Basics of aggregates - Texas A&M University...BASICS OF AGGREGATES Aggregate Quality Monitoring Program Tex-499-A Michael Dawidczik, P.G. Construction Division/Materials & Pavements

2017 Transportation Short Course October 11, 2017

BASICS OF AGGREGATES

Aggregate Quality Monitoring Program

Tex-499-A

Michael Dawidczik, P.G.

Construction Division/Materials & Pavements Section

Geotechnical, Soils, & Aggregates Branch

October 11, 2017


Table of contents

2

7-15

16-19

20-32

33-40

41

3-6Aggregate Quality Monitoring Program (AQMP)

Purpose & Responsibilities of AQMP

Products & Laboratory Tests of AQMP

Laboratory Tests of AQMP in Detail

Process of Adding & Removing Sources from AQMP

Questions

1

2

3

4

5

6



Aggregate Quality Monitoring Program (AQMP) managed by the Geotechnical,

Soils and Aggregates Branch within TxDOT’s Construction Division/Materials

& Pavements Section (CST/M&P)

Monitors the quality of aggregate products supplied to TxDOT projects

Single sources are included based on the testing history of aggregate

products used for TxDOT construction projects

– Bituminous coarse aggregate

– Concrete fine aggregate

– Concrete coarse aggregate

– Micro-surfacing aggregate

3



Durability laboratory tests performed biannually for each source:

• L.A. Abrasion

• Magnesium Sulfate Soundness

• Micro-Deval

• Acid Insoluble

• Coefficient of Thermal Expansion (CoTE)

Statistical evaluation of recent testing history

– Rated values produced and published online & reported in Site Manager

– Bituminous Rated Source Quality Catalog (BRSQC)

– Concrete Rated Source Quality Catalog (CRSQC)

4


What is the AQMP?

Sources currently in the program are located in:

– Texas

– New Mexico

– Oklahoma

– Arkansas

– Louisiana

– Mexico.

97 sources on the BRSQC

168 sources on the CRSQC

61 sources on both catalogs

5


Aggregate Sources on the BRSQC and CRSQC

6


The Purpose of the AQMP

Provides requirements & procedures for CST/M&P to monitor aggregate

products demonstrating continuous quality and uniformity

Allows TxDOT Districts to use the rated values from sources on the AQMP

without project specific testing

– Districts do not have to perform laboratory tests on AQMP

– Expedites acceptance of aggregate meeting specification requirements

Provides continuous quality assurance of aggregate products

7


Polling Question #1

Which District has the most sources

listed on the AQMP?

8

2017 Transportation Short Course October 11, 2017 9


Responsibilities

10

CST/M&P

TxDOT Districts

Aggregate Producers


Responsibilities

11

Did you know?

Over the last 10 years, CST/M&P - Aggregates Lab on average has completed the

testing of 1650 samples annually.

Requesting Quality Monitoring (QM) samples biannually

Laboratory testing of QM, project & informational samples for

properties listed on AQMP

Performing & reporting test results

Maintaining the BRSQC and CRSQC

Notifying Districts & aggregate producer of any quality concerns

Evaluation of source’s quality control plan and test results

CST/M&P


Responsibilities

12

Did you know?

The San Antonio District has the most sources on the AQMP and the Tyler District

has the least.

Sampling QM & project samples and providing documentation

Shipping or delivering samples to CST/M&P

Offering split samples at the time of sampling with aggregate producer

Job control (project level) testing

Final acceptance of aggregate

Submitting a QM sample from project when material has questionable

quality

Safety - Signing in/out at the quarry & following site specific safety

procedures

TxDOT Districts


Responsibilities

13

Did you know?

Since 2000, the Aggregates Lab has tested aggregate from over 450 sources.

Notifying CST/M&P of changes in ownership and maintaining current

contact information

Submitting a mining & quality control plan, GPS data and requested

documents

Submitting driving directions to the source from District Lab

Maintaining identification of stockpiles at the quarry at all times

Notifying CST/M&P and the District if split samples are desired

Aggregate Producers


Polling Question #2

How often are the aggregate MPLs

updated within a year?

14



Products and Tests Covered in AQMP

16

Aggregate Products

Laboratory Tests

L.A.

Abrasion

(Tex-410-A)

MgSO4

Soundness

(Tex-411-A)

Micro-Deval

(Tex-461-A)

Acid Insoluble

Residue

(Tex-612-J)

CoTE

(Tex-428-A)

Concrete Fine Aggregate

Concrete Coarse Aggregate

Bituminous Coarse Aggregate

Micro-Surfacing Aggregate


Products and Tests Covered in AQMP

17

SAC A SAC B SAC C

Magnesium Sulfate Soundness

(Tex-411-A)

Maximum value

25 30 35

Acid Insoluble Residue

(Tex-612-J)

Minimum value

55 -- --

Crushed Face Count

(Tex-460-A)

Minimum value

85 85 85

Surface Aggregate Classification (SAC)

As determined in Tex-499-A, Table 1


Polling Question #3

How many project samples are

necessary to complete before the rated

values can be calculated?

18



AQMP Tests

Performed in accordance to Tex-410-A (ASTM C131)

Resistance to degradation by impact and abrasion forces

Test samples of different gradations A, B, C, and D

500 revolutions at 33 rpms

Steel spheres with a diameter of ~2 inches and weight of ~1 lb

Loss determined by material passing the #12 sieve

Specification limits vary

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L.A. Abrasion


L.A. Abrasion (Tex-410-A)

21


Specification Limits

L.A. Abrasion

22

0 5 10 15 20 25 30 35 40 45

Item 342,

346, 347,

348

Item 302,

344

Item 330,

340, 341,

42140%

35%

30%

%

Limestone Rock Asphalt (LRA), Dense-Graded HMA, Concrete

Seal Coat & Superpave HMA

Permeable Friction Course (PFC), Stone Matrix

Asphalt (SMA), Thin Overlay Mixtures (TOM), &

Thin Bonded Friction Courses


AQMP Tests

Performed in accordance to Tex-411-A

Resistance to degradation/disintegration by wetting and drying cycles

Wetting duration of 16-18 hours submerged in magnesium sulfate solution

Drying duration of 4-6 hours in 230°F oven

Rinse cycle in 110°F water until samples completely free of salt

Magnesium Sulfate soundness solution temperature and specific gravity

controls

Loss determined by normalized gradation specific to product type

Specification limits vary

23



Magnesium Sulfate Soundness (Tex-411-A)

24


Magnesium Sulfate Soundness (Tex-411-A)

25




26

0 5 10 15 20 25 30 35

Item 342,

346, 347,

348

Item 302,

344, 350

Item 330,

340, 341,

42130%

25%

20%

%

Limestone Rock Asphalt (LRA), Dense-Graded HMA, Concrete

Seal Coat & Superpave HMA, Microsurfacing

PFC, SMA, TOM, & Thin Bonded Friction Courses


AQMP Tests


Resistance to degradation by abrasion forces

Aggregate added to 3/8” diameter steel spheres and water for test

Tested at 100 rpms for 120, 105, 95 or 15 minutes depending on gradation

Rinsed over stacked sieves and oven dried to determine the loss

No specification limit, used as quality control test

27

Micro-Deval


Micro-Deval (Tex-461-A)

28


AQMP Tests

Performed in accordance to Tex-612-J

Resistance to dissolution by Hydrochloric (HCl) acid

Test sample consists of 25 grams

HCl acid added to sample until reaction is complete

Sample rinsed with distilled or deionized water

Specification limits for concrete fine aggregate and bituminous coarse

aggregate to determine SAC

29





30

0 10 20 30 40 50 60 70

SAC B & C

SAC A

Item 421

Fine

Aggregate

No Requirement

60%

55%

%

Hydraulic Cement Concrete

Hot-Mix Asphalt & Seal Coats


AQMP Tests


Determine the thermal expansion of aggregate in concrete

Standard mix design

Test cylinders are cured for 28 days before testing

Temperature cycling from 50°F to 120°F and reduced to 50°F

3 cycles and continuous data collection

Specification limit of 5.5 µstrains/°F for Item 360

No project level testing for a source which has a rated value on the CRSQC

31

Coefficient of Thermal Expansion (CoTE)


Coefficient of Thermal Expansion (Tex-428-A)

32


Polling Question #4

Does a source have to be on the AQMP

in order to supply aggregate to a TxDOT

project?

33



AQMP Process of Adding Sources

35

Testing &

Approval of

Project

Samples

Mining Plan

Submitted

Ratings

Developed for

Aggregate

Product

Site

Manager

Updated

Aggregate

Producer

and District

Informed

Informational

Sample

Provide

Producer –

Quarry

Information

Supply

Aggregate

Product to

TxDOT Project

Catalogs Updated



36

Informational

Sample

Provide

Producer –

Quarry

Information

One informational sample can be sampled and tested from final product

stockpiles for each aggregate product per aggregate source

Raw uncrushed/unprocessed rock will not be tested

The results from the informational sample can be used to solicit material to

contractors for potential use for TxDOT projects

The informational sample does not count towards the AQMP and does not

pre-approve a stockpile or source

Owner of aggregate source completes Producer-Quarry Information form

Ship samples to CST/M&P at Cedar Park Campus in Austin



37

Supply

Aggregate

Product to

TxDOT ProjectTesting &

Approval of

Project

Samples

Once the aggregate product from a source is being supplied to a TxDOT

project(s), the aggregate producer will coordinate with the TxDOT District

to begin sampling the stockpiles designated for the project

Stockpile approval is on a stockpile by stockpile basis

CST/M&P performs durability testing as testing lab for TxDOT Districts



38

Mining Plan

Submitted

The aggregate producer is responsible for furnishing the mining

plan and quality control testing of their aggregate

Mining plan - a topographical or aerial map showing the

property lines and shaded areas of current and future

production

Flow chart - description of the production of the aggregate

from the ground to the final product in stockpiles

Aggregate supplier’s quality control testing plan and testing

frequency

Driving directions to pit or quarry


Ratings

Developed for

Aggregate

Product

Site

Manager

Updated


39

Five project samples per aggregate product conforming to the items

found in Section 4 of Tex-499-A are used to develop the rated value

One month between each project sample

Test results meet all the standard specification quality

requirements

Statistical ratings of the test results meet the standard

specification requirements

The results of the aggregate product are reviewed prior to being

approved for addition to the AQMP

Site Manager updated for District use



40

Aggregate

Producer

and District

Informed

Catalogs Updated

The aggregate producer and the TxDOT District will be

notified via e-mail of the source’s addition to the AQMP

The e-mail will contain the rated values, the AQMP

producer code and the Site Manager producer code

The online catalog will be updated accordingly with the

next scheduled update

For out of state/country sources, TxDOT must have

access to aggregate stockpile(s) within Texas to

sample for the AQMP to check for routine compliance

and material consistency


Basics of Aggregates

41

Questions?

Documents

Basics of aggregates - Texas A&M University...BASICS OF AGGREGATES Aggregate Quality Monitoring Program Tex-499-A Michael Dawidczik, P.G. Construction Division/Materials & Pavements