION
TUBE- 4 in �0.2 cm!INSIDE DIAMETER24 in �1.0 cm! TAL,L
Figure k. Schematic of tremie flow test apparatus.
Figure 5. Tremie flow test apparatus.
Figure 6. Tremie flow test being performed. Tubeis being lifted off of bottom of pail.
10
54Jaj
aj
Qaj
A OD
0 0 0
X CL
11
Coarse aggregate: 3/4 in. �9.0 nen! maximum.Admixture: Water reducer/retarder, in accord-
ance with manufacturers reconnnendations.Slump: 6 l/2 in. + 3/4 in. �6.5 cm + 1.9 cm!.
It is interesting to note that the character-istics of this reference mixture, which wasderived from the experience of many engineerson a variety of tremie concrete plscements,meet very closely the several requirementslisted above section 1.2.1! as indicatinggood workability for s concrete mixture.
It must be noted that cwo of the items describ-ing the reference mixture, high slump anda Low water-cement ratio, could not be achievedin sll of the mixtures evaluated. In thosecases where there was a conflict, achievementof a slump in the desired range vas used as thedetermining factor.
Once the reference mixture wae established,the remainder of the mixtures in the programwere developed. Table 2 presents a emmnaryof sll of the mixtures evaluated. Detailsof each mixture design may be found in AppendixA.
The first group of mixtures Mixtures 2 and3! were direct variatians af the referencemixture which require no description.
The next group of mixtures wae developedin response to the authors' concrern thatlittle, if any, consideration wse being givento problems of heat generation in massive tremieplacements. While much work has been doneconcerning temperature development in massiveplacemente done in the dry, as of the timeof this testing, no such effort had been putforward for underwater placemente,
The authars felt chat one af the techniquesfrequently used for reducing temperature problemsof mass concrete placed in the dry � possolanicreplacement of s percentage af the cementwould also be suitable for use in underwaterplacements. However, unlike mass placementsin the dry where tocel cement plus porzolancontents are very !ow, the pozzolanic replace-ments for the candidate tremie mixtures werebased upon the original 705 lb/yd3 �18 kg/m3!cement cancent since e harsh, no slump concretewould nat have been acceptable. Mixtures 4, 5,and 6 were developed to evaluate potrolanicreplacements.
The next group of mixtures wae based upon workpublished by The Netherlands Casenittee forConcrete Research ref, 3! describing researchon admixtures to improve the quality of cremie-placed concrete: "The Cosnnittee vas on thelook-aut for sdmixturee which, as s result ofexercising a 'g!ue-like ' effect, would givethe fresh concrete better cohesion so that itwould be lees severely attacked by vater."
A variety of edmixcures were evaluated primarilyon the basis af two factors: the compressivestrength of cubes manufactured above and belowwater; snd, the washing out of cement framthe concrete when dropped through water.
Their findings were:
a. The addition of s small amount of bentonite�.52 by weight of cemenc! gave the greatestretie of underwater to dry strength for thecubes.
b. Larger amounts of bentonite up to 52!showed improvements in cement wash-out atthe expense of compressive strength for cubesmanufactured both above and belov water.
Thus it appeared that bentonite sdditon orreplacement would be beneficial. Mixtures 7,8, snd 9 were developed to examine a vide rangeof concentrations of bentonite.
The final group of mixtures wse developed basedupon experience in grouting where a chixo-tropic agent may be added to thicken grouts.It was beLieved that such an agent could helpa tremie-placed concrete resist mashing out ofcement. A proprietary agent vas selected andused to develop Mi~tures 10 snd 11. Due to theextreme thixotropic behavior of these mixturesss noted during trial batch preparations, thecement in Mixture ll was reduced to 611 lb/yd3�62.5 kg/m3! in an effort to develop a moreecanomical mixture.
Due to problems with the behavior of Mixtures10 and 11 which raised doubts about theirsui,tability for use in a gravity feed cremiesituation, testing of these tvo mixtures waslimited to one repetition only. The problemswhich developed are described below.
Description of the materials used in the testmixtures may be found in Appendix B,
1.3 Observations and discussion. Table 3 pre-sents a smmnsry of the results of the tests forall of the mixtures. Susnnaries for each mix-ture are in Appendix C while data from eachof the individual tests performed are inAppendix D. Discussion of the results of thespecific tesce is presented in the followingsections. This data should be reviewed withthe thought in «ind that there were two basictypes of tests in the test program � those inwhich s high ranking is believed to be indica-tive of improved performance as tremie-placedconcrete and those in which the ranking is notparticularly significant. The latter type oftest was included to insure that no anomoliesin performance hsd been caused by the variousadmixtures and additives.
1.3,1 Slum unit wei ht air content sndtern erature tests. The data for sll of themixtures were within acceptable ranges. Thefollowing minor discrepancies were noted:
1. The slump for Mixture 9 wse slightly belowthe stated range. However, this vae toleratedto prevent increasing the wster-cement ratiosny higher than 0,67 which wss necessary toachieve the 5.3 in. �3.5 cm! slump.
2. The slump for Mixture 11 wss slightly abovethe stated range. This was attributed to the
12
TABLE 2 � SUMMARY OP CONCRETE MIXTURES TESTED
Water-cement
Ratio+*Description*No.
0. 45Standard Mixture reference!
Standard Mixture without Water Reducing/RetardingAdmixture
0.46
Standard Mixture without Water Reducing/RetardingAdmixture with Air-Entraining Admixture
0. 44
Standard Mixture with 20 Percent Replacement ofCement by Pozzolan
0. 51
Standard Mixture without Water Reducing/RetardingAdmixture with 20 Percent Replacement of Cement byPozzolan
0. 53
0. 62Standard Mixture with 50 Percent Replacement ofCement by Pozzolan
0.45Standard Mixture with 1 Percent by Weight ofCement! Addition of Bentonite
0.58Standard Mixture with 10 Percent Replacement ofCement by Bentonite
0.67Standard Mixture with 20 Percent Replacement ofCement by Bentonite
0. 48Standard Mixture with 1 Percent by Weight ofCement! Thixotropic Additive
Standard Mixture less 94 lbs/yd �5.8 kg/m !3 3
Cement with 1 Percent by Weight of Cement!Thixotropic Additive without Water Reducing/Retarding Admixture
10
0 ~ 54
*Replacements of cement by pozzolan or bentonite are given in terms ofweight of cement. See Appendix A for mixture details.
13
** Water-cement ratio is based on weight of cement plus any replacementmaterial.
TABLE 3 - SUMMARY OF MIKTURE EVALUATION TEST DATA
MixtureTest Item
10* ll*
Slump, in. cm! 6.7 6.517.0 16.5
6.616.8
6.316.0
6.0 6 ' 615.2 �6.8
5.3 6.8 7.513.5 �7. 3 �9 ' 1!
7 ' 218. 3
6,717.0
Unit Weight, lb/ft k /m3
147.1 146.42357 �345!
145.2 140,4 145.6 147.62326! �249 2333 2365!
0.9 1.3 4.6 2.5
150.5 142.4�411 �281
140.6 150.3�252 2408
150.62413!
Air Content Percent 1.4 1.31.2 6,9 1.31.6
Temperature, 'F 'C! 72�2
7222
7423
7323
7423
7423
7323
7122
73�3!
7323
7222
Iremie Flaw, in. cm! 10,4 12,5�6.4! �1.8!
12.4 9.431.5 �3.9!
11.7 9.2 11.729,7 �3.4! �9.7!
11..4�9.0!
12.5�1.8
11. 529.2
11. 1�8.2
Time of Setting, mininitial
� final346535
363489
387583
268366
305439
368593
347461
383497
350485
266409
Bleeding, Percent ofAvailable Water
1.6 0.9 0.6 2.4 0.02,1 1.7 0.3 0.02.4 1.2
0.00 0.06
1.00 0,83
0.03 0. 00 0. 10 0. 16
0.86 1.00 0.88 0.84
0.04 0.05
0.82 0.88
Cohesion Index
Stabilit Factor
0.08 0.01
0.68 0.93
0.07
0. 79
Temperature Development- max. increase F 'C 19 33
�1! �8!16,5 16.9
34 34 31�9! �9! �7!
16.6 14.4 21,6
31 34�7! �9!
15.1 15.9
NA34�9!
19.0
29 29�6! �6!
17.6 15.8� time to max. hours
Compryssive Strength,lb/in. MPa!
7 days 3600 2600�4.8! �7.9!
5570 4680�8,4! �2.3!
NA NA
28 days
� 90 days
Splitting Tensi/eStrength, 1b/10 MPa
745�.1!
4353.0
535 3953. 7 2.7
720�.0
6754.7
6604.6
720�. 0!
NA630�.3
MIXTURE INFORMATION
Cement and Replacement 3Materials, Ib/yd> kg/m !
705�18!
564�35!
705�18!
705�18!
635�77!
611�63!
Cement 705�18!
705�18!
� Pozzolan
8�!
141 84!
Bentonite 71�2!
0,58Water-Cement + pozzolanor + bentonite ratio! 0.46 0.440.45 0.51 0,53 0.62 0 45 0.540.67 0.48
P il P, TNone
Data for mixtures 10 and ll based on one day's test only.
Did not set within observation period; achieved only 150 lb/in.2 �.0 Mpa! penetration resistanceat 523 min.
14
Slump Loss, Percent ofOriginal Slump Remaining
T - 15 min30 min60 min90 min
120 min
AdmixtureA : � Air entraining
Water reducer/retarder
T = Thixotropic
4330�9.9!
6140�2.3!
730050.3
7978555042
3750�5.9!
5630�8.8!
696048.0!
9183726258
2930�0.2!
4320�9.8!
5390�7.2!
8787827768
2790�9.2!
5340�6.8!
6250�3.1!
8480696653
564�35!141 84!
2600�7.9!
4950�4.1!
585040.3
9182766459
564�35!141 84!
930 6.4!
2860�9.7!
466032.1
100-92786450
353�09!353
�09!
3990�7.5!
5640�8.9!
7040�8. 5!
6164575542
2150�4.8!
3770�6.0!
4730�2.6!
8878675443
1420 9-8!
2520�7.4!
318021.9
9286604229
9696
1007680
9194634738
difficulty of determining a slump versus mix"ing water relationship for an extremely thixo-tropic mixture. This difficulty in controllingthe mixture by slump was one of the factors~hich eliminated this mixture from the completetest program.
3. The air content of Hixture 3 was slightlyabove the planned level. The discrepancy wasaccepted since it was nat large enough Co bedecrimental to the test program,
1.3.2. Tremie flow test. Table 4 presents aranking of the mixtures based upon this test.The greatest flaw was given the highest rank-ing. Six of the mixtures ranked higher thanthe reference mixture in this test. The tremieflow value does not appear ta be directly re-lated to slump, as might be expected. The beatperformances vere from the air-entrained con-crete Hixture 3! and che twa concretes withthe water reducer/retarder Hixtures 4 and 6!.
1.3.3 Time of sectin test. Table 5 presentsrankings of the mixtures based upon borh initialand final setting times. The greatest time toachieve the defined penetration resistance sett'ing! was given the highest ranking in eachcase. This ranking scheme should not be inter"preted to mean that greater times co achievesetting indicate more suitable tremie concretemixtures, If time of setting is determined tobe significant for a particular tremie place-ment, it can be easily concralled by use ofappropriate admixtures.
With the exception of Hixture 10, none of themixtures exhibited unsatisfactory settingcharacteristics. Hixture 10 showed an extremeretardation due to the combined action of thewater reducei /retarder and the thixotrapicadditive. This occurrence points out thenecessity for insuring that all admixtures arecompat ible.
1.3.4 Bleedin test. Table 6 presence a rank-ing for the mixtures based upon the percentageof available water lost through bleeding. The 'highest ranking has been given ca the smallest 'amount of bleeding. Based upon this criteria,all of the mixtures bettered or equalled anemixture! the performance of the reference mix-ture. Again, this ranking should not be inter-preted co mean that no bleeding is necessarily ~bet'ter for a tremie concrete mixture, gather,it may be stated that none af the mixturesevaluated ~ould be expected to perform adverse-ly based on this one factor.
It should be noted that for certain applicationIsother than massive bridge piers or similarstructures, large amounts of bleeding, may bedetrimental. One such case vauld be tremie-placed concrete used to fill a void beneath thebase af an existing structure.
1.3 5 Se re ation susce tibilic tests.Table 7 presents rankings for the mixtures baseupon the Cohesion Index and Stability Factor asdetermined in the segregation susceptibilitytests. The basis for each of the rankings isexplained bc I ow i
1. Cohesion Index. The Cahesiaa Index was de-fined earlier as
CI " 8/*
vhere B veight of concrete on the large discA weight of concrete on the small disc
Thus the Cohesion Index is actually a measureof how veil the mass of concrete holds to-gether. For a very cohesive mixture no con-crete would be found on the Large disc aud Bwould be sera. Therefore, a Cohesion Index of0.0 would be the best case; and, the mixcuresare ranked vith the dmaLLest Cohesion Index atthe top of the rankings,
2. Stability Fac'tor. Hughes ref, 13! definedthe stability of a concrete as its "ability toresisr. segregation of the coarse aggregate fromthe finer constituents ~bile ia sn unconsolidat-ed condir ion" His Stability Fac t or was definedearlier as:
SF Aa/A!/ Ba/B!
where A sad B = as abaveAa = weight of coarse aggregate, small
disc.Ba = weight of coarse aggregate, large
disc.
Each of the terms in the right side af theequation Aa/A and Ba/B! define the ratio ofthe weight of the coaise aggregate in chesaisple to the total weight of thar sample. Ifchere is no segregation of coarse aggregateduring the tesr., the Stability Factor will be1.0, the best case The mixtures are ranked inorder of decreasing Stability Factor.
The preferred performance af a trcmie concretewould be the highest ranking in eicher factor.For the Cohesion Index all but three af themixtures ranked above the reference mixture.For the Stability Factor, all but one mixtureout performed the reference. Consideringboth tests, the best results were seen fai the5OX passolan replacement Hixture 6!, the 201bentonite replacement Mixture 9!, and the air-entrained concrete Hixture 3!.
The poor rankins based on Cohesion Index forthe two mixtures �0 and 11! containing thethixotropic additive vas surpi'ising and notreadily explainable. perhaps the energy devel-oped by the concrete falling onto the cone wassufficient to overcame the chixatropic natureof the mixtures thus allowing a portion of themass ca flaw onto the large disc.
1 3.6 Tem rature develo nt test. Table 8presents rankings of the mixtures based uponincrease in temperatbre after mixing. Thesmallest increase in temperature vas given thehighest ranking.
The mixtures are ranked essentially as vouldbe expected on the basis of cementiciousmaterial content. However, the twa mixturesconcainiag the signi.ficant ~uncs of bentonite !fixtures 8 and 9! show surprisingly large
15
TABLE 4 � BANKIMGS, TBEMre FLOW TESTS
TABLE 5 � RAHKINGS, TIME OF SETTING TESTS*
Initial SettingFinal Setting
Minutes Mixture MixtureMinutes
387 593
383 583 1 1**
368 535
363 497
350 489
347 485
346 461
305 439268 409266 366
*Mixture 10 had not achieved initial set after 523 min.
Denotes mixtures which did not contain the water reducer/retarder.
TABLE 6 � RANKINGS, BLEEDING TESTS
Nixture
0.480.0
0.54
0.3 0.67
0.62
0.53
0.58
1.6 0.51
1.7
2.1
0.44
0.462e
2.4 0.45
0.45
* Denotes mixtures which did not contain the water reducer/retarderwhich promotes bleeding.
TABLE 7 - RANEINGS, SEGREGATION SUSCEPTIBILITY TESTS
Cohesion Index* Stabilit Factor**C. I. Mixture S. P. Hixture
ie0.00
0.01
0.03
0.86 8
0.84 11
0.04
0.05
0.830.06
0.820.07
0.79
0.68
0.08
100. 10
0.16
eFor C. I., beer. ranking ia 0.00.**For S. P., best ranking ie 1.00.
I7
Bleeding,Percent
AvaiLableMater
0.6
0.9
1.2
:
s.oo
0.93 3
0.88
Nater-CementRatio
TABLE 8 � RANKINGS, TEMPERATURE DEVELOPMENT TESTS
Temperature IncreaseF C!
Mixtures
19 �1!
29 �6!
10»»
31 �7!
33 �8!
34 �9!
»Insufficient data were available for mixture ll*»
Based on two cylinders only.
TABLE 9 � RANKINGS, COMPRESSIVE STRENGTH TESTS
7 Days 90 Days>28 Days
Water-CementRatio
Comp. Str .,lb/in.2 MPa!
Comp. Str.,lb/in.2 Mps!
Comp. Str.,lb/in.2 MPs!
0.45
0.45
0.46
IV 0.481010
0.51
VI 0.53
VII 0.54
VIII 0.44
IK 0.58
0.62
0.67
Mixtures 10 and ll not tested at 90 days.
4330 �9,9!
3990 �7.5!
3750 �5.9!
3600 �4.8!
2930 �0.2!
2790 �9.2!
2600 �7.9!
2600 �7.9!
2150 �4.8!
1420 9 ' 8!
930 6.4!
6140 �2.3!
5640 �8.9!
5630 �8.8!
5570 �8.4!
5340 �6.8!
4950 �4.1!
4680 �2.3!
4320 �9.8!
3770 �6.0!
2860 �9.7!
2520 �7.4!
7300 �0.3!
7040 �8.5!
6960 �8.0!
6250 �3.1!
5850 �0.3!
5390 �7.2!
4730 �2.6!
4660 �2.1!
3180 �1.9!
19
temperature increases considering the reducedamounts of cement in chem. These two mixtucesalso shoved shorter than typical times todevelop the maximum temperatures recorded seeTable 3!, The cause of these anomalies isunknown. Additional temperature investigationsshould be conducted prior to use of a highbentonite content mixcure.
A cour io» co»ter»ink this temperature dacemust be raised. These cescs were intended toprovide relacive comparisons of the variousmixtures only. The tests vere not adiabaticand the data should noc be interpreted astemperature incteases to expect in actualplaeements. See Chapters 3 and 5 concerningtemperatures in actual placemencs.
1.3.7 Com ressive scren th tests. Table 9preaentS rankzngS Of the mSXCures baaed upOnthe compressive strength data. The highestranking vas given to the highes c compressivestrength. This data shove no surprises - themixtures are ranked as wou!d be expected basedupO» «ster-cement ratios Snd cementitiousmaterial contents. None of the mixtures appearsto have been adversely affected by the variouschemical and mineral admixcures.
As «i.ch several of the other tests, a high rank-ing in compressive strength does not necessarilyimply that a concrete mixture is better suitedfor tremie placement, The strength requited ofthe concrete should be a function of the par-ticular placement structural or nonstructural!.
1. 3.8 s litcin tensile stren ch test. Table 10presents s ranking of the mixtures based uponsplitting tensile strength. As for cOmpressivescrengch, the mixtures are listed in order ofdecreasing, screngch. This data shows no adversereadings; sll of the mixcures achieved an appro-priate percentage of the compressive strength.
1.3.9 Slum loss test, Table 11 presentsrankings of the mixtures based upon slump losschsrscteriscics, The highest rsnkings veregiven co the mixtures retaining the greatestpercentage of initial slump at each time incre-ment. A slow loss of slump indicating that theconcrete is stiffening slowly would be beneficisl in s cremie placement - particularly in alarge plscemenc «ith long flov distances.
Neatly all of che ~ixtures performed betterchan che reference concrete on chi.s test - nonevas ranked lower than the reference mixture atsll time intervals.
An overall ranking for slump Loss performancemsy be obtained by adding the rsnkings oi eachmixture at each of the five time intervals. Xfthe suamacions are chen ranked, the followinglisting of slump loss performance best toworst! is obtained: Mixture 10, 3, 6, 5, 2, 4,11, 8, 9, and 7 and 1 tie!.
'h&ile the mixtures are a~what scattered inslump loss performance, the following generaLpoints may be made:
1. The best performer, Mixture 10 thixotropicaddi tive and ws ter reducet/retarder! shovedextremely long set times due to an apparentinCOmpatibiliey Of the tvo admixeures. Theslow setting characteristics are sppsrenclybeing seen in the slump loss performance.
2. The mixtures concaining bentonite �, 8, 9!are sll grouped neat the bottom end of therankings,
3. The mixtures containing pozzolan �, 5, 6,!sre near the upper end of che rsnkings. Mix-ture 4, Lo«est ranked of the three, showedimproving slump loss characteristics in chelater time intervals 90 and ! 20 win!.
1.3. 10 Overall etformance. Of the varioustests performed, three are believed to be di-rectly indicative of performance ss tremie-plsced concrete: tremie flow, segregationsusceptibility, and slump loss. A fourth "esc,temperature development, may slsO be Signifi-cant, depending upon the placemenc situation,Table 12 presents a suiary of the performanceof the various mixtures on these four Cost's.This table shows the ordinal rank ings of themixtures on each of the four tests. The over-all rankings were determined by sussning theindividual ranks. The invest total in thesurmsation «as given the highesc overall rank-ing. All four of the tests were weightedequally co develop ehe ovetall ranking.
Based on this approach, the mixtures msy belisted from best to wots> performers as follovs:Mixture 6, 3, 4, 5, 9 LO, 8, 2, and 1 snd 7 tie! Hixtute 11, for vhich there was nocemperacure data, vould rank no lower than fifthoverall> and it would probably be somewhathigher, Polloving are comments on the perfor-mance of the cop five mixtures.
1, Mixture 6 �OX pozzolan replacement withthe water reducer/retarder!. Although thisconcrete ouc did all others, it msy noc bepractical for use due co its slow strength gaincharacteristics.
2. Mixture 3 air-entrained!. Although perform-ing, well, this mixture developed higher temper-atures than did the mixtures containing pozzolan.Therefore, it msy not be suited to all plsce-ments.
3. Mixture 4 �0X pozsolsn replacement viehthe water reducer/retarder!, Notes below vichMixture 5.
4. Mixture 5 �OX pozsolsn replacement withoutthe vaeer reducer/retarder!. Mixtures 4 and 5showed quite favorable performances. There werehovever, minor inconsistencies in each: Mixture5 failed to tank highly in the eteaie flow tesewhile Mixture 4 vas somewhat lov in the segt'e-gation SusCeptibiliCy test due to a low rank-ing, in the stability factor portion of chattest.
5. Mixture 9 �OX bentonite replacement with thavater reducer/retarder!. Although this mixture
TABLE 10 � RANXINGS> SPLITTING TENSILE STRENGTH TESTS e
Percent of 28-dayCompressive Strength
Splitting TensileStrength ib/in,2 Mpa! Mixture
745 �,1!
720 �.0!
12. I
12,8
12.6
13. 3
14,6
14. 2
15,2
15,7
Mixtures 10 and 11 not evaluated in this test.
T ~ 90 min.* T ~ 120 min.*T ~ 60 min.~T 15 min.a T 30 min.e
Per-cent**
Per-cent**
P er-cent**
Pez- «» Mixturecents*
Per-cents*MixtureMixture Mixture Mixture
96100 10 100 10 1.0
96 10 94 Ilf 82 3f 76 6810
92 92 78 66 59 5f
91 2f 87 76 58
1 lf I 865f l 83
72 53
2f 69. 62 50
st ' 67
63
82
80
[ 78
88 55
87 54 42
8 I 60
1 57
84 50
79 38
6461 7 55 29
e Time since completion of mixing.**
Percentage remaining of initial T - 0! slump.fDenotes those mixtures not containing the water reducer/retarder.
20
675 �,7!
660 �.6!
630 �. 3!
535 �, 7!
435 �.0!
395 �. 7!
TABLE 11 - RANKINGS, SLUMP LOSS TESTS
0
O
Ic4
21
0
A 0 0 4 04i
44
4J
'04O O
4
kJ
g e0 Cl
W 4 0Jt
'0S 0
22
was ranked fifth overall, its potential for useappears limited due ta poor performance on theslump lass test. Additionally, this mixturewas consistently ranked near the bottom in thecompressive and splitting tensile strength eval-uations.
In general, the mixtures containing pazzolanseem to offer the greatest potential for use ina massive tremie placement. The appropriate re-placement rate between 20 and 50K! should bedetermined to meet the strength requirements ofthe in-place concrete.
In regard to the remaining mixtures, the fallow-ing points may be made:
1. The reference mixture �! did not performparticularly well. 5either did the mixturesvhich most closely resembled the reference,Hixtures 2 and 7. It therefore appears thatit is practical and feasible to improve uponthe traditional tremie mixture design.
2. The addition of varying, amounts of benton-ite seems to have done little to improve theperformance of the three concretes. Mixture 7 EX bentonite addition! was ranked ninth.Mixture 8 10X bentonite replacement! wasranked seventh. Mixture 9 �0K bentonie re-placement! ~bile ranked fifth had low strengthand poor slump loss behavior as discussed above.It is noted that mixtures similar to these per-formed best in the Dutch tests ref. 3!.
3. The addition of the thixatropic agent didnot seem to offer any particular advantages.Mixture ll would have certainly ranked out ofthe top performers had temperature data beenavailable. If only the three tests for whichcomplete data are available for Mixture 11are considered, it would rank seventh overall.Although Nixture 10 ranked sixth overall, itsusefulness would be impaired by the long settime.
Additionally, based upon these small-scale testsand the large-scale tests described in Chapter 2,it appears that the use of any thixotropic agent bentonite or admixture! may nat be appropriatefor mass concrete placed by tremie. This con-clusion is based on two considerations. First,if a thixotropic concrete stops flowing dueto a break in placement production, transpor-tation, etc.!, the material vill stiffen due toits thixotropic nature. Depending upon thegeometry of the placement, to restart the con-crete flow may require significant energy in-puts. The veight of the concrete in the tremiepipe may not be sufficient to provide the re-quired shearing action to restart flow. Thesecond consideration relates to the practicalproblem of controlling a thixotropic mixture.The temptation to add additional water to austiff" mix should be obvious. A pract icalmeans of controlling the concrete other thanslump would certainly be necessary.
~14 S . Ih f ll g tthese tests:
I, Eleven different concrete mixtures wereevaluated far use in massive rremie placements.These concretes included a reference mixture,an air-entrained concrete, several mixtures withpozzolanic or bentonite replacements uf varyingamounts of cement, and two mixtures containinga thixotropic admixture.
2. The concretes were evaluated using a seriesaf standard and nan-standard tests which allowedcomparison with the reference mixture to bemade,
3. The mixtures containing the pozzolanic re-placements and rhe air-entrained concrete werethe be"t overall performers. These mixturesout performed the reference mixture.
4. The thixotropic mixtures achieved throughaddition of bentonite or thixotropic admixture!did not perform well and do not seem to be wellsuited for massive tremie placements.
CHAPTER 2
2. 2 B~kd.
23
LARGE-SCALE LABORATORY TESTS OFTRK!<IE CONCRETE PLACEFfENT
2.1 Ob ective. The objective of this portionof fhe project was to conduct large � scale tvemieconcrete placement s in the labor'ator y us ingseveral different concrete mixtur»s. The follow-inp areas were of part iculsr interest:
a. Det ermination of flow patt»ms ol the con-cret«aft«v <xit from the tremie pipe;
b, Fxaminat ion oi Lremie concrete mixt.ureacontaining pozzolanic replacemenr of varyingpercentages of t' he cement; and,
c. Evaluation of the effect of various admix�Lures on the flow pattern and surface slope oft ramie-placed concr» te.
2.2.1 Descri tion of th» test proc»duri. Thereare severs] reports in the lit»rature of tremieconcrete placcments done on a model scalet xWhi L» these research prog rams have unques t ion-ably added to our understanding of trcmie con-crete performance, they have generally beenionduc ted wit.h mur tar ra 1 her than concrete andh«nci fai led to model the hk. t»roguneous char-acter ol concrete. It was believed that laige-SCali LeSLS uaing a true CanC<'Cte miXture WOuldmore accurate ly mode 1 underwater plauerrrents ofconcrete in the t.'ield.
Therefore, a ser les of 1<rbnrarorI< placimcntswas conducted using 6 yd3 �, 6 m ! of. concretefor each test. A total of five srrch f"sts wereperformed.
A placement box was const ru«ted with a size ot4 by 4 by 20 ft �.2 hy 1.2 x 6,1 m!. This box
built of fr'aming lumber and p1 ywood sheet s.Fivures 8 and 9 show the placement box.
A variety of techniques wire used Lo sca! jointsof the box t.u al low t ill ing with wat.ir todepth ot 3. 5 tt l. l m!. An overflow spi1lwayw'rs used to maintain a constant water I«v< 1 oncea placement was begun.
A length o[ I O-in, �'r.4 cm! d lameter sr.eel pipewas usr d for rh«r remi«pipe. A lroppe< wasfabricated ouL of plywood to ta»ilit.aLe trans-ferr ing concrete into Lh» tremi«. pipe. Figure 10shows details of the tremie and hopper in»se<turing a placemerrt. Figure 11 shows a schemat ico f the ent ire placement set:up.
A curlcrete pump w:ts used to transf»r t1re concr»tcfrom t.he transit.-mix truck to ttre trerrri» hopperfor the first test. A concrete bucket mountedon a fork lift was used during, the remainder ofthe Les<a.
See references 3, 15, and 16.
The tests were begun with the t remi e pipe de-watered � the bottom was sealed with a plate.The plate and tremie! wt're initially restingon the bottom of the plaiement box. Onceenough concrete was placed into th< pipe tofill it, the tr»mi«was 'lowly raised 7 in.�8 cm! using a fork Lift, allowing concreteflow to begin. The pipe was blocked in itsraised position and held there until the place-ment was comp let.ed. Figure 12 shows an overs llview ot the placement process.
In ordii to be ab te <o ident.ify Lhe concreteduring the subsequ»nt coring operar iona, colorsw«rt add<'d to vrrious portions of the concretedurirrg placement.. The first third was placedwittrout added color. Thc next third was coloredred, and the 1 inal third was colored black. Thecoloring agents used weri inorganic mineraladdit.ivi»s. These. colors p< ovid eas! Lo 1:rac»,and the technique worked we]1.
Dur irrg tire p lac»ment, thi fresh concrete wasSump I ed and t.<<St»d fOV S lump, air c On<»nt, and<rni t weight. Add 2 t iona t. ly, cy1 inders weretaken lor 28-day compressive strengrh t»sLs.T1'ri' ri' Su 1 t S Ot Lh<.S» tC St a are pre Serried be 1 OW.
hl srt during the placement, SOundings were takenr.tri conclusion Of plaiing each CO'.Or segmenL.
Thus«soundings were used to describ» <low andt< correlate data obtained in the coring program.Figure 13 s1<<dws soundinga being Lakt n.
Onc< a placement was comp!eted, the concrete wasa 1 low«i t o cure tor several days, and thent!re box was dewat.redd. The. surface of thi con-crete was examined and photograptred. Measure-ments wer< made to establish convict< th ickness-es uv<.r ttre entire sample.
Xaminati on and photugrap!rycoring program was begun,
using both 3 and 6 in. �, 6ter bit s. The coring pat ter rri.g<l< e 14 ~ Fig'<r« ' 15 st'rowsconcret« of oni test aft.er
ed.
One« the surfacew»r.: completed, rhCov»s wer e dr i 1 ledand lb.2 cm! drsmeused is shown in I'Ltre surface Of t.h»curing was complot
The cur< s obrained were examined, logged, phoLo-graphed, arid weighed to establish km iL wuiglrts.Th<' re su! t s of t h< se test~ are dcscr ihed below.Th» different colors of th< var iok>s concreteS»gm»rrts Weri readily Viaibl <2 On t.he CureS
Aft< r the coring was compt»re, the concrete wasbvokin inro pi«ccs whiclr could bc ha <died by thcava i lab le equipment. A numb«r o 1 concr<. f ». piecesw< r<' taken to a I uca I plan< for c<rt ting with awire saw in ord«r to provide a mot<' readilyvisible. indiCaL<un of 1 tre flow patterna, PhOto-graphs of th se sections aie included and dis-«rss«1 below.
Ou< e the concret.e sections were removed, tlr»forms were cleaned, reassembled, resealed andttr« next test was conducted.
2.2.~20 ' t' ~ 2 « t t 2 d.Th«small � scale evaluations of concrete mixturesconduc Led earl ier Chapter 1! 'had shown that
Figure 8. Partially assembledtremie placement box.
24
Figure 9. Tremie placement boxcompletely assembledand ready for placement.
25
Figure 10. Details of tremie hopper and pipeduring a placement. The tremie hasbeen raised by the fork-lift on theleft and is blocked with the mouth
7 in. �8 cm! above the bottom ofthe box.
Figure 11. Schematic of tremie placement box. Tremie p ipe is shown in the raised position. Elevation
view.! Figure 12. Overall view of placement operation.Note the overflow water from theplacement box.
27
Figure I3. Taking soundings during breakin concrete placement.
TREMIE LOCATIONOF CORES
BO 0 I.5 3 5 7 9 I I l3 l5 l7 l9 20�.5! �.9! I.5! �. I ! �.7! �.4! �.0! �.6! �.2! �.8! �.I!
STATIONS, FT. m!
Figure 14. Coring pattern for large-scale laboratory placements. Plan view.!
28
Figure 15. Tremie-placed concreteat completion of coringprogram. This sample isTest 1. Note core holes.
expectedece. The
the de-in the
e place-er 3! andthe selec-varyinglarge-
mixtures containing pozzolans could beto perform well as tremie-placed concrresults of those srsall scale tests andcisions to use pozzolanic replacementsconcrete mixtures to be used for tremiments in a major cof cerdam seal Chapta deep cutoff wall Chapter 4! led totion of a group of mixtures containingamounts of pozzolan far the laboratoryscale placements.
In addition to the di ffering amounts of pozzolan,two di f ferent water reducing, re tard ing admix-tures were used in the mixtures to determine thed ifferences, if any, in the performance of Lheresulting concretes.
The mixtures which were tested were not selectedto model a mixture from a particular project.Instead, as was done in the small-scale labora-tory tests, a reference mixt rre and severalvariat ions were developed . The reference mixtur'ewas the same as that used in Lhe small-scaletests, Materials cement, aggregate, naturalpozzolan! were from the same sources as for thesmall-scale tests. Table 13 shows the propertiesof the mixtures used in the large-scale tests.
2. 2. 3 Flow of tremie concrete. The subject oftremic concrete flow pat cerns has at erectedmany researchers, probably due to the relation-ship between concrete flow and laitance formation which is a measuz'e of the quality of tremieconczete!, A wide variety of reports and pro-posed flow schemes may be found in the litera-ture. A summary of severa 1 of these reportsfollows:
Several i'epresentative repar ts fram che litera-ture followr'
I, The Arserican Concrete Institute in itsRecommended zac tice far Neasurin NixinTrans ortin and Placin Concrete Ref. 1!achates: "Tremie conc~ate flows outward from thebottom of the pipe pushing the existing sur faceof the concrete outward and upward."
The initial concrete which flows out of the tre-mie builds up a small mound at the mouth of thepipe. I c is this mound which seals the tremiefor subsequent concrete flow. This initial con-crete is in direct contact with water and ische most susceptible to washing and segregation;therefore, it contributes the mosc ro the forma-tion of laitance. Subsequent concrete has beenassumed to flow into che concrete rsass and there-fore nat be subjected to direct contact with thewater. In same manner usually unexplained inthe reports! the initial concrete mass expandsso that all of the later concrece flows intoconcrete and is nor exposed to che water. Thistheory implies that the first concrete p1acedshould be found abave some or all of the concretewhich is placed subsequently. Clearly, theremust be some Limit to this concept since theinitial concrete volume undefined! can only bestretched so far. Fuzther, this inicial con-crete would ultimately set making additionalexpans ion impossible .
This statement clearly implies that newerconcrete should be found under earlier concreteat least until the tremie pipe is raised tostar t the process over.
2. Halloran and Talbot writing in the Journalof the Amer ican Concrete Institute ref. 17!state: "As soon as the bottom cf the pipe tremiewas covered with concz'ete, the flow became anextrusion from within and through che mass ofconcrete and not a flow over the tap of thealready placed concrete."
A figure in this paper shows that the concretewill be found in essentially vertical layerspara 1 lel to the tremie pipe. The newer concretewill be found in the layers closest to the pipewith successively older concrete being foundat greater distances from the pipe.
3. Strunge, in a paper prepared for the Off-shore Technology Conference in 1970, ref. 15!wrote: "The principle of che method is co bringthe concrete through a pipe to the interior ofthe concrete being poured, thus preventing con-tact with che surrounding water."
Fig~res in this paper, based upon small � scaleflow tests, show bulbs of concrete surroundinga L.remie pipe. Successive concrete forms newbulbs which force the older concrete away f.romthe pipe. Again, the end result is concretewhich is layered vertically.
4. Wi 1 1 iams, also writing, in the Journal of theAmerican Concrete Institute ref. 18!, describedmodel tests in which seven batches of 0. 75 ft3�.02 m ! each weze placed at 20minute inter-vals. Figures in this papez show definite hori-zunLal layering. Williams reports for one mix,"Part of che mix 'rolled ' down the steep s lope, ."
The intervals between the batches apparentlynecessitated raising the cremie pipe whichcould have contributed to the layering notrd.
Additional examples could be cited, bur theseshould be sufficient to establish that a digreeof uncertainty exists concerning Cremie concreteflaw patterns. It was felt that the large-sca!etests would be beneficial in providing addition-s! information on this subject.
2. 3 Observat ians and discuss ion
2. 3.1 Direct observations of concrete flowThis section is based upon visual observationsmade during the f ive placemencs, This informa-tion is intended to describe only a portion ofthe flaw phenomenon. Following sec tions wil 1add additional information.
Two significant items were observed during theplacements: l. As was expected, there was animmediate flow which occurred as soon as thetremie pipe was lifted. This flow was made upaf cwo components. Firsr., there was a flow ofconcrete which quickly established a moundaround the mouth of the pipe, Second, therewas a flow layer of a colloidal suspension of
30
TABLE 13 � CHARACTERISTICS OF CONCRETE MIXTURES USED IN LABOEATORT PLACEMEHTS
28-day Comprgseive Strengthlb/ln.r Mpa! [Note 6]
UnitWeightlb/ft3 kg/m3!
PozzolanContent Aumixt i tresPercentBv Weight
PozzolanContemptlb/yt[3
kg/m~>
CementContentlb/yd3 hg/m3!
Slump,in. cm!
AirContent
ConcreteMixture Standard
CuredTest Rite
Cured
[Mote 7][Note 1] [Note 2] [Note 6][Note 4][Note 3]
0. SX7.3�8.5!
705�18!
1 Standard!
353'�09!
2.3X6.8�7.3!
353�09!
50
528�13!
1.2X7.3�8 ~ 5>
176�04!
142�,270!
25
147�,360!
0.4X�9.1>
705�18!
5,020�4.6!
0.4X 5,470�7.7!
9.4�3.9!
147�,360>
a andb[Hots 5]
528�13!
176�04!
25
'NOTES:
5. Both admixtures inadvervently addedto this mixture.
1. For all mixtures:
6. Average of three samples ~
7. Cylinders sealed and stored next toplacement box until capped snd tested.
4. Admixtures:
s. Water reducer/retarder; 'Master Builders Pozzollth 300R,b. Water reducer/retarder: Sike Plastiment,
31
� Fine aggregate 45 percent of total aggregate by weight- Maximum water-cementitious material ratio: 0.45- Design slump: 7 inches �8 cm!� Maximum aggregate: 3/4 inch �9.0 sm>
2. Cement was Type II manufactured by Kaiser.
3. Pozzolsn wsa a natural material meeting requirementsof ASTM C618, Type H.
154�,470!
142�,270!
5,390�7.2!
3,560�4.5!
2,910�0, 1!
5,270�6.3!
5,190�5,8>
3.030�0.9!
2,510�7. 8>
4,960�4.2!
32
fine psrtic!ee v!Lie|< traveled Very rapidly tpthe far end of the placement box. These par-tic1ee vere apparently cement graf'ns which vere'wa'dh'ed aut of the concrete that initially flawedaut of the tremie. The presence of the flow
'-'layer vas unanticipated, and th'e speed of theflow'was eurprising � the layer wss seen at thefax end of the box �7.5 ft �.3 m!! withinseveral seconds.
Due co the, collaidally suspended particles, thedensity of this flaw layer was such that itremained as a cloudy layer on the bottom of thebox. As the placement progressed, additionalp'articles Vent ifd'tXx suspension, and the identityof the or-'ginaL-qeyer wse vieue}.1y obscured'
The speed at which .the cOL oidal layer CraVeledproved ta be directly related to the speed at
.which the cremie pipe was raised to begin cheplacement.. The faster the pipe vae raised,the faster the layer f!oved to the far end ofthe plscemenx box.
These observations of the flov from the tremiepipe indicate an initial radial flov of sub-stantial force which affects a much larger areathan vze anticipated. The actual volume ofmaterial in this colloidal suspension is veryerne!L indeed. This phenomenon reemphaeisesthe necessity for cere in beginning s tremieplacement, Hoc only could the seal be lost,bux excessive !aitance may be formed if thepipe is raised cao rapidly or ie agitated.
Equally important, if a tremie were beingrestarted in fresh concrete as vould happenwhen tremies are relocated during a large place-ment!, the rapid flow observed could contri,buteto washing the surface of the existing concreteand thus increase laitsnce.
2. The second observation concerns flow of theconcrete after a mound of concrete bae built uparound the mouth of the tremie pipe. During thefirst three tests, concrete vas seen to be flow-ing verticaLly up alongside the tremie pipe,Once a sufficient amount of fresh concrete hadbuilt up around the tremie, the concrete appear-ed to slough aff similar to a soil elope fail-ure!, !n these instances, cbe concrete may havepushed the earlier concrete away from the tremiepipe, or it may have simply flawed over theearlier cancrete Figure 16!. Due to the tur-bidity of the water from the colloidal suspen-sion, the exact mechanisms of flaw could not beaccurately determined.
Ix shou!d be noted that these teste were essen-tially continuous placements. They vere con-ducted quickly enough to prevent excessivestiffening of the first concrete placed beforerhe 'est vsc completed.
these visual observations indicated a complexflow mechanism which may be a combination ofcome ar all of these noted abave. The obeerva-tiax<s do nat seem to support s purely vertical'ylayered theory, nox' do they support the conceptvf continuous flaw underneath the older concrete.
2.3,2 Flow durin Lacement as determined b~ ou~d~aaa. da deec 'ddd ea d ' td t cprocedure, each test of 6 yd �.6 m ! wasbroken into three approximately equal segments by volume! which vere colored differently.Betveen placing each of 'the segments end alsofollowing the final segment, soundings were takenat 20 points witkin the test box to determineconcrete flow patterns.. The soundings pointswere located as is shown in Figure 17. Concretethicknesses as determined by the soundings arein Appendix K.
The soundi.ng data have been used to drav center-line profiles for each of the teste Figures !8through 22!. Plotting of these data showedvery little lateral variation in the surface ofthe concrete during the placements; therefore, nocross sections are presented.
It must be noted that concrete for these testswas purchased from a resdy~ix .supplier. There-fore, the quantity of concrete placed may havevaried slightly fram test to test. Also, thefirst test wss conducted using a concrete pumpt<d transfer the mix to the tremie hopper, re-s~!t.ing in a certain amount of concrete loss inthe pump end lines. Based on these considera-tions, the plots should not be superimposed fordirect comparison. Rather, the plots are intend-ed to show relative flow characteristics.
The following points may be made from the sound-xngs.
1. This evaluation of soundings dose not showwhich roncrete is in which layer � only therelative thicknesses during the placement.Identification of specific concrete can only beaccomplished from the cores. The profiles mustnot be interpreted as successive Layers ofdifferently colored concretes.
2. All of the mixtures showed the same basicflov pattern. The differences were in the degreeof maunding at the tremie lacatian, the ovex'-allslope of che concrete, the amount of concretewhich reached the far end of the box, and therate at which concrete reached the far end. Thesoundings do not indicate whether the concrete«as flowing into or over the existing concrete..
3. The first three tests produced results whichwere quite similar. For all three chere «assignificant maunding near the tremie location Figures 18, 19, 20!. As a result of this mound-ing, very little concrete reached the far end ofthe placement. Rane of the three mixes appearsto have a distinct advantage over either of theother tvo.
4, The final tvo tests were quite similar andshowed a drastic difference from the first threeteste Figures 21 and 22!. The wounding wasessentially eliminated, the overall surfaceelopes vere much flattex, and s much greateramount of concrete reached the far end of theplacemenc. There is no clear advantage to eitherof these Last' cwo mixes, bath would be quitesatisfactory in an actual placement based uponflow considerations!.
a. Observed flow parallel to tremie pipe.
b. Postulated flow over base concrete after build-up in "a", above.
c. Postulated flow into base concrete pushing older concreteaway from tremie after build-up in "a", above.
Figure 16. Observed and postulated flow ofconcrete near tremie pipe.
33
TREMIE CONCRETE FLOWSOUNOING LOCATIONAND NUM8ER
10
C.eo
TREMIE
0l5
�.6!IO
�.0!
STATIONS, FT. m!
30
4 I 2!
E
3CO �.9!
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Figure 18. Yrenie concrete profilea during placement, along centerline of box, Test l.
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Figure 20. Tremie concrete profiles during placement, along centerline of box, Test 3.
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4.alon centerline of box, Testofiles during placement, along cenFigure 21. Tremie concrete pro es n
37
5, On the basis of the flow during placement,rhe governing factor appears to be the additionof the second type of water zeducer/retarder,regardless of whether pozzolan was incorporatedinto the concrete. When the mixtures are cate-gorized as containing or not containing thesecond type of water' reducer/retardez, the mix-ture with pozzolen performed as well as thereference mixture in each category.
2,3,3 Surface rofiles and surface a earanceIn addition ta the soundings described above,e detailed mapping was conducted over the surfaceof the concrete samples after the bax wes de-wetered �20 date points versus 20 for thesoundings!. Measurements were made to deter-mine the concrete thickness at five locationslaterally outside edges, 12 in, �0.5 cm! framoutside edzes. and centerline! and at every 1 ft�0.5 cm! interval along the long axis of thebox. The data obtained from these measurementsare in Appendix F, Pzofilea Showing the concretethickness along the centerline and one edge aregiven in Figures 23 through 27. These profilesare included since they show a much more detail-ed view of the concrete sur face than do thesoundings. Since there is very little lateralvariation, no cross sections are presented.
photographs of the sur faces of the five testsare in Figures 2S through 33. A close-up afthe surface of Test 1 is shown in Figuze 29.
The following paints may be made frors the surfacemeasurement data:
1. The profiles reinforce what was noted fromthe soundings concerning mounding and concreteflow to the far end. Additionally, the surfacemeasurements show that the most severe moundingoccurred dizectly under the thremie pipe forTests 1, 2, and 3. Obviously, some of the mound-ing was caused by the withdrawal. of the pipe.
2. The photographs show the surface appearanceto be very similar for the first three tests.In these tests, the concrete surface was ex-tremely rough, with Test 1 being the roughest.Figure 29 shows the developmenC of ridges per-pendicular to the flow direction in TestThese ridges were not seen in any of the othertests. The appearance of the ridges seems taindicate that the mass of concrete was beingpushed away from the tremie es additional con-crete was being added.
3. The surface profiles of the concrete forTests 4 and 5 were also very similar and showede significant improvement over the fzrst threetests. Both tests showed much smoother andmore uniform surfaces than the earlier' tests.
As was true with the soundings data, thesur face profiles end surface appearance appearto be e function of the admixtures used. Thepresence of the pazzolen does nat appear tohave a significant influence. However, in thefirst three tests the two mixes containing poz-zalsn did provide slightly smoother surfaces!.Based upon the surface profiles and texturesobtained, the mixes containing the second type
of water reducer/retarder would have been per-ferable in an actual placement.
5. The mounds at the tremie location in thefirst three tests were very similar to themounds seen on the tremie seal discussed inChapter 3.
2,3.4 Oistribution of concrete colors. As isdescribed above tn the test procedure, exten-sive coring of the tremie-placed conc~ate wasaccomplished to determine the final distribu-tion of concrete by its colors. The coringpattern used was presented earlier in Figure14.
The information obtained from the cores wascorrelated with the overall profile data toproduce approximate profiles of the color dis-tribution along the centerline and right edgeaf the placement box. These profiles arepresented in Figures 34 through 38. The dataupon which these profiles are based are givenin Appendix G.
The following considerations apply to thesepro files:
l. In several instances less than completerecovery of cores was obtained. These caseswere believed to be due to caring problemsrather than sand layers.! In these casesthicknesses of colors were approximated fromthe portions of cores z'ecovered end fram tot'alsample thickness data at the point of coring.
2. The quantities of concrete of a given colormey have varied slightly fram test to test.However, the sequence of colors wes always thesame: gray/brown depending upon pozsolancontent!, red, and black.
3. Except for minor variations caused by flowaround reinforcing steel described below insection 2.3.6!, tbe color distributions werequite syrmsetrical across the short dimensionof the placement box. Theze fore, only oneedge profile is shown,
Several blocks of concrete from these testswere cut with a wire saw ta provide e moregraphic representation of the coLor distribu-tion. Photographs of these cross sectiorrs erepresented in Figures 39 through 45.
The following poi.ts may be made concerning theconcrete flow pattern as determined by the colordistributions:
1. Ha single flow pattern wes seen which wouldestablish one of the theories described above section 2.2.3! as the characteristic tremieflow mechanism. Several mechanisms appear tobe invol.ved.
2, The color distributions do not substantiateflow descriptions of the type which hold thatthe initial concrete is pushed upward by con-crete placed subsequently. Concrete of enearlier color was found above later concretein only a few minor instances. These in-
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Figure 26. Ceaterliae am! right edge surface profiles, Test i.
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Figure 28. Concrete surface,Test l.
Figure 29. Close-up of concrete surface, Test l.
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Figure 30. Concrete surface,Test 2.
Figure 31. Concrete surface,Test 3,
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Figure 32. Concrete surface,Test 4.
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Figure 33. Concrete surface,Test 5.
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Figure 35. Color distribution, Test 2.
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Signore 37. Co1or distribution, Test 4.
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a. Photograph with boundariesbetween colors enhanced.
b. Schema t ic .
Figure 39. Gross section, Test 2, 8 ft �.0 m! line.
a. Photograph with boundariesbetween colors enhanced.
b. Schematic.
Figure 40. Cross section, Test 2, 12 ft �.7 m! line.
a. Photograph with boundaries between colors enhanced.Exact division between red and brown not visible onthis photograph.
b. Schematic.
Figure 4l. Cross section, Test 3, 8 f t �.4 m! ifne.
a. Photograph with boundariesbetween colors enhanced.
b. Schematic.
Pigure 42. Cross section, Test. 3, l2 ft �.7 m! line.
a. Photograph with boundariesbetween colors enhanced.
b. Schematic.
Figure 43. Cross section, Test 4, 8 ft �.4 m! line.
52
a. Photograph with boundariesbetween colors enhanced.
b. Schematic.
Figure 44. Cross section, Test 4, 12 ft �.7 m! line.Note reinforcing steel.
53
a. Photograph with boundariesbetween colors enhanced.
b. Schematic.
Figure 45. Cross section, Test 4, 14 ft �.3 m! line. Redcolored concrete is offset due to flow aroundreinforcing steel.
stances were of the nature of that shown inFigure 43. It appears that these instances are"noses" of concrete pushing into earlier con-crete. They are probably the result of theformation of bulbs of concrete around themouth of the Cremie. The sides of the place-ment box eisa may have had s role in the forma-tion of these areas by reducing lateral flaw.
3. Two basic flow mechanisms seem ca be pre-sent in these tents. With the exception ofTest 1, the mixtures can again be categorizedby the presence of the second type of waterreducer/retarder.! In Tests 2 and 3, the patternseems to be hocizontal layers with the laterconcrete flaming over earlier concrete. InTests 1, 4, and 5, the pattern appears to in-dicate that later concrete was pushing earlierconcrete svay from the tremie rather thanflowing, over it.
4. The color distributions af Tests 2 and 3support the earlier COmments SeCCiOn 2.3.1!describing flow bsck-up alongside the tremiepipe, before lateral fLow took place. Forthese tests, the concrete could have flowedupward first and then down snd aver the ear-lier concrete creating the horizontal Layersnoted.
5. The data from Tents 4 snd 5 could alsosupport the concept of flow backup alongsideand parallel to the cremie pipe. However, ifthis vere the cane, the flaw after the upwardrise vas probably essentially a shear failurewhich caused s movement of the entire massaway from the tremie pipe. Since mixtures 4snd 5 contained the second type of water reducer/retarder, there may have been less shear re-sistance in the fresh concrete.
6. Perhaps s better theory for Tests 4 snd 5is che formation of s bulb of concrete aroundthe tremie pipe. Rather than flowing upward,nev concrete would simply push earlier concretesway from the tremie. Again, this theorywould depend upon the lovered shear cspaciryof the concrete in these tests. This theoryvould also account far the small amounts ofred concrete found aver black concrete.
7. The data for Test 1 sees to fit the bulbpattern described above, except that upvard flowalongside the cremie »as detected during thistest. This mixture did not contain the secondtype af water reducer/retarder. It must be notedthat Test 1 was conducted by pumping che concretefrom the truck co the cremie hopper. The incre-mental volumes of concrete placed and thus thechanges in color! were determined in a much moreapproximate and inaccurate manner than during theother tests. These inaccuracies msy make closeCamper inOne With the Other testn somewhat in"appropriate.
8. It is interesting ca note thee ridges wereseen on the surface of Test 1 ac approximatelythe 9 and ll fc �.1 and 3,4 m! lines. Theridges csn be interpreted, on the basis of thecolor distribution, as being farmed by the redCOnCrete puShing the gray COnCrete Sway frOm thetremie.
9. Item 2, above, indicates chat the generalnotion of concrete flowing into an existingmound snd thus being protected fran contactvith the water may not always be correct. Inthe layer type of flaw, there is s significantchance that most of the tremie concrete vill beexposed directly to water during the placement.
10. It wss pointed out earlier nat to equatesounding data with color layers. The need forthat warning csn be seen by comparing thefigures shoving sounding data with those showingcolor distributions. Concrete from the firstcolor placed continued to move as additionalconcrete was added. Apparently, tremie concretemsy be expecced to be moving for a long periodof time after it exits fram che tremie pipe.
ll. Although the coring, program did providevaluable data, it was extremely time-consuming,difficult, snd expensive, Development of analternative approach, if investigations of thisnature sre undertaken in the future, is highlyreconmmnded.
2.3,5 Concrete densit . The cares obtainedfrom the last four placemencs vere also used toevaluate the density of the in-place tremie con-crete. Density and unit vei,ghc vere determinedaccording, co the following formula:
ws
Unit weight 'Y vv vs
vhere w weight in aira
w ~ weight in water
unit veight of vater
Selected data frcxn these calculations sre pre-sented in Table 14. Unit veigbts of freshconcrete calculated in accordance vith ASTNC-13B are also presented in this table for com-parison.
The following points msy be made concerning theconcrete densities:
l. In-place unit weights for concrete at thelocation af the tremie were very close tothose determined for the fresh concrete by thestandard ASTN test. Differences for the fourtests ranged from O.L ta 2.2 percent with thein-place concrete being heavier in all cases.Thus, the process af flowing through the rre-mie does produce s dense concrete near thecremie pipe.
2. There is a general decrease in concreteunit weight as distance from the tremie in-creases. When the effects of laitance accumu-lation on the surface are neglected by usingcores not affected by the laitance, chis de-crease is not significant, as is shown below smounts of laitance accumulation are discussedin section 2.3.7, below!:
55
Unit WeightDepth *Tes't Station
lb/ft ~g/~ !3 3
142.0
2 355147.0ASTM C 138
TABLE 14 - REPRESENTATIVE CONCRETE UNIT WEIGHTS
SEE FIGURE 14 FOR CORE LOCATIONS
~Indicates cores which included surface laitance.
No entry indicates core was recovered full depth in one piece.
2,2632r2072,2122,2122 195
Bar sAt TremieTeer.
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145.8 lb/ft �335 kg/m !
3 15
4 19
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57
2 14 1. 3 lb/fc �263 kg/m !
3 143.1 lb/fr. �292 kg/m !
4 145. 5 lb/ f t3�331 kg/m3!
5 145,2 lb/ft3�326 kg/m3!
Test Station At Station
2 15 137.0 lb/fr, �195 kg/m !
3. When laitance is included in the cal-calculations, the decrease becomes much greater.The data below are for cores which had asurface layer of laitance.
Test 3, Core.19L ~1,5 in. �.8 cm!laitance!: 127.9 lb/fc �049 kg/m3!
Test 5, Core 19R ~3.0 ln. �.6 cm!laitance!; 134.6 lb/ft �156 kg/m !
It may be argued that some of the lsitanceresulted from an "end-effects" phenomenon asthe concrete reached the end of the placementbox. However, the same effects vill occur inactual placements as the concrete reaches theboundaries of the placement. Therefore, thesedata reemphasize the requirement for removalof washed material at the far end of a place-ment to insure thee such material does notbecome trapped in or part of the final cOn-crete product.
4. As is described below, flow of tremie con-crete around reinforcing steel vas also exam-ined during these tests. Flow around the barsseems to have little effect on the concreredensity as is shown below:
Coze 9R, bottom, 146.8 lb/ft �352 kg/m !
Core llR, top, 144.5 lb/ft �315 kg/m !
Bars
Core 13R, bottom, 147.1 lb/ft3 �357 kg/m3!
Core 15R, top, 136.8 lb/fc �192 kg/m3! includes surface laitance, 3.0 in. �.6 cm!!
Test 5
Core 9R, bottom, 149.0 lb/ft3 �387 kg/m3!
Core 11R, bottom, 147.7 lb/fc. �366 kg/zs !
Core 13R, bottom, 147.2 lb/fc3 �358 kg/m3!
Bar s
Coze 15R, bottom, 148.2 lb/ft �374 kg/m !
The change in density caused by the reinforc-ing steel does not appear to be significant,as long as lsitance is not trapped near thesteel.
2.3.6. Flow around reinforcin steel. Rein-forcing steel was placed in four of the teststo simulate reinforced tremie placements.Obsez'vations vere zsade of the flow of theconcrete around these bars.
For Tests 1 snd 2, the bars were placed in arov across the end of the placement box. ForTests 4 snd 5, che bars were assembled into acage along the side of the box. Details ofthe bar placement are in Figure 46.
The material reaching the end of the box inthe fs.rsc two tests was largely lsitance.This material did flov well around the barsbut it would not have provided satisfactorybond had these been actual placezsents. Fig-ure 47 shows flow around bars in Test 1.
Moving the bars closer co the trezsie piperesolved the laitance problems and allowedmore valid observations of concrete flowaround the steel, The results were extremelygood, as shown in Figure 48. While the barshad very little influence on the concrete,there were two noticeable effects.
1. There was a minor buildup of concreteupstream of the bars, as can be seen in theprofiles along the right edge given earlier.This buildup was on the order of a few inchesand would cause no problem in an actual place-ment.
2. The bars did cause concrete flow to skewaway from the steel. This is clearly seen inFigure 45. Although interesting, rhis phenom-enon would not affect the quality of theconcrete.
Overall, concrete Tests 4 and 5! flowed welland embedded Che bars sar.isfactorily. Theslight buildup behind the bars reemphasizesthe necessity for carefu! detailing of re-inforcing steel for tremie applications toinsure wide enough spaces for the concrete toflow through. There was no difference detectedin the flow and baz. embedment betveen theconcretes with and without the pozzolan.
2,3.7. Leitance formation. One area whichis always of concern during a trezsie place-ment is the washing out of some of the cementpaste from the concrete and the subsequentformation of laicance. The fear of thisoccurrence is one of the two reasons the
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Figure 46. Reinforcing steel placement. Plan view.!Stee! u ed was No, 11 bars,
Figure 47. Concrete laitance! flow around reinforcing steel, Test l.
59
Ffgure 48. Concrete flow around reinforcingsteeI, Teat 5.
60
61
other being improved workability and flow!traditionally given for increasing the cementcontent for tremie placements.
The results of these placements show thatcerient loss/Laitance formation is indeed aproblem which must be considered.
For the first cwo tears, the material whichreached che far end of the placement was almostentirely laitance. Test 3 did show concreteat the end of the box, but there was also asignificant amount of Laitance. The qualityof the concrete near che end of the box inthese tests was unsatisfactory for the firsttwo tests and marginal for the third.
The concrete at the far end of the box foi' thelast two tests showed s much smaller amountof laitance - only a few inches, with thislaitance being on top of sound concrete.
The change in the amount of Laitance may bethe result of the following:
1. The second type of water reducing/retardingadmixture may have increased the bond of thecesmnt into the concrete.
2. The type of flow observed for Tests 4 and5 may have exposed less of the concrete tocontacc with che water; and therefore, therewas less opportunity fax' cement to be washed .out. The flow seea in Tests 2 and 3, horizontallayers, would have exposed more concrete towashing.
When washing out does occur, little of thecement seems to go inco suspension in thewater. The majority appears to stay near thesurface of the concrete and to flow toward theLow end of the placement. Ia all nf the tests,there was a minimal layer �/4 to 1/2 in. �,6-l. 3 cm!! of laitance which was deposited overthe entire sample by cement precipitating outof suspension after the placement was completed.
No difference was detected in laitance forma-tion for the concretes with and without porzo-lan, However, the laitance in Test 2 whichcontained significant proportions of pozzolanwhich had washed ouc, was soft and did not set,as did the other accumulations of laitance.
~2.4 4 . T4 411 4 '4these tests:
l. Five concrete mixtures of approximately 6yd each �.6 m ! were placed by tremie underwater in a laboratory placement box. Themixtures differed in pozzolaa content and in,the types of admixtures used.
2, The concrete placements were divided intothree equal segments which were colored dif fer-ently to allow for later identification of theco~crete.
3. Data were collecced during snd after theconcrete placements covering concrete flow
patterns, final color distribution, density,flow around reinforcing steel, and Laitanceformation,
4. No single flow mechanism for tremie placedconcrete was identified. Instead, two basicflow patterns were seen, The first of thesewas horizontally layered while the second wasvertically Layered. The latter produced muchflatter concrete slopes, pi'ovided better qualityconcrete at the far end of the placemenc, andproduced much less laitance, making it thepreferred flow pattern for actual placements,
5. The type of flow mechanism which developsappears to be a function of the concrete beingplaced. The tests with the vertically layeredflow used concrete containing the second type ofwater reducer/retarder. Apparently, this admix-ture reduced the shear resistance of the freshconcrete allowing the vertically layered typeof flow to take place,
6. The results of these flow tests lead to theconclusion that determination of the shear re-sistance of a potential tremie concrete mixtureis a critical step in the mixture design andevaluation process. Additional effort to developa usable shear test for fresh concrete appearsto be justified.
7, The concrete mixtures containing thepozzolanic replacements performed very wellindicating that the recoszsendacions of thesmall-scale tests Chapter 1! were correct.
8. These large-scale flow tests have led toa better understanding of the tremie placementprocess. By designing concrete mixtures togive a particular type of flow, the engineerwill have a greater degree of concrol overunderwater placemencs which should Lead toimproved results on future projects,
CHAPTER 3
3.2 Back round.
62
TRENTE CONCRETE PLACEMENT,1-205 COLUMBIA RIVER BRIDGE
of the project was to observe tremie concreteplacement of a nonstructural seal for apier of a major bridge. The following azeaswere of particular interest:
a. Behavior of a tzemie concrete mixturecontaining a fly ash replacement of aportion of the cement;
b. Prediction and measurement of ternpera-tures developed within the seal con-crete; and,
c. Examination of flow patterns of thetremie concrete.
3.2.1 Descri cion of the brid e. This bridge,when completed, will cross the Columbia River.east of Por tland, Oregon. The bridge willprovide a bypass around the downtown Portlandarea for I-5 users as well as carry local com-muter traffic.
The total project length is 11,750 fc �,580m! ~ Included in this total are major bridgesover the north and south channels of theColumbia River and a 1,100 fc �35 e! fillsection across an island. The North Channelcrossing is two entirely separate structureswhich share a common foundation at Piers 12 and13 only. The South Channel crossing is twoseparate structures for all of its length. TheSouth Channel Bridges will be 3,120 ft 951 m!long and will be constructed using a cast-in-place technique. The North Channel Bridgeswill be constructed using a segmented box gir-der technique. These structures will have atotal length of 7,460 ft �,274 m! with mainspans of 480; 600; and 480 ft �46; 183; 146 m!.When complete, the North Channel scructureswill be the longest segmented box girder bridgesin North America.
The contractor who was awarded che substructurecontract foz the North Channel Bridges is ajoint venture of Willamette-Western Corp,Alaska Constructors, Inc., and General Con-struction Co. He is using both structural andnonstructural tremie concrete on the project,Reusable steel forms are being used to cast 26double bell piers incorporating reinforcedtremie concrete. Two additional piers arebeing constructed using cofferdams with tremde-placed seals. Except where specifically noted,the work covered in chis report deals withnonstructural tremie-placed concrete seal ofPier 12 of the North Channel Crossing,
3.2.2 Geometr of Pier 12. This pier is thenorthernmost river pier in the project. Themain 600 ft �83 rn! span of the two bridgeswill be between Pier 12 and Pier 13, the next
pier to the south. Pier 12 was constructedusing a cofferdam made up of ARBED interlockedN-piles, Two levels of internal bracing wereused to strengthen the cofferdam. The nominalinside dimensions of the cofferdam wer'e 54 x140 ft �6. 5 x 42.6 rn!. The base of the sealwas designed to be at a depth of 78 ft�3.8 m! with the top of the seal at a depthof 45 ft �3.7 m!, These nominal dimensionslead to a volume of concrete required of9,240 yd �,065 m3!.
The actual dimensions of the cofferdam variedslightly as did the top and bottom r!levationsof the seal. A total of 9,750 yd3 �,455 rn !of concrete were actually placed by tremie.-
3. 2. 3 Tem erature redictions. Early in theplanning process, the State of Oregon and thecontractor raised the question of problemsassociated with temperature development insuch a large placement. At their request,several analyses were performed using acomputer progrmn based upon a one-dimensionalheat flow evaluation technique usuallyreferred to as the Garison Method after itsdeveloper, Roy Carlson ref. 24!.
The following assumptions weve made whileapplying the Carlson Method:
a. Heat flow is considered in one directiononly. For the tremie placement of Pier 12,heat low in the vert. ical direction wasevaluated.
b. Heat generation within the concrete isadiabatic.
c. The adiabatic temperature increase for amix being evaluated is directly proportionalto the adiabatic temperature increase of areference mix whose adiabatic curve is known.The proportional constant is the cement con-tent of the trial mix divided by the cementcontent of the reference mix.
d. Heat generation for a given amount ofposnolanic material is one-half thatof the same weight of cement.
e. The thermal diffusivity of the concrete andthe underlying rock is 1.00 ft /day �.08 x10 m2/s!.
f. The initiaL temperature of the underlyingmaterial is the same as the river' water.
g. The continuous placement of the tremie maybe modelled by an incremental technique.
Due to the assumptions noted and to uncertaintiesabout the input data for actual materials to beused, the results of the predictions were viewedas only relative indications of the temperatures
* For more information on the bridge icself andthe construction techniques being used, seereferences 19 through 23.
63
which would be developed by the various mix-tures. Thc temperature predictior,s are shownin Tabl.e 15.
These predictions indicated that high tempera-tures cauld be expected in the seal concreteand that replaCen:ent of a portion of the cerreer.would be Lhe most feasible way of meeting theState 's desize for a 140 F �0 C! maximumten'perature.
The desire to reduce temperaruze in the sealconcrete was heightened by surface cracking ofa large pier sha ft on shore which occurred atabout the time the calculations were beingdane. This cracking was attributed to thermalgradient problems.
It must be stressed that one of the mostsignificant assumptions oi' the Carlson Hethcdis that heat flux occurs only in the verticaIdirection. Thus, I he predictions above arevalid only far the center of I he concrete mass.For those areas near the edges of the seal,where patentia11y significant temperaturegradients may develop, another technique mustbe used. To overcome this problem, a programwas writLen to allow use of an existing finite-element program for prediction of temperaturesin I.remie concrete as is described rn Chapter5,
3,2,4 Tremie concrete mixture. Based upon thepredictions above, the concrete Inixture des-cribed in Table 16 was selected for use. Thismixture was developed as is our 1 ined in thetable. As is also shown in Tabl» 16, thismixture has an equivalent cement content forheaL. generation purposes of 611 lb/yd �6!kg/m3!.
3.2.5 Placement techni ue. Tremie concreteplacement for Pier 12 began at 8 A.H. on 15 Hay1978, and was essentially continuous for 72hours. The majority of the concrete was barchedin a floating plant moored at the site. Twopumps were used to transfer concrete from theplant ta the tremies. Additional concrete wasbarched at a nearby zcady~ix plant and wastrucked ro rhe site. This concrete was pumpedaloof a causeway leading from shore to thecof ferdarn, Figures 49 and 50 show the sire andthr cofferdam during the placement pz'ocess.
The tremies were manufactured fram 10 in. �5.4cm! pipe. Connections were Elanged and gasket-ed. A hopper was bolted onto the top of eachtremie and each tremie had its own frame andair � hoist to al low for vertical movement. Theupper portions of the tremies were Inade up of 5ft l. 5 m! sections which allowed for removalof sections as the placement progressed. Detailsof the tremies and the support frames are shownin Figures 51 and 52.
The tremies were started dry with the lower endsealed with a metal plate and rubber gasket Figure 53!. The plate was wired onto the endof the tremie. The concrere used ta fi 1 1 thethe tremies initially was therefore droppedapproximately 80 ft �4.4 m!. Once full ofconcrete, the tremies were lifted breaking the
wires which allowed the concrete flow to begin.The same sealing techniques were used when atremie was moved and restarted.
Three tremies rwo supplied by the floating plantand one supplied from shore! were normally in useat one time. Placement was started with all threerremies along the short centerline of the coffer-dam. As the seal in this area was brought up tograde, rhe tremies were moved toward the ends ofthe cofferdam, The locations for restarting atremie were established by soundings,
3,3 Observations and Discussian
3.3.1 Heasured tern eratures. The temperatureswhich developed in the tremie concrete were mea-sured using 34 resistance thermometers placed inthe northeast quadr ant of the cofferdam. Theseinsrruments were Located at various elevations infour planes Rows 1-4! perpendicular to rhe longaxis of the cofferdam as is shown in Figure 54.Exacr. instrument locations are given in Appendix 8,
Readings were made manually using a variableresistance box nominally every Lwo hours for thefirst 80 hours after tbe placement began Figure55!, Readings were then taken two or three timesdaily for an additional 13 days until the contractorbegan pzepar ing r.a place thc next lift of concretefor the pier, Temperature data, a description ofthe data recording technique, and data reductionmethods are given in Appendix I. The data ob-tained are d iscussed be low:
a. Haximum tempera I.ores. Tl e maximum tenIpera-ture recorded for each instrument and a brie fdescipt ion of instrument locarions are given inTable 17. Rote that the river temperature duringand following placement was approximately 55a F 13oC!. The concrete placement temperature rang-eed from 60 to 65 F �6 to 18 C!. The maximumconcrete temperar.ure recorded therefore repre-sents a 90 to 95 F �2 to 35a C! increase.
The remperatures recorded for instruments 5, 7,and 9 are less than antic ipated. These instru-ments may have ma 1 functioned or the law readingsmay have been caused by a zone of incernentedmaterial descr ibed below in section 3. 3.4 !.
A summary of temperatures based upon instrumentgroupings is given in Table 18. As anticipated,the maximum temperatures developed in the centerof the concrete mass.
The temperatures which developed near the out-side edges of the seal and near the top surfacerepresent potentially significant thermal gra-dients as is discussed below, The range oftemperatures in the group of instruments nearthe top surface of the seal may be attributedto the varying depths of concrete cover whichwere actually achieved.
b. Temperature histories, The locations offour representat ive instruments are shown inFigure 56. Time versus temperature curves fozthese instruments are presented in Figures 57through 60.
TABLE 15 � TEMPERATURES PREDICTED USING THE CARLSON METHOD
NOTES; �! Predicted temperatures at 10 days after beginning ofplacement.
�! All predictions assume river water temperatures of 45 F�'C! .
Figure 49. Overall view of site during placement of tremieconcrete for Pier 12 of I-205 Bridge.
64
TABLE 16 � TREHIE COHCRETE HIXTURK, PIER 12, I-205 BRIDGE
Cement: 7 sacks/yd3
Less 20 percent
Net
98 kg/m !3Fly Ash: 125 percent of cement.
re duct ion
Figure 50. View inside cofferdam during tremie concrete placement.
65
This mixture was developed as follows:
~ 658 lb /yd 3
-132
526 lb /yd3
165 Ib /yd3
�90 kg/m !3'
� 78 !
�12 kg/m' !3
Details of tremie placement equipment � framesupporting hopper and pipe. Note airhoist which allowed vertical movement of pipeduring placement.
66
Figure 52. Tremie system being moved to new location. Noteflanged connections on upper portion of the tr ernie pipe.
67
Figure 53. Steel end plate and rubber washer being tied toend of tremie pipe to seal pipe during a changeof tremie location.
68
INTERLOCKEDH- PILES
PIPE STRUTS
INTERIOR BRACE RING
O U IX4J
0
03
OO
~ INDICATES A VERTICALLINE OF INSTRUMENTS
IN STRUMENTROW I
IN ST RUMENTROW 2
IN STRUMENT
ROW 3
INSTRUMENT
ROW 4
Figure 54. General instrumentation plan, Pier 12, I-205 Bridge.
69
NOMINAL 54 x 140ft, I6,5 x 42.7 m! INSIDE SHEET PILES
Figure 55. Manual recording of temperatures in seal concrete.Note interlocked ARBED H-pile system.
70
TABLE 17 MA!HMDM TEMPERATURES RECORDED IH PIER 12 SEAL CONCRETE
ElapsedTime,
Hrs.
Temp at29 Days,
F 'C!
Temp ac386 Mrs,OF oc!
NaxTemp,
OF oc>Instrument LocationInst.
Mo. Horisontally Ver t x ca 1 ly
Nid-Depth of Water inCofferdam
Water, 1 Fc AboveDesign Seal Surface
�4!140�4! 57
�4! �4!34058
57 �4!92 �3!
129 �4!119 �8!
79 �6!155 �8!106 �1!
60 �6!61 �6!74 �3!81 �7!
57 �4!110 �3!129 �4>122 �0!
95 �5!155 �8!116 �7!82 �8!
107 �2!92 �3!94 �4>
Instrument Lost
90 �2!150 �6!119 -�8!121 �9!105 �1!101 �8>114 �6>139 �9!154 �8!118 <48>108 �2!127 <53>125 �2!102 �9!
94 �4!142 �1!100 �8!116 �7!143 �2!
87 �1!
1401LO180130250310220
90100
6624
EdgeEdgeEdgeEdgetside
EdgeEdgeEdge
EdgeEdgeEdgeEdge
EdgeEdgeEdge
was not embedded in concrete as planned.elnstrumenc located in water, not in concrete. Instrument 3
** Readings for chese instruments appear to be questionable. See text.
71
3*4»ee674*89**
10111213141516171819202122232425262728293031323334
C-LC-LC-LC-LOff C-LOff C-LOff C-LOuta ideOut s ideOutsideOutsideWater OuC � LC-LC-LOutsideOutsideOutsideC-LC-LC-LC-LOuts ideOut s ideOuts ideOutsideC-LC-LC-LOutsideOutsideOutside
Top oZ SeelTop of SealMid � depthBottomTop Qtr PtBottom Qtr PtMid-depthTop of SealTop of SealMid-depthBottomCofferdamTop of SealMid-depthBottomTop of SealMid-depthBottomTop of SealTop of SealMid depthBottomTop of SealTop of Seal
Mid depthBottomTop of sealNid-depthBottomTop of SealMid depthBottom
120380150130210
50140180370180140170180100130170
70140150
22
82 �8!150 �6>117 �7>
93 �4!81 �7!84 �9!
101 �8!130 �4!154 �8!116 �7!86 �0!
105 �1!109 �3!
78 �6!70 �1!
121 �9590 �2!90 �2!
112 �4!64 �8!
MAMA
150 �6!
HA
78 �6!154 �8!111 �4!
llA
148 <64>HA
7» �4>87 �1>96 �6>67 �9!
TABLE 18 � MAXIMDM TEMPERATURES GROUPED BY INSTRHMI3NT LOCATION
Instruments and Te eratures
op
�4!�5!�8!�7!�6!�8!
At or near center-line of pier,mid-depth of seal. Excluding Row 4!
¹ 6¹17¹24
�0!�8!�8!
At or near center-line of pier,bottom of seal Excluding Row 4!
122
119
118
Outside edge of cofferdam,mid-depth of seal
¹12¹19¹30¹33
�3!�1!�1!�2!
92
105
142
143
¹13¹20¹28
Outside edge of cofferdam,bottom of seal
Near top surface, all locations
NOTE: *Readings for these instruments appear to be questionable.See texts
72
¹ 5*¹ 7»¹. 8
9e
¹16¹23
¹ 4¹10¹15¹18¹21¹25
¹29¹32
129
95
155
116150
154
94
101102
100
87
110
82
90
121
114108
94
116
�4!�8!�9!�8! »!
�3!�8!�2!�9!�6!�2!�4!�7!
73
160�1.1
140�0.0
IM!
50 lo,o!p
Ff.gure $7. Temperature history, Xnst. Ho. 8, near centerline, mid-depth of eeai.
160�1.1!
140�0.0!
�5.8!
50 Iao!o
Figure 58. Temperature ldstory, Inst. No. 11, outside edge, top of seal.
74
De
1201. �8.9
0;X
IOP�7.8
LU
LLI
8OZ �678
C30
120�8.9!
0
IOO�7.8!
I-LU
u 80~O �<7!O
50 lpo 150 200 250 300 350 400
TIME SINGE BEGINNING OF PLACEMENT, HRS.
50 100 150 200 250 300 350 400
TIME SINGE BEGINNING OF PLACEMENT, HRS.
I60�I.I !
I40�ao!
PI 20
I �8.8!
R:X
IOO�7,8!
O 80Z �6.7!8
I5.6!
50 IO,O� 50 l00 l50 200 250 300
TIME SINCE BEGINNING OF PLACEMENT, HRS.
Figure 59. Temperature history, lost, Ilo. 24, ceaterline, bottcna of seal.
I 60�I.I!
l40�0.0!
4I20
I, �8.9!
Ipo�7.8!
�8.7!8
60 IL6!
IIM!p 50 l00 l50 R00 R50 300TIME NNCE BEGINNING OF PLACEMENT, HAS.
Figure 60. Teaperature history, lest. Ho. 29, caaterliae, top of seal.
75
where crAT
RFor KFor 8
5: 129 P �4o C!7; 92oF �3o C8: 153aP �7o C!
16: 145 F �3a C!23, 150oF �6o C
Inst.Inst.Inst.Inst.Inst,
No.Na.No.Na.No.
Ar7 - E aAT!R
ATR
For EE
76
Readings for several instruments were taken on13 June 1978, 29 days afcer placement began.These temperatures are also shown in Table 17,A sunnnary of temperatures 386 hours after placementbegan the end of regular readings! is as follows:
60-85oF �6-29oC! Ll instruments exterior locations!
86-105aP �0-41oC! 7 instr uments tap of seal Locations!
106-125 F �2-52oC! 1 instruments various locations!
126-155 F �3-68 C! 5 instruments interior locations!
Thus, after 386 hours, the interior of theconcrete remained very close to its maximumtemperature while the edges and surfaces wereshowing significant cooling.
c. Gradients. The data for those instrumentsnear the edge or near the top of the seal wereexamined co determine the temper'ature gradientswhich developed in the extreme, portions of theconcrete. The outside surface of the concretewas assumed to be at the water temperature,55 F �3 C!. Table 19 summarizes these gra-dients by instrument Location, The data inthis table point out the following:
1. Large temperature differentials developedin the outside portions of the concrete � amaximum dif ference of 88 F �1 C! above theriver temperature was recorded.
2. When the distances of the instruments fromthe face of the concrete are taken into accountto develop a gradient in terms of temperaturechange per unit length, the various instrumentsmay be compared. The gradients for the mid-depth and top instruments, taken to the outsideof che seal, are both approximately L.5 F/in.�.4 C/cm!. For the top instruments takentoward the top surface, the gradients were morevaried and ranged up to 4.4 F/in. L,O C/cm!.
3. The rate of gradient development was gen-erally consistent at 0.4oF/hr �.2 C/hr! whenthe bottom instruments are excluded. Thebottom instruments developed their maximum valuesat a faster rate since the underlying materialwas not as efficient a heat sink as the riverwater.
d. Temperature induced stress. A derailed exam-ination of temperature induced stress is beyondthe scope of this report. However, che followingcalculations are presenced based upon typicalgradients described above to point out the sig-nificance of the temperatures which were develop-ed in the seal concrete.
Consider a mid-depth location 40 in. � m! fromthe outside of the seal typical temperatureinstrument location! at which the gradient is1.5oF/in. �.33 C/cm!. Assuming complete con-straint and neglecting creep the approximatechange. in scress across the concrete section may
be calculated using the following equationr*
E crAT! R
5 . 5 x 10 6in. /in. / P1.5o F/in, x 40 in. = 60op1.0 for complete constrainc
x 106 lb/in 2 Aa = 330 lb/j,n 23,0 x 10 lb/in.2 Aa 990 lb/in.
Further, assume a rate of temperature develop-ment of 0.4 F/hr �,22 C/hr!. For the totaldifferential of 60 F �3oC!, the stress calcu-lated above would be developed in 150 hours.
Since the exact properties of the concrete atearly ages are unknown, it is impossible tosay with certainty what effects the stressescalculated above would have on the seal. Itappears that these stresses are large enoughand develop rapidly enough to be of concern.
3.3.2 Measured versus redicted tern etatures,After the placement was complete, the CarlsonMethod program described above was used topredict temperatures within the seal basedupon the actual placement conditions mixturedesign, water temperature and concrete ternpera-ture!; The temperatures predicted by thisrun were compared with the measured temperaturesto determine the reliability of the predictiontechnique. Overall, the prediction techniquewas accurate to within approximately tenpercent of measured values when consideringlocations near the center of the concretemass. A sunnnary of predicted versus measuredtemperatures for various elevations withinthe seal is given in Table 20 Camparisonsof the various instrument groups are givenbelow. Tables of predicted versus measuredtemperacures are given in Appendix J.
A. Hid&epth instrumencs. The maximum tempera-ture predicted at the end of 10 days afterthe beginning of placement was 144 P �2 C!at a station appraximately 13 Et � rn! abovethe base of che seal, From about 7 ft � m!to 28 ft 9 m! above the base of the seal,the predicted temperature was slightly above140 F �0oC!, A comparison af the midMepthinstruments along or near' the center line ofthe seal at the end of 10 days shows:
The readings for instruments 5 and 7 are notconsistent with similarly placed instruments,
Where m = 2.5 x 10 5 cm/cm/o G
= 0.33 C/cm x 102 cm ~ 34 C1.0 for complete constraint
~ 6895 Mpa, Ao' ~ 2.3 NPa- 20685 MPa,ha = 6.9 Npa
ThSLE 19- TEMPERATURE GRN!IENTS XN OUTER PORTIONS OF SEhL CONCRETE
77
TABLE 20 � PREDICTED VERSUS MEASURED TEMPERATURES AT VARIOUSELEVATIONS, 240 HOURS AFTER BEGINNING OF PLACEMENT
ElevationAbove
Bottom ofSeal, Ft,
m!
Measured TemperatureInst ¹/oF oC!
Multiple inst at sameelevation are on same line!
PredictedTemp oF
oC!
55 �3!71 zz!
110 �3!127 �3!138 �9!142 �1!143 �2!143 �z!143 �2!143 �2!143 �2!144 �2!144 �2!143 �2!141 �1!137 �8!130 �4!118 �8!103 �9!100 �8!
¹3/56 <13!; ¹15/86 �0!¹4/101 �8!; ¹21/108 �2!¹22/137 �8!
¹7~/92 �3!
¹16/145 �3!¹5*/129 �4!> ¹9*/116 �7!; ¹23/150 �6!
¹8/153 �7!
¹6/122 �0!; ¹17/119 �8!; ¹24/118 �8!
*Readings for these instruments appear to be questionable. See text.
TABLE 21 SUMMARY OF CONCRETE PRODUCTION FOR PIER 12
Production, yd m !3 3
Time,hours TotalFloatine
PlantLand
Plant
0 - 10
10 � 20
20 - 30
30 � 40
40 � 50
50 � 60
60 � 72
*NOTE'- Totals for SI units differ due to rounding.
7B
35 �0.7!343239 9.1!282624 �.3!222018 �.5!161412 �.7!10
86 �.8!4210 <0!
477 365!
450 344!
405 310!
482 369!
578 442!
544 416!
528 < 404!
3,464 �,648!
1>074 821!
984 752!
990 757!
558 427!
636 486!
1,194 913!
834 638!
6,270 �,794!
1,551 �,186!
1,434 �.096!
1,395 �,067!
1,040 796!
1,214 928!
1,73e �,329!
1,362 �>042!
9,734 �,442!
Heasuredtemperatures
OF OC
Predictedtemperatures
oF oC
5.0 days10.0 days
79
The remainder of the instruments are in goodagreement with the predictions, with the pre-dictions being about 10oF �.5oC! below measuredvalues.
b. Bottom instruments. A comparison of threeinstruments shoved very good agreement vithpredicted values. The maximum predicted temper-ature vas 110 F �3 C! at a station approxi-mately 1 ft �.3 m! above the base of the seal.measured temperastures vere as follows:
Inst Ho. 6' .123 F �1 C!Inst Ha 17: 119 F �8 C!Inst No. 24: 119o F �8a C!
Again, the predictions are below tha measuredvalues by about the same difference as for themid-depth instruments.
c. Tap instruments. A comparison of four instru-ments near the top of the seal also showed verygood agreement with predicted values, Due tothe variable cover which was achieved over theinstruments, the comparisons below are given inranges of temperarures representing the top 5ft �.5 m! of the seal.Time afterplacement
sterted
80-120 �7-49! 90-125 �2-52!71-132 �2-56! 86-138 �0-59!
As above, the measured values were above thepredicted values by about the same difference.
d. Edge instruments. As noted earlier, theCarlson Hethod assumes heat flow in one direc-tion only. For those instruments near the out-side edges of the seal where significant lateralheat flov could be expected, the measured temper-atures were weLL beLow predicted values. How-ever, two instruments, 30 and 33, both located atmid-depth at the end of the cofferdam, developedmaximum temperastures higher than anticipatedfor their outside positions. Both instrumentsdid show significant temperature decreases by380 hours shoving the influence of the outsidelocations, The extra concrete thickness be-tween these instruments and the cofferdam wall when compared to other edge instruments! mayaccount for the higher temperatures vhichdeveloped.
3 . 3. 3 Conci'ete flow atterns . Soundings wei etaken by State inspectors throughout the place-ment period to monitor progress and to providedata for examining, the flow of the tremie con-crete. After the placement, the soundings verealso correlated with temperature readings in, anattempt to discover why measured temperatureswere not as high as anticipated far instruments5, 7, and 9. The following items are basedupon this sounding data and upon concrete pro-duction data.
a. Concrete production rare. Table 21 showsconcrete production data for the placement per-iod. Since there vas little delay between
concrete production and placement, this datamay be viewed as essentially a record of concreteplacement. The total production wss 9,734 yd3�,442 m ! vith an average of 13S yd /hr �03m3/hr! for the 72 hr placement period. Thisrate agrees veil with that assumed for the
3 3temperature predictions of 150 yd /hr �15 m /hr!.
Production shoved the most noticeable dropduring the 30 ta 40 hour period due ta diffi-culties of resupplying cement ta the floatingbatch plant. This slowdown can be seen inthe cross-sections presented below.
For the first 21.S hrs while the tremies verealong the short centerline of the cof ferdam,the production rate translated into an averageconcrete rate of rise of 0.8 fr/hr �4 cm/hr!adjacent to the tremies and 0.4 ft/hr �2cm/hr! at the far ends of the seal. Theserates are both well below recommended ratesfound in the literature refs. 1, 4, and 15!.
b. Concrete flow distance. Concrete was de-tected both by temperature and by soundings atthe ends of the cofferdam within about 5 hrsafter 'placement began. This concrete vasflowing in excess of 70 ft �1 m!, again higherthan normally recommended limits refs. 1 and4!.
c. Placement cross-sections. Figures 61 through64 shov cross-sections of the seal during theplacement for four different locations. Thevar iations in production noted above are apparentin these figures. Two items are of specialinterest in these figures,'
1. Temperature instiument locations vere plottedon Figure 63 in an attempt to explain the lawreadings for instruments 5, 7, and 9. The fig-ure does not indicate any abnormality in therate at which these instruments were embedded inthe concrete.
2. The location marked * ! in Figures 6 1 and63 indicates an area in vhich a major zone ofuncemented material was found after the place-ment was completed. The placement rate atthis location appears to be higher than average,but would not normally draw attention duringthe placement. The unusually steep slope ofthe concrete at the 30 hour line of Figure 63may have contributed to the formation of thepoor quality zone by trapping laitance.
c. Concrete slopes. The sounding data wasused to determine the surface slope of thetremie concrete during and after completion ofthe placement. The paints made below may alsobe seen on Figures 61 through 64.
l. The slope of the concrete parallel ta theshort axis of the cofferdam was much flatterthan that in the long direction. This shortaxis slope had an average value af 1:23 along,the centerline and 1:47 at the ends of thecofferdam. These flat slopes probably result-ed from the close lateral spacing of the tre-mies. While all three tremies were along the
PLAN!
-40�2.2!
-50�5. 2!
C
u. -60�8,3!
I�
LLI-70
�1.3!
-80
�4.4! DOWNSTREAMVPSTREAM
Figure 61, Tremie concrete profiles at various times after beginning ofplacement, long axis of seal, adjacent to north side of cofferdam,
PLAN!
-40�2.2!
-50�5.2!
8I-
-80Z �8.3!I-
uI-70
�1. 31
-80�4.4!
Figure 62. Tremie concrete profiles st various times after beginning ofplacement, long axis of seal, north of center line.
80
-40 IR,2!
PLAN!
-50�5.2!
CI-
~ -60�8.3!
I-cC
-70�1,3!
O
-80 R4.4!
Figure 63, Tremie concrete profiles at various times after beginning ofplacement, short axis of seal, along centerline.
-40 I 2.2!
PL AH!-50
�5,2!6
b.~ -60
I 6,3!I
UI70
Rl.g!
O
-ep�4.4!
Figure 64. Tremie concrete profiles at various times after beginning ofplacement, short axis of seal, upstream end of cofferdam.
81
82
short cenCerline approximately the first 21.5hours!, the spacing was less than 20 ft � m!from tremie to Cremie.
2. The slope along the long axis vas usuallygreater than that described above. It rangedfrom an average of 1;6 for the zone nearestthe tremies to an average of 1:10 for theareas closest ta the ends of the cofferdam.
3. The slopes based upon soundings taken afterthe placement vas completed vary considerablybetween sounding points approximacely 18 fc�.5 m! apart! ranging from 1:7 to flat. Ingeneral, the soundings shoved that a reason-ably flat surface was obtained.
3.3.4 Concrete ualit . One author Holland !vistied the site once the cofferdam was de-watered and inspected the concrete. The follov-ing is based upon his observations, Che resultsof core sampling, and observations af the Pro-ject Engineer.
a. Visual inspection. The concrete which wasvisible not under water in low areas! wassound and a minimum of laitance was present.The surface concrete which was tested with aheavy steel px'obe was resistant to penetration.No cracking was visible on the surface.
One noticeable problem was very evident, how-ever. The surface of Che concrete was extreme-ly uneven -- much more so chan was anticipatedfrom the soundings which showed a maximum dif-ferential between adjacent soundings of 2.6 ft O,B m!. A number of mounds 3 to 4 ft �.9 co1.2 m! tall were present as vere several lovareas. The maximum differential betveen themounds snd low areas was approximately 4 to 6 fc.�.2 co 1.8 m!. The mounds were located at thepositions of the cremie pipes near the end ofthe placement when attempts were being made tobring the top of the seal to grade. See Figures65 and 66.
The mounding problem probably resulted fromthe typically low volumes of concrete placedthrough the tremies at the end of the place-ment and the steep slopes being achieved nearthe tremie pipes. Not enough concrete vasbeing placed to overcome flaw resistance andflatten out the slopes.
The mounds forced the contracCox to removeconcrete to allow for correct positioning ofreinforcing steel for the next lift of con-crete.
b. Cores, Initially, four cores were drilledinto the seal as is shown in Figure67. When inspected, these cores vere verygood and shoved virtually no bad concrete.Two cores, ¹4 and ¹1., shoved several inches ofpossibly trapped liatsnce Figure 68!.
Water vas flowing from all core holes, withthe greatest flow coming from bole ¹2, whichwent all the way through the seal. Sincethere vas flow from the other cores which didnot go thxough the seal, a system of small
seams of permeable material is probably pre-sent. The flov may a1so be partially attribu-table to any cracking which was caused by thethermal gradients which were developed. Figure69 sho~s this water flow from one core hole.
One of the investigators mentioned in theIntroduction, Lavrence Livermore Laboratory,reported an anamoly in their readings in thesouthwest quadrant of the cofferdam.Core ¹5 Figure 67! vas drilled to determineche validiry of the reading,s. This core turn-ed out to be sound «ith no bad material foundat any depth.
c. Najor void. A major void area vas dis-covered on the north side of the seal in thevicinity of Che intersection Of the noth edgeand the short centerline. This area has beenmentioned earlier and is shawn on Figures 61and 63. The void consisted of sn area of un-cemented aggregates. No explanation for theorigin of this void area is readily available.
This void was actually Cwo distinct areas.The first began about 4 ft �.2 m! below chetap of the seal and was 12 to 18 in. �0 to 46cm! thick. This area extended 10 to 12 ft �to 3.7 m! in the long direction of the sealand vas xeported as reaching about 20 in. �1cm! into the seal from the edge by a diver.
The second area began 8 to 10 ft �.4 to 3 m!belo~ the top of the seal and was approximately3 fc � m! thick. The diver could measure alength of 15 ft �, 6 m! snd estimated a totallength of 20 to 25 ft �,1 to 7.6 m!, This areaextended at least 6 ft �.8 m! into the seaLfrom the outside edge.
The lack of cemented xsaterial in the lowervoid is pxobsbly the cause of the low readingsof instruments 7 and 9 and possibly instrutsent5. No hydration was occurring and there vasapparently water present to help carry heat tothe outside of the cofferdam. Both of thesefactors could have contributed to the lowreading s.
d. Diver inspection. In addition to examiningthe voids described above, a diver inspectedthe vertical surfaces of the seal concreteafter the piling vas pulled. Na cracks werefound, but this does not necessarily rule outcracking caused by thermal expansion since theinspection was conducted under conditions ofpoor visibility. Also, the subsequent coolingof the concrete mass could have closed earlycracks.
~3I S . Yh f ll '~ 'tthis placement:
1, A total of 9,734 yd �,442 m3! of concretewere placed by tremie for a nonstructural sealfor Pier 12 of the 1-205 Columbia River Bridge.The placement vas continuous for 72 hours withan average concrete placement rate of 135 yd3/hr 102 m 3/hr ! .
Figure 65. Mounding on surface of seal. This mound waslocated at one of the final tremie locations.
Figure 66, Low area in surface of seal. This photo wastaken during preparation of the next lift ofconcrete.
83
20,0 f ff.m!
O
Q'
K 03
O � Figure 67. Core locations, Pier 12, Dimensions to insideof interlocked piles.
84
Section of core taken from tremie concrete. Notethe area at the 23 f t �.0 m! mark. This smallzone of laitance was the worst concrete seen on thefour cores.
Figure 68.
B5
Figure 69. Water flowing from core hole in tremie seal.
2. The concrete mixCure used included fly ashas approximately 24 percent by weight of thecementitious material. The fly ash was in-cluded to reduce the heat generated by thehydration process. This is, as far as is known,the first. major underwater placement to includefly ash for thc purpose of reducing heat.
3, Temperature prcd ict ions raade for the sca Iconcrete using the Garison one-dimensionalprediction technique proved Co be accurate towithirr 10 percent of measured values. The pre-dictions were, in this case, on the low side ofthe measured temperatures. The predictionswere accurate for. the entire vertical sec Lionof the seal at those locations where lateralheat flow co the outside of che mass could beneglected.
4. A maximum temperature of 155 F �S C!deve]oped in the center of the concrete mass.Concrete temperatures developed as expected forvarious instruraent locaCions with the exceptionof one zone of low temperature which is believedto have been caused by an area later found tobe largely uncemented aggregate.
5. Steep temperature gradienCs developed acrossrelatively thin concrete sections between outer-most ceraperature instruments and the exteriorof the seal. These gradients developed rapid lyand may have been high enough co generate stresseslarge enough to cause cracking in the concretewith consequent water entry into the mass.
6. Tremie concrete flowed a maximum distance ofovr'r 70 f t � J m! wi thnut apparent de tr imenra1effects, Cores taken near che extremes of theflow revealed sound concrete. Cross sectionsand calculacions based on soundings showedrather steep slopes in the direction of flownearest the tremies, 1:6, while near the endsof the cofferdam the slope had I'let tened to1: 10.
7, The concrete produced was generally verysound and capable of pcr forming its intendedfunction, Localized mounding necessitatedextra work for the conCractor in preparing forthe next li fr of concrete for the pier. Twoareas of uncemented aggregates were foundwithin the seal which required grouting.
g, Inspection of che seal concrete upper surfaceafter dewaterinp revealed no cracking. Inspec-tion of the vertical concrete surfaces by adiver after removal of the cofferdam pilingalso failed to reveal evidence of cracking.
9. Water flow was observed from core holesincluding hales which did not penetrate thefu11 thickness of the seal. Thin seams ofpermeable material or cracks caused by therm-ally induced ~tress or a combination of bothare postulated as the source of the flows.
86
87
CHAPTER 4TRENIE COHCRETE CUTOFF WALL,
WOLF CREEK DAW
of the project was to observe and reviev place-ment of tremie concrete during construction ofa cutoff wail through an existing earthfilldam. Three areas were of particular interest:
a. Behavior of a tremie concrete mixture con-taining a fly ash replacemenC of a portion ofthe cement;
b. Placement of tremie concrete at extremedepths; and
c, Identification of problems in mixture designor placement technique which resulted in ronesof poor quality concrete,
4.2,1 Descri tion of the dam.» Wolf Creek Damis a multi-purpose structure pover generation,flood control, recreation! located on CheCumberland River near Jamestovn, KY. It liesin nr area of karst topography approximatelysixty miles 97 km! from I ammoth Cave. LakeCumberland, impounded by the dam, is the largestmanmade lake east of the !Iississippi River.
Construction of the dam was begun in 1941, butwoik was discontinued for three years duringWorld War II. The work accomplished prior tothe wai was mainly site preparation and con-struction of the cutoff trench under the earth-fill portion of the dam. The project wascompleted for full beneficial use in 1952.
The darn consists of an eai'thf ill section 3940ft �20! m! long and a concrete gravity section1796 ft �47 m! iong. The maximum height ofthe embankment section is 258 ft �9 m!. Theconcrete section includes a gated spillway vithten radial gates having a rated discharge of553,000 ft3/sec �5,660 m3/s!. The power planthas an installed capacity of 270,000 kw in sixunits.
4.2.2 Descri tion of roblem. In October,1967, a muddy flov appeared in the tailrace ofthe dam. In Harch ~ 1968, a sink hole appearedon the toe of the dam near the switchyard. Aninvestigation of this hole shoved it was con-nected to a solution cavity, In April, 1968, asecond sink hole appeared near the first. Dyeplaced in this hole appeared in the tailracewhere the muddy flow had originally been seen.
As a result of these occurrences, an emergencygrout ing program vas under taken. This programresulted in placement of 260,000 f t 7,360 m3!of grout but provided no assurance of completelyresoi.ving the problems.
*For additional descriptions of this projectsee references 25, 26, 27, 28, 29, and 30.
After extensive site investigations, the Corpsof Engineers and its consultants theorizedthat the flow was either through the originalcutoff trench or through a combination of thecutof f trench and a series of solution featui'es. It should be noted that Che original cutofftrench is only about 10 ft � m! wide at itsnarrowest point, Photographs indicate that therock in the veils of the trench is fracturedand jointed and in many cases the walls areverCical oi even overhang the excavated portion.!The repair procedure recommended was to constructa positive cutoff wall through the earthfillportion reaching into sound rock belov thedam. Additionally, a cutoff wall vas to beconstructed to isolate the switchyard area.
4.2.3 Re air rocedures. The constructionprocedure selecCed to install the cutoff wallswas modification of the slurry vail procedureoften used on foundation excavations.» Theembankment cutoff vali is 2240 ft �83 m!long and has a maximum depth of 280 ft 85 m!.Due to concern over the stabilityof the dam during construction, the wall vasconstructed of alternating primary cased, 26in. �6 cm! diameter on 4.5 ft �37 cm! centers!and secondary uncased! elements rather thanof panels as is frequenC iy done on slurry wallfoundation projects. Figure 70 shows a sche-matic of these elements.
A total of 1256 elements were placed to con-struct. both of the veils for a total contractcost of $96.4 million. These elements verebroken dovn as follows:
Over 250 ft �6 m! deep: 158200 to 250 ft �1 to 76 m! deep: 666150 to 200 ft �6 to 61 m! deep: 16890 to 150 ft �7 to 46 m! deep: 174less than 90 ft �7 m! deep: 90
The contractor avarded the project, ICOS Cor-poration of America, is a pioneer in the fieldof slurry walk consCruction. Following is astep-by-step description of the procedure usedfor the embankment wail.»»
a. Site Preparation. Since Che crest vidth ofthe dam is only 32 ft �0 m!, the contractorconstructed a work platfoi'm 170 ft '�2 m! videinside parallel walls of sheet piling. Actualexcavation took place in a concrete linedstarter trench which vas constructed along theaxis of the wall. Much of the excavation andcasing handling equipment was especially de-signed by the contractor foi rhis project Figure 71!.
*For a general description of the slurry walltechnique see references 31 and 32.
»»Since the switchyaid vail vas much sha!loverand since no problems were encountered duringita construction, the remainder of the chapterdeals only with the embankment wall.
W 04J
I
I I
l
08 CJr5
0 IQ ~
gAe 8
v
W Q ~V4J
1S VVl
Figure 71, Casing handling machine which rotates casing andapplies vertical. force for casing installationor removal.
Figure 72. Breather tube in tremie hopper. The tube extendsto the top of the hopper and allows air to escapeduring placement.
b, Pt imary elements. Initially, a 53 in. �35cm! diameter hole was excavated with a clamshell to a depth of approximately 76 ft �3 m!.At that point a 47 in. �19 cm! diameter casingwas inserted and excavation was continued insidethe ~asing, Additional sections of casing wereadded as necessary vich especially designedjoincs which were flush inside and outside!until the casing reached down 142 ft �3 m!.Ftom chere to the top of the rock, a 41 in.�04 cm! diameter casing was used. Excavationbelow the 76 ft �3 m! poinr was done throughbentonite slurry,
When rock was reached, a rock dri 1 1 was used t.odz ill a 36 in. 91 cm! d iarne ter hale co theplanned bottom of the wall. Then, a NX corehole was taken 25 ft 8 rn! deeper into Cherock. This hole vas pressure tested and, ifsar isfactory, filled with grout, If the rockf~iled the pressure test, the 36 in. 91 cm!diameter hole was continued deeper.
Once che hole was founded in saund rock, the 26in, �6 cm! diameter permanent casing vaspl.aced. This casing was filled with water tokeep it in place, After the permanent casingwas in place, the annular space between thepermanent and excavation casings was filledwith grout as the 41 and 47 in. �04 and 119cm! diameter casings were removed. The annularspace grout was allowed to set 10 days beforean element was filled with tremie concrete.
To begin the filling process, enough bentoniteslur ry was placed into the casing ca disp!aceLhe lower 20 EL � m! of water. The purpOSe ofthis benLanite was co lubricate the insidewalls of the casing during concrete placement.Concrete was bacched and mixed at a plant nearthe dam and transported to the cremie site bytrucks, Two unusual items concerning Chettemie placement are worthy of noting here.First, the tremie hopper was equipped with abreaching tube vhich allowed ait to escapeduring concreting Figure 72! . Almost no airvan seen bubbling to the surface as is commonan most tremie placemencs. Second, the con-tractor developed a novel technique for support-ing the Czernie pipe. Figure 73 shows how thistechnique ~orked.
c. Secondary Elements. Construction of asecondary element followed cornplet ian of twoad jacent primary elements. The overall can-sttuction sequence vas planned to allav anadequate curing period for the concrete in theprimary elements before work was started on theintervening secondary elemenc,
The construction process for secondary elementswas identical to that described above with thefollowing exceptions: First, the excavation wasaccomplished using a clam shell which followedthe walls of the adjacent primary elements Figure 74!. This procedure removed the annu-lar grout on one side af the primary elementsand insured a concrete to casing bond once thesecondary elements were concreted, Second, rhesecondary e lements were excavated through ben-tonite slurry for their full depth since theywere noc cased.
The secondary elements, once socketed into soundrock, were then filled with tremie concrete todisplace the slurry.
4.3 Observations and discussion, The followingcomments are based upon site visits be Ben C.Gerwick, Jr., and T. C. Halland, and upon corre-spondence with the Resident Engineer at the site.
4. 3.1 alit of cremie concrete. One item inthe consLruction proceduze which is not mentionedabave is the extensive drilling of cores whichwas done � approximately cen percent of theelements were cored, This caring program re-vealed minor but consisCent problems in the qualityof the concret:e in the primary elements. Theseproblems included minor areas of segregated sandand/or coarse aggregate, zones of trapped lsitance,snd zones of lightly to extremely honeycombedconcrete. These bad areas are scattered verticallyin the cores and do nat appear to follow a dis-cernable pattern. Figure 75 shows a portion of acore from one elemenC showing the variations inconcrete qualiLy,
Multiple borings taken in the same element haveshown chat the zones af poor quality concrete varyhorizontally as well as vertically. For example,in element P-465 the first boring showed a 41. 5 ft�2.6 m! loss of cote, A secand baring shavedvas made which showed good concrete for its fulldepth.
Ic is important to note that these problems havebeen found in the pzimary elements only. Thoseanomalies which have shown up in the cores of thesecondary elements have been explained by suchfactors as loss of drill vertically causing coresta cuc into the annular grout near the primaryelements or by drilling into a stepped portionof the foundation rock causing loss of a portionof the core. Professional staff at the site aresatisfied that all anomalies which have appear'edin the cores of the secondary elements can beexplained. However, as will be shown below, thereare noc as readily available explanatians for cheproblems discovered in the primary elements.
4.3. 2 Tremie starcin rocedures. One of theareas suspected of contributing to the concreteproblems was the procedure used initially to sealthe tremie pipe. The placements were begun withthe tremie pipe full of water,
Initially, a rubber basketball vas used asugo-devilu to start the tremie placements. Theba11, initially floating inside the tremie, wasforced down the pipe as concrete was introducedinto Che hopper. The ball separated the waterand the fresh concrete and pushed the water aheadof itself aut of the mouth of Che czemie. Thisprocedure was abandoned due to the realizationthat the hydrostatic head in the deep halescollapsed the ball causing a loss of seal inthe tremie and a subsequent segregation and wash-ing o f the concrete.
The techn'ique selected to replace the basket-ball was Lhe use of a pine sphere produced atthe site. While this did resolve the question
a. Loop is used to raise tremie as sections of pipe are removed.Tremie pipe is supported by coupling resting on plate.
b. Tremie pipe being raised. Note how plates open to allowpassage of couplings.
Figure 73. Tremie support scheme.
91
Figure 74. Secondary element excavation device. The curvedsections ride the ad]scent primary elements.
Figure 75. Cores taken from primary element, p-773. Notevariations in concrete quality.
92
of bal 1 collapse, the wooden bal ls did not fitsnugly inside the rremie pipes neither did thebasketballs! Figure 76!. There is approxi-mately 0. 25 in. �.64 cm! clearance between thepine sphere and che tremic pipe; therefore, asthe ball and concrete moved vertically down thepipe, sorse amount af washing of the concretewas taking place.
The procedure followed to introduce the firstconcrete into the tremie was also designed taguard against loss of seal. The pipe was ini-tially raised only 0,3 ft 9 cm! as the firstconcrete was placed. After about 40 seconds approxirsately one cubic yard �.8 m3!!, thetremie was raised an additional 0.6 ft �8 cm!to allow the pine sphere to escape. By thetime the tremie was raised this second incre-ment, sufficient concrete had been fed into thetremie to insure that the rsouch was adequatelyembedded.
Although there was undoubtedly leakage aroundthe sphere, a zone of poor quality concrete hasnat been consistently found at or near thebottom of various elements as would be expect-ed. Perhaps the Iaitance or abashed material wascarried upward on the sound concrete of perhapsit was Lost as an identifiable area due to re-mixing. There is no evidence ta indicate thatche zones of poor quality concrete foundthroughout the vertical sections are a resultaf initial. leakage around the sphere. Finally,chc queston remains, if the leakage were re-sponsible for the poor qualiry concrete, whywas the problem evident only in the primaryelemencs?
One possible explanation relates not to theleakage but to che sphere itself. Due to thesize of the primary elements, it was not possiblefor the sphere to pass the tremie on the wayback up to casing Figure 77!. Perhaps thesphere vas following the tremia as it vaswithdrawn and was inhibiting concrete flow andrersixing. Since the secondary elements werelarger, the spheres were able to return to thesurface without causing a problem.
4.3. 3 Tremie aint leaka e, One factor whichis often suspect in cases of vertically scat-tered paor concrete is leakage between jointsin the t'remie pipe . The rapid downward flow afconcrete in the cremie can suck water throughany leaks which may be present at the joints.The resulr is a randomly washed and segregatedconr.rete.
At Wolf Creek the cremie sections were threadedtogether and the threads vere liberally coveredwith grease each time the cremie was assembled,The secr.ians vere carqued toge cher by tvo menwhile a third hit the pipe with a sledge hammerto tighten the connection. The tremie wastested for leakage by lowering a light insideand found ca be satisfactory. From the pre-cautions being taken, it is doutbful that tremieleakage was causing the problems.
4. 3.4 Tremie center in, Another potentialproblem area was the centering of the tc'ernie in
the boles � particularly the primary elements.If the pipe vere not centered, there waspassibility of inhibiting the flow of the con-crete as it left the cremie mouth. To elimi-nate this possibility, centering fins wereadded to one secrion of the tremie pipe Fig-ure 78!. Cores taken after addition of thefins conte inued ta shaw anomalies, indicatingthat poor centering was not the sole cause ofthe poor quality concrete.
4.3.5 Concrete lacement rate. In large valumeplacersents such as Pier 12 of Chapter 3! theplacement rate of tremie concrete is often anarea of concern. Too slow a placement rateallows the concrete in place to stiffen whichinhibits flow. Table 22 examines placementrates for six elements at Wolf Creek far vhichdata were available. These rates are basedupon total elapsed time from beginning ta endof the placement and, ther afore, include timefar removal of pipe sections, waiting on con-crete trucks, etc,
The lower volumetric rate yd3/hr ! m /hr! forthe primary elements is a reflection of themore frequent stopping for removal of pipesections. Yec even with this slower volumetricrate, the primary elements have a higher 1 inearrate ft/hr! m/hr! duc to their smaller cross-sectional area. The linear rate appears to besignif icantly higher for the primary e lersents.
Although problems with race are usually associ-ated with too slav a placement, perhaps toorapid a rate may also be decrimental. Noreports on the effects of too rapid a placementhave been found in the literature, Intuitively,however, a higher rate would seem to favorremixiag within the elements as the concreteis placed.
4.3.6 Tremio rersoval rate. An aspect closelyrelated to the placersent rate is the rate atwhich the tremie pipe is raised as sectionsare removed thc mouth of che tremie rsustremain embedded in the concrete!. Here, thetheory is that too rapid a pull rate couldresult in voids or honeycomb i f the concretedid not flow fully into the void left by thecYemie pipe. This problem is particularly pre-valent if overall placement rates are low,
To guard against too rapid removal of the pipefrom the e laments, an inspector timed andrecorded the pull rate for each section of thetrersie. The same rate �.3 ft/sec! 9 cm/sec!was used for both the pr imary and secondaryelements.
Again, the question may be raised as co whythe problems, if a result of pipe pull speed,were evident in only the primary elements,This question is particularly bothersorse sincethe tr ernie sections were removed more frequentlyfrom the primary elarsents. Hence, the concretehad less time to stiffen and Lose the abilityco flaw inta the void created by the withdraw-ing tremie. Therefore, if pipe removal ratewere a factor, the problers vould seem ro beLoss likely to occur in the primary elements.
93
Figure 76. Pine sphere inside tremie at beginning of placement.Note leakage around sphere. 25-/h/ O.O. CASII|IG/25.44N. /.D /
VN. I.D.hIIE PIPED I/I CEh/TEIII/VS
h/. DIAh/.SIIPERE
Figure 77. Position of pine sphere upon leaving tremie. Notepossible inhibition of concrete flow � in. = 2.54 cm!,
94
Figure 78. Pins added to tremie pipe to insure proper centering.
TABLE 22 � TRENIE CONCRETE PLACENENT RATES
VolumetricVolume of
RateConcrete,
ln3 /hr!
Linear Rate,ft/hr m/hr!
P611
P771 1.2
P773 1,4
F791
P795 1.2
F807 1.2
F985 0.9
0.9P1001
NA NA 26 �0!182 �6!PRIHARY ELEMENT AVERAGE
8576 1.6
8594 1.7
8676 2.1
S746 1.8
8858 2.2
8956 1.5
NA NA 42 �2!119 �6!SECONDARY ELEMENT AVERAGE
95
Element DepthElapsed
Element Time,ft m!hr
212.8 �4.9!
212.1 �4.9!
213,1 �5.0!
212.9 �4.9!
212.9 �4.9!
212.7 �4.8!
173.2 �2.8!
173.3 �2.8!
212. 5 �4. 8!
212.6 �4.8!
212.7 �4.8!
212.9 �4,9!
263,2 80,2!
172,7 �2.6!
193 �9!
177 �4!
152 �6!
194 �9!
177 �4!
177 �4!
192 �9!
193 �9!
133 �1!
125 �8!
101 �1!
118 �6!
120 �6!
115 �5!
30 �3!
29.5 �3!
29.5 �3!
30 �3!
30 �3!
29.5 �3!
25 �9!
25 �9!
72 �5!
72 �5!
75 �7!
73 �6!
97 �4!
64 �9!
27 �1!
25 �9!
21 �6!
27 �1!
25 �9!
25 �9!
28 �1!
28 �1!
45 �4!
42 �2!
36 �7!
41 �1!
44 �4!
43 �3!
96
-,.3.7 Breaks in lacin . Another area of con-cern was the resumption of concrete placing atthe beginning of each new truck load. A certainamount of sand and laitance does collect on thetop of the tremie concrete as the placementmoves up the hole. To prevent trapping thismaterial and to insure a better remixing at theresumption of placement, the initial amount ofconcrete was trickled into the tremie. Theremainder of the load vas unloaded at normalspeed. This same procedure was followed vhen atruck laad was broken into two placements toallow removal of a tremie section. As can beseen from the figures in section 4,3,11, below,there does not appear to be a correlation be-tween stopping/ restarting points and zones ofpoor quality concrete.
4,3,8 Water tern erature durin lacement. Inthe original construction sequence there vasnat a delay between placement of the grout inthe annular space surrounding the primaryelements and placement of the tremie concretein the elements. The temperature of the waterin one element was measured at 100 F �8 C! dueto the heat generated by the hydratian of cem-ent in the annular grout. placement of tremiecancrete into hot water can result in rapid andunpredictable setting or loss of slump, both ofwhich could inhibit f lovability, In one in-stance, a rapid set required removal of a por-tion of the concrete in an element.
These problems let to the practice of alloving10 days between placement af annular grout andtremie concrete. The water in t' he primaryelements vas also exchanged for cooler waterprior to concrete placement.
Although this change in procedure did eliminaterapid set problems, it did not preclude theconcrete quality problems as described.
4.3,9 Concrete mixture. One area in whichthere was a naticable improvement was the tremieconcrete mixture itself, Characteristics ofthe mixture are shown in Table 23. This mixtureis of particular interest due to the use of thefly ash vhieh was used to improve workabilityand to reduce heat generation.
None of the problems observed have been attri-buted to the mix. However, the slump losscharacteristics of such a rich mix and thehigh ambient temperature at the site suggestedthat the addition of a retarder to the mixwould be beneficial. A retarder was added andsubsequent pl.acements appeared to be verysuccessful. The Resident Engineer stated thatthe retarder made a significant difference,most noticeably in the appearance of the con-crete as it returned to the top of the holes atthe conc!.usion of a placement.
4.3.10 Obervation of lacements. Shortlyafter the addition of the retarder to the mix,one of the authors of this report Holland!visited the site and observed placement ofseveral primary elements and one secondaryelement. During the placements which were ob-served, the concrete returning to the surface
appeared to be of the same quality as thatwhich was being supplied to the tremie Figure79!.
Another area which had been questioned was howto determine when sound concrete had t'cachedthe top of the elements. For the primaryelements there was no difticulty making thisdetermination, Initially, clear water aver-f loved the casing. Hear the end of the place-ment, the small amount of slurry which wasadded to the pr imary elements began to appear.This slurry gradually thickened and containedmore and more granular material. Approximately12-18 in. 130-46 cm! of very granular materialcame to the surface before a concrete contain-ing fine and coarse aggregate was visible.This concrete appeared evenly on all sides afthe tremie and had a very uniform appearance, Before the retarder vas added, elevationdifferentials of up to 18 in. �6 cm! on oppositesides of the tremie were reported as theconcrete began to return.!
The placement of the concrete in the secondaryelement vas identical to that in the primaryelements except that all fluid which was dis-placed vas slurry rather than water. The samethickening of the slurry was noted and, again,there was no difficulty determining when soundconcrete had returned,
As of the date of this visit, none of theelements containing the retarded mix had beencored. The personnel at the site agreed thatthe placements had been very successful andwere quite confident about the expected coringresults.
4.3.11 Care and Iacement~lo s. The Iesultsobtained from coring those elements which vereobserved being placed were surprising anddisappointing. While the secondary elemencscontinued to be free of problems, the zones ofpoor quality concrete continued ta be found inthe primary elements. While the problems didnot appear to be as severe as before the addi-tion of the retarder, they were still evident.
The Resident Engineer established an excellentsystem for inspecting, and recording the work,excavation, tremie concreting, and coring.Reports vere filed on a day by day and on anelement by element basis. Using the recordsof four placements and the corresponding corelogs, Figures 80 through 84 vere prepared inan attempt to correlate zones of poor qualityconcrete with any of the fo11owing factors:
Initial pipe embedment;Breaks in placement ta withdraw tremie
sections, and;Location of the end of the tremie.
As can be seen by studying these figures, noneof these factors appears to be related to thezones of poor quality concrete.
4 . 3, 12 Tremie resi stance to flow. Anotherarea considered vas the balance of the tremie
TABLE 23 � TREMIE CONCRETE MIXTURE, WOLF CREFX DAN
Figure 79. Primary element at completion of tremie placement.Concrete returning to the surface appeared to be ofexcellent quality.
97
l. Each Figure 81 through 84! presents an analysis of the tremie pipelocation on the lef t of the page and a summary of the core log on theright of the page.
2, Each ver tical line represents placement of concrete from the bot tom tothe top of the line. The tremie is fixed during each placement withthe mouth at the bottom of the line.
3. Example:
shows placement from-63 ft, When concrete
tremie mouth was
75 ft. Embedment at Start of LiftEmbedment at End of Lift
Figure 80. Key for Figures 8l through 84.All distances and elevations in
feet � ft = 0.3048 m!.
98
SAND SEGR EGATION
� BMALLAGGREGATESEG R EGATION
MODERATELY HONEYCOMBED
SLIGHTLY TO MODE RATELYHONEYCOMBEDMODERATELY TD BADLYHONEYCOMBED
BADLY HONEYCOMBED
SLIGHTLY HONEYCOMBED
SLIGHTLY TO MODERATELYHONEYCOMBED
BADLY HONEYCOMBED
MODERATELY HONE YCQMBED
SLIGHTLY HONEYCOMBED
! BROKEN BY DRILL
212.7 BOTTOM OI' CORE
ING
Figure 8l. Analysis of element P-611. See Figure 80 for explanation.Al? distances and elevatlons are in feet � ft 0.3048 m! .
99
VERT SEAM
24
BADLY HONEYCOMBEDSAND SEG R EGATIONBADLY HONEYCOMBED
35
SAND SEGREGATION
~j MODERATELY HONEYCOMBEDSAND SEGREGATION
119.0 RAN INTO CASING
BOTTOM OF CASING
100
Figure 82. Analysis of element P-985. See Figure 80 for explanation.A11 distances and elevations are in feet � ft 0.3048 m!.
SANO WASHED
~ BROKEN BY DRILLPOROUS CONCRETE
SLIGHTLY HONEYCOMBED
SLIGHT SAND SEGREGATION
104.9 RAN INTO CASING
TTOM OF CASING
Figure 83. Analysis of element P-1001. See Figure 80 for explanation.All distances and elevations are in feet �. ft 0.3048!.
101
SAND SEG R EGATION SOLID CORE!
207.5 INTERCEPTEDLIMESTONE
Figure 84. Analysis of element S-576. See Figure 80 for explanation.All distances and elevations are in feet O ft 0.3048!.
102
103
system when flow a was not occurring due tobreaks in the placement. This balance may bethought of in terms of resistance to .flow whichmay be calculated as the difference between thetheoretical hydrostatic balance of the tremiesystem and the actual measured value. Thedifference which is obtained may be attributedco friction between the concrete and the tremiepipe, to internal friction or cohesion of checoncrete, or to a blockage or any other type ofrestriction to flow. Figure 85 shows the geo-metry of the tremie system snd che techniqueused co calculate this resistance to flow.
Heasuremencs made on ocher projects have in-dicated that che tremie system is normally veryclose to the balance point and very littleresistance to f!ow can be measured . One set ofmeasurements vss made by Gerwick st Wolf Creek.This data is presented in TabLe 24.*
The resistance to flow varies greatly frommeasurement to measurement. The variations inthe range of 500 to 1000 Lb/ft2 �.39 x 104 to4.79 x 10 ps! are believed to be typical.Ho~ever, note readings number 1 and 4 which arean order of magnitude greater than the remain-der. This variation is not believed to betypical, It was not possible to correlate thesemeasurements with a core log of the element.
While these variations in resistance to floware not believed to be causing the problemsseen in the concrete, they may be indicative ofa blockage or other restrictions to concreteflov which could result in the anomalies de-tected. Lf these variations are related tozones of poor quality concrete, measurementsmade inside and outside the tremie pipe duringplacement could serve as an additional inspec-tion tool. Further research should be con-ducted in this area.
4.3. 13 Potential for concrete se re ation. Thedata used to develop the resistance to flowvalues also show that a significant potentialfor segregation occurred whenever there was abreak in the placement. Since the system returnedvery near'ly to the balanced point, concreteplaced isnnediately after a break could havefallen through distances great enough to causesegregation.
ln massive tremie concrete placements the flowof the concrete through the tremie is con-trolled by the depth of the pipe mouth embed-ment in che fresh concrete. Such control wasnot possible in the limited volume placementsof Wolf Creek since the concrete in the ele-mencs did noc have adequate time to stiffen andbe able co control the flow. Therefore, notonly the concrete placed after breaks but alsomone of the concrete placed msy have been sub-jected co long free falls resulting in segrega-tion.
«Additional data concerning resiscsnce to flowis avaiLable in re ference 30.
There is no reason to believe that the poten-tial for segregation was different for theprimary snd secondary elements.
4L .rf ftl gr'*rriplacement:
1, A concrete cutoff wall was constructedthrough an existing esrthfill dam using tremie-piaced concrete. A total of 1,256 individualelements were constructed, with the deepesttrernie placement being approximately 280 ft 85nr! .
2. The cutoff wall vas made up of alternatingcased primary! and uncased secondary! elements.The primary elements were cased with 26 in. �6cm! diameter steel pipe, The secondary elementswere rectangular and were slightly wider thanthe primary elements, Their volume was approx-imately cwo and one-half times char of theprimary elements.
3. An extensive coring program hss shown thequality of the concrete in the secondaryelements to be excellent. The concrete in theprimary elements has been plagued with minor butpersistent problems of segregated materials,trapped laitance, and moderate to severehoneycomb. The anomalies are scattered ver-tically and horizontally within the primaryelements and do not seem to follow any pattern.
4. The construction of the tremie concrete cut-off wall has been a highly successful operationwhich will help to insure the continued safetyof the structure, Since the concrete problemswere limited to the cased elements, there is noreason to believe that the wall will not performits indended functions.
5. An examination of the mixture design and var-ious aspects of the placement technique such asstarting procedure, joint leakage, tremiecentering, placement rate, tremie removal. rate,snd breaks in placement has failed to disclose asingle, responsible factor for the small local-ized areas of poor quality concrete. Instead,the problems are beLieved to result from theinteraction of at least two factors. First, theconcrete was probably segregating during its fallthrough the tremie pipe. Second, the concretein che secondary elements wss apparently remix-ing and overcoming the segregation while thecorrcrete in the primary elements wss not assuccessful in remixing. The inhibition of re-mixing in the primary eLements is believed to bedue to the following items:
s. The primary elements had s much smaller crosssectional area than the secondary elements.This smaller ares msy have been acting in con-junction with the wooden sphere and centeringfins to create a condition which restrictedflov and remixing.
b, The walla Of the permanent caeinga WhiCh WerefiLLed to create the primary elements were muchsmoother than the walls of the secondaryerements. These smoother walls may have reduced
WORK PLATFORM
WATER SURFACE
MEASURED CONCRETELE V E L . INSIDE PIPE
MEASURED CONCRETELEVEL - OUTSIDE PIPE
REMIE PIPE TIP
NOTE; AT PIPE TIP: by ey + ay �+ RESISTANCE TO FLOW!REslsTANcE To Fl.ow = !b-a! y -eycarte water '
Figure S5. Tremie geometry and derivation of reaiatance to fIow.
TABLE 24 � TREHIE RESISTANCE TO FLOW MEASUREMENTS
NOTES. '�! Deck 3 ft . �m! above water�! Unit weight of concrete 147 1b/ft � ' 355 kg/z !�! Unit weight of water 63 1b/ft �,OO9 kg/z3!
104
the tendency of the concrete to tumble andremix. The slurry put into the primary elementsst the beginning of a placement may glen havereduced wall roughness and thus contrjbutdd tothe problem. I
c. The concrete wss placed in the prfmaryelements very rapidly. The rate may have beentoo rapid to allow for adequate remixing totake place.
6. A definite reduction in concrete problemswss seen over the duration of the project.This reduction may be attributed to s seriesof modifications in the placement techniquesnd to the addition of s retarder to the con-crete mixture. All of the modificationsenhanced the flowability of the concrete andtherefore contributed to better remixing inthe primary elements. Since the effects ofthese modifications were cumulative, it isimpossible to state which made the greatestdifference. The Resident Engineer stronglybelieves that the addition of the retarder tothe concrete mixture was the most significantchange.
7. Measurements made to determine the state ofhydrostatic balance of the tremie system arepostulated to be an indication of areas inwhich to expect anomalies to occur. Additionalmeasurements snd correlations with core logsneed to be completed to evaluate this hypothesis.
5,2 Back round.
106
CHAPTER 5
TENPERATURE PREDICTIONS POR TRENIE CONCRETE
of the project was co develop a generalizedfinite-element approach for predicting tempera-tures in massive tremie concrete placements.Emphasis was placed upon developing a programwhich, given the characteristics of the place-menc, would develop an appropriate grid systemend output the grid in a format suitable foruse as input to an independent finite-elementprogram which would perform the temperaturecalculations.
5,2.1. Need for finite-element anal sis. Theuse of a simple one-dimensional technique Carlson Nethod! for predicting tersperaturedevelopment in a tremie concrete placement hasbeen described in Chaptex 3. As was notedthere, this technique accurately predicts tem-pex'acure development in the center of the masswhere hear flow in other than the verticaldirection may be neglected. Hawever, chetechnique is not applicable to areas near theexcrerses of the placement. These areas ax'e ofparticular interest due to the possibility ofthermally-induced cracking as was also describedin Chapter 3.
It was felt that the best way to obtain thetempex'ature distribution at the boundaries ofthe structure was to develop a capability toper form e finite-element analysis of a tremieplaeersent.
5.2.2, Finite-element ro ram selected, Thefinite-element program selected to perform theanalysis was one which is carmsercially avail-able ac U.C. Berkeley, It was developed byRonald N. Pal ivka and Edward L. Wilson in 1976 ref. 33!. This program, entitled DETECT DEtermination of Tlbrrperaturee in ConsTruction!,provides a two � dimensional linear analysis ofstructures constructed incrementally. Acomplete Listing end description of the prograrsmay be found in the reference.
5.2.3. Crackin redictions. Prediction oftemperatures in a massive concrete placementis only the first step in predicting if ther-mally-induced cracking will occur. Borh thefactors which rend to cause cracking primarilytersperature changes for tremie-placed concrete!and those factors which resist cracking tensile creep and strength of the cancrete!rsust be examined. A detailed examination ofthese factors is beyond the scope of thepresent work. Carlson, Houghton, end Polivka ref. 34! present an excellent overview of thefactors involved in cracking of mass concrete,
Therefore ~ development of a program which willallow predictions of temperatures in massivetremie placements will not lead directly topredictions of cx eeking. However, use of cheprogram will allow comparisons of temperatures
and gradients based upon changes in placementtemperature, cementitious materials types andamounts, and placement x'aces,
5.3. Observations and discussion
5 ' 3,1. General descri tion of ro ram TENP.The progrars which was developed, TENP, producesimpuc data compatible for use with programDETECT, The output available includes elementidentificatian and creation information and anappropriate heac generation function. A listingof program TENP is in Appendix K.
The user of px'ogram TENP has the fallowingoptions:
1, Very placement geometry.
2. Vary placement rate.
3. Vary heat generation characteristics of theconcrete being placed.
4. Use of incremental or naniacremental con-struction approach.
5. Use of own racher than program generared gridsystem,
6, Use of own rather than program generated hestfunc tron.
7. Vary site conditions to include effects afinsular ing sur f aces, if any. insulating s ur-faces are handled directly through input toprogram DETECT.!
5.3.2, User o cions and variables. Followingis a detailed description of Che options avail-able to the user and a description of how theseoptions relate to the variables which areinvolved in a typical tremie placement. Detaileduser instructions for program TENP are inAppendix L, while instructions for interfacewith program DETECT are in Appendix N.
1. Pier geometry. The length, width, snd thick-ness of the concrete placement may be variedaS desired. The OrienCatiOn Of the aXeS iS aSshown in Figure 86. Elements are generatedfor input co DETECT for two-dimensional analysisin che X-Y plane.
2. Trerxie locac ion. The program assumes thatone tremie pipe, located at 0.0 on the X-axis,is in use in any plane perpendicular ta the2-axis. Additional tremie pipes may be simu-lated by adjusting the placement rate as isdescribed below,
3. Grid genex'ation. The program will auto-matically generate an appropriate grid, or theuser may input e specific grid, if desired.
The automatic grid generation option establishesa rwa-dimensional grid which will allow for an
adequate evaluation of the temperature distri-bution within any size structure while mini-mizing the number of elements necessary todefine the structure fox the finite-elementtemperature anal.ysis. The grid spacing gener-ated is the most intense at the boundaries ofthe structure where the temperature gradientsare expected to be the greatest. The griddecreases in intensity near the center of thestructure .
In Figuxe 81 a total of six grid spacings areillustrated for different base lengths andheights. For.a given structure, the base andheight gride are created and then superimpos-ed to obtain the two-dimensional grid pattern,
Prom Figure 87 it can be noted that the basegrid is established using even 20, 10, 5, 2,and I ft �.1, 3.0, 1.5, 0.6, and 0.3 m!intervale from the center outwaxd with astandard boundary established at the outsideedge of the structure. The height grid iscreated using a similar scheme except thatthe spacing is based upon 10, 5, 4, 2, and 1ft �.0, 1.5, 1.2, 0.6, and 0.3 m! intervalewith standard boundaries at the top and baseof the structure, In addition, two founda-tion elements with boundaries 10 and 20 ft�.1 and 3.0 m! below the base of the stx'uc-ture are included in the grid layout.
The grid interval at all boundaries is set at0.5 ft �,2 m!, a spacing found to provide anadequate definition of the temperature distri-bution at the boundaries.
The automatic grid generation is recosssendedfor use in preliminary analysis. If desired,the automatic spacings may be modified bychanging the appropriate values in subroutineGENGRD in program TEMP.
4. Incremental construction, The normal modefor the program is to create elements atappropriate times in accordance with theplacement option selected. There is also theoption of creating all elements simultaneously.
5 . Concrete placement rate . There are threeoptions available:
a. Constant rate of concrete rise over theentire placement area. The user is asked tospecify a production rate yd /hr! m3/hr! ora total time to complete the placement forthis option.
b . Specified rate of rise at center tremiepipe location! or at the X-boundary. Thisrate is then constant over the entire suxface.
c. Specified x'ate of rise at center and at X-boundary. When this option is selected, alinear variation is used between these twopoints, The production rate specified forthe center is used as a constant along the Z-axis.
6. Concrete heat generation. The user isasked to specify the amount of cement andpozzolan in the mixture to be evaluated . Threeheat generation curves are then available forselection.* These curves represent a typicalType 1 cement, typical Type II cement, and ahigher than average heat Type II cement. Thecement and pozzolan data is used in conjunc-tion with the curve selected to produce theheat generation function used as input forDETECT,
The user also has the option of modifying anyor all of the 13 points which make up each ofthe three available curves by entering desiredmultiplication factors.
Finally, the user has the option to completelybypass this portion of the program and enter aheat generation function directly into programDETECT.
7. Boundary conditions. Values for the follov-ing variables must be entered directly intoDETECT: concrete placement temperatux'e, ther-mal characteristics of concrete, water tempera-ture during and after PIacement, insulationcharacteristics, if any, and thermal character-istics of foundation materials. The number oftime periods to be included in the evaluationis also handled directly by DETKCT. See hppen-dix M and the user instructi.ons f' or DETKCT formore details concerning input of these varia-bles.
5.3.3 Exam le of ro ram TEMP usa e. ProgramsTEMP end DETECT were used to produce tempera-ture predictions for a placexsent similar tothat of Pier 12 of the I-205 Bridge describedearlier in Chapter 3. Variables were selectedto be consistent with those in the actualplacement. 'Table 25 presents the values ofthe variables involved,
The option for a continuous placement rate of150 yd3/hr �15 m3/hr! was selected for pro-gram TEMP. This rate corresponds well to theactual average placement rate of 135 yd3/hr�03 m3/hr!.
Two of the optional heat curves available j.nprogram TEMP Type II average heat cement andType II higher than average heat cement! wereused to produce heat function input data forprogram DETECT. Additionally, three otherheat functions were used by being input direct-ly into DETECT. Table 26 shows the valuesassociated with these five heat functions.
Temperatures predicted by Program DETECTusing input generated by Program TEMP are
* These curves are taken from those shown inReference 34.
108
TOP
a. TYPICAL VERTICAL GRIOS, FT. m!
OUTSIDESURFACE
0.0 M 70 8.0 80 $5 IM�'a! I.S! �'.I! N.4! �.7! R9! �0!
OUTSIDESURFACE
0 7.0 ap! I,5! �.0! �,6!�.I! �7! �.3! �.6! �.9! S.I! 8.2!
OUTSIDESURFACE
0.0 GO 209 25.0 3QO 35.0 370 39.04M 420 43.0 4M 44.0�,0!�0!�.t! �.6! 9.I! l07! II.3! I1.9! I2.5! I29! I3.l�33! I34!
b,FfPICAL HORIZONTAL GRIDS, FT. m!
Figure 87. Typical finite-element grids generated by Program TENF schematic � no scale!.
109
IO.O �.0!9.5 �.9!9a �.7!89 �.4!7.0 �.I !5.O I.s!3.0 �.9!
2a �.6!I 9 �.3!
OS �2!
OQ �.0!-IO.O eo!-20.0 KI !
TOPSURFACE 250 �6!
24.5 �.5!24.0 �.3!
239 �.0!2I.O �.4!I 7,0 �.2!
I3D �0!ea �4!6.0 I.e!4.0 I.2!
29 �.6!I 0 �3!
0.5 �2!OD �.0!
-IO.O ao!
-20' {4.I !
TOPSURFACE 330
32.53 I .0
29.0
25.0
2 I.O
I7.0
I2.0
8.0
402.0
0.5
OQ-10.0
-209
IO.I! 9,9! 9.4!
8.8!
�.6! 6.4! 5.2!
3.7! 2.4! I .2! 0.6!
0.2! 0.0! -3.0!
-6. I!
TABLE 25 VARIABLES USED IN EXAMPLE PROBLEM
X: 54.0 ft �6.5 m!Y: 33.0 ft �0.1 BL!2: 142.0 ft �3.3!
Total volume: 9372 yd �166 m !3 3
Placement rate. '150 yd /hr �15 m /hr!Foundation material:
Thermal conductivity: 0.917 BTU/hr-ft-'F �.59 W/m-K!Specific heat; 0.194 BTU/Ib-'F 812 J/kg-K!Density: 125 lb/ft3 �002 !rg/m3!
Concrete:
Thermal conductivity: 1.30 BTU/hr-ft-'F �.25 W/m-K!Specific heat: 0.2 BTU/lb 'F 967 J/kg-K!Density; 148 lb/ft �371 !sg/m3!
Concrete lacement tern erature: 60 F �6 C!Water Tem erature: 55 F �3'C!Mixture ro orations: Used for heat functions generated
internally by Program TEMP!
Cement: 526 lb/yd �12 kg/m j3 3
Pozzolan: 165 lb/yd 98 kg/m !
26 - HEAT FUNCTIONS USED FOR TEMPERATURE PREDICTIONS+
Tame,hrs
HeatFunction
tl
HeatFunction
k2
Type II,higher than
~Ae *
Type II,Average
heat*a
HeatFunction
k3
* Values shown are BTU/Ft -hr. Multiply by 10.34 to obtain W/m ,3 3
eeCurves available within program TEMP.
110
0 2
4 6 8122032486096
180290
1000
07988
103
1096427ll
7
4 10 0
08290
105
11065281510
6 20 0
20030
100106
75
2010151510
5 10
20030
100106
75
20101512
5 3 10
20030
10010660
1514131210
3 2 I
compared to temperatures measured in Pier 12in Figures 88, 89, 90 and 91. For thesefigures, representative temperature instrumentsat various locations in the seal were selected.*Then, the finite-element node closest to theinstrument location was determined. Thefigures show the measured temperatures as wellas the predicted values based upon all five heatfunctions.
Figure 88 presents measured temperatures fortwo instruments located at mid-depth in theseal, on the centerline X ~ 0. Y ~ 18.5 ft�.6 rn! for Program TEMP!,
Figure 90 presents measured temperatures for aninstrument below mid-depth, off of the center-line X 13,0 ft �.0 m!, Y = 10.25 ft �.1 m!for Program TEMP! .
Figure 91 presents measured temperatures fortwo instruments located at mid&epeh near theoutside of the seal X 23.7 ft �.2 m!,Y ~ 18.5 ft �.6 rn! for Program TEMP!.
The following points may be made concerningthese curves:
1. The predicted temperatures are in goodgeneral agreement with the measured values.
2. There does not appear to be one heat functionwhich provides the most accurate agreement inall cases. The curves based upon the Type IIaverage heat cement are close in Figures 89and 90 while the curve based upon heat functiontwo appears to be the closest in Figure 88,The curves based upon heat functions one andthree appear to be the closest in Figure 91.
3. The predicted temperatures are obviouslyvery dependent upon The heat function used.Minor differences in the heat functions canlead to major differences in predicted tempera-tures during the period of interest. If pre-dictions of actual temperatures within a place-ment are desired, it is reconnnended that theconcrete to be used be tested to develop anaccurate heat function. However, if relativepredictions concerning the effect of changingplacenent variables such as placement tempera-ture or cement or pozzolan content are desired,the heat curves built into Program TEMPshould be adequate.
4. The sensitivity of the temperature predic-tions to variations in difficult-to-definevariables such as the thermal characteristicsof the conci'ete and the underlying rock wasnot examined. Such an examination is recom-mended prior to use of the program for actualtemperature predictions.
In addition to the comparison made with actualmeasured temperatures, curves were preparedshowing temperature variations horizontally andvertical l.y within the seal. These curves wereprepared for the heat function based upon thehigher than average Type II cement as is avail.-able within Program TEMP. Figure 92 shows ehelocations of the nodes which were plotted whileFigure 93 shows horizontal variations and Fig-ure 94 shows vertical variations.
Using the data presented in Figures 92 and 93,two additional figures were prepared which showtemperature gradients within the seal concreteat 80 and 200 hours after the beginning of theplacement. Figure 95 shows the gradients whichexist across s horizontal plane 12 ft �.7 m!above the base of the seal. Figure 96 showsthe gradients which exist in a vertical planeae the centerline of the seal. Mote that thesetwo figures are plotted as temperatures ofconcrete above the temperature of ehe watersurrounding the seal.
The following points can be made concerningthese figures:
1. Significant temperature gradients can beexpeceed to develop near the outside surfacesof a massive tremie-placed seal. These gradientsdevelop soon after placement begins and remainevident for a significant period of time.
2. The gradients predicted by the finite-element program are consistent with the dataobtained in the Pier 12 seal placement describedin Chapter 3.
3. Without specific strain capacity and modulusdata, predictions of cracking cannot be made.However, the temperature gradients appear tobe large enough to be capable of inducingcracking in most concretes.
this portion of the project:
l. A Fortran program, TEMP, was preparedwhich accepts variables associated with amassive trenie placement and processes thosevariables to develop input for. an existingfinite element program, DETECT, which can beused to predict temperatures within the tremieconcrete. Program TEMP has a wide range ofoptions available to the user to allowaccurate modeling of s planned placement.
2. Predictions of maximum temperature andtemperature gradients near sur faces of tremie-placed concrete made using programs TEMP andDETECT were shown to be in good general agree-ment with temperatures measured in an actualplacement.
" Temperature instrument locations are pre-sented in Appendix H,
3. Predicted temperatures were shown to bevery dependent upon the heat function used.The sensitivity to other variables was notexplored.
18O 82.2!
170
a 160�1,1!
0;
150I-
I-IIJ0: 140
�o,o!
130
120�8.9! 50 100 150 200 250 300 350
TIME SINCE BEGINNING OF PLACEMENT, HRS.
Figure 88. Predicted versus measured temIperatures, centerline,mid-depth.
H.F, +112�8.9!
I IO
s IOOI �7J!!
4 X I IIJ 90LIJ
IIJ80
~ �6.7!
O O 7060
�5,6!TIME SINCE BEGNNING OF PLACEMENT, HRS.
Figure 89. Predicted versus raeasured tIssperatures,outside edge, upper surface.
««+
160�I. I !
I 50
I I 0
IOO�7.8! 0
� H.F. + Il40
�0.0!
I 30
o l20~ �8.9!4
90
80�6.7!
113
o l40�0.0!
XlaI �0
ILII-IaI
l209 �8.9!O O
XIIO
LLI
l00~ �7.8!O O
50 60 l50 200 250 300TIME SINCE BEGINNING OF PLACEMENT, HRS.
Figure 90. Predicted versus measured temperatures, off center-line, raid-depth.
TIME SINCE BEGINNG OF PLACEMENT, HRS.
Figure 91. Predicted versus measured temperatures,outside edge, mid-depth.
TOP OF SEAL
l44
I33~ indicates node and
node number locate.
l22
2 I.o�.4!
IOO
84 8687~ OO
8280I2.0�.7!
78
4.0 I.2!
56
0.0 23I QO�.0!
00
FT. m!
114
33.0 IO. I!32.5 9.9!3 I.O 9.4!
29.0 8.'8!
200 24.0 26.0 X�. I! �.3! �.9!
P8.!! IBS!Figure 92. Section through seal showing locations
of nodes plotted in Figures 93 and 94.
I70�6.7!
I50�5.6!
70�l.l!
50000l 0
l70�6.7!
78
l50�5.6! 56
l33
70�I. I !
50 IOO!
Figure 94, Vertical variation in predicted temperatures,See Figure 92 for location of nodes shown.
115
4 l 30~ �4.4!0'* llog �3,4!
90Z �2.2!OO
4 I 30�4.4!
E l�~ �3.4!
I-LJ
90~ �2.2!O
50 l00 l50 200 250 300TIME SINCE BEGINNING OF PLACEMENT, MRS.
Figure 93. Horizontal variation in predicted teuperatures.See Figure 92 for location of nodes shown.
TIME SINCE BEGINNING OF PLACEMENT, MRS,
5 �j D X
64 O0 X
R
W
ChCl
dOO
lf38 W 3M3 3JOSihO
O-.cvgj
$P IBe PO ~e!tO Ã!
+! i9 lV3S 30 3@f8 3h085 39NVLSI0
Oa! 3a '83lVhh SNIONA088AS 3AO9lf 3L380NOO W 38AJV83dW3A
C
O Z
4
u IllB
~ 0 0a m
eSIal
ba0Ql 0
0 al0 g beN u 0
4Cf uu I4g
00 0u
8ual u
0 alal ~b04 4
ao0 aI4 aI 0
ODu gal M
0 4 04I 4
u 0 NV g a0
CHAPTER 6
FLOW PREDICT1ONS FORTREMIE CONCRETE
6.2. Back round.
117
of the project was to examine the possibilityof using a computer model to predict flawpatterns of tremie-placed concrete. Two areasrelating to tx'ernie concrete flow were of partic-ular interest. first, the relationship of con-crete placement rate and pipe spacing to con-crete quality; and second, the influence of thedepth of cremie pipe ernbedrnent an the flatnessa f the completed concrete sur face. Additional-ly, it was thought that if an accurate flawprediction model could be developed, that madelcould be used in conjunction with the tempera-ture prediction programs described in Chapter 5to increase the accuracy of the temperaturepredictions.
6,2.1. Literature review. A brief sampling ofthe literature dealing vith tremie concreteflow, pipe spacing, and pipe embedment follows:
l. The American Concrete Institute Committee 304in its "Reconnnended Practice for Measuring, Mix-ing, Transporting, and Placing Concrete" re f. 1! wr ites:
"Pipe spacing varies depending onthe thickness of placement and con-gestion fram piles or reinforcement.The spacing is usually about onepipe for every 300 sq fc approx,28 m2! of surface or abouc 15 fr. approx. 4 1/2 m! centers. However,chin may be increased co as much as40 ft approx. 12 m! centers in anuncongested deep mass using retardedconcrete."
The Cosnnictee also writes concerning the con-crete surface that, "Paster rates may produceflatter surfaces" and "the deeper the embedmentin concrete, the flattex' the finished slopewill be." A placement rate resulting in avertical rise of concrete of 1.5 to 10 ft/hr�.5 to 3.0 m/hr! is recommended.
2. The Corps of Engineers in its Civil WorksConstruction Guide S ecification, Concreteref. 35 requires that a sufficient number of
tremies shall be provided so that che maximumhorizontal flow will be limited to 15 feet"� 6 m!. The Corps ' Standaxd Practice forConcrete ref. 36! reconnnends a 5 ft 1.5 m!embedment depth, but does not relate embedmentdepth to surface flatness.
3. Scrunge ref. 15! recommended the following:
a. The coverage of each tremie pipe should beapproximately 250 ft �3 m2!.
b. The largest horizontal dimension of the formsshould be less than 15 ft �,6 m!. Partitionsshould be used to break up larger plaaements.
c. The maximum distance from s trernie to afarra should not be greater than 10 ft �,0 m!.
d. The deprh of embedment should be a minimum of3 fc �.0 Til!.
e. Vertical rise of the concrete should be2 fr/hr �.6 xa/hx'!.
4. Concrete Construction magazine ref. 2! madesimilar recosnaendations which included coverageper tremie pipe of approximacely 300 ft2 �8 ra2!ar a spacing of 15 ft �.6 ra! on centers, andchat a higher placement rate will lead toflatter slopes in the tremie concrete. A tateof concrete rise of 3 ft/hr �.0 m/hr! wasrecormnended. Concerning embedment, a depth of2 ta 5 ft �.6 to 1.5 rn! was given with thecormnent "to get flatter sl.opes in che seal, adeeper embedment is required."
5. Gerwick refs. 4 and 5! also recossaended acoverage of 300 ft2 �8 m2! or 15 ft �.6 m!centers for the tremies along with an embedmentdepth af 1.5 to 5 ft �.5 ta 1.5 m!. He wrote"Deeper embedment gives a flatter slope providedinitial set has not caken place." Concerningplacement rate, Gexwick recommended 1,5 to10 ft /hr �.5 to 3,0 m/hr!,
6. Ha 1 loran and Talbot re f. 17!, vr i ting o ftheir experiences constructing tremie-placeddrydacks during World War II, made thesecomments:
s. Tremie spacing should depend upon the con-tinuity vitb which concrete is delivered to thetremies.
b. The tremies should be spaced on 12 to 16 ft�.7 to 4.9 m! centers with the outside trexaiebeing less than 9 ft �.7 m! froxa the forms,
c. Closer spacing of tremies leads to flattersurfaces.
d. A deeper embedment of the tremie pipe leadsta flatter slopes, with an embedment of 3 to5 ft �.0 to 1,5 m! recommended.
e. Placement rate should be sufficient to pro-vide a rate of rise for the concrete of 2 to3 ft/hr �. 6 to l. 0 xn/hr!.
The recarmnendations given by the authors abovevere based on experience gained on a widevariety af tremie placements. These sourcesmay be summarized as follows: Trexaies shouldbe closely spaced to minimize flaw distance;the greater the embedmenc depth af the tremiepipe, the flatter the surface of the completedplacement:; and, the higher the concrece place-ment rate, the flatter the concrete surface.Typical numerical values for these reconmxenda-tions are:
- pipe spacing: 15 to 40 ft �,6 co 12.2 m! oncenters.
118
pipe coverage: 300 ft2 �8 m !.
� pipe embedment: 3 ta 5 ft �.0 to 1.5 m!.
� rate of rise: 1 to 3 ft/hr �.3 to 1.0 m/hr!.
Only one source was found in the literaturewhich attempted a mathematical description ofthese flow cansideratians. That work is des-cribed in the next section.
6.2.2. Dutch investi ation. The work publishedby the Netherlands Corsmittee for ConcreteResearch ref. 3! also included a chapter inwhich the factors of pipe spacing, placementrate, and cremie ersbedment were treated in amathematical model. The basic Dutch model wasfounded upon the theory of viscous fluids andwas solved using an iterative finite differencepiocedvre. The Dutch investigators noted animportant limitation in their approach whichmust be kept in mind: "Although the calculatedresults appear reliable, their value must not beoverrated. To treat fresh concr'ete as a viscousfluid in svch calculations is a rough approxi-rsation."
The parameters of the basic flow model werefollowing:
the cofferdam is circular, with a diamecerof 5.30 m �7.4 ft!; at the start of the cal-culations a layer of concrete is assumed tobe already present in the cofferdam; thethickness of this even and horirontal layeris H;
- at the center of the cofferdam is a verticalconcreting pipe with a diameter d =300 sss! 11.8 in.!;
at the start of the calculation the pipe isembedded a distance h in the concrete;
the effect of the dead weight of the concreteis neglected;
the viscosit~ of the fresh concrete is O. 1 rs2/sec, l.l fc /sec.!.
The findings of the Dutch investigators basedupon the use of this model are susssarized below.
l. A movnd of concrete built up around the tremiepipe similar to the mound seen in the large-scaleplacement tests Chapter 2!. The mound extendedfor a distance of approximately twice the embed-ment depth from the center of the tremie pipe.There is nothing in the Dutch descriptions whichsuggests that the mound was forrsed by verticalflaw adjacent to the tremie.
2. The shape of the concrete surface was foundto be independent of the distance from the pipeoutlet t'o the cofferdam bottom.
* The model is deve Loped in terms of meters.Since the vse of the model is independent ofthe units involved, only meters will be shownin the text.
3. "If there is suf ficient ismrersian depth, theconcrete feed into the cofferdam will take placein such a manner that concrete which is at thesur face will remain at the surface." Thisstatement, and figures in the Dutch reportdescribe a horizontally layered flow pattern inwhich the first concrete placed may be expectedto be found on the surface of the finishedplacement. Such a flow pattern is inconsistentwith the data obtained during the large-scaleplacement tests Chapter 2!.
4, The concrete mound which builds up around thetremie develops a slope of approximately 1:5.The mound continues to develop until the shearresistance of the fresh concrete is overcomeAc chat time, a faiIvre occurs a semi-circularsoils type failure! which results in a rsixingoccurring at the toe of the mound Figure 97!.This failvre can occur after only a small volumeof concrete has been placed and must be tolerated,The Committee explains
"In the mixing zone the concrete, so longas it has not stiffened, will be able tocoalesce. With sufficient concretingcapacity to maintain an adequate rate offeed ic will be possible to ensure thatthis will happen."
5. The COmmittee uSed its findingS On tremieconcrete flow ta develop a model which relatespipe spacing and production rates for a squareplacement. This madel is examined in detailin section 6,3.1, below.
6, Recognizing that the initial model imposedLimitations that might not be realistic insctval placements, a model without the require-rsent that the placement be divided intosquares was developed. This model uses anadvancing sloping front; and it is desex'ibed indetail in section 6.3.2, below.
7. The Dutch investigators also considered thehydrostacic balance of che tremie system todetermine how much concrete would be requiredin the tremie pipe to achieve flow, This workis considered in section 6.3.4, below.
8, In regard co tremie pipe embedment, theDutch wrote, "It should be borne in mind, how-ever, that better surface evenness is obtainedaccording as the pipe immersion depth is greater."Unfortunately, they do not explain the basis ofthat statemenc.
6.3. Observations and discussion. The variousDutch models noted above are examined in thefollowing sections. Additionally, samplecalculations based vpon maximum flow distancesand concrete production capability are presentedfor a typical placement.
6.3.1. S uare lacersent model. The basic Dutchplacersenc model involves a tremie placementwhich is divided into squares with a length ofD units on a side,e The other parameters areshown in Figure 98.
MEDLRE
CE
Figure 97. Dutch failure model after ref. 3!.
PRODUCTION RATE Q, m thr.SET TIHIE ~ r, hours
Figure 98, Dutch square placement model. Case shown ia H< �. 25 D + C! .Shearing can be expected throughout the placement after ref. 3!.
119
Ex, 1.0=40mC =0.25UI
2.0 hrsH = l. 0 meter
Volume required = l6 m
H err,25 D+ c
Q ~ D2 H/t
= 8 m3/hr
H = 3,0 m
Volume required = 48 m3
H > 0.25 D + C
Q = D �.25 D + 0.25!/t
l0 rn3/hr
120
Based on consideration af a 1r'5 slope and shearfailures in the tae of the slope resulting inthe mixing described above, the objective ofthe model is ta reach che point ac which chepipe embedment becomes equal to 0. 25 D by thetime the set time of the concrete is reached.If that depth of embedment is not reached beforethe sec time is exceeded, the concrete would notbe able to remix and coalesce when the shearfailures occur. Once the embedment exceeds0. 25 D, the toe af the slope will theoreticallybe outside the placement area and no furthershear failureS may be eXpected ta OCCur.
Two cases may exist for the variables describ-ing the thickness and size of the concreteplacement. Each case leads co a differentrequired placemenL raLe.
Case I: H �,25 0 + C!m-"
Q = D2H/c m3/hr
Case II: H > �,25 D + C!
Q = D �.25 D + C!/r m /hr
Consider the fa'llowing two examples..
Shear failures can be expected to occur through-out the placement, However, the placement villbe completed ac the same time the first concreteplaced reaches its sec.
Ex. 2. Same conditions except
Time of placement = 4. 8 hours.
Shearing will take place until the concretereaches a depth of h s 0,25 D + 0.25, h1.25 m!. This depth requires a placement of
* Variables are defined in Figure 98.
20 m3 which is two hours production which isalso the set time of the concrete, The workingsof the model are unclear during the r'emaining2.8 hours of che placement since the concrete atthe surface has set, The Dutch report doesno t cons ide r t h i s pr'ob lcm.
Disregarding the above short coming, the twoequations for determining placement rate may berewritten ta solve for pipe spacing given avail-able production capacity. Using this approach,the curves shown in Figure 99 were developed.The curves are used as follows. 'With a place-ment capacity of 75 m3/hr, a seal thicknessaf 2.0 m, and a set cirne of 2 hours, what is themaximum allowable pipe spacing? The answer,from the curves is 8,6 m. Using these curvesleads ta pipe spacings which are generally wellabove those recanmrended in the literature.
The failure of the model to consider place-rnenc time after the set time of the cancrereleads to the same curve being developed for allplacements above a critical thickness foreach set time, where Hcric 0.25 D + C. Oncethis critical thickness is exceeded, pipe spac-ing becomes fixed for a given production rate.For example, given s placement capacity of75 m3/hr and a set time of 3 hrs, the maximumrecommended spacing for all placements 3 m ormore in thickness is 9.3 m. Hovever, Her it~ 0.25 9.3! + 0.25 ~ 2.6 m, which means thatno such placements would be completed before theinitial concrete placed has set. To overcomethis problem, placements which are thicker thanHcric spparentiy must be divided into squaressmall enough to be completed within the set timeaf che concrete, 6 very thick placement, there-fore, would require sub-division into manysmaller placement s.
6.3,2, Advancin slo e lacement model. Realiz-ing that it will not always be practical todivide a crernie placement into the squares re-quired for the above model, the Dutch investiga-tors modified their model to use an advancing,slopinF, front edge. The geometry af this modelis shown in Figure 100. The model requires theconcrete shown as cross-hatched be placed withthe tr ernie in the location shown. Then, chetremie will be moved toward the far end of theplacemest co place the next increment of con-crete,
The same requirement that no shear failures occurafter the time chat it takes far the concreteto set is also imposed: "This can be satisfiedby choosing the rate of placing at least sa highthat the concrete which at first is at the topaf the slope will, on completion of the con-creting, have arrived ac che final surface ofthe concrete." Thus, the required productionrate becomes equal to the volume to be placeddivided by the set time of che concrete. Usingthe notation shovn on Figure 100, the requiredplacement raLe becomes:
Q = �H2 x width!/t rn3/hr
Consider che following examples:
I50
125
I 00
I-CJ
Q.75
ttjXUJ
50
G.
25
IO7 8
TREMIE SPACING, m.
Figure 99. Placement curves derived from Dutch square placement model.
SHADED AREA ' 5H gSHADED VOEUME =5H x WIDTH
Figure 100. Dutch advancing slope placement model after Ref. 3!.
Q = 400 m3/hr
Q = 2160 m3/hr
Lc 1.1 h + 2h + z/y!
10 �. 0!20 �.1!30 9.1!40 �2.2!50 �5.2!
14.5 �,4!19.1 �.8!23.7 �.2!28.2 8.6!32.8 �0,0!
7.2 �.2!11.3 �,4!15.5 �.7!19.6 �,0!23.8 �.3!
z, ft m! h, ft m!
20 �,1!40 �2.2!6C �8.3!
5.6 �.7!10.3 �.1!15.3 �.6!
Kx. 1. A tremie seal is t.o be 15 x 30 m in pIanand 4 m thick. The set time of the concrete is3 hrs.
Ex. 2. A tremie seal is to be 26 x 43 m in p1anand 9 m thick approximate dixsensions of Pier 12of the I-205 Bridge described in Chapter 3!.The set time of the concrete is 3 hrs.
Obviously, such production rates are beyond thosenormally available.
6.3.3. Summer of Dutch lacement models. TheDutch Coasaxt tee susmarized its work on thesetwo placement models in the following statements:
"If high quality of the concrete is requiredand the slab to be constructed is of con-siderable thickness, it may be advisableto concrete it in individual bays. Thiswill, of couxse, necessitate extra arrange-ments.
"If the cofferdam is not subdivided intobays, the concrete obtained is likely tobe of somewhat poorer quality unless theconcreting capacity is high enough tocompensate for this. In the Committee'sinvestigations on core specimens it wasfound that the tremie methods producedrelatively homogeneous concrete possessinghigh compressive strength. Yet theconcreting capacity used on the jobsinspected was substantially lover thanthe theoretically required capacity.
"From this it can be inferred that a sub-division into bays or a very high concret-ing capacity appear necessary only incases vhere very stringent demands areapplied to homogeneity,"
The Committee further stated, "In practice theconcreting scheme wi11 be drawn up, suited tothe available capacity.u This statementidentifies the greatest shortcoming of themodels.
The two models do provide additional general in-sight into the flow of tremie concrete. Perhapstheir most practical use is to serve as astarting point for calculations of the nature ofthose shown in section 6.3.5, below. The use-fulness of the models for determining pipe spec-ing or required placement rates appears to belimited.
6,3.4, Dutch h drostatic balance model. Anotherarea covered by the Dutch investigators was thehydrostatic balance of the tx'ernie system thisbalance was described earlier in Chapter 4 andthe geometry was shown in Figure 85!. It isnot cleax' if the Dutch balance model wasalso based on the viscous fluid calculationsused to develop the two flow models.
The Dutch model was developed using these con-siderationa:
l. The depth of embedment of the tremie is h.
2, The height of water above the concretesurface is z.
3. The ratio of unit weights of concrete andwater is y, which is approximately 2,4.
4. The height of concrete necessary to over-come internal concrete 1'riction is twice theembedment depth, 2h.
5. Approximately 10 pex'cent additional heightof concrete is required to overcome the frictionbetween the concrete and the trexsie pipe.
Therefore, the level of concrete requiredabove the mouth of the tremie for flow tooccur wil! be:
This equation xsay be solved for various valuesof z and an assumed embedment depth of 3 ft�.0 m! as is shown below. Also shown is theheight of concrete required above the tremiemouth to achieve a hydrostatically balancedcondition, neglecting internal friction.
z, ft m! Lc, ft m! Balance, ft m!
Limited measurements made at actual massiveplacements have shown that the concrete returnsvery nearly to the balanced condition whenevex.there is a break in the placements, Additionalwork performed at Wolf Creek Dam x'ef. 30!involved numerous measurements in the confinedplacements. In those placements the concretealso returned very closely to the balancedcondition. Thus it appears that the Dutchmodel some~hat over estimates the frictionwhich resists flow,
The Dutch model xsay be rearranged and used tosolve for the depth of embedment necessary tocontrol concrete flow. Based upon recoasaenda-tions found in much of the 1.iterature that thetremie hopper be kept full of concrete duringthe placement, assume that a concrete level 2ft �.6 m! above the water surface is desired.The values below are obtained:
Obviously, in a massive placement such embedmentdepths would be impractical without very high
placement rates. These calculations and thehydrostatic balance measurements made certainlyquestion the feasibility of controlling theflow of tremie concrete solely by ad justing theembedment depth of the tremie pipe.
6,3,5. Exam le lacement calculations. Thebasic scheme suggested by the Dutch models, butwithout the restriction Chat the first concreteplaced must remain alive throughout the placement,may be used to relate the factors of pipe spac-ing, concrete flow distance, and planC produc-tion rate, The calculations in the examplebelow represent the considerations which shouldbe included in a pre-placement evaluation,
1. Situation A ttemie-placed seal which is tobe 60 x 150 fC �8.3 x 45.7 m! in plan and 42ft �2.8 m! thick. Total volume required is14,000 yd3 �0,700 m3!, Concrete productioncapacity is L50 yd3/hr �15 m /hr! leading toan anticipated placement duration of 94 hrs,
2. Tzemie locations and spacing. Both fixedpipe locations and advancing s!ope techniquesare to be considered, Figure l01 shows thegeometry and notation involved,
a, Fixed locations. All tremies will be startedsimultaneously and will remain in their originallocations for the duration of Che placement.
b, Advancing slope. Tremies st one end of theplacement will be started initially. Additionaltremies will be started once a predetermintedembedment depth is reached. This approachrequires calculation of longitudinal flow dis-tance when each new tremie is started as isshown in Figure 102.
Data showing concrete flow distances for variousnumbers of tremies in the Cwo placement methodsare given in Table 27. This data may be evalu-ated by selecting the single row of tremies inthe fixed locations as a base against which theother cases may be compared. This comparisonis shown in Table 2S,
The use of a single row of tremies startedsimultaneously appears to offer favorable maximumflow distances with a minimun number of tremies.However, it must be remembered that the apparentmaximum for the sloping front technique existsonly until the next row of tremies is started.Then, the maximum flow reverts to the diagonaldistance for the number of tremies involved.
Additionally, the problem of laitance accumula-tion should be considered. Placements involvingsimulataneous starting of Cremies offer thepotential for laitance accumulation at allintersecting faces of concrete. The advancingslope technique forces laitance toward Che endwall where it may be collected and removed.
3. Volume considerations. Assume that theadvancing slope technique with five pairs oftremies is selected. Using the geometry shownearlier in Figure 102, the volume of concretein place when each new row of tremies is started,the time when each row is started, and the rate
of rise of Che concrete may be caLculated.These values are shown in Table 29.
4. Susssary. These calculations offer a roughapproximation of an acCual tremie placement.While reasonable flow distances have beenachieved, the practical problem of deliveringconcrete to ten tremies has been raised. Also,once all ten rremies are in use, the rate ofrise becomes slow enough thaC there is a dangerof the concrete setting stound the tremie ifembedment depths are not closely monitored.
The solution to these problems appears to havethree parts:
tolerate greater flow distances.
� use a retarder in the concrete to allow fora sLower rate of rise.
� examine the possibility of adding additionalconcrete production capacity.
~6.4. S th L 11 g t *this portion of the project;
1. The recosssendations found in the literaturefor pipe spacing and rate of concrete place-ment appear to be very conservative and difficultto achieve in actual massive placements.
2, The flow models, based on viscous flowtheory, which were examined do not appear tooffer potential for determining optimum pipespacing and required production rates, Themodels do provide a starting point for examiningthe variables involved using a simplifiedapproach.
3, An example of simplified calculations examiningtremie spacing and concrete production ratesfor a typical seal was presented. Such calculationsoffer a good approximation of actual placementconditions with enough accuracy for pre-construc-tion planning,
a. GEOMETRY FOR SINGLE ROW OF TREMIES FLAN!.THREE TREMIES SHOWN.
b. GEOMETRY FOR OOUBLE ROW OF TREMIES IPLAN!. TWOROWS QF THREE TREMIES SHOWN.
Figure 101. Geometry and notation for example spacing calculations. IIotationremains the same as additional tremies are added.
I Z laIalCP
s a O Q Z
aI d ~ OEPTH OF EMBEOklENT REQUIREDTO START NEXT TREMIE
f ~ CONCRETE FLOW OISTANCF. BEYONDPIPE WHEN 4 IS ACHIKVKO
~ < HORIZONTAL COMPONKNT OF SLOPK
f ~ ds
Figure 102. Geometry and notation of advancing slope technique elevation!.Concrete ui 11 floe 2x + f vhen each tremie after the first isstarred.
124
Case I � Sin le Row of Tremies Started Simultaneousl
Plow distances, ft m!No ~ ofTremies
30.0 9.1! all!
Case II � Double Row of Tremies Started Simultaneousl
Plow distances, ft m!No. ofTremies
15 �. 6! all!
Case III � Sin le Row of Tremies Advancin Slo e Techni ue
Flow distances, ft m!No. ofTremies 2x+ f
Case IV � Double Row of Tremies Advancin Slo e Techni ue
Same constraints as Case III
Plow distances, ft m!No. ofTremies 2x+ f
*See Pigures 101 and 102 for notation used.
125
.1 2 34 5 6
2
4 6 81012
4 6 81012
TABLB 27 � CALCULATBD FLOW DISTANCBS*
75.0 �2.9!37.5 �1.4!25.0 7.6!18.8 5 7!15.0 4.6!12.5 3.8!
75.0 �2.9!37.5 �1.4!25,0 7.6!18.8 5.7!15.0 4,6!12.5 3. 8!
Slope of concrete 1:6Depth when next tremie is started 2 ft �.6 m!
48.0 �4.6!39.1 �1.9!35.4 �0.8!33.5 �0 ' 2!32.5 9.9!
40. 4 �2. 3!29.2 8,9!24.1 7.3!21.2 6.5!19.5 5.9!
80.8 �4.6!48.0 �4.6!39.1 �1.9!35.4 �0.8!33.5 �0.2!32.5 9.9!
76.5 �3.3!40.4 �2.3!29.2 8.9!24.1 7.3!21.2 6.5>19.5 5.9!
87.0 �6.5!62.0 �$.9!49.6 �5.1!42. 0 �2. 8!37.0 �1.3!
87.0 �6 5!62.0 �8.9!49.6 �5.1>42.0 �2.$!37.0 �1.3!
TABLE 28 � COMPARISON OF PLACEMENT ALTERNATIVES
Needed to Better Case I
Case I Case IVCase II Case III
42. 0 �2.8!
37.0 �1.3!
48. 0 �4.6!
39.1 �1.9!
35.4 �0.8!
5 42.0 �2.8! 33.5 �0.2! 10
6 37. 0 �1. 3! 32. 5 9. 9! 12
4 40.4 �2.3!
6 29.2 8.9!
6 29 ' 2 8.9! >12>6
*Nominal flow ~ maximum flaw distance once next row of tremies is started.
TABLE 29 - ESTIMATED PLACEMENT COHDITIONS*
+Values derived from geometry previously shown. Assumptions:
� Concrete is level across short dimension of seal;
� slope in long dimension is 1:6;
� production rate is 150 yd3/hour �15 m3/hour!;� production is evenly distributed among tremies in use.
eeTheoretical rate of rise based on production capability andsize of seal.
1 '7 6
No.af
Trem-
ies
Maximum
flow
ft m!
No.of
Trem-
ies
Maxi,mum
flow
ft m!
No.of
Trem-ies
Kmimum
f low
ft m!
Nominalflowe
ft m!
No.of
Trem-
ies
Maximumflow
ft m!
Nominalf lowe
ft m!
21. 2 �. 5!
19.5 �.9!
127
CHAPTER I
CONCLUSIONS AND RKCONNENDATIONS
7.1 S ecific conclusions. The conclusionspresented in this section relate to the statedobjectives in the six areas of this investiga-tion. These conclusions are presented in thesame topic sequence as are the chapters ofthis report.
1. For the concrete characteristics evaluatedusing a eeriee of standard and non-standardtests, a traditional tremie concrete mixturewae significantly outperformed. Concretemixtures containing potzolanic replacements ofsignificant amounts of the cement up to 50percent! or containing entrained air were thebest overall performers.
2. Development and selection of a concretemixture far placexxent by tremie should be basedupon more information than is available framthe standard slump test. Three of the non-standard tests evaluated, the tremie flow testand Che two segregation sueceptibiliCy teste,appear to have potential fox' further uee inevaluating tremie concrete mixtures. Finally,the slump loss tesC, conducted using thestandard slump test, should be included in thetesting program .
3. AddiCives which lead to thixotx'opic con-cxetes appesx' to offer no advantages for uee inmassive tx'ernie placemente. Such concretes havepoor flow characteristics, are extremely diffi-cult to restart flowing after e break, and offerproblees of manufacture and control during fielduse. Thixotropic additives may be af benefitin other types of underwater placemente such asvery small volume ar thin sections ar in place-ments subjected to floving water.
4, The flow pattern of tremie-placed concreteis extremely caxxplex � xxuch more so than isnormally described in the literature. Theflow pattern ee seen in these teste does notappear to be that of a simple injection into amass of previously placed concrete. Instead,the process appears ta be as follows: Concreteleaving the tremie forms a bulb around themouth of the pipe. The size and nature of thisbulb appear to depend upon the nature and con-sistency of the cancreCe mixture. For concreteevith law shear resistance, the bulb simplyexpands and for~es previously placed concretex'adially away fram the tremie pipe. For a con-crete mixture vhich is stiffer, the bulb tendsto be quite constricted. In this csee, initia!flow takes place vertically adjacent to thetremie pipe, After flowing upward, this con-crete then flavs outward over the concreCeplaced earlier rather than pushing it away fromthe tremie pipe. In both modes of flow theresultant concrete can be of high quality andhomogeneity.
It appears that the differing deecriptione ofCremie concrete flow presented by other re-
searchere see Chapter 2! mey have resultedfram differences in the concrete mixturestested rathex' than fram observations of differ-ent flow mechanisms. As far as ie known, therale that the concrete mixture plays in the flowpattern of tremie-placed concrete hss not beenreported previously.
5. The configuration of the surface of tremie-placed concrete appears to be a function of thetype of flaw which occurred when the concretewes placed. For the first type of flow de-scribed expanded bulb!, surfaces were veryflat and there was essentially na wounding atthe tremie location. Fox the second type offlow upward and over!, surfaces were muchrougher and s significant mound developed atthe tremie location.
6. The density of tremie-placed concrete de-creased with distance from the tremie pipe.Although these decx'eases were very small forthe resultant sound portions of concrete,significant reductions were observed whenlaitance was included in the calculations.This reduction in unit weight cauld have seriousconsequences in a seal. placement in which theweight of the concrete is necessary to offsetuplift forces. Therefore, a conservativeapproach in evaluating required seal thicknessis indicated.
7. The observations of the colloidal layer atthe beginning of the placements reemphasizethe requirement for care in starting, handling,snd restarting concrete flow through tremiepipes. In particular, when a tremie pipe ismoved, care should be taken to restart con-crete flow slowly in order to minimize formationaf such a layer and the subsequent washing afthe concrete already in place.
8. Reinforcing steel was secux'ely embedded bytremie-placed concrete in the laboratory tests.Rowevex', as has been shown, even the presenceof well-epaced bare vill impede the concreteflov to same extent. These tests have reempha-sized the need for care in detailing reinfor-cing steel for tremie concrete plscements toinsure adequate clear space for flav betweenbars.
The possibility of embedxxent of the reinforcingsteel in laitance rather than concrete as oc-curred in Tests 1 and 2! must be kept in mind.Positive measures must be talxen to insure thatsound concrete reaches and surrounds the steel,parCicularly if bars are near the extremitiesof the concrete flow pattern.
9. Even in carefully controlled laboratoryplacemente, varying amounts of laitance vereformed. Planning for the rexaovsl of this lait-ence ~durin placement is a necessity, particu-larly for reinforced tremie concrete structuralelements, Monitoring of concrete surface eleva-tions during placement should be done to iden-tify any low areas in which laitsnce may betrapped. Suitable equipment eir lifts or
128
pumps! must be available for use in any Lowareas that may develop during a placement.
10. The presence of substantial amounts ofpozzolan up to 50 percent by weight! in theconcrete pLaced by tremie in the large scalelaboratory tests seemed to have no detrimentaleffects on the nature of the product of theplacement. The use of substantial proportionsof pozzolsn offers potential economy and reduc-tion in thermal strains, but may require alonger curing period in order to gain adequatestrength,
11. The presence of a water reducing and retard-ing admixture had a significant beneficialeffect on the tremie-placed concrete -- surfaceslopes were flatter, the mound at the tremielocation was eliminated, and laitance wasreduced. This effect is believed to be due tos reduction in the shear resistance in the freshconcrete which allowed a more favorable flowpattern to develop. This beneficial effect wasnot seen with all types of water reducing andretarding admixtures which were tested.
12. The work on Pier 12 of the 1-205 Bridgeshowed that temperatures within the generalmass of the tremie concrete may be evaluatedwith reasonable accuracy using s simple itera-tive method. However, this method is subjectto serious limitations in providing tempers-ture predictions for concrete at and near theoutside surfaces of the placement.
13, The temperatures measured in the criticaloutside areas of the Pier 12 seal showed thatsteep thermal gradients develop. Since preciseinformation on the early age characteristicsof the concrete was not obtained, it is notpossible to state with certainty that thermally-induced cracking did occui. However, the tem-perature gradients observed were within therange of values which could cause such cracking.
14. Acceptable quality concrete was found at theextremes of the seal of Pier 12 after flowingapproximately 70 ft �1 m!. This flow distanceXs much greater than that normally recommendedin the existing literature for tremie-placedconcrete.
15. An area in the seal concrete was seen tohave abnormally low temperature developmentduring the placement. This area was laterfound to contain poorly cemented and uncementedmaterials. This same area appeared as an anom-aly in the placement cross sections developedby soundings although not striking enough tocause concern during the placement!. This in-dicates that temperature snd sounding data canbe used ss indicators of locations of possibleanomalies and thus suggest locations for cor-ing in order to verify quality of tremie con-crete.
16. Water flow was seen in core holes which didnot penetrate the full thickness of the seal.This flow is believed to have been due to a
combination of thin seams of laitance andthermally-induced cracks in the concrete.
17. The concrete placed for the Pier 12 sealcontained a fly ash replacement in order toreduce temperatures. This concrete performedwell and no problems were attributed to thepresence of the fly ash,
Lg. The mounds seen on the surface of the sealwere very similar to those seen in the labora-tory placements. The same flow mechanism mayhave been responsible for both cases of mound-ing. The sounding data do not provide sufficientinformation to determine the precise flow mech-anism which occurred during the Pier 12 sealplacement.
19. The examination of the Wo1 f Creek place-ment revealed generally high quality concretedSome minor nonhomogeneities snd laitance werefound in the primary elements. There appearsto be no procedural step which could be easilychanged and which would clear up the scatteredproblems found in these prisiary elements, Theconcrete was apparently segregating while flow-ing down the tremie pipe itself. Due to acombination of several factors listed below!,there was not adequate remixing to overcomethe initial segi'egation. The factors believedto have been responsible are:
a. The small cross-sectional area of the primarye92.ements;
b. The smooth walls of the primary elements;
c. The rapid rate of placement in the primaryelements,
20. Measurements taken inside and outside thetremie pipe at Wolf Creek indicated that theplacement system was nearly at balance wheneverthe placement was stopped, with the exception ofa few anomalies. The significance of theseanomalies is not understood. The return of thetremie system to a hydrostatically balanced stateindicates that earlier concepts recommendingthe control of flow by means of pipe embedmentdepth msy not be correct or may require embed-ment lengths too great to be practical, partic-ularly for small volume placements,
21. With the exception of the few scatteredanomalies found in the primary elements, highquality concrete was successfully placed bytremie at Wolf Creek in very deep �78 ft 85 m!!confined elements. Given adequate conditions toallow remixing and a properly designed concretemixture, there is no reason to believe thattremie placement depths could not be extended.
22. There is no reason to expect that the WolfCreek cutoff wall should not perform in asatisfactory manner since the primary elementswere encased in permanent steel pipes. However,the use of very small diameter, uncased elementsfor cutoff walls, as used in some previous damrehabilitation and improvement projects, doesnot appear to insure a complete cutoff.
23. The concrete mixture which contained a flyash replacement of a portion of the cement! usedat Wolf Creek was cohesive and flowed well, Theinclusion of fly ash in this tremie concretemixture had no apparent detrimental effects.
24. An accurate prediction of temperatureswithin a tremie seal including areas nearthe concrete surfaces! can be obtained using afinite-element approach. The program whichwas developed allows the significant variablesin a tremie placement to be changed easily forinput to an existing finite-element program,Use of this technique will allow for moreaccurate and complete evaluation of thermalconsiderations for massive underwater place�ments than has been the case to date.
25. The flow models which were examined werederived from viscous flow theory. Their useful-ness for direct predictions concerning tremiepipe spacing and placement rates appears tobe very limited. However, the models do pro-vide a good starting point for an analysis ofthese variables.
26. Simple calculations which consider thevariables involved in s tremie placement appearto offer an acceptably accurate evaluation forconstruction purposes. Such calculations areeasily performed and will highlight areaswhich should be mare closely examined--excessive flow distances or low placementrates. Once such areas have been identified,they must be resolved to the satisfaction ofall parties involved in the placement.
27. In most cases, the critical factor in amassive tremie placement will be the concreteproduction capacity available. Use of a pro-perly proportioned concrete mixture will do asmuch as any other factor ta offset productionlimitations.
7. 2. General conclusions. The following con-clusions are of a more general nature or weredeveloped from the interrelationships of thevarious portions of this project:
1. Testing dane during this project indicatesthat the flowability characteristics of theconcrete are extremely important, Thesecharacteristics determine the nature of theflow pattern which the concrete exhibits afterleaving the tremie pipe which in turn determinesthe sur face characteristics of the concreteplacement.
2. measurements taken inside and outside thetremie pipe during placements have revealedthat concrete being placed by tremie does notflow gently down the pipe. Instead, it msy fallsignificant distances inside the pipe resultingin segregation. This segregation is generallyovercome provided there is adequate space androughness within the placement area to allowremixing to occur. Care is recommended for anyplacement in which there may be factors whichcauld inhibit this necessary remixing.
3. The development of high temperatures fromhydration of cement within concrete placed bytremie must be taken into account as would bedone for any other mass concrete placement.Due to the typically rich concrete mixtures usedand the inaccessible placement locations, temper-ature problems are potentially more serious fora tremie placement than for other mass place-ments. Adequate techniques are available tapredict temperature distributions within tremie-placed concrete.
4. The three items mentioned above lead to anincreased understanding of the required charac-teristics for a concrete mixture which will beused in a massive tremie placement. The concretemust resist segregation during what may be asignificant fall in the tremie pipe; it must flowreadily to provide for adequate remixing and toprovide a flat surface; and it must not generateexcessive amounts of heat. A fourt'h require-ment, the ability to resist washing out of cementfrom the concrete may not be as significant asis traditionally believed, particularly if theconcrete is designed to develop the expandingbulb type of flow pattern. Additionally, aconcrete which resists segregation will in-herently resist loss of cement.
S. Unfortunately, with the exception of theheat generation requirement, measurement ofthese desired concrete characteristics cannot bemade using standardized procedures. It is clearthat the slump test must be supplemented by non-standard tests during mixture development. Asa final step, large-scale placements similar tothose in Chapter 2 but nat necessarily ascomplex! are recommended prior to actual use ofa concrete mixture. Once the mixture has beendeveloped and verified, the standard tests shouldbe adequate for production control.
6. A "good" tremie concrete has traditionallybeen characterized as being cohesive yet posses-sing good flow characteristics. Unfortunately,neither of these qualities are readily measur-able! These characteristics are usually achievedby means of a high cement content, high per-centage of fine aggregate, and a low water-cementratio. Both the small- and large-scale testsshowed that the traditional tremie concrete mix-ture can be improved upon. These improvementsinclude replacement of a portion of the cementwith a natural pozzolan or fly ash, use of en-trained air, and use of a water reducing andretarding admixture. Concrete mixtures whichfollowed the traditional "recipe" but which inaddition possessed increased flowability due tothe addition of a water reducing and retardingadmixture performed bette» in the large-scalelaboratory test placements. This confirmsreports from field placements conducted over anumber of years. However, note that. improve-ments in flowability were not seen with alltypes of water reducing and retarding admixtureswhich were tested.
7. The significance of possible thermally-inducedcracking in tremie-placed concrete is a function
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of the role of the concrete. In a massive coffer-dam seal, 1.irni ted cracking may be acceptable andextensive precautions may not be necessary. Fora reinforced structural tremie placement, thepossibility of thermally-induced cracking mayrequire additional temperature control measures.The degree of restraint must also be consideredwhen evaluating the potential for cracking. Tre-mie plecemente may range from essentially un-restrained conditions such as in a seal on aeo f t found at ion, to highly res trained cond it ionaif the tremie concrete is placed on rock or onpreviously placed concrete. I E deemed necessary,the techniques for controlling temperaturedevelopment in mess concrete placed above wateras described by Garison, Houghton, and Polivka ref. 34! may be applied, with some exceptions,co tremie-placed concrete.
g. Of che available techniques for controllingtemperatures within mess concrete, perhaps themost readily adaptable to tremie concrete is thereplacement af a portion of the cement with apaznolanic mater'ial, Hone of the field place-ments covered by this report showed any detri-mental effects due to a concrete containing apanxolan being placed by tremie, Additionally,concrete mixcures containing ponsolan replace-ments were among the outstanding performers inthe small- and large-scale laboratory tests.
9. Recanrmendations from the literature on pipespacing and placement rates appear to be veryconservative and extremely difficult to achievein massive placemente. In the placement ofPier 12 and others! concrete was allowed t:oflow much greater distances and waa placed muchmore slowly than is normally recannnended. Thisconcrete turned out: to be of very high quality.Longer flow distances and slower placement ratesshould be allowed in specifications far massivetremie placements.
10. Very accurate temperature predictions wereachieved using simple models of concrete flov.
is doubtful that significant improvements intemperature predictions could be achieved bydeveloping and using a more complex flow model.
11. Existing recannnendations concerning concrol-ling the Elaw of concrete through a tremie byraising and Lowering the tremie may be mislead-ing. Tbe concrete in the tremie will generallycome to rest st or near the hydroecacicallybalanced condition. In most instances «ith anormal embedrneat depth � ta 5 ft �.0 to 1.5 m!,it will not be possible to keep the tremie happerfull ae ie often recommended. To keep the tremiehopper full, pipe embedment would have ta be deepenough to extend into concrete which is stiffen-ing, In such a case the expanding bulb type offlow may be prevented from occurring. Thus fordeep placements, it will usually be necessaryto accept a concrete leveL somewhere in the tremie
pipe below the hopper and to realize the potentialfor segregation which will exist, Although inmost cases, adequate remixing will take place inthe pipe or after exit from the pipe!.
12. Ho definitive reiationshfp between pips
embedment depth and flatness of the concretesurface was found, The work done in che large-scale tests suggests that very flat surfaces canbe achieved if the proper concrete mixture isused. Proper embedment may be more important formaintaining the tremie seal than Ear surfaceslope control,
13. Tremie concrete was success fully placed ina massive seal 9700 yd �400 rn ! and in deepconfined elements �78 ft 85 rn!! during theprojects observed while preparing this report.At first glance it may seem that the mechanismsand phenomena identified herein may only serveta add additional restraints and ccnnplexity toan already complex process. However, it is thehope of the authors that the identification andexamination of these areas will serve to insuregreater reliability in future applications ofunderwater concrete placement technalagy.
14. The work done in this research project hasshown that high quality concrete, ecruccuraland nonstructural, can be placed under vater bytremie methods. This work is believed to makea significant contribution to improve practiceand results.
7.3. Recommended ractice. Following is arecommended practice for massive tremie place-ments. This recanenended practice is intendedta serve as a planning tool and to amplify theitems included in the Guide Specification pre-sented in section 7.4.
These reconnnendations are based on the researchpresented in this report, other research con-ducted by the authors, and upon the experienceof the authors on a variety of placements.
1. A licsbilit . This recommended practice isapplicable to all massive tremie concrete place-ments - structural or nonstructural reinforcedor nonreinforced!. Typical. placements vouldinclude cofferdam seals, filling of precast con-crete elements or steel forms for bridge piers,or elements of offshore structures.
These reconnnendations are also generally applic-able to other types of tremia concrete place-rnents such as small volume placements, thinoverlay placemente, snd deep confined placements.However, the special requirements of these non-mass plscemente must be considered in conjunctionwith these reconnnendatians.
2, 8aeic cones ts. These recoennendstiona arebased on the following:
a, The concrete is placed under water usinggravity flow through a tremie pipe.
b. Appropriate steps must be taken to insurethat the first concrete introduced into thetremie ia protected from the water until a moundof concrete has built up at the mouth of thetremie and a seal is established.
c. The mouth of the tremie pipe must be kept
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embedded within the mass of fresh concrete. Atno time should concrere be allowed to falldirectly through water.
d, The tremie pipe must remain in a fixed posi-tion horizontally at all times while concreteis flowing, Horizontal distribution of the con-crete is accomplished by the flow of the concreteafter exiting the tremie; by halting placement,moving the tremie, reestablishing the seal, andresuming placement; or, by the use of multipletremies.
3. Concrete materials and mixture desi n.
s. General materials requirements. The pre-cautions normally applied to concrete materialsshould also. be applied for materials intendedfor use in tremie-placed concrete, Cement andporzolsns must meet appropriate specifications.Aggregates must be clean, sound, free ofdeleterious materials, snd evaluated forpotential harmful chemical reactions. Mixingwater must be clean snd free of potentiallyharmful materials. Admixtures must meet appro-priate specific'ations. All materials should betested to insure compatibility.
b. Cement and pozxolans. Selection of theappropriate type of cement snd determination ofthe suitability of including pozxolans mustbe based upon evaluation of service conditions,available aggregates, heat generation, sndavailabilities of various types of cements sndpozzolsns. The acceptability of a particularpoxxolen incressed workability, changes inwater demand, rate of strength gain! should beverified before final selection.
c. Aggregates Well rounded natural aggregatesare preferred due to the increased flowabilityof cancretes containing these aggregates. Ifmanufactured aggregates are used, the fineaggregate and cementitious materials contentsmsy have to be increased to achieve satisfactoryflowability. Aggregates should be well graded.Maximum size for aggregates used in reinforcedplscements should be 3/4 in. �9,0 mm! and innonreinforced placements should be 1 1/2 in.�8.1 mm!. Fine aggregate content should be 42to 502 of the total aggregate weight.
d. Desired characteristics, Concrete for tremieplacements must be cohesive and resist segrega-tion as well as flow readily. Nonstandardtests are available which allow evaluation ofthese characteristics for comparison of con-crete mixtures. Tremie concrete should not beproportioned on the basis of strength snd/orslump alone.
e. Basic mixture proportions. A starter mix-ture, developed to include these characteristicsfound ta be beneficial in the present report,is as follows:
Cement: 600 lb/yd �56 kg/m3!Pazzolsn: �5X by weight of cementitious
materials! 105 lb/yd �2 kg/m3!
Coarse Aggregate; 3/4 in. �9.0 mm!Fine Aggregate: 45X by weight of total aggregate
contentAir Content. 5 percent � 1 percent+
Maximum water-cementitious material ratio: 0.45Admixtures: Water reducer and retarderSlump: 6 to 7 1/2 in. �5 ta 19 cm!
f . Mod i f ic at iona to the basic mixture�. Thebasic mixture may be modified as necessary de-pending upon materials availability, serviceconditions, temperature considerations, etc.Modifications should be made with an sim ofretaining the flow and cohesiveness of thebsszc mzxturs,
g. Testing. 'The proposed concrete mixturesshould be tested using standard ASTM tests forbleeding, time of set, air content, unit weight,slump loss, compressive strength and yield toinsure compatibility of components and suit-ability of the concrete for its intended pur-pose.
h, Final selection. Final selection of a con-crete mixture should be based upon test place-ments made under water in a placement devicesimilar to that described in Chapter 2 of thisrepart or in a pit which can be dewateredafter the placement. Test placements shouldbe examined for concrete surface flatness,amount of laitance present, quality of cancreteat the extreme flow distance of the test, and.flow around embedded items, if appropriate.
4, Tem erature Caneideratianz.
a. The potential temperature increase should beevaluated using a simple interative or afinite-element technique. Anticipated thermalgradients should also be considered
b. Sexed upon predicted concrete temperaturesand gradients and the nature of the concreteplacement, s determinatian of the seriousnessof the predictions may be made. Limited crack-ing msy be acceptable in a nonstructural placementwhile 'he same degree of cracking may be un-acceptable in a structural element.
c. Maximus temperatures and gradients may bereduced by employing the following steps:
� Use a lower hest cement.
� Replace increased amounts of cement with asuitable pozzolan.
� Lower the concrete placement temperature.
5. Concrete manufacture.
s. Materials handling, The same requirementsfor materials storage and handling used for-iagredients for concrete to be placed in thedry must be imposed for concretes placedunder water,
b. Fetching and mixing. The same requirements
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6. Placement e ui ent.
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.or accuracy in batching concrete ingredientsused for concrete placed in the dry must beused for concrete placed under water. Controlof the amounts of concret'e ingredients is oneof the most important inspection items avail-able for underwater placements. The samereq >irements for concrete mixer performanceused for placements in the dry must also beapplied for placements under water.
c. Testing during production Once a concretemixture hes been approved, slump, air contentiunit weight., end compressive strength testingshould be adequate for production control.Because of the significance of the flowabilityof the concrete t'o the success of the place-ment, slump end air content tests should beperformed more frequently than is done forconcrete placed in the dry. A minimum testingschedule would be:
Slump: every 250 yd �90 m !Air content.' same as slumpUnit weight: every 500 yds �80 m !Compressive strength: 6 cylinders for every100t7 yd3 �65 ts3!Temperature: Whenever other testing is done
Compressive strength testing should be accomp-lished at. 7 and 28 days. Seven. day strengthsmay be used as a basis for determining when theconcrete has gained enough strength to allowdewstering the structure,
d. Sampling during production. The locationf>r sampling during production and placementvill depend upon the elapsed time between pro-duction end arrival at the tremie hopper. Forexemple, in the placement described in Chapter3 a portion of the concrete was produced in afloating piant at the site, Sampling at themixer was essentially the same as sampling etthe tremie hopper. The remainder of the con-crete was produced off site and was truckedand pumped to the tremies. For that concrete,sampling at the tremie hopper would be moreappropriate. In any case, the objective isto insure that concrete with the proper char-acteristics is arriving at the cremies.
e, Slump and eir content loss. Tests todetermine the slump and air loss characteris-tics of the selected mixture should be per-formed using the type of equipment which willbe used to transport the concrete from thepoint of manufacture to the tremies. Based onthi= testi.ng, limits may be established on thelength of time between mixing and arrival atthr. trcmie or on the number of revolutions ofthe transit mixer drum, if appropriate.Sp~ cification provisions limiti-g elapi edtime i r drum revolutions must complement anyprov is ious for tea t ing at the tremie hopper,i f inc1uded In cases of conflict, concreteperformance provisions rather than time orrevolutions should prevail. A summary ofrecommended testing would be as follows:
�.! Hix at site - Test st mixe-.
�! Mix off site � De'iver within speci fiedtime or revolutions � and - Tost at t.rctiie
f. Concrete temperature. The maximum al]owebteconcrete temperature should be establishedbased upon anticipated thermal conditions with-in the placement. Depending upon the volume ofthe placement, maximum temperatur.. s in t.herange of 60 to 90oF �6o to 32o C! have beenspecified.
A Ninimum conciete temperature of 40 F �5o C!should be imposed. Normally, freezing of con-crete placed under water will not be a problem.However, the flowability of concrete at lowertemperatures may be reduced. Because of thepotential for erratic slump loss behavior,extreme care should be used in heating wateror aggregates to raise concrete temperatures.
a, The tremie should be fabricated of heavyguage steel pipe. The pipe and all connectionsmust be strong enough to withstand all sntic-
pated handling stresses.
b. The tremie should have e diameter largeenough to insure that aggregate caused block-ages will not occur. Pipes in the range of8 to 12 in. diameter �0 to 30 cm! are adequatefor the range of aggregates recommend -d,
c. For deep placements the tremie should befabricated in sections such that the uppersections can be removed as the placement pro-gresses. Sections may be joined by flanged,bolted connections with gaskets! or may bescrewed together. Whatever joint technique isselected »oints between tremie sections tsustbe water-tight. The joint system selectedshould be tested for watertightness beforebeginning placement. Flanged connections areincluded in the Guide Specification.!
d. The tremie pipe should be marked to allowqu i ck de te rmina t ion o f the d is t anc e f romthe surface of the water to the mouth of thetremie.
e. The tremie should be provided with a funnelor hopper to facilitare transfer of concretefrom the deliverv device to the tremie.
f. A stable platform should be provi.ded tosupport the tremie during the placement.Floating platforms are gsnerallyt not suitable.The platform should be capable of supportingthe tremie while sections are being removedfrom the upper end of the tremie.
g. A suitable power hoist should be on thetremie support platform to facilitate verticaltsovement of the tremie during the placement.Use of e crane to provide this vei't.ical adjust-ment is not recommended.
h. A crane should be available to lift theentire tremie pipe in case the tremie must bemoved or lifted out of the water to be resealed.
7, Pre lacement lannin
8. lacement rocedures.
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i. Depending upon the method selected forsealing the tremie at the beginning of theplacement see paragraph 8!, an adequate supplyof end closure devices or go-devils should beavailable.
j . Airlifts or pumps must be available toremove laitance and other unsuitable materialwhich accumulates in low areas during theplacement.
a. Planning for the tremie placement must beginas soon as the decision to use tremie-placedconcrete is made, not. just prior to the begin-ning of actual placements. Items with a longlead time in the tremie process include:
- detailing reinforcing steel if any! to mini-mize restrictions to flow.
- detailing of forms, particularly if precastelements are to be filled with tremie con-crete, to eliminate abrupt changes in sec-tions, openings, or areas in which laitancecould accumulate or be trapped.
- consideration of overexcavating the placementarea to preclude concrete removal if tremie-placed concrete is above design grade.
- consideration of incorporating members re-quired to support. the tremie platforms intothe internal bracing scheme of a cofferdam,if appropriate.
b. The overall placement scheme should be de-veloped considering the following items:
� Available concrete production capability.
- Availability and capacity of equipment fortransferring concrete to the tremies.
� The total volume of concrete to be placed.
� The various placement schemes available�fixed tremie locations or an advancing slope.
- Any restrictions to flow such as reinforcingsteel or piles which must be embedded in theconcrete.
- Maximum flow distance of the concrete. Plowsin the range of 30 to 70 ft 9 to 21 m! haveproduced concrete of excellent quality.
c. Consideration of the above items should re-sult in the development of a placement planwhich includes tremie pipe spacings and loca-tions throughout the duration of the placement.The plan should also include the planned loca-tions to be used for relocating tremies as theplacement progresses.
d. The method of sealing the tremies at thebeginning of the placement must be consideredin detail. The most common techniques are:
� Initial dry pipe achieved by using a plateand gasket tied to the mouth of the tremie.This method is recommended for most place-ments and is included in the Guide Specifica-tion.!.
- Use of a go-devil to separate concrete andwater. This method can be very disruptiveto material beneath the mouth of the tremieas the go-devil forces water out of thetremie. Due to the possibility for washingconcrete in place, this method should not beused to restart tremies. If inflatable ballsare used as go-devils, consideration shouldbe given to the depth at which the balls willcollapse due to water pressure.
� Use of a double pipe for deep placements inwhich pipe bouyancy ie a problem. Thismethod involves use of a smaller diametertremie within the main tremie to gain theinitial seal.
e. An inspection plan detailing sounding loca-tions and frequency of soundings should be de-veloped. Soundings should be taken over theentire area of the placement on a regular basis,such as every hour or every 200 yd3 �5 m3!.Locations for taking soundings should be markedon the structure to insure that all soundingsare made at the same location. Additionally,soundings should be required on a more frequentbasis adj scent to each tremie to monitor pipeembedment. Data obtained from soundings shouldbe plotted immediately to monitor the progressof the placement.
f A concrete sampling and testing plan, con-sistent with the agency's other concrete test-ing requirements and the recommendations above paragraph 5c! should also be developed, Thisplan should detail all testing and correctiveactions to be taken by the contractor toinsure that concrete of the desired character-istics is delivered to the tremie.
g. A preplacement conference should be held inwhich all details of the placement are presentedto the owner's engineer. Placement should notbe allowed until the placement plan, concretemixture, inspection plan, and concrete samplingplan are approved.
a. All areas in which there is to be bondbetween steel, wood, or hardened concrete andfresh concrete should be thoroughly cleanediseeediately prior to beginning concrete place-ment to remove mud, algae or other objection-able materials.
b. Tremiee started using a dry pipe techniqueshould be filled with concrete before beingraised off of the bottom. The tremie shouldthen be raised a maximum of 6 in, �5 cm! toinitiate flow. These tremies should not belifted further until a mound is establishedaround the mouth of the tremie pipe. Initial
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lifting of the tremie should be done elawlyto minimize disturbance of material surroundingthe mouth of the tremie.
c, Tremies started using a go-devil should belifted a maximum of 6 in. �5 cm! to allowwater to escape, Concrete should be added tothe tremie slowly to force the go-devil downward.Once the go-devil reaches the mouth of thetremie, the tremie should be lifted enough toallow the go-devil to escape. After that, atremie shovld not be lifted again until asufficient mound is established around themouth of the tremie.
d. Concrete supply to a tremie at the beginningof a placement should be uninterrupted until amound sufficient to seal the tremie has beenestablished.
e. Tremiea should be embedded in the fresh con-crete from 3 to 5 ft �,0 to 1,5 m!. Exactembedment depths should depend upon placementrates and set times of the concrete,
f. Tremies shall not be moved horizontallywhile placing concrete.
g. All vertical movements af the tremie pipemust be done slowly and carefully to preventloss of seal,
h. If loss of seal occurs in the tremie, place-ment through that tremie must be halted imsedi-ately, The tremie must be removed, the endplate must be replaced, and flow must be re-started as described above. To prevent wash-ing of concrete in place, a go-devil shouldnot be used to restart a tremie after loss ofseal.
i. Concrete placement should be as continuousas possible through each tremie. Excessivebreaks in placement may allow the concrete tostiffen and resist restarting of flow onceplacement reaumea. Interruptions of placementof up to approximately 30 minutes should allowrestarting without any special procedures,Interruptions o f between 30 minutes and theinitial set time of the concrete should betreated by x'emoving, resealing, and restartingthe tremie. Interruptions of a duration greaterthan the initial eet time of the concrete shouldbe tieated as a construction joint as discussedbelow.
j. If a bxcak in placement results in a planned or unplanned! horizontal construction joint,the concrete surface should be "green-cut" afterit sets. The concrete surface should be jettediaxaediately prior ta resuming concrete place-ment,
k. The rate of placement should be ae high asthe production capacity allows. Representativerates of concrete rise range upward from0.5 ft/hr �.2 m/hr!. These values should becalculated by dividing tbe er,tire placementaxes by the plant capacity, ae wes done in the
example provided in Chapter 6
1. The volume of concrete in place should bemonitored throughout the placement, Undex'runsare indicative of loss of tremie seal sinre thewashed and segregated aggregates will occupy agreater volume. Overruns are indicative ofloss of concrete from the forms.
Tremies and airlifts should be relocated asgoverned by soundings and the placement plan.Tremies which are relocated should be resealedin secor'dance with the procedures given above.
n. Tremie blockages which occur during place-ment should be cleared extremely carefully toprevent loss of seal. If a blockage occurs,the tremie should be quickly raised � in. to2 ft �5 to 61 cm! ! and then lowered in anattempt to dislodge the blackie. The depthof pipe embedment must be cia!sly monitaredduring all such attempts. If the blockagecannot be cleared readily, the tremie shouldbe removed, cleared, resealed, and restarted.
o. Soundings should be taken as specified inthe inspection plan,
p. Cancrete samples should be tested in accord-ance with the concrete saxapling plan.
9. Poet- lacement evaluation.
a. Coring should be conducted in areas ofmaximum concrete flora or in areas of suspectconcrete quality.
b. After dewatering, the surface of the con-crete should be accurately surveyed to evalu-ate the adequacy of the concx'ete mixture andthe placement plan.
c. After removal of forms or sheet piling, theexterior svrface of the concrete should beinspected by divers for evidence of cracking,voids, honeycomb, etc.
7.4 Guide s ecification. The following specifi-cation is based upon the recommended practicepresented above. This specification is intendedfor massive placements such ae for bridge piersor major offshore construction. The guidespecification was prepared based upon the follow-ing aseumptiona:
1. The using agency has its own specificationscovering concrete materials akd manvfacture.
2. This guide specification vill be part of a1srger project specification; it is not intendedto stand alone.
3, The contractor will be responsible for qualitycontro1 testing ee speci fied by the owner.
4. The term "Contracting Officer" has been usedto denote the owner's representative. This termshould be replaced by "Resident Engineer" asappx'opriate.
1.1 General
1.2. Materials1.4, Concrete Nanufscture
NOTE: Speci fy requ iredrieights and volumes,!
1.3. Concrete ro ortions
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Underwater Mass Concrete Tremie Concrete!
1.1.1. Underwater mass concrete in bid itemshall be placed by the tremie process.
1.1.2. The contractor shall conduct a preplace-ment conference to review all details of theconcrete rsixture proportions, tremie equipment,placement procedure plan, concrete sampling andtesting plan, and inspection plan.
1,1.3. No underwater placements shell be madeuntil all concrete materials, concrete mixtureproportions, tremie equipment, placement pro-cedure plan, concrete sampling and testing plan,and inspection plan are approved by the Con-tracting Officer.
1.2.1. All materials for underwater mass con-crete shall meet the requirements for materialsfor concrete placed in the dry as specified insection of these specifications. Thefollowing additional requirements shall alsoapply:
a. Cersenc shall be Type I or II meeting therequirements of ASTN C 150. NOTEr The option-al heat of hydration requirement of ASTN C 150shall be invoked if calculations indicatethermal problems.!
b. Chemical admixtures governed by ASTM C 494shall be tested in conjunction with the air-entraining, admixture and cement proposed for useon the project to insure compatibility.
1.2.2. The following weights and volumes ofproposed concrece rsaterials shall be providedto the Contracting Officer for approval andmixture proportioning! no later than daysprior to the beginning of placements.
Coarse AggregateFine AggregateCementPozzolan if any!Admixture sWater
1. 3. 1. Concrete proportions shall be providerlby the contractor provided by the ContractingOfficer!, The following mixture shall be usedfor bidding purposes:
Cement; 705 1b/yd �56 kg/m !, Type I or II.Pozzolan: If required or permitted, replace upto 15X by weight of cersent with an equal weightof pozzolan rseeting the requirements of ASTM C618, Glass F or N,Coarse Aggregate: 3/4 in. �9.0 mm! maximum forreinforced placemerrt; 1 1/2 in. �8.1 mm!msxirsum for unreinforced plscements.Gravel aggregate rounded! shall be used.
NOTE: If gravel is unavailable, suitable work-ability will normally require higher sand per-centages up to 50X and additional cementitious material!Pine Aggregate: 42-50 percent by weight of totalaggregate,Air Content: 5 percent - 1 percentMaximum Water-Cementitious Material Ratio: 0.45Slump: 6 to 7 in. �5 to 19 cm!Admixtures; Water Reducer and retarder.
1.3.2 Final approval of a concrete mixturedeveloped by the contractor shall be based onconcrete performance in a large-scale flow testin which a minimum of 10 yd 8 m ! shall beplaced per test. Concrete for these tests shallbe placed in s water-filled box or pit using thetremie equipment and procedure proposed for theproject. The water temperature shall be closeto that anticipated in the actual field place-ment.
1.4.1 All materials for concrete placed underwater shall be stored in accordance with therequirements for materials for concrete placedin the dry as specified in section ofthese specifications.
1.4.2. All bstching, rsixing, and transportingequipment for concrete placed under water shallmeet the requirements for batching, mixing andtransporting equipment for concrete placed inthe dry as specified in section of thesespecifications.
1.4.3. The method s! of transporting concreteto be placed under water from the point ofmanufacture to the tremie hopper shall ensuredelivery without segregation or excessive delay,
1.4,4, Concrete to be placed under water shallhave a minimurs temperature of 40 F �5 C! anda maximum temperature of oF. NOTE,Maximum tersperature should normally be between60o to 90oF �6 to 32oC! and should be deter-mined on the basis of anticipated thermalproblems.
1.4.5. Concrete to be placed under vater shallarrive at the tremie hopper no later than
minutes after discharge from the mixer! a f ter no more than revolutions of thetransit mixer drum!.~NOTE: These limitsshould be established by slump and sir contentloss testing.! NOTE: The provisions of thissection must agree with those of section 1.5.4.
1.5. Sam lin snd Testin Re uirements
1.5.1. The contractor shall develop a concretesampling and testing plan which shall includethe testing shown in Table 1.1. This planshall be submitted to the Contracting Officer
days prior to beginning placement.
1.5.2. The contractor shall be responsiblefor conducting all testing on the sampling andtesting approved plan,
TABLE 1. ! MINIMUM TESTING REQUIREMENTS
At Tremie~Ho er
Pre quency1 Tes t for each: At MixerS tandardTes c
250 yd3�90 m3!
ASTM C 143Slump
250 yd3�90 m3!
3-6Z5+ 12ASTM C 231Air Content
500 yd3�80 m3!
ASTM C 138Unit Weight
6 cyla1000 yd3�65 m3'!
Comp re s s iveStrength
ASTM C 31ASTM C 39 3500 psi
�4 Mpa!3500 psi�4 Mpa!
+ No requirement - report measured value.
1.5.3, Results of testing except for compres-sive strength testing! shall be provided to theContracting Officer at the end of each shiftduring which testing is conducted. Results ofcompressive strength testing shall be reportedwithin 24 hours of testing.
1.5.4. Testing shall be accomplished usingsanrples of concrete taken at the point ofdischarge from the mixer! the tremie hopper! or both!, NOTE: Location of sampling shouldbe based upon elapsed time between mixing andarrival at tremie hopper,! NOTE: The provisionsof this section must agree with those of section1.4.5.!.
1.7. Placemaat Procedure
1.5.5. Compressive strength tests shown inTable 1.1 shall be conducted using three 6- by12-in, �5- by 30 cm! cylinders at 7 and 28days.
1.5.6. Concrete temperature shall be measuredrrnd recorded whenever other test irrg is conducted.
1.6.1. The tremie pipe shall be of heavy guage minimum 0.25 in. �.4 mm! wall thickness!steel pipe with a minimum inside diameter of10 in. �5 cm!. The tremie shall be marked toallow determination of depth to the mouth ofthe tremie.
1.6.2, Joints between sections of tremie pipeshall be gasketed and bolted so as to be water-tight under project placement conditions.
1.6. 3. A hopper or funnel of at least 0.5 yd3�.4 m3! capacity shall be prrvided or top ofthe tremie pipe to facilitate transfer ofconcrete to the tremie.
1.6.4. A power hoist which is capable ofsteady vertical control! shall be provided toaccommodate vertical movements of the tremie.A stable platform shall be provided to supportthe tremie pipe, hopper, and hoist.
136
1.6. Placement E ui nt
6-7.5 in. 6-7 in. �5-18 cm!�5-19 cm!
1,6,5, A supply of extra end plates and gasketsshall be maintained to allow resealing of tre-mies, if necessary,
1.6.6. A crane or other lifting device shall beavailable to completely remove the tremie fromthe water for the purpose of resealing orhorixontal relocation.
1.7.1. The contractor shall develop a compre-hensive placement procedure plan in accordancewith the provisions of this specification. Thisplan shall be submitted to the ContractingOfficer for approval at least days priorto beginning placements.
1.7.2. All areas in which there is to be bondbetween steel, wood, or hardened concrete sndfresh concrete placed under water, shall bethoroughly cleaned isxsediately prior to begia-ning placements. Cleaning shall. be accomplishedusing high pressure air or water jetting. Air-lifts or pumps shall be used to remove mud, silt,or sand from placement areas.
1,7.3. Placement of underwater mass concreteshall be as continuous an operation as possible.Placement shall continue uninterrupted untilthe entire placement is completed. Interrup-tions of placement through a single tremie sha11,not exceed 30 minutes without removal of thetremie and carrying out the restarting pro-cedure.
1.7.4. The concrere placement rate shall besufficient to produce a minirmrm vertical riseof concrete of 0.5 ft/hr �.2 m/hr!, calculatedby dividing, the entire placement area ft m2!! by the concrete production rate fts/hr! m3/hr!!.
1.7.5, Tremie pipes shall be spaced to give amaximum concrete flow distance of 50 ft �5 m!.
1,8 Ins ection
137
1.7.6. The placement shall begin with the tremiepipe sealed with a watertight plate, The emptytremie pipe shall be sufficiently heavy to benegatively bouyant when empty. "Rabbits"or "go-devils shall not be used to start thetremie. The tremie shall be sealed, loweredto the bottom, and fi11ed with concrete. Thetremie shall then be lifted 6 in. �5 cm! toinitiate concrete flow. Concrete supply shallbe continuous until soundings indicate the re-quired embedment is developed.
I ~ 7,7. The mouth of the tremie shall remainembedded in the fresh concrete at all timesunless the tremie is being completely removedfrom the water. At no time shall concrete beallowe'd to fa11 through water. Embedment shallbe from 3 to 5 ft I to I 5 m! at all times.
1.7.8 A tremie shall not be moved horixontaliywhile concrete is flowing through it. To re-locate a tremie, it shall be lifted from thewater, resealed, relocated, and restarted inaccordance with section 1.7,6.
1.7.9. AII vertical movements of the tremieshall be carefully controlled to prevent loss ofseal. If loss of seal occurs, placementthrough that tremie shall be halted immediately.The tremie shall be removed, resealed, replacedand restarted in accordance with section 1.7.6.
1.7.10, Tremies shall be relocated during theplacement in accordance with the placement planand as ind ic a ted by sounding s.
1.7.11. If circumstances force a suspension inplacement greater than the time of initial set as determined by testing during mixturedevelopment!, then the surface of the concreteshall be green-cut after the concrete has set.Placement shall not be resumed until the con-crete surface has been prepared in accordancewith section 1,7.2.
'.7.12. Airlifts or pumps shall be provided toremove laitance which accumulates during place-ment. Airlifts and pumps shall be relocatedas indicated by soundings.
1.$.1 The contractor shall develop an inspec-tion plan covering locations and methods oftaking soundings during the placement andpost-placement inspection. Soundings shall betaken each hour during placement. Soundingsshall be spaced so as to cover the area, pluscorners and at the tremie pipe discharge. Thisplan shall be submitted approval by theContracting Officer days prior to begin-ning placements,
.8.2. Data from soundings shall be furnishedto the Contracting Officer at the end of eachshift during which concrete is placed. Datafrom post-placement inspections shall be fur-nished oo later than days after theinspections are completed,
1.8.3. After the cofferdam is dewatered, asurvey shall be made to establish final surfaceelevations of the concrete placed under water.Klevations shall be determined at each locationfor which soundings were required.
1.8,4. Cores shall be drilled and recovered' asdirected by the Contracting Officer For bid-ding purposes, a minimum of cores shallbe drilled at locations of maximum horixontalconcrete flow. Additional cores may be requiredat no expense to the owner at all locations inwhich tremie seal is lost.
1.8.5. After removal of sheet piles! externalforms!, the surface of the concrete placedunder water shall be inspected by diver forevidence of cracking, voids, honeycomb, orother unsatisfactory concrete. A writtenreport of this inspection shall be furnishedwithin days of completion of the inspec-tion. Suitable repairs shal1 be made, by groutinjection or underwater epoxy injection, asindicated and approved.
7,5. Recommendations for further work, Follow-ing are several areas in which the authors be-lieve additionaI study wouid be beneficial.'
I, Confined placements. Determine if theproblems seen in the primary elements of WolfCreek have occurred in other placements and ifsimilar problems seen in filling piles and smalldiameter shafts with tremie concrete are related.Determine if there is a critical diameter orcross-sectional area below which successfulpIacements are impracticable.
2. Hydrostatic balance. The anomalies in hydro-static balance noted in the Wolf Creek place-ments need to be evaluated further in a programwhich includes measurements and coring. Do theanomalies represent areas of poor quality con-crete? If so, measurements of concrete levelsmade during a placement could serve as anadditional inspection too1,
3. Temperature monitoring system. An inexpensivesystem to monitor temperatures in a tremie place-ment and to compare measured and predictedtemperatures needs to be developed. Such asystem could alert field personnel to unexpectedoccurrences during a placement and present astarting point for post-placement verificationcoring.
4. Concrete density. Examine cores from severalplacements to determine the loss of densitywhich may be expected for tremie-placed concreteas a function of flow distance from tremie pipeand depth of water in which placed.
5. Temperature predictions. The finite elementapproach to temperature prediction in tremie-placed mass concrete should be extended todetermine the sensitivity of the predictionsto the many variables involved.
6. Confined placements. Examine the feasibilityof using s vibrator attached near the mouth ofthe tremie pipe for deep, confined placementsand perhaps for all mass placements. Such stechnique appears of interest-but has not yetbeen tested nor proven and hence should not beused on prototype placements until testing hasbeen carried out.
7. Temperature cracking. Examine the crack re-sistance of concrete which hss set and curedunder the thermal gradients known to existnear the extremes of a massive tremi,e placement.
8, Concrete flowabiliry. The flowability of aco~crete appeared to determine the flow patternwhich was exhibited once the concrete left thetremie. There needs to be a test which canmeasure that flowability directly, Perhaps avariation of the vane shear test used in soilstesting could be developed.
9. Thixotropic admixtures. Examine uses forthixotropic admixtures for concretes to beplaced under water, A thixotropic concretewould be beneficial in applications in whichonly limited flow is desired after the concreteleaves the mouth of the tremie or is exposedto running water.
10. Nixture optirsixation, Develop moreeconomical concrete mixtures for mass tremieplacements. The work done in this project hasdefined the characteristics for successfulplacement. Can more economical mixtures bedeveloped to match those chsracteristicsf
13S
REFERENCES
139
1. American Concrete Institute Committee 304."Recommended Practice for Measuring, Mixing,Transporting, and Placing Concrete," Journal ofche American Concrete Institute ProceedingsVol. 69, No. 7, July 1972 pp 374-414.
2. "Concrete Down the Spout," Concrete Construc-~tion Vol. 13, No. 7, July 1968, pp 247-250.
3. Netherlands Cosssittee for Concrete Research CUR!, Cosmittee C17. "Underwater Concrete,"Heron, Val. 19, No. 3, 1973.
4. Gerwick, Ben C., Jr. "Placement of TremieConcrete," S m osium on Concrete Canstzuctionin ueous Environments American ConcreteInstitute Special Publication No. 8, 1964.
5, Gerwick, Ben C., Jr. "Under~ster ConcreteConstruction," Mechanical En ineerin Vol. 94,No. 11, November 1972, pp 29-34.
6. Powers, T. C. "Studies of Workability ofConcrete," Journal of the American ConcreteI ttt t 9* dt g V l. 28, 1932, pp 419-448.
7. Hezschel, W. H., and Pisapia, E, A, "Factorsof Workability of Portland Cement Concrete,"Journal of the American Concrete InstituteProceedings Vol, 32, 1936, pp 641-658.
8. Tattersall, G. H. The Workabilit of ConcreteThe Cement and Concrete Association, London,England, 1976.
9 ~ American Society for Testing and Materials.Annual Book of ASTH Standards Part 14, Concreteand Hineral A re ates ASTH, Philadelphia,Penn., Latest Edition.
10. U. S. Army Engineer Waterways ExperimentStation WES!. Handbook for Concrete and CementVicksburg, Mississippi, 1949.
ll. American Concrete Inscicute Cosssictee 211.Recommended Practice foz Select in Pro ertionsfor Ha-slugs Concrete ACI 211. 3-75, Amer icanConcrete Inscitute, Detroit, Hichigan, 1975.
12. Hacher, Bryanc. "Partially Compacted Weightof Concrete as a Measure of Workability,"Journal of the American Concrete InstituteProceedings Val, 63, 1966, pp 441%49.
13. Hughes, B. P. "Development of an Apparatusto Determine the Resistance to Segregation ofFresh Concrete," Civil En ineerin and Public17 k 8* '* V l. 56, 9 . 658, 8 y 1961, pp633-634.
14. Ritchie, Alistair, G. B. "Stability ofFreSh COnCZeCe MiXeS," Jpurnal Of the CanatructionDivision ASCE Vol. 92, No. C01, January 1966,pp. 17-36,
15. Scrunge, Christian. "Submarine Placing of6 * t by th I'* I ~ -8 th 4," ~72 t Ithe 1970 Of f shore Technola Conference Vol.2, Paper 1311, pp 813-818.
16. Anderson, Arthur R. "A Study of Sub-AqueousConcrete," Journal of the American ConcreteI t t t P * d g 9 1. 33, J y 9 b y1937, pp 339-346.
17. Halloran, P. J. and Talbot, K, H. "TheProperties and Behavior Underwater of PlasticConcrete," Journal of the American ConcreteI tlt t Ptptt ~ 1 8 V l. 39, I * 1943. pp.461-492,
18. Williams, J. W., Jr, "Tremie Concrete Con-trolled with Admixturesp" Journal of theAmerican Concrete Institute Proceedings Vol.55, February 1959, pp 839-850,
19. Ozegon Department of Transportation. TheColumbia River �-205! Br id e Undatedbr achur e .
20, "Record Segmented Bridge Making Headway,"En ineezin News Record Vol. 199, Na. 20,November 17, 1977, p, 16.
21. "Long Box Girders Will Span Columbia River,"En ineezin News Record Vol. 187, No. 15,October 7, 1979, p. 15.
22. "Tight Bids Fall Low on Bax Girder Bridge,"En ineerin News Record Vol, 202, No. 25,January 18, 1979, p. 38.
23. "Special Forms, Equipment Cast River Piers,"En ineerin News Record Vol. 200, Na. 25,June 22, 1978, pp 58-59,
24. Carlson, Ray W. "A Simple Method for theComputation of Temperatures in ConcreteStructures," Journal of the American Concrete1*t tt 9 d' g Vl. 34,77 ob9 b 1937, pp 89-192.
25. Couch, Frank B., Jr., and Ressi de Cervia,Azturo L. "Seepage Cutoff Wall InstalledThrough Dsm is Construccion First," Civil~gpl. 49, II. !,J *y 1979, pp62%6.
26. "Concrete Cutoff Extends 278 ft to SealOld Dam's Foundation," En ineerin News RecordVol. 197, No, 4, July 22, 1976, pp 14-15.
27. Dunn, Albert. "Diaphragm Wall for WolfCreek Dam," USCOLD Newsletter Issue No. 53,July 1977, pp 3-7.
28. Fetter, Claude A. "Wolf Creek Dam Dia-phragm Wall Completed," USCOLD NewsletterIssue No, 60. November 1979, pp 16-19.
29. Fetser, Claude A. "Wolf Creek Dam RemedialWork, Engineering Concepts, Actions, andResults," Transactions of the Thirteenth Inter-national Con ress on Lat e Dams ICOLD, NewDelhi, India, 1979, Vol. 2, pp 57-81.
30. Holland, Terence C., and Turner, JosephR. Construction af Tremie Concrete CutoffWall Wolf Creek Dam Kentuck MiscellaneousPaper SL-S0-10, U. S. Army Engineer WaterwaysExperiment Station, Vfcksburg, Mississippi,
September 1980.
31. "Slurry Wall Construction," Concrete Con-t t'ee V !. 78, 8 . 3, M 7 6 1973, pp 98-
93.
32. Nash, Kevin L.,"Diaphragm Wam 1 ConstructionTechniques," Journal of the ConstructionDivision ASCE, Vol, 100, No. C04, December1974, pp 605%20.
33. Polivka, Ronald N. and Wilson, Edward L.Finite-Element Anal sis of Non-linear BeatTransfer Problems Department of Civil Engineer-ing, University of California, Berkeley. ReportNo. UC SESN 76-2, June 1976.
34. Carlson, Roy W., Houghton, Donald L68 andPolivka, Nilos. "Causes and Control of Cracking,in Unreinforced Nasa Concrete," Journal of the8 'ce C *ce 1 t'c t 1 8' 8 Vcl.76, 8 . 7, 3 ly 1979, pp 811-837,
35. Corps of Engineers, Civil Works ConstructionGuide S ecification Concrete CW � 03305, December1978.
36. Corps of Engineers. Standard Practice forConcrete, EN 1110-2-200, November 1971.
140
APPENDIX A: CONCRETE MIXTURE PROPORTIONS � MIXTURE EVALUATION TESTS
1. Mixture proportions for each of the 11 mixtures evaluated in the small-
scale laboratory tests described in Chapter 1 are presented in Tables A-1
through A-11.
2. Data presented in this appendix are summarized in Table 2 of Chapter 1.
3. Only data for Mixture 1 Table A-1! are presented in this volume. Data
from remaining mixtures may be obtained from the authors.
4. The following conversion factors are required for the tables in this
appendix:
1 lb mass! - 0.4536 kg
1 lb mass!/ft 16.02 kg/m3 3
1 fl oz/lb 65.2 ml/kg
1 yd 0.7646 m3 3
141
APPENDIX B: CONCRETE MATERIALS � MIXTURE EVALUATION TESTS
1. The components of the concretes evaluated during the small-scale tests de-scribed in Chapter 1 are described in the following paragraphs. As far as waspossible, the same materials i.e., same sources! were used for the large-scale
placements described in Chapter 2.
and Gravel and were from that company's Pleasanton, California, quarry operation.
� Coarse aggregate: 3/4-in. !9-mm! nominal maximum size
Absorption: 1.0 percent
Specific gravity: 2.68
� Fine aggregate: Top sand
Absorption: 2. 0 percent
Specific gravity: 2.68
3. Cement. Cement was purchased from the Kaiser Cement Company plant at
Permanente, California. The cement was a Type II conforming to ASTM C 0.
4. Pozzolan. The pozzolan used was a natural material sold by Airox EarthResources, Santa Maria, California. The material met the requirements ofASTM C 618, Class N. The specific gravity was 2. 54.
5. Bentonite. The bentonite used was sold by the American Colloid Company and
was marked with the trade name "Volclay 200." The specific gravity was 2,71.
6. Admixtures. Admixtures used were from laboratory stocks with the excep-
tion of the thixotropic additive!.
� Water reducer/retarder: Sika Plastiment.
� Air-entraining agent: Master Builders AE-�.
� Thixotropic additive: Sikathix manufactured by Sika Chemical Corporation.
7. Water. City water, Berkeley, California.
143
APPENDIX C: SUMMARIZED DATA � MIXTURE EVALUATION TESTS
1. Data for each of the three tests performed on the ll concrete mixtures are
presented in Tables C-1 through C-10. These data are summarized in Table 3,
Chapter 1 ~
2. Each test for which data are presented in this appendix represents three
batches of concrete, as is explained in Chapter 1. Detailed data on a batch-
by-batch basis are presented in Appendix D.
3. Only data for Mixture 1 Table C-1! are presented in this volume. Data from
remaining tests may be obtained from the authors.
4. The fol1owing conversion factors are required for the tables in this
appendix:
1 in. 2.54 cm
1 lb mass!/ft = 16.02 kg/m3= 3
1 lb force! - 4.448 N
1 lb force!/in. 0.006895 MPa2
To convert deg F to deg C,
deg C = deg F � 32!/1.8
144
APPENDIX D: DETAILED DATA � MIXTURE EVALUATION TESTS
l. Detailed data for the tests performed on each batch of concrete of the ll
mixtures tested are presented in Tables D-1 through D-29. These data are sum-
marized in Appendix C and in Table 3, Chapter 1.
2. Only data for Nixture 1, Test 1 Table D-l!, are presented in this volume.
Data from remaining tests may be obtained from the authors.
3. The following conversion factors are required for the tables in this
appendix:
1 in. = 2.54 cm
1 lb mass!/ft = 16.02 kg/m3 3
1 lb force! 4.448 N
1 lb force! /in. = 0. 006895 HPa2=
To convert deg F to deg C,
deg C = deg F � 32!/1.8
146
M iXWURE i TEST
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T A BL E D � I . C ON T I NU E D!
APPENDIX E: SOUNDING DATA � LABORATORY PLACEMENT TESTS
1. As is described in Chapter 2, the tremie concrete placed in the large-scale
laboratory placements was broken into three approximately equal segments.
Soundings were taken at 20 locations over the surface of the placement box at
the conclusion of placing each of the three segments of concrete. The sounding
pattern used was shown in Figure 17, Chapter 2.
2. Soundings were taken using a weighted plate attached to a measuring tape.
The plate was of sufficient area to prevent its sinking into the soft concrete.
3. The data was obtained as distance from a fixed reference point to the sur-
face of the concrete under water. This data has been converted to thickness of
concrete in place by subtracting test readings from those obtained at each point
prior to each test. These reduced data for each test are presented in Tables E-1
through E-5.
4. Only data from Test 1 Table E-1! are included in this volume. Data from
remaining tests may be obtained from the authors.
149
T'ABLE E- I . C INCR EVE T'H 1C K,-.NE,S'5 AS DKTKRM t4c.pBY SOUNDING5, ~iE'5T' 1.
APPENDIX F: SURFACE PROFILE DATA � LABORATORY PLACENENT TESTS
As is described in Chapter 2, the surface of each of the tremie concreteplacements in the laboratory was mapped to establish surface profiles. Measure-ments were taken at five locations laterally outside edges, 1 ft �0.5 cm! infrom the outside edges, and centerline! and at every 1-ft �0.5 cm! intervalalong the long axis of the box.
2. Measurements were made down from a fixed plane to the surface of the con-crete. The data presented in Tables F-1 through F-5 have been reduced to give
act~1 concrete thickness.
3. Figure 14, Chapter 2, shows the left/right orientation of the placement box.The tremie was located at station 1.5 with flow toward station 20.
4. Only data from Test 1 Table F-1! are. included in this volume. Data fromremaining tests may be obtained from the authors.
151
FlNAL CONCRETETH i C KNE.S'S, lNC HES,TES'T i . J-iN.= 2..54c~!
APPENDIX G: COLOR LAYER- DATA � LABORATORY PLACEMENT TESTS
1. As is described in Chapter 2, cores were drilled in the hardened concreteto determine the final distribution of the variously colored segments of con-crete. The coring pattern used was presented in Figure 14, Chapter 2.
2. Cores were recovered, measured, and logged. In cases where complete corerecovery was not possible usually due to mechanical rather than concrete prob-lems!, the total thickness of the concrete at the location of the core was usedto determine the color distribution. For several cores it will be noted thatthe length of core recovered is not equal to the thickness of the concrete asreported in Appendix F, The discrepancies are due to ridges on the concretesurface and minor errors in measuring the lengths of the cores. In these in-stances, the total thickness of the colored layers has been made equal to thethickness determined during the surface profile measurements.
3. Data for the centerline and right edge of the box for the five tests arepresented in Tables G-1 through G-10.
4. Only data from the centerline, Test 1 Table G-l!, are included in thisvolume. Data from remaining tests may be obtained from the authors.
153
APPENDIX H: TEMPERATURE INSTRUMENTATION PLAN � PIER 12, I-205 BRIDGE
1. The instruments used to record temperature development in the tremie con-
crete seal of Pier 12 of the I-205 Bridge were Resistance Thermometers supplied
by the Carlson Instrument Company, Campbell, California. A total of 34 instru-ments and 4523 ft �379 m! of lead cable were used.
2. All instruments, cables, and switches were tested under hot and cold condi-
tions in the laboratory prior to being used in the field. All elements performed
satisfactorily during testing and during actual field use.
3. As noted in Chapter 3, one quadrant of the pier was instrumented, Instru-
ments were placed in four planes perpendicular to the long axis of the coffer-dam.. These planes were designated Row 1 through Row 4. Each row was made up
of two or more vertical lines of instruments. Figure H-l shows the general in-
strumentation plan in relation to the cofferdam. Figure H-2 shows a blow-up of
the instrumented quadrant while Figures H-3 through H-6 show the horizontal
locations of the instrument lines within each of the four rows. Figures H-7
through H-17 show the detailed vertical locations of the instruments on eachline. *
4. Vertical instrument lines were made up of a steel supporting cable with
the instruments attached to the cable at the appropriate elevations. The steel
cables were heavily weighted at the lower end and were attached to the cofferdam
bracing at the upper end.
5. All lead-in cables from the instruments were connected to a central terminal/switching board. This board was in turn connected to a variable resistance
bridge Carlson Box! which was balanced to obtain the readings. A schematic
of the system is shown in Figure H-18.
6. A listing of instrument numbers and recording channels is shown in Table H-l.The particular sequence shown was selected to allow channels 1 through 6 to beconnected to the instruments which initially would be in contact with the concrete.
* Of the figures showing locations on each vertical line, only Figure H-7 isincluded in this volume. Remaining figures may be obtained from the authors.
155
SECT I ON T HRO<G H TRE.MIE5 F- Al L.OOK IN G DON/N STREAM
F IGURE H-6 . SCHEMAT'I C OF IklST'R.'J-MENT ROW 4 . SEEPIGS. H-I& ~~a I-I-l7 FOREX AC. T VERT ICALLOC AT' ION 5, NOT T'0SC>I a. IFT=O.SO<ea!
C Q A H g E'L5ZS- S4
P'I SUP,E. H-IQ., SCHE NA ITIC DiA6RAOF lbJSTRUhAENTAT I NTE R M I NA L B OA R D.
163
CHANNELS
1- LZ.
i-N= I XeoR'E sly'TOADS ~
C HeMNELSl3 -24
l- t= lseXREMI STAN~K
APPENDIX I: DATA RECORDING AND REDUCTION � TEMPERATURES IN PIER 12 SEAL CONCRETE
1. Temperatures were read nominally every 2 hours' Actual reading times variedslightly due to conflicting activities within the cofferdam and the schedulesof the persons taking the readings. Actual start and stop times for the read-ings were recorded on the data sheets. These two times were averaged to estab-
lish the reading time for each set of data.
2. Total time required to complete one set of readings was approximately
20 minutes. Six of the data channels were read at the beginning and end of
each sequence. The values for these two readings were then averaged to offsetany discrepancies which might have ocurred due to the time required to complete
the entire sequence of readings.
3. Readings were taken in ohms by balancing a variable resistance bridge
Carlson Box!. This raw data was converted into temperatures following instruc-
tions provided by the manufacturer of the resistance thermometers.
4. The temperatures obtained at the actual reading times were further reduced
to provide temperatures at the nominal reading times every 2 hours through
80 hours and every 10 hours from 80 to 380 hours! using a straight line inter-
polation technique. This last step was done to allow easier comparison with
predicted temperatures.
5. Reduced temperature data for the 33 instruments are presented in Tables I-1
through I-33.
6. Only data from Instrument 8 Table I-8! are included in this volume. Datafrom remaining instruments may be obtained from the authors.
165
APPENDIX J: PREDICTED VERSUS MEASURED TEMPERATURES � PIER 12, I-205 BRIDGE
a. Table 3-1, Top of seal instruments.
b. Table 3-2, Mid-depth instruments.
c. Table J-3, Bottom of seal instruments.
4. Note that in Table 3-1 a range of predicted values is given. This was done
since a variable thickness of concrete was actually placed over the top instru-
ments. The cover was calculated to be:
2.0 ft �.6 m!
0.7 ft �.2 Hi!.
2.6 ft �.8 m!
4.6 ft �.4 m!
Instrument No. 4
Instrument No. 15
Instrument No. 21
Instrument No. 22
5. Note that the readings for instruments No. 5, 7, and 9 are significantly
below the predicted values. See Section 3.3.4 of the text.
I
l67
1. The tables in this appendix compare the temperatures predicted using the
Garison Method with those actually measured in the seal concrete of Pier 12 of
the I-205 Bridge as is described in Chapter 3.
2. Due to the limitations of the Carlson Method which are described in the text,
predictions made using that technique are valid only for instruments for which
one-dimensional heat flow can be assumed. Therefore, the following tables in-
clude only those instruments in the interior of the pier for which this assump-
tion is valid.
3. The following tables are included:
F J � z . PIED' c TK 9 vs. MEAG URF 0T'ENl'PFR, &TURF-~, M t DDE P TH . lM sTR UMEN t 5NE A R. t" KNw~RL-l4 F-
TR.RV iE +E44-.
P'W gB>v E wAsa ~F. st&~
169
TASK-E, J - 3. PRRDlGTBD VS, MEASUREDTKNtPE,R,&TURKS, 507-7 o<oF SEAL iQWEF.ioR,{ w~swzu wawwc.
2�5!!
30! g NE 30!
A aB
5i;i~0 a53doa
ila0 L
P iJIJ C~Vol.
Dri'4- I1 I= J.J I~ J!
la N I
~ 0 ~ ! 9=21 a N3
J � I ~%I< !
v L I ~ LT4d J
7 +
172
1
5060
110
136
APPENDIX K: LISTING OF PROGRAM TEMP
Note: Flow chart follows listing.!
PROGRAM TEMP 1 NP UT a OUTPUT a PUNCHlCOlarNIQN /DES / 8 ~ Ha 0 f HED 18 ! ~ WED
COMMON /E I DAEVA/ V ~ PR, NFC q NF8 ~ T C 400COMMON /GRlOCU/ X�0!, Y�0!D I MENS 1 CIN PX�0a 30! a PY 30 ~D 1 |alE N 5 l C. Iv NOD 5 !R EAO 900 y MODF a WEDa HE D2I F iirlGDE ~ EQ ~ 5HSTUP ! GO To QQOQCALL T [ TLEHEAD 1000 q da WaD y INr Nda NH ~ ISa lPI F I P ~ EU ~ I ! PUNC H 900' MCDEg HEDPRlNT 20&Of 8 f Hf DV =8+ H' D/2 7 ~8 = H/2 ~0 = 0/2 ~IF IK ~ t4 ~ 0! Gati TG a0IPEAD 1050a X l ! a I If NH!REAIJ I050a Y I ! a 1=!a NH!GO ErJ 60CALL CEN aRD N8aNH!NH1 = NH 1NO 1 = NI:I � 1Np = NH~NHNFE = NFa14r4H1I'=-Y 1!DO 110 L = I a NHDO 110 J = 1a N8PX a J! = X J!P V L, J! = Y L!CQNT[NUEChl L C CNCQP NB 1 a NHl !C ALi. HEAT~II P !C ALL 1 TLEra e I N E 2 0 r.'i 0 a N d a 3, NI r a H a e a 4 P a N F TIak INE 20'00I F I P ~ FO ~ 0 ! raQ T Q 139
L=2A =8 HN C D L,~r. Il' =at-N T DA TAlF Ia' ~ trJ ~ 1 ! raUNCH 9000y AyQ ~ Anil ~ A ~ 8qr-'UNCW 5 300 ~ N9 a L
1.~ " J = 92 a .'4 HD l 13 i 1=1 a I4I4K =K+1HJRCH >lu3 ~ Kg~A. Ja I! SPY J ~ 1!CCNE l xu;"-K = 0L= 1J=2A = r < Hr-' L F ~ r=. N T� =BI-r 'A1 AIr II' E ! ~ I ! I INCUBI QOOOyA ~ 8 ~ AqdyAyf<qPiJNCH 5i�0a LaNEE yLyKyK ~ Ka JyL
IF J ~ EC ~ 9t4!N J! = tl-T +IF La EO ~ NH 1K = K +NaO�! = KkOD�! = NO +NOD 3} = NOD NGD�! = NQO NOD�! = trOO IF Ir ~ EV ~ 1!CONT IKUF.K 1= NH + IPRINT 2100 r PPRINT 2101! F L eEQ e NH!NZ ' = NDI riLtv = NET + 1!N 1 = N + NdlP HI NY 24'3 0r PR INT 2400 ~CCNT INUEPRINT 2200 ~PRINT 4000PRI NT 64308=0L='DD 200 t =1 r NHIF PV Lr 1! ~ Ght=M+1CON 7 I tQ UEN= NU 1 +NHI-hi
IP ~ 6'0 ~ 0!A=9HCUNVECTIti=RHCN DATA
UieCH v040rArPUNCH 5000r LL=1
f 4M+NI3J= I+Nt'IF I P.EQ ~ I !Pk INT eao00r L r
=NHI � htI = lP-NUJ =NPIF I P ~ t..O ~ 1 !Pa INT trhi�rL r
GQ TG 140J - L+NR I !
GG TG 140
K+L2! -t.3! � NB4! + 1P'JNCH eOoor NtjD I ! f I 1 r5 l ~ Nt ~ TC K!
T ~ 0 ~ ! GG TU 210
Ga TV 220
Br' t3rArRrA ~ 8
V= IL=L+ II =Nt3~ NH 1+?J= I-IIF I P ~ Fu ~ 1 !PP I NT o.i00r L rL =t.. 0 t< I.' 11 =NPJ= I � IIF I+ ~ Cid I jPl-' I N T <>rit! 0 r L rGC Tti l
wlg3 FLeMA T Air 3Xt 900 FFtP4fAT >F10 ~
Ddt! F Ot<i'@AT HF 1 '! ~2 0 0 0 F t.~ ~ i~i h T t / // r
l/r K ~ '" ANAiVS I ii'/.:. Y JTAt
6Kq ' iA~J -.i/v TOTAL4 l; K ~ I I I.-. I i et t
T O l' 'tt.ir /-i Tii I Al
l73
140
150
Zt�210
220
LY Kl ~ 1!r X Jl r J = 1 ~ NUl
GD TG 150
N21
NE J! ~ J = I r NBI !TC J!r J = N ~ NI!
PX I ~ J! r J = I ~ %8l
P'JNCtr 6500 ~ t r I ~ J r NBIr JrNi!
PUNCH 6500 r L ~ I r J r NUIr J ~ NB
P JNCH 6500 rLr I ~ J r KI ~ JrK
PUNCH ei500 r L r I ~ J,KIr JrK
r 1 dA4 ~ /1 5A4 '!0r 515!0!
Tw~-DI Mc NGICiNAL FIN! TEOF 5 E CT IPtit 5 YA!METR I C ABCtUTV J!IHi= h .!F H ASE 3 I V I 5 I ONS
=. r t-'r, ~ 1 r < FEi= T CEVTERLINF TS J AOt= t !F Ht= I GHT 0 IV I ~t IGNS
T =r rF t slrr FEET + ~ ~ F5 ~ 1 rw'VJ At!EP <1F NUDAL P~lINTSN >%RED i!F ELF:4ENT~
ELEMENT ANALV5 I S'+ ~ /CENTERLINE OF STRVCrv»a
=wr 14 ~0 K-HUUNDAAY! + r
=~r r4,FEET QF FOUNDAT ION+r/
-i!r r 14 ~=itr e 14r !
20Xy20Xq204r
+ g% ~¹ ~ ¹ p¹ ~ ~ ~ ~ X¹
SUe QUT INE T I TLECQM»tbN /DE / Jq Hy O HEQ 18 ! q HFD2 15 I
-ik I'NT 23�0' HE'3t HE322000 FORMAT �HI ~ 2X r 19A4«15A41
k E TUHNE t«i t!
Ut!f'OUT INg CONCOP NUI f NHIC 4 4:!N /!LS / 8 y H pD «HEQ 18 ! ~ HED2 15 I
COWL !N /T {Mr=V A/ V p»7g NFC ~ NFR ~ TC 490 'I4EAI! 1!Ol! PR kT NFC NFi3IF ~ T ~ 3 ~ 0 ~ ! RT= V/PRIF t~+ ~ EO ~ '! ~ ! P»= V/PT8R=H/t' 'fN= 1I < NFC ~ T ~ 01Il= f N<S ~T Oi,+RI l T 201 0> N.Q T ! �0,20i30! >N
PRINT 207 1{C TOPR ltd I 2t!l 2GC 1Pill t«1 2078PR it,1 2100 « V I P>l ERR «RTC ALL I I <t-CR N y Nd I y NHI !Ft!RMAT rl'10 ~ 0 2 IS!FD 'M ' T //3X i!HC 'hK.RETINA OPERATING 8X, 18HUSER OPTION NU4ldER y 13 3FOic 4'A T 8 C p < { PRO'!UCT I UN RAT E Sl EC lf I EQg CONST ANT RATE QF R I SE
1 i»uaR LN T IP«: SURFACE I » « //!i ii'<'»h l " .K y . ' >AT E OF R I 5 K 5PEC IF I ET! AT CENTER OF ST<'>C TUN 5 q1 '«Ct <51 ii <1 i» AT= LiF N I SL 'VCR ~«NT I RL s JRF ACE I ¹ ~ // !Ft!i ' ' I 3K»: +4Tt 5 CtF RISF SPECIF I klan AT CENTER ANt! AT + ~
20
I'! �2 ! i' ~!2 i�1
'! 72
.! ,! 7 3
174
20 ~ ! F ORM AT ///2K, 0 0 I MENS ION 5 QF S TRUC TVRE ¹ ~ 2OX ~1/ 4'4Xq ¹ ~ w y2/ LENGTH X! => /F5 ~ I f¹ FEET¹ y3/ HE 1GHT Y 1 =¹yF5 ~ 1 y ¹ FEET¹4/ w I!! THT Z } ~¹yFS ~ 1 ~ + FEET¹ ~5/ 4HX« '+e¹y6/ 45Xy WZ r4 I20'«t0 FORM AT //1X,¹ HL IGt T NODAL PGI NTS FOR TEMPERATURE ANALVS IS ELEM1F NT N JNtHERS 4N3 ELEMENT CREATION TI MES HOURS! ¹ I
21 00 FQAYAT / «F7 ~ 1 y 3H ¹ y 20F6 ~ Oq/!'101 FOHMA T » ¹ !
2200 FORMAT BX ~ 121� H+ i y /IOXg 20F6 ~ 1 l2300 F ORhitAT 1 3K i 20I6 I2400 FORMAT 13X ~ 23!FA ~ 1 !4000 FORMA T /+ C E NT 6 RL I NE ¹ ~ 25X ¹ HQR I ZQNT AL 0 I STANCE FROM CEN TERL INE
l OF STRUCTUHE> FEET¹1500t! F !RMAT { 8 I 5 !5 1 00 F QRMA T I 5 y SK y 2F 1 0 ~ 4 !60 00 f QRM AT a 15 g 20 X ~ I'5e 10X yF 10 ~ 4 IO4 00 t- ORMAZD //// 3 X ¹ CQNVFCT I Ghl ELEMENTS AND NQOAL PQ IN T OA TA ¹ /
I 8X, i< El t WENT 4 ~ I OX ¹ NODAL PQINTS + ~ 1 OX +STEP FUNCT I 0 4¹ /8 X q ~ NUMB ER '-> ~ 1 0 X ~ * I ¹1
6500 F QRMAT �I 5 I SX IS!c>o 00 FORMAT QX y I 5 y 11Xy ISED 16 y 15Xy I 519000 F CREAT �X «RAN!
S TOPI= ND
SVORO V I INL GEIVGavCCI Hl k Q.'0 /O E 5 /
Ci3NlikON /G HI DCQ/ XOI-'HEr $ ION G�! r GOA1 A G I ! 1=1 r5OaTa GI I I rDATA G2 l!r I=itDATA G3 I ! r I=1 rH2 = W/2 ~NH2 = H2CALL GR Ill HP rNW = NAP +IY�!=-20 'Y�! =- IO ~V�! =0 ~V NH! =HK1 = N � 1OQ 100 L = lr KlY L + 3 ! =ilI I 2- X 8- l !I F Y L+3! ~ EO ~ '! ~K =NH-LY K !=W- Y Lt 3!
100 CONT I rtU~CALL GR IO '3 r NBRETURNE,NO
wig rnlW!f! t W ~ O r HF O 1 I! !
�0 } r Y �0!1�! r G2�! rG3�!! /20 ~ r !Os r5 ~ f 2t r I ~ /5! /75 ~ r 31 ~ f IO ~ r 5t f 0 ~ /
/43 ~ r 18 ~ r6 ~ r2 ~ rO ~ /5! /I|! ~ r5 ~ t4 ~ t2 ~ tle/
Xr G3rG2!
l Y L+3!= ~ 5
Xr Gr Gl!
IQ t< r 4r Ztbr Gl lZ i0!r �!r Gl�!
.'~ Ji 3 - IJ 'JT IAU ikI 43l 3HZ�! = 0
OQ a'0 JC = II Z IF C ~ LTDQ 10 II's N + 1Z d! = i IF Z 4!
I J CQ 9 I I I<V'20 < OIU1 I h.ur
ra !If Z N- II~ F�- 1 g.~ IiI;, hd
lrSl~ G1 J ! ! tU TQ 20
10
4-I ! t G J!GT 's-GI Jl ! ! GQ TQ 20
! ~ EQ ~ 4 l Z N- 1 ! = Z hl ! -Gt 5 ! /2 ~
1 «X-BOUNDARY QF STRUCTUREt/29Xr >LINEA% VARI ATION BETWEEN CEHTER AN5 X BOUNOARY r
3 /29X r UNIFORM R ISE BET WEEN CENTERLINE AHO i BOUHOARY! 4 t //!21 00 F !RMAT �X ~ 4TQTAL CONCRETE VOLUME 4r23X r IH=r F8 ~ 2t + CUBIC YARDS +r /
I 6X +PROOUCT 10lV HATEr AVERAGE'0 ~ 2 IX t IH= rF S 2r+ CUBIC YARDS >ER+HI UR4 ~ / Irr X <RATE OF RISE AV ERA ' E AT CENTER QF STRUCTUREtFH ~ 2 r " FEET +E R HOUR '~ r / 6X ~ + Tlrr E TO CO!IIr LET ION% r27X t 'I H~ r F8t2r
HOURS» !RET UIR t
a EGO
� 0
80100150
200
240
250
P F3 0
�00!
I I !-T2 I ! !
yD2iPHOD
SUQhUUT INK-. T I HECR N ~ NDI. ~ Nkl !CGWWQN /DES / S,f >D HFO lB!
CORRI >N /GR IDCQ/ X�0! y Y 30!covwGf /TI.~L-vA/ v,aR,NFC, NFef TCDIMhNSIC!N T 1 100! ~ T2 100!I 1=HI 2=H+ 1 ~V !"-P>2 ~ +D/27 ~V 2=0 ~IF < Vf-C ~ c,u ~ 0! GQ TQ 50are li I 2400CALL T I iME NFC ~ Ti gHIIF reve Ez 0! GQ TG 100PRI NT 241 0CALI T ITIC NFB y T2 y H !GG TQ 150Tl�! =0 ~3U F10 1=7 y t 7V2=vl +V2Tl I }=2 ~ + V2/PRT2 1! =T 1 1!CALL T I TLCPRINT 200 0Pfei!'T 2050 > Tl 1 ! e T2 I !DQ 200 I = 1 I 1IF NeLT ~ 3! T2< I+!!=T1 1+1!PrCGD = 4 ~ «V1/ T 1 I+! ! + T2 1+1 ! - TD I= Tl I ! /24 ~Di =72 1 !/24 ~PHI r T 2�0' I GATI I+! I >DI vT2 I+1}CUhl1 INUEDO 240 I = 1 | N�1X<I!= X I!+X I+I} I/P.K=0Df'J <50 I = I iNH1IF Y I ! ~ LT ~ 0 ~ ! GO T ! 250K =K+ IY K! Y I !+Y I+! ! !/2 ac QN1 I r. UFV=hlf f I -K
DQ 250 J=-1!K1 I! =0 ~I 3=.NW 1-0I 4=1DO 320 I=ltI3VQ 3!O L=l>F11IF Y<1! ~ ~T. L ! GQ TQ 310F 3= � 1 L+ 1! � T2 f +1! !/l3r 4= T1 L! -12 L! !/o
~ 0 0 J =- 1 > r ~s 1K=Kt 1Fl= Tl L!-X 4! >F4F 2= T 1 L i 1 !- X J ! '+f. 3
3{-0
310320
2 3002 0~0
i l 00"400i' 'i 1 0
1C f;!=F 1+C N'f IREEI 4=LGO TO 320CCNT I r UFC4NT I RUEF 'Hr;AT /F i ! fe 9 A T t.
I -H Jf~S l.' <0 X i 1 .3 i.f
C/1'.~X i >0
F QwflAT 1F '1 fc I4", A T < /> GHANA //' 'LT L<iVt ND
Fc'. f' ll~< I ~ L Y I! !!
/2X + PR !DuCT ION PATE 4 / !HE I G�T ~ f EET T II4lt:. y WOJ RS CAYS ! T IHC s
DAY S ! aRODUC. T ION HATE PER FOOT QF 8 I SE 'f ~ /A t' Cf'O'TEHL I tvE i 13X i 13HAT X-t9OVNDARY v 15X ~Ui3 IC YhkD~ PER WGUR
> t9X gf 7 ~ 2i 21X y Ff ~ 2!2X t 4i2 < >i tF+ ~ 2 t2H < yF6 ~ 2 y2WI I y !SXyFB ~ 2!//. x > ~!iaLC IF tFD RATE 'jf RI SF AT CFNTERL I VP QF STAUCTURE4 !/3 x e " 'iaLC IF I ED RATe GF R I SE AT x-BQUNDAHY OF 5TRUC TURF+ !
176
~U8F'JLT I '4E I I ME Lr T H!IM~NS IO'4 T 100! r F T 50! r FH 50!
AEAI! 1 000 r FT I ! r F H I ! ! ~ I = 1 r L !PR IYT' 1900PRINT 2000r FH I ! rFT l! ! r l=1 r !I 1=HT�!=FT 1!N=2DO 100 I =I ~ 11
40 IF I +LE ~ FH N! ! GO TO 50N =N+1GO TO 40
50 T I +I ! =T I ! + FT N !-FT N-1 ! !/ Fk N !~FH N-I ! !1 JQ CONTI kUE
1000 FORMAT ��F10 ~ 0! !I'900 FORMAT /8 X r + HE IGHT r FK'ETr!'r 6X r <7 IME ~ HOURS 4 ~ /!2000 FORMAT trX rF tl ~ 2 rQXrF 8+2!
PETURk6 NO
GUBht!UT I NL r<EATGN IP !O 1 M t N 5 I LiN T Y I I "-I ! r T Y 2 1 3 ! r H T Y 2 1 3 !OAT A TY 1 I ! r I= I r 13 ! /0 ~ r ~ 195 r ~ 218 ~ ~ 238r ~ 248r ~ 145r ~ 060r e 023 r a 015r
1 ~ 008, 0 02 r ~ 3001 r 0001/DATA TY2 I ! I= 1 13! /0 ~ ~ 130 ~ IRS 170 ~ 180 1 05 ~ 044 018 r ~ 0121 ~ 007 f ~ 0 Ql f ~ 0001 r ~ 0001/'DATA HTY I ! I=1 t3! /0 ~ ~ 135 ~ 148 ~ IT3r ~ 181 ~ ~ 107 ~ ~ 046 ~ 025 ~ 0161 ~ 010 r ~ ! 03 ~ ~ 0001 r ~ 0001/
VcEAO IGiG r CFMrPOZr I ~ MI F C LM ~ Ei! ~ 0 ~ } GO TA 50CALt TITLEPRINT 2 't 0GO TO IOr20r30!r I
10 PRI NT 201 OrCCMPht NT 21i! 0 ~ POZCALI HFATVL TY1 CLH ~ POZ ~ Mr IP!GU TO
20 PR t ,T 20ii! r Ct.'4VS>I NT 2I,>0r VCZCALL hf A1 VL 92 TY2r CEMrPOZr M ~ IP!GL' TO
30 PRINT 2 03 0 ~ CF-42& lkT 2 �0r POZCALL P'PATVL HTY2 ~ CENri l!Zr Mf tP!
1'3 J 3 F .iver'A 'r -'F 10 ~ i! r 21 '5!2QGi! P i>:MAT /rr 3x, ''CLM~NT SPECIFICATIONS «,/!; ot v va~MAT ~x, + TY~E I 4,Fo.l, ~ poUNDS pEa cUetc YARD ~,I -' AV Lh AGE HP A T rF NERAT ION202 ~! I CRMAT A X r + TYPE I I 4 r F8 ~ I r 4 POUNDS VER CUBIC YARD
A V. k A~6 iILA I <iE NE RA Tl UN >!2G <0 F '@MAT h!i r TYPE 11 4 ~ F8 ~ 1 ~ + POUNDS PER CUBIC YARDI 4 HI GHEr THAN A VERAGE HEAT GENERAT ION r!IVG i 'h4 AT 8X P JZZULLAN ir F8 ~ 1 + POUNDS PER CUBIC YARD ' !
'i0 i-'I:I Uh'k~- N;>
177
90100
1'o.0200
I 000200021 OO2200
2300300031 00OOOO9999
SUAR04T INE HEATVI T ~ Away My IP!D 1'At NS IfIN T 13! pF 1 13! ~ AGE 13!DATA ACiE I ! p l=1 f 13! /0 ~ f 20 ~ 40 f 60 f 12 ~ 0 ~ �2 ~ �8 ~ f600 f 96 ~ f 180 ~
l" 290 ~ >1000 ~ /IF T 12! EQ ~ ~ 0001! T 12! =0lF T �3! ~ EO 0001 ! T l3! ~0 ~
PA INT 2000rF Z~.En.O! ra TQ VaHEAD 1 000 sF 1PR lNT ? 200GQ TO 100PRINT 2100DO ZOO l=1t 13HI~ = A t B/? . ! 4T I !
M +ED ~ 0! GQ TO 150I F F 1 ! ! +EQ ~ 0 ~ ! Fl I 1= 1 ~HRM =HR4F 1 I !PRINT 2300yAGF 1! yhfkyF1 I! yHRMGO TQ 190
0 PRINT ?300y*GE I ! fHRHRM~HV
CONl I'VEI F IP ~ F. J ~ 0 ! GQ TC 999 !L=1K=12A =OHHEAT GENR=8HFUNCT ~PUNCH 9000yAgHpAy ByAy8 Ag8PUNCH 3000tLtKPUNCH S100q ACiF l! y T l ! ! il 1 ~ 13!F DRMAT 1 3F'5 ~ 01FVRM A T I //3Xi ViREAT GENERATI Oh FUNCT l QN + !f f.lRI~AT 8 X y *T VE.y HOURS HEAT RAT Ey 9TU/FT 3/HOURF UR4'Al 15 X T I NE HUVRS HEAT RATE ~ BTU/FT 3/HOUR
AX O' FACTOR NIQDIF IEQ HEAT RATEO'QHMAT OX FS ~ 1 9X UFO 1 20X F6 2$6r>F8 1!FORMAT 3IS!FGRMAT OF 10 ~ 2!F dHkAT � X y OAO!RETURNI- h,D
j.78
180
~~o+ WlM PVAGQgpss~ fÃ>A7F zrfM i'd% case ararat~g$'M% Pe YB-CV.
181
APPENDIX I,: USER INSTRUCTIONS � PROGRAM TEMP
Program TEMP is described in general in Chapter 5. Below are specific instruc-
the cards required to run the program.tions concerning preparation of
I. Problem Initiation and Title - A5,3X,ISA4,15A4! Total Cards = 2
Column Variable
Punch START, Problem InitiationMODE
BLANK
Description for Identifying OutputHED
Continuation of Description can be blank card!
l- 60 HED2
Note:
II. Structure Dimensions, Grid Generation and Punch Control Card�F10.0,5I5! Total Cards = 1
Column Variable
Tots.l Base Length of Structure, feet X-dix'ection!
1- 10
11 - 20
21 - 30 Total Depth of Structure, feet Z-direction, normal to 2-D grid!
31 � 34
35 IN
36- 39
40
41 � 44
45
1 - 5
6 - 8
9-80
Second Card
Only information on first cax'd can be useddirectly with DETECT.
Height of Structure above foundation!, feet Y-direction!
Option a! 0: Automatic Grid Generation.Option b! 1". Grid coordinates specified by
programmer.
Only specified if Option b! IN = 1; otherwise,leave blank for Option a!. Total number of gridlines specified along base length of structurefx'om centerline to X-boundary max. = 18 for DETECTprogram!.
Only specified if Option b! IN = 1; otherwise,leave blank for Option a!. Total number ofgrid lines specified along height of structure,including any in foundation max. = 18 for DETECTprogram!.
182
Variable
Option c! 0:
Option d! 1:
51- 5455 Option e! 0: No data cards punched for input
into DETECT program.IP
Option f! 1: punch data cards.
III. Grid Generation Cards 8P10.0! If Option a!, total cards = 0 no cards!.If Option b!, two sets of cards, as manyas necessary to specify X and Y coordinatesof grid.
Column
.X coordinate of grid measured from centerline ofstructure. X l! must equal 0.
X�!1- 10
Consecutive X-coordinate from centerline to X-boundary.
X�!ll- 20
etc.
Consecutive X-coordinate from centerline to X-boundary.
X 8!71 - 80
Next Card if necessary!
1 � 10 X 9!
etc,
Last X-coordinate must equal total base length2 total number of X-coordinate lines equals
NB specified on Card II!.
X NB!
Column Vari ah 1 e
If foundation coordinate, specify distance belowstructures as negative value example: 20 feetbelow structures = -20!. If no foundation elements,Y l! must equal 0.0.
10 Y l!
183
Column
46 � 49 Incremental Construction - Allelements have specific creationtimes established in this program.
All elements exist at start ofprogram - used for analysis ofexisting structure.
Y �!17 - 20
etc.
IV. �F10.0,215!
Variable
Option l b!11 � 20 RT
Constant rate of production, constantrate of rise over entire surface.
Option 1: 021- 25 NFC
Option 2:
Option 1 or 2: 026 � 30 NFB
Note:
Option 1: Constant rate of rise over entire surface.
Option 2: Rate of rise specified at center of structure or X-boundary!,constant over entire surface.
Option 3: Rate of rise specified at center and at X-boundary of structure,linear variation between center and X-boundaryconstant rate between center and 2-boundary
184
Column
1- 10
Foundation or structure coordinate at foundationand structure intercept. The ordinate must equal0.0.
Y NH! hast Y-coordinate must equal height of structure above foundation!. Total number of Y-coordinateslines equals NH specified on Card II.
Option 1 a! - Production rate specified, averagecubic yards per hour. Can be leftblank if Option l b! selected.
Total time to completion, from startto finish for structure concretingoperation. Can be left blank ifOption 1 a! selected.
Specify total number of specific dataset points given to establish rate ofrise at centerline of' structure max.number = SO!.
Option 3: Specify total number of specific dataset points given to establish rate ofrise at X-boundary of structure.
Rates of Rise S ecified 4�F10.0!V.
'a d
Column Variable
Time at height No. 1 must = 0.
Height No. 1 must = 0.
Time at height No. 2.
Height No. 2.
FT l!
FH�!
FT�!
FH {2!
etc. etc.
FT NFC! Time of completion must = RT value on Card IV.
FH NFC! Total height of structure above foundation must= H on Card I.
*
Same as for Option {2! set of cards � Option �! cards follow Option �!cards.
Column Variable
FT NFB! Time of completion must = RT value on Card IV.
FH NFB! Must = total height of structure = H on Card Iabove foundation.
VI. Heat Generation Function �F10.0,215!
VariableColumn
Number of pounds of cement per cubic yard ofconcrete {if blank, no heat generation functionformulated!.
CEM1-10
Number of pounds of pozxolan per cubic yard ofconcrete.
11 - 20 POZ
Option A: 1: Type I cement heat generation average!.Option B.' 2: Type II cement heat generation average!.Option C: 3: Type II higher than average heat generation.
21 - 25
185
1-10
11 � 20
21 - 30
31- 40
If Option �!,If Option �!,to specify NFC time, height!If Option �!,to specify NFB time, height!
total cards = 0 no cards!.as many cards as requirednumber of data pointsat centerline of structure.as many cards as requirednumber of data pointsat X-boundary.
Variable Descri tionColumn
26- 29
30
VII. Modification Factors �3FS.O! � No cards if Option D.One card if Option E. Blank card if no
modification.!
F 1 �!
6 � 10 F 1 �!
etc.
Note: On first run through,'no modification need be made. Heat rate functionsare printed out so future adjustments can be made if necessary.
186
56- 60
6l � 65
Fl �2!
F 1 �3!
Option D: 0: No modifications to internal programheat generation functions.
Option E: 1: Modifications made to internal heatgeneration functions.
Decimal factor multiplication of heat rate functionNumber l.
Decimal factor multiplication of heat r+e functionNumber 2.
Function number appears as 0.0 on output, but isassumed to be .0001~CEM + POZ/2 before modifi.cationmade.
APPENDIX M: INTERFACE INSTRUCTIONS PROGRAMS TEMP AND DETECT
As is described in Chapter 5, program TEMP was written to provide input, based
upon common variables found in a tremie concrete placement, to the finite-
element program, DETECT, which does the actual temperature calculations. Beloware instructions which indicate how the output from program TEMP interfaces
on program DETECT may be found in
Polivka and Wilson's description of the program Reference 33!.
I. Problem Initiation and Title
II. Master Control Card
III. Nodal Point Coordinates
IV. Boundary Condition Functions
A. Control Information
B. Time Function Data
I
I IAs many as
' specified
IIV A! ' 1
I
1
One for eachmaterial-
I
I1. concrete
2. foundationI
V. ' Nodal Point Boundary Conditions
VI. Element Specification
~e 1 - A. Control InformationB. Material Properties
Information
187
with program DETECT. Additional information
I
I Numbe ofCards
1
I1
I
I> As many as~ number of, nodes.II
I! 3I
Source
Program ~ Must Indiv.I
"TEMP" y Punch
*Partial
Info.I
v
1
I
«Partial CheckInfo.
Heat Gen. >Values
Function ~1!
lAny Additional
IBoundary ValueFunctions
I
I
Check
Cards
suppliedwith 1 6
2 punched,
I
Number ofCards
Source
Program I Must Indiv.~ ITEMPII I Punch
C. Element Data
II As speci-
fied on
I VI I A!to follow
I
I a card.
Same as I through VII.
188
Type 2 - A. Control InformationB. Element Data
Type 3 � Cooling Pipe Elements
VII. Solution Time Span Data
A. Lift Data Control Cards
B, Initial Conditions
VIII. New Problem Data
IX. Termination Card "STOP"
I As many asi number of
~ elements.I
! As many as~ required. 1 INone Required
I I!Nu ber of, cards speci-e fied on II!.'
I I I I I I I I I I I I
APPENDIX N: SAMPLE OUTPUT � PROGRAMS TEMP AND DETECT
1. Figures N-I through N-5 present samples of output from Programs TEMP and
DETECT which are described in Chapter 5,
2. The output from Program TEMP shows the automatic grid generation and the
constant rate of concrete production options. The geometry of the placement
is that shown in Figure i86 of Chapter 5.
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FEDERALLY COORDINATED PROGRAM FCP! OF HIGH%'AYRESEARCH AND DEVELOPMENT
The Offices of Research and Development R&D! ofthe Federal Highway Administration FHWA! areresponsible for a broad program of staff and contractresearch and development and a Federal-aidprogram, conducted by or tht.ough the State highwaytransportation agencies, that includes the HighwayPlanning and Research HP&R! program and theNational Cooperative Highway Research Program NCHRP! managed by the Transportation ResearchBoard. The FCP is a carefully selected group of proj-ects that uses research and development resources toobtain timely solutions to urgent national highwayengineering problems.'
The diagonal double stripe on the cover of this reportrepresents a highway and is color-coded to identifythe FCP category that the report falls under. A redstripe is used for category 1, dark blue for category 2,light blue for category 3, brown for category 4, grayfor category 5, green for categories 6 and. 7, and anorange stripe identifies category 0.
FCP Category DescriptiorgaI. Improved Highway Design and Operation
for SafetySafety R&D addresses problems associated withthe responsibilities of the FHWA under theHighway Safety Act and includes investigation ofappropriate design standards, roadside hardware,signing, and physical and scientific data l'or theformulation o improved safety regulations.
2. Reduction of Traffic Congestion, andImproved Operational EfficiencyTraffic R&D is concerned with increasing theoperational efficiency of existing highways byadvancing technology, by improving designs forexisting as wel! as new facilities, and by balancingthe demandwapacity relationship through trafficmanagement techniques such as bus and carpoolpreferential treatment, motorist information, andrerouting of tral'fic.
$. Environmental Considerations in HighwayDesign, Location, Construction, and Opera-tion
Environmental R&D is directed toward identify-ing and evaluating highway elements that affect
v The complete seven volume o finial statement o the FCP is available fromthe National Technical In ormation Service, Springfield, Va. 22161. Singlecopies of the introductory volume ate availab1e ndthout charge from ProgramAnalysis Q RD-3h Offices>f Research and Development, Federal HighwayAdministration, washington, D.C. 20590.
the quality of the human environ nent. The goalsare reduction o adverse highway and trafficimpacts, and protection and enhancement of theenvironment.
Improved MaterialsDurabilityMateria!s R&D is concerned with expanding theknowledge and technology of materials properties,using availab!e natural materials, improving struc-tural foundation materials, recycling highwaymaterials, converting industrial wastes into usefulhighway products, developing extender orsubstitute materials for those in short supply, anddeve!oping more rapid and reliable testingprocedures. The goals are lower highway con-struction costs and extended inaintenance-free
operation
Ignproved Design to Reduce Costs, ExtendLife Expectancy, and Insure StructuralSafety
Structural R&D is concerned with furthering thelatest technological advances in structural andhydraulic designs, fabrication processes, andconstruction techniques to provide safe, efficienthighways at reasonable costs.
6. Improved Technology for HighwayConstruction
This category is concerned with the research,development, and implementation of highwayconstruction technology to increase productivity,reduce energy consumption, conserve dwindlingresources, and reduce costs whi!e improving thequality and methods of construction.
7. Improved Technology for HighwayMaintenance
This category addresses prob!ems in preservingthe Nation's highways and includes activities inphysics! maintenance, traffic services, manage-ment, and equipment. The goal is to maximizeoperational efficiency and safety to the travelingpublic while conserving resources.
0. Other New Studies
This category, not included in the seven. volumeofficia! statelnent of the FCP, is concerned withHP&R and NCHRP studies not specifically relatedto FCP projects. These studies involve R&Dsupport of other FHWA program office research.
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