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Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.
इंटरनेट मानक
“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”
“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru
“Step Out From the Old to the New”
“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan
“The Right to Information, The Right to Live”
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
“Invent a New India Using Knowledge”
है”ह”ह
IS 2185-4 (2008): Concrete masonry units, Part 4: Preformedfoam cellular concrete blocks [CED 53: Cement MatrixProducts]
IS 2185 (Part 4) : 2008
Indian Standard
CONCRETE MASONRY UNITS - SPECIFICATIONPART 4 PREFORMED FOAM CELLULAR CONCRETE BLOCKS
res 91.080.30; 91.loo.30
© BIS 2008
BUREAU OF INDIAN STANDARDSMANAK BHAVAN. 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002
May 2008 Price Group 7
Cement Matrix Products Sectional Committee, CED 53
FOREWORD
This Indian Standard (Part 4) was adopted by the Bureau of Indian Standards, after the draft finalized by theCement Matrix Products Sectional Committee had been approved by the Civil Engineering Division Council.
Concrete masonry already extensively used in building construction abroad, is now making considerable headwayin this country, because of many advantages, such as durability, strength, structural stability, fire resistance,insulation and sound absorption it possesses. Concrete masonry construction is also economical because of thefollowing aspects:
a) The units are relatively large and true in size and shape. This ensures rapid construction so that morewall is laid per man-hour than in other types of wall constructions;
b) Fewer joints result in considerable saving in mortar as compared to normal masonry construction, andalso in increasing the strength of the wall; and
c) The true plain surfaces obtained obviate necessity of plaster for unimportant buildings situated in lowrainfall areas. Even when plaster is used for any reason the quantity required for satisfactory coverage issignificantly small.
Concrete masonry has attractive appearance and is readily adaptable to any type of architecture. It lends itself toa wide variety of surface finishes for both exterior and interior walls. It may also be finished with cement plaster,gauged with lime or a plasticizer. Concrete masonry units provide a strong mechanical key uniting the concretemasonry backing and the plaster finish in a strong permanent bond.
Cellular concrete is a class of material, which has been developed commercially abroad and is coming in voguein this country also. This standard is intended for foamed concrete masonry blocks manufactured at site/factories,using preformed stable foam. Foamed concrete in the form ofblocks or poured in-situ is used for thermal insulationover flat roofs or for cold storage walls or as non-load bearing walls in RCC/steel framed buildings or for loadbearing walls for low-rise buildings; as backing for other types of facing materials, for piers, pilasters and columns;for retaining walls, garden walls, chimneys and fire places etc. The provision pertaining to use of low densitypreformed foamed cellular lightweight concrete blocks for thermal insulation produced using preformed stablefoam are covered under IS 6598 : 1972 'Cellular concrete for thermal in solution' . This standard covers applicationof medium and high density blocks for partitions and load bearing walls .
This standard is a part of a series of standards formulat~don concrete masonry units. The other parts in this seriesare:
Part I
Part 2
Part 3
Hollow and solid concrete blocks,
Hollow and solid lightweight concrete blocks, and
Autoclaved cellular (aerated) concrete blocks. .
The composition of the Committee responsible for the formulation of the standard is given in Annex H.
For the purpose of deciding whether a particular requirement of this standard, is complied with, the final value,observed or calculated, expressing the result of a test or analysis shall be rounded off in accordance withIS 2 : 1960 'Rules for rounding off numerical values (revisedi' . The number of significant places retained in therounded off value should be the same as that of the specified value in this standard.
IS 2185 (Part 4) : 2008
Indian Standard
CONCRETE MASONRY UNITS - SPECIFICATIONPART 4 PREFORMED FOAM CELLULAR CONCRETE BLOCKS
1 SCOPE
This standard (Part 4) co vers the req uirements ofce llul ar con crete blocks produced under ambientcond ition s using preformed stab le foam and havingden sity from 800 kg/m '' to I 800 kg/rn': and primarilyused for the con struction of load be aring and non-loadbearing walls .
2 REFERENCES
The standards listed in Annex A contain provisionswhich through reference in th is te xt , constituteprovi sion s of this standard. At the time of publication,the editions indicated were val id. All standards aresubject to rev ision and parties to agreements based onthi s standard are en couraged to in ve stigate thepossibility of applying the most recent editions of thestanda rds indicated at Ann ex A.
and then subseq uently dried to constant length, allunder spec ified conditions: expressed as a percentageof the dry length of the specimen.
3.5 Gross Area - The total area occupied by the blockon its bedding face, including areas of cavities and endrece sses.
3.6 Height - The vertical dimension of the exposedface of a block, excluding any tongue or other devicedesigned to provide mechanical keying.
3.7 Length - The horizontal dimension of the exposedface of a block, excluding any tongue or other devicede signed to provide mechanical keying .
3.8 Width - The external dimension of a block at thebedding plane , mea sured at right angles to the lengthand height of the block.
4 DIMENSIONS AND TOLERANCES
In add ition, block shall be manufactured in halflengthsof 200, 250 or 300 mm to correspond to the full lengths.
4.2.2 Blocks of sizes other than those spec ified in 4.2.1may also be used, if so agreed between purchaser andmanufacturer. In the case of special concrete masonryunits such as jallie or screen wall block and ornamental
The nominal dimensions of the unit s are so designedthat taking account of the thickness of the mort ar jointsthey should produce wall lengths and heights whichshould conform to the principle of modular coordination.
400, 500 or 600 mm
250 or 300 mm
IDO, 150, zoo or 250 mm
Length
Height
Width
4.1 Concrete masonry units shall be made in sizes andshapes to fit different construction needs. They includestretcher, comer, double comer or pier, jamb, header,bull nose and partition block and floor units .
4.2 Concrete block shall be referred to by its nominald imensions. The term ' nom ina l' means that thedimension includes the thickness of the mortar joint.Actual dimensions (length and height) shall be 10 mmshort of the nominal dimension (or 6 mm short inspecial ca ses where finer jointing is specified).
4.2.1 The nominal dimensions of the concrete blocksshall be as follows :
3 TERMINOLOGY
For th e purpose of thi s s ta nd ard , the fo ll owingdefinitions shall apply.
3.1 Cellular Concrete - The ce ll ular concretereferred here is concrete which contains stable air orgas cell s uniformly distributed in the mix. It is a productconsisting of Portland cement, s ilica, po zzolana orpastes containing blends of these ingredients andhaving homogeneous void or cell structure, attainedwith preformed stable foam. The air cells are usuallyadded at the mixer as stable preformed foam meteredfrom a calibrated nozzle and thoroughly blended intothe mix. In preformed foam cellular concrete thedensity control is achieved by sub stituting macroscopicair cell s for all or part of the fine aggregate. Normalweight coarse aggregate is usually not used .
3.2 Block - A concrete masonry unit, anyone ofexternal dimensions of which is greater than thecorresponding dimension of a brick as specified inIS 3952 and of such size and mass as to permit it to behandled by one man. Further more to avoid confusionwith slabs and panels, the height of the block shall notexceed either its length or six time s its width.
3.3 Block Density - The density calcul ated by dividingthe mass of an oven dry block by the overall volume,including the holes or cavities and end recesses.
3.4 Drying Shrinkage - The difference between thelength of specimen which has been immersed in water
IS 2185 (Part 4) : 2008
block, the specified sizes may not necessarily apply.
4.2.3 The maximum variation in the length of the unitshall not be more than ±5 mm and the maximumvariation in the height and width of the unit shall notbe more than ±3 mm (see Fig. 1 for mode ofmeasurement).
4.3 Blocks with Special Faces
Blocks with special faces shall be manufactured andsupplied if so specified.
4.4 The faces of masonry units shall be flat andrectangular, opposite faces shall be parallel and allarises shall be square, subject to tolerance specifiedin 4.2.3 and the provisions of 4.3.The bedding surfacesshall be at right angles to the faces of the blocks .
5 CLASSIFICATION
Preformed foam cel1ular concrete blocks shall beclassified into two categories:
a) Non-load bearing units - These are blocksin density ranges 800 kg/m' and I 000 kg/m'and having grade designations of G-2.5 andG-3.5 as per Table 1.
b) Load bearing units- These are the blocks indensity range I 200 kg/m? to I 800 kg/m',having grade designations G-6 .5, G-12 .0,G-17.5 and G-25.
6 MATERIALS
6.1 Cement
Cement complying with any of the fol1owing IndianStandards may be used at the discretion of themanufacturer:
a) 43 Grade ordinary Portland cementconforming to IS 8112,
b) 53 Grade ordinary Portland cementconforming to IS 12269,
c) Rapid harden ing Portland cement conformingto IS 8041,
d) Sulphate resisting Portland cementconforming to IS 12330,
e) Portland pozzolana cement conforming toIS 1489 (Part I), and
f) Portland slag cement conforming to IS 455 .
6.2 Sand
Sand conforming to IS 383 and to suit the final productdensity shall be used.
6.3 Fly Ash
Fly ash conforming to IS 3812 (Part I) may be used, ifcements enumerated in 6.1(a) to (d) are used andprovided uniform blending with cement is ensured.
6.4 Water
The water used in the manufacture of the concretemasonry units shal1 be free from matter harmful toconcrete or reinforcement, or matter likely to causeefflorescence in the units and shall meet therequirements of IS 456.
6.5 Foaming Agent
The foam concentrate shal1 be of such chemicalcomposition that is capable of producing stable foamcel1s in concrete, which can resist the physical andchemical forces imposed during mixing, transporting,pumping, placing and setting of concrete. The foamingagent should meet the requirements of 9 of IS 9103and the foam produced shall be stable for durationbeyond the final setting time of Portland cements. Suchfoaming agents shall be completely harmless toconcrete and embedded steel reinforcement and be nontoxic, non-flammable and biodegradable.
NOTE - Foaming agents may be produced with hydrolizedprotein base with the addit ion of foam stabilizers. metal salts,highly surface -active fluorotensides and compensating agents.
Table 1 Physical Properties of Preformed Foam Cellular Concrete Blocks(Clauses 5, 9.3, 9.4, 9.5 and 9.8)
51 Block Density in Grade Compressive Strength Thermal Conductivity Water AbsorptionNo. Oven Dry N/mm' in Air Dry Condition (Oven Dry Density)
Condition .-A kcaVrnIhJOC Percentage(kg/m') r ""Average Individual
Min Min
(I) (2) (3) (4) (5) (6) (7)
i) 800 G-2.5 2.5 2.0 0.32 12.5ii) 1000 G-3.5 3.5 2.8 0.36 12.5iii) 1200 G-6.5 6.5 5.2 0.38 10.0iv) 1400 G-12 12.0 9.0 0.45 10.0v) 1600 G-17.5 17.5 14.5 0.50 7.5vi) 1800 G-25 25.0 22.0 0.54 7.5
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IS 2185 (Part 4) : 2008
a) Four positions for checking length of whole blocks andfor measuring length of cut specimens
b) Six positions for checking heigth of whole blocks
c) Six measurements of width
FIG . I CHECKING AND M EASURING DIM ENSIONS OF BLOCK
6.6 Admixtures
Additives or admixtures as enl isted below, may beadded either as additives to the cement or as admixturesto the concrete mix :
a) accelerating, water-reducing admix turesconforming to IS 9103,
b) waterproofing agents conforming to IS 2645,and
c) colouring pigments.
NOTE - Where no Indian Standards apply, the additives or
3
admixture s shall be shown by test or experience . not to bedetr imental to the durabilit y of concrete. The compatibility ofadmixtures with each other and with other ingredients in themix should be det ermined by test s as agreed between themanufacturer and the purchaser.
7 MANUFACTURE
7.1 Mix
The concrete mix design indicating the proportions ofvarious ingredients should be worked out carefullykeeping in view the desired physical properties of thefinished blocks.
IS 2185 (Part 4) : 2008
7.2 Batching
The quantities of various ingredients should .beproportioned on the basis of weight, with due correctionbeing made to the quantity of solid ingredients onaccount of their inherent moisture content.
7.3 Mixing
The ingredients shall be mixed in a mechanical mixerhaving rotating drum. These may also be mixed in amobile truck mixer. The dry ingredients like sand, flyash and cement shall be fed into the mixer first andthoroughly mixed to ensure even di stribution ofcement. The appropriate amount of water shall beadded thereafter continuing the mixing. The preformedfoam, which is made by blending the foam concentrate,waterand compressed air in predetermined proportionsin a foam generator, calibrated for a specific dischargerate, shall be added in measured amount to the slurryof cement, sand, fly ash and water in the batch mixer.After an additional mixing to get uniform consistency,the slurry form of foamed cellular concrete of desiredwet unit weight shall be ready to be poured out intoforms/moulds, etc.
When truck mixing equipment is used for foamedcellular concrete, the preformed foam should be addedat the job site just prior to pumping or otherwiseconveying the concrete into forms, unless it isdemonstrated that a mix of the desired density and otherproperties can be delivered to the job site after addingthe foam at the batching plant.
7.4 Moulds
Gang moulds of required sizes of blocks may beconstructed either of wood, steel , rigid plastics,aluminium, concrete or other acceptable materials. Themould surfaces should be pre-coated with an approved'mould releasing agent' to ensure proper surface finish.
7.5 Conveying and Placing
All equipments for conveying and placing, whethermanual like wheel barrows or big buckets, ormechanical like mortar pumps, should be of such sizeand design and used in such a manner as to ensureun iform unsegregated concrete at the point ofplacement. Cellular concrete is a fluid mass and dueto the absence of coarse aggregate and the ball bearingeffect of minute foam bubbles, the fluid mass of cellularconcrete fills up and levels into moulds by itself withoutthe need of external vibration or compaction.
7.6 De-moulding of Cast Elements
Depending on the ambient temperature and quality ofcement used, the building blocks may be de-mouldedafter 24 h from pouring of foam concrete unless
4
accelerated curing proce sses are used, and shifted tothe curing/stacking yard.
7.7 Curing
Curing shall be done as per IS 456 .
7.8 Drying
After curing, the blocks shall be allowed to dry undershade for a period of 2 to 3 week s, so as to completetheir initial shrinkage before being used in the work.
8 SURFACE FINISH
8.1 Concrete masonry units may be given a variety ofsurface finishes on the expo sed face by casting againsttextured surface plate. Colour may be introduced byincorporating non-fading mineral pigments in thefacing concrete or by applying a coloured Portlandcement grout or paint to the face of the units soon afterthey are removed from the moulds.
8.2 Concrete masonry units used in constructingexposed walls shall be free from visible stain s anddiscolouration, blemishes or defe cts which distract thedesired appearance of the finished wall.
9 PHYSICAL REQUIREMENTS
9.1 General
All units shall be sound and free of cracks or otherdefects which interfere with the proper placing of theunit or impair the strength or performance of theconstruction. Minor chipping resulting from customarymethods of handling during delivery, shall not bedeemed to be ground for rejection.
9.1.1 Where units are to be used in exposed wallconstruction, the face or the faces that are to be exposedshall be free of chips, cracks or other imperfections,except that in a consignment not more than 5 percentof the units with small chippings not larger than 25 mmmay be accepted as per agreement betweenmanufacturer and purchaser.
9.2 Dimensions
The overall dimensions of the unit , when measured asgiven in Annex B shall be in accordance with 4.2.1,subject to tolerances mentioned in 4.2.3.
9.3 Block Density
The average block density, when determined as givenin Annex C shall not vary by more than ± 5 percent ofthe density specified in Table I.
9.4 Compressive Strength
The average and the minimum individual compressivestrength when determined in the manner described inAnnex D shall be not less than that prescribed in Table I.
9.5 Water Absorption
The average water absorption, when determined in themanner prescribed in Annex E shall not exceed thevalues prescribed in Table I .
9.6 Drying Shrinkage
The drying shrinkage of the units when unrestrained,being the average of three units, shall be determinedin the manner described in Annex F. Drying shrinkageshall be a maximum of 0.05 percent for the load bearingclass of blocks and a maximum of 0.08 percent for thenon-load bearing class of blocks.
9.7 Moisture Movement
The moisture movement of the dried blocks onimmersion in water, being the average of three units,when measured in the manner prescribed in Annex Gshall be less than the drying shrinkage specified in 9.6by at least 0.01 percent.
9.8 Thermal Conductivity
Thermal conductivity shall not be more than the valuesspecified in Table 1, when tested in accordance withIS 3346.
10 TESTS
Tests as described in Annex B to Annex G shall beconducted on samples of units selected according to thesampling procedure given in 11, to ensure conformitywith the physical requirements specified in 9.
11 SAMPLING
11.1 The blocks required for carrying out the tests laiddown in this standard shall be taken by one of themethods given in 11.2 and 11.3. In either case a sampleof 23 blocks shall be taken at random from every lotof 10000 blocks or part thereof of the same size, gradeand same batch of manufacture, if manufacturing isdone in plant. In case of site/yard manufacture, thenumber of samples may be doubled. In order to ensurerandomness of selection, all the blocks in a lot may bearranged in a serial order. Starting from any randomblock every rth block may be selected till the requisitenumber is obtained, r being the integral part of N/23,where N is the lot size.
11.2 Sampling Blocks in Motion
Whenever practicable, samples of blocks shall be takenwhen the blocks are being moved as in the case ofloading, unloading, etc .
11.3 Sampling Blocks from Stack
The number of blocks required for the test shall be
5
IS 2185 (Part 4) : 2008
taken at random from across the top of the stack, thesides accessible and from the interior of the stacks byopening trenches from the top.
11.4 The sample of blocks shall be suitably markedfor future identification of the batch it represents. Theblocks shall be kept under cover and protected fromextreme conditions of temperature, relative humidityand wind until these are required for test. The testsshall be undertaken as soon as practicable after thesample has been taken .
11.5 Number of Tests
11.5.1 All the 23 blocks shall be checked fordimensions and inspected for visual defects (see 9.1and 9.2).
11.5.2 Out of 23 blocks, 3 blocks shall be subjected tothe test for block density (see 9.3) , 8 blocks to the testfor compressive strength (see 9.4), 3 blocks to the testfor water absorption (see 9.5), 3 blocks to test forthermal conductivity (see 9.8) and 3 blocks to the testfor drying shrinkage (see 9.6) and later to the test formoisture movement (see 9.7). The remaining threeblocks shall be reserved for retest for drying shrinkageand moisture movement, if a need arises.
12 CRITERIA FOR CONFORMITY
12.1 The lot shall be considered as conforming to therequirements of specification, if the conditionsmentioned in 12.2 to 12.7 are satisfied.
12.2 The number of blocks with dimensions outsidethe tolerance limit and/or with visual defects, amongthose inspected shall be not more than two.
12.3 For block density the mean value determined shallnot vary by more than the limits specified in 9.3.
12.4 For compressive strength, the average value andthe minimum individual value determined shall begreater than or equal to the minimum limits specifiedin 9.4.
12.5 For thermal conductivity, the mean value shall beequal to or less than the value specified in 9.8.
12.6 For drying shrinkage and moisture movement. allthe test specimens shall satisfy the requirements of thetests specified in 9,6 and 9.7, respectively. If one ormore specimens fail to satisfy the requirements, theremaining 3 blocks shall be subjected to these tests.All the three blocks shall satisfy the requirements.
12.7 For water absorption, the mean value determinedshall be equal to or less than the maximum limitspecified in 9.5.
IS 2185 (Part 4) : 2008
13 MANUFACTURER'S CERTIFICATE
The manufacturer shall satisfy himself that the masonryunits conform to the requirements of this specificationand if requested, shall supply a test certificate to thiseffect to the purchaser or his representative.
14 INDEPENDENT TESTS
14.1 If the purchaser or his representative requiresindependent tests, the samples shall be taken before orimmediately after delivery, at the option of thepurchaser or his representative and the tests shall becarried out in accordance with this standard.
14.2 The manufacturer shall supply free of charge theunits required for testing.
14.3 Cost of Testing
Unless otherwise specified in the enquiry or order, thecost of the tests ~hall be borne as follows:
a) By the manufacturer in the event of resultsshowing that the blocks do not conform tothis standard, or
b) By the purchaser in the event of resultsshowing that the blocks conform to thestandard.
15 STORAGE
General requirement s of storage of cellular concreteblocks shall be as described in IS 4082.
16 MARKING
16.1 Concrete masonry units manufactured inaccordance with this standard shall be suitably markedwith the following information:
a) Identification of the manufacturer,
b) Grade and block density of the unit, and
c) Month and year of manufacture.
16.2 BIS Certification Marking
16.2.1 Each block may also be marked with theStandard Mark.
16.2.1.1 The use of the Standard Mark is governed bythe provisions of the Bureau of Indian StandardsAct.1986 and the Rules and Regulations madethereunder. The details of conditions under which alicence for the use of the Standard Mark may begrantedto manufacturers or producers may be obtained fromthe Bureau of Indian Standards.
ANNEXA
(Clause 2)
LIST OF REFERRED INDIAN STANDARDS
IS No.
383: 1970
455 : 1989
456 : 2000
1489(Part I) : 1989
2645: 2003
3346: 1980
Title
Specification for coarse and fineaggregates from natural sources forconcrete (second revision)Specification for Portland slagcement (fourth revision)Code of practice for plain andreinforced concrete (fourth revision)Specification for Portland pozzolanacement: Part I Ayash based (thirdrevision)
Integral waterproofing compoundsfor cement mortar and concrete _Specification (second revision)Method for determination of thermalconductivity of thermal insulationmaterials (two slab guarded hot platemethod) (first revision)
6
IS No.
3812(Part I): 2003
3952 : 1988
4082: 1996
8041 : 1990
8Il2: 1989
9103: 1999
12269 : 1987
12330: 1988
Title
Pulverized fuel ash - Specification:Part I For use as pozzolana incement, cement mortar and concrete(second revision)Specification for burnt clay hollowbricks for walls and partitions(second revision)Recommendations on stacking andstorage of construction materials andcomponents at site (second revision)Specification for rapid hardeningPortland cement (second revision)Specification for 43 grade ordinaryPortland cement (first revision)Concrete admixtur esSpecification (first revision)Specification for 53 grade ordinaryPortland cementSpecification for sulphate resistingPortland cement
IS 2185 (Part 4) : 2008
ANNEXB
(Clauses 9.2 and 10)
MEASUREMENT OF DIMENSIONS
B-1 APPARATUS
Overalldimensions shall be measured with a steel scalegraduated in I mm divisions.
B-2 Twenty-three full sized units shall be measuredfor length, width and height.
NOTE - These specimens shall be used for other tests also.
B-3 MEASUREMENTS AND REPORT
B-3.1 Individual measurements of dimensions of each
unit shall be read to the nearest division of the scale.
B-3.2 Length shall be measured on the longitudinalcentre line of each face. width across the top andbottom bearing surfaces and height at both faces. Themanner of measurement is also pictorially depictedin Fig.l.
B-3.3 The report shall show the average length. widthand height of each specimen .
ANNEXC
(Clauses 9.3 and 10)
METHOD FOR THE Dt:TERMlNATION OF BLOCK DENSITY
C-1 PROCEDURE
C-1.1 Three blocks taken at random from the samplesselected in accordance with 11, shall be dried to aconstant mass in a suitable oven heated toapproximately lOO"C. After cooling the blocks to roomtemperature, the dimensions of each block shall bemeasured in centimeters (to the nearest millimetres)and the overall volume computed in cubic centimetres.
The blocks shall then be weighted in kilograms (to thenearest 10 g) and the density of each block calculatedas follows:
Mass of block, in kg x 106 kg/m?Density = -------'----'='----:-Volume of specimen, in cnr'
C-1.2 The average of the densities forthe three blocksshall be taken as the average density.
ANNEXD
(Clauses 9.4 and 10)
METHOD FOR THE DETERMINATION OF COMPRESSIVE STRENGTH
0-1 APPARATUS
0-1.1 Testing Machine
The testing machine shall be equipped with two steelbearing blocks (see Note) one of which is a sphericallyseated block that will transmit load to the upper surfaceof the masonry specimen. and the other a plane rigidblock on which the specimen will rest. When thebearing area of the steel blocks is not sufficient to coverthe bearing area of the masonry specimen, steel bearingplates meeting the requirements of D-l.2 shall beplaced between the bearing blocks and the capped
7
specimen after the centroid of the masonry bearingsurface has been aligned with the centre of thrust ofthe bearing blocks (see 0-4.1).
NOTE - It is desirable that the bearing faces of blocks andplates used for compression testing of concrete masonry havea hardness of not less than 60 (HRC).
0-1.2 Steel Bearing Blocks and Plates
The surfaces of the steel bearing blocks and platesshall not depart from a plane by more than 0.025 mmin any 15 mm dimension. The centre of the sphere ofthe spherically seated upper bearing block shall
IS 2185 (Part 4) : 2008
coincide with the centre of its bear ing face. If abearing plate is used, the centre of the sphere of thespherically seated bearing block shall lie on a linepassing vertically through the centroid of thespecimen bearing face. The spherically seated blockshall be held closely in its seat, but shall be free toturn in any direction . The diameter of the face of thebearing blocks shall be at least 15 ern. When steelplates are employed between the steel bearing blocksand masonry specimen (see D-4.1) the plates shallhave a thickness equal to at least one-third of thedistance from the edge of the bearing block to themost distant corner of the specimen . In no case shallthe plate thickness be less than 12 mm.
D-2 TEST SPECIMENS
D-2.1 Eight full size units shall be tested within 72 hafterdelivery to the laboratory, during which time theyshall be stored continuously in normal room air.
D-2.2 Units of unusual size, shape or strength may besawed into segments, some or all of which shall betested individually in the same manner as prescribedfor full size units. The strength of the full size unitsshall be considered as that which is calculated fromthe average measured strength of the segments.
D·2.3 For the purpose of acceptance, age of testingthe specimens shall be 28 days . The age shall bereckoned from the time of the addition of water to thedry ingredients.
D-3 CAPPING TEST SPECIMEN
D-3.0 Bearing surfaces of the units shall be kept byone of the methods described in D-3.I and D-3.2.
D-3.1 Sulphur and Granular Materials
Propriety or laboratory prepared mixtures of 40 to60 percent sulphur (by mass) and the remainder beingground fire clay or other suitable inert materialpassing ISO-micron IS sieve with or without aplasticizer, shall be spread evenly on a non-absorbentsurface that has been lightly quoted with oil (seeNote) . The sulphur mixture shall be heated in athermostatically controlled heating pot to atemperature sufficient to maintain fluidity for areasonable period of time after contact with thecapping surface. Care shall be exercised to preventoverheating, and the liquid shall be stirred in the potjust before use. The capping surface shall be planewithin 0.075 mm in 40 em and shall be sufficientlyrigid and so supported as not to be measurablydeflected during the capping operation. Four 25 mmsquare steel bars shall be placed on the surface plateto form a rectangular mould approximately 12 mmgreater in either inside dimension than the masonry
8
unit. The mould shall be filled to a depth of 6 mmwith molten sulphur material. The surface of the unitto be capped shall quicldy be brought into contact withthe liquid and the specimen held so that its axis is atright angles to the surface of the capping liquid andshall be inserted. The unit shall be allowed to remainundisturbed until solidification is complete. The capsshall be allowed to cool for a minimum of 2 h beforethe specimens are tested. Patching of caps shall not bepermitted. Imperfect caps shall be removed and bereplaced with new ones.
NOTE - The use of oil on capping plates may be omitted, ifit is found that plate and unit can be separated withoutdamaging the cap.
D·3.2 Gypsum Plaster Capping
A neat paste of special high-strength plaster (see Noteunder D-4.1) and water shall be spread evenly on anon-absorbent surface that has been lightly coated withoil. Such gypsum plaster, when gauged with water atthe capping consistency shall have a compressivestrength at a 2 h age of not less than 25 Nzrnrn-, whentested as 50 mm cubes. The coating surface plate shallconform to the requirements described in D-3.!. Thesurface of the unit to be capped shall be brought intocontact with the capping paste; the specimen which isheld with its axis at right angles to the capping surface,shall be firmly pressed down with a single motion. Theaverage thickness of the cap shall be not more than3 mm. Patching of caps shall not be permitted.Imperfect caps shall be removed and replaced with newones. The caps shall be aged for at least 2 h before thespecimens are tested.
D-4 PROCEDURE
D-4.1 Position ofSpecimens
Specimens shall be tested with the centroid of theirbearing surfaces aligned vertically with the centre ofthrust of the spherically seated bearing block of thetesting machine (see Note). Except for special unitsintended for use with their cores in a horizontaldirection, all concrete masonry units shall be testedwith their cores in a vertical direction. Masonry unitsthat are hundred percent solid and special hollow unitsintended for use with their hollow cores in a horizontaldirection may be tested in the same direction as inservice.
NOTE - For homogeneous materials. the centroid of thebearing surface shall be considered to be vertically above thecentre of gravity of the masonry unit.
D-4.~ Speed of Testing
The load up to one-half of the expected maximum loadmay be applied at any convenient rate, after which thecontrol of the machine shall be adjusted as required to
give a uniform rate of travel of the moving head suchthat the remaining load is applied in not less than onenor more than two minutes .
D-5 CALCULATION AND REPORT
D-5.1 The compressive strength of a concrete masonryunit shall be taken as the maximum load in Newtons,divided by the gros s cross-sectional area of the unit in
IS 2185 (Part 4) : 2008
square millimetres. The gross area of a unit is the totalarea of a section perpendicular to the direction of theload, including areas within cells and within re-entrantspaces unless these spaces are to be occupied in themasonry by portions of adjacent masonry.
D-5.2 Report be results to the nearest 0.1 Nzmrrr'separately for each unit and the average for the 8 units.
ANNEXE
(Clauses 9.5 and 10)
METHOD FOR THE DETERMINATION OF WATER ABSORPTION
E-l APPARATUS
E-l.l The balance used shall be sensitive to within0.5 percent of the mass of the smallest specimen tested.
E-2 TEST SPECIMENS
Three full-size units shall be used.
E-3 PROCEDURE
E-3.1 Saturation
The test specimens shall be completely immersed inwater at room temperature for 24 h. The specimensshall then be weighed , while suspended by a metal wireand completely submerged in water. They shall beremoved from the water and allowed to drain for I minby placing them on a 10 mm or coarser wire mesh,visible surface water being removed with a damp cloth,and immediately weighed.
E-3.2 Drying
Subsequent to saturation, all specimens shall be driedin a ventilated oven at 100°C to 115°C for not less
than 24 h and until two successive weighing at intervalsof 2 h show an increments of loss not greater than0.2 percent of the last previously determined mass ofthe specimen.
E-4 CALCULATION AND REPORT
E-4.1 Water Absorption
Calculate the water absorption as follows:
A-BWater absorption, kg/rn' = -- x I 000
A-C
A-BWater absorption, percent = -- x I 000
B
where
A = wet mass of unit, in kg;
B = dry mass of unit, in kg; and
C = suspended immersed mass of unit. in kg.
E-4.2 Report
Report all results as the average for the three units.
ANNEXF
(Clauses 9.6 and 10)
METHOD FOR THE DETERMINATION OF DRYING SHRINKAGE
F-l NUMBER OF TESTS
F-l.l Of the samples selected in accordance with 11,three shall be tested for drying shrinkage. Three moreblocks shall be set aside and stored in air-tightcontainers at normal room temperature so as to be
9
available for duplicate tests, if they are required at alater stage (see Note).
NOTE - In order to fac ilitate storage . instead of blocks.sect ions cut from these additional blocks may be stored untilnecessary in separate air-right conramers at normal roomtemperature .
IS 2185 (Part 4) : 2008
F-2 APPARATUS
F-2.1 Measuring Apparatus
A measuring apparatus shall be used whichincorporates a micrometer gauge or a suitable dialgauge reading accurately to 0.002 5 mm. This gaugeshall be rigidly mounted in a measuring frame and havea recessed end which may be located upon a 5 mmdiameter ball or other reference point cemented on thespecimens. The other end of the frame shall have asimilar recessed seating which may be located uponthe other ball or reference point in the specimen. AnInvar steel rod of suitable length with 5 mm diameterhemispherical ends or with 5 mm diameter steel ballsmounted on the ends, shall be used as a standard oflength against which readings of the gauge may bechecked, thus enabling corrections to be made for anychange in the dimensions of the apparatus betweensuccessive measurements of tests specimen . Theapparatus shall preferably be adjusted for specimensof different lengths and Invar rods of length near tothose of the specimens to be tested shall be available .
F-2.2 Drying Oven
The drying oven shall comply with the followingrequirements:
a) It shall have an internal volume equivalent tonot less than 8 litres per specimen, with aminimum total volume of 50 litres.
b) It shall be reasonably air-tight and shall beprovided with a fan to keep the air circulatingeffectively during the drying of the specimen.
c) It shall be capable of maintaining a constanttemperature of 50 ± 1°C.
d) The relative humidity of the air in the ovenshall be controlled at approximately17 percent by means of saturated calciumchloride solution. Suitable dishes or trayscontaining this solution shall be provided togive an exposed area of solution not less than10 em? for each litre of volume of the oven.The dishes or trays shall contain sufficientsolid calcium chloride to show above thesurface of the solution throughout the test.
F-3 PREPARATION OF SPECIMENS
One sample shall be cut from each of the blocks suchthat the length of each specimen is not less than 15 cmand the cross-section is as near to 7.5 em x 7.5 ern aspracticable in the case of solid blocks and 7.5 em xthickness of the wall in the case of other blocks . Tworeference points consisting of 5 mm diameter steel ballsor other suitable reference points providing a
IO
hemispherical bearing shall be cemented with neatrapid-hardening Portland cement or other suitablecementing material at the centre of each end of eachspecimen after drilling or cuttin g a shallow depression.After fixing, the surface of the steel balls shall be wipedclean of cement, and dried and coated with lubricatinggrease to prevent corrosion. The specimens shall thenbe completely immersed in water for 4 days. thetemperature being maintained at 27 ± 2°C at least forthe last 4 h.
F·4 PROCEDURE FOR TESTING
F-4.1 Immediately after removal of the specimens fromthe water, the grease shall be wiped from the steel ballsand the length of each specimen mea sured to anaccuracy 0.002 5 mm by the apparatus describedin F-2.1. This shall be taken as the original wetmeasurement.
NOTE - The instrument reading required is not the absolutelength of the specimen but the differen ce in length betweenthe specimens and an Invar rod of approximately the samelength.
F-4.2 The specimen shall then be dried for at least 44 hin an oven of the type described in F-2.2, at thespecified temperature and humidity. The specimensshall then be removed from the oven and cooled for atleast 4 h in a desiccator containing solid calciumchloride or a saturated solution of calcium chloride.Each specimen shall then be measured as describedin F-4.1, at a temperature of 27 ± 2°C.
F-4.3 The cycle ofdrying, cool ing and measuring shallbe repeated until constant length is attained, that iswhen the difference between con secutive read ingsseparated by a period of drying of at least 44 h followedby cooling for at least 4 h, is less than 0.005 mm for a15 em specimen and pro rata for a larger specimen.The final reading shall be taken as the drymeasurement.
F-4 .4 During the drying process further wet specimenshall not be placed in the same oven and there shall befree access of air to all surfaces of the specimen.
F-4.5 After the dry measurement has been taken, thelength of the specimen shall be measured, adjacent tothe steel balls, to the nearest millimetre and this shallbe taken as the dry length.
F-5 CALCULATION OF RESULTS
F-5.1 The drying shrinkage shall be calculated for eachspecimen as the difference between the original wetmeasurement and dry measurement expressed as apercentage of the dry length .
F-5.2 Report all results separately for each unit.
IS 2185 (Part 4) : 2008
G-l.2 Should the value obtained with anyone of thethree specimens tested, be greater than the limitspecified in 9.7, the test shall be repeated on the furtherthr~e blocks which were set aside. In repeating themoisture movement test, the shrinkage test shall berepeated if the previous specimens have failed on thattest.also; otherwise, the drying shrinkage test may beomitted. The three new specimens, in that event, shallbe dried to constant length at 50 ± 1°C measured aftercooling and the moisture movement test carried out asdescribed in G-!.I.
ANNEXG
(Clauses 9.7 and 10)
METHOD FOR THE DETERMINATION OF MOISTURE MOVEMENT
G-l PROCEDURE
G-!.1 The specimens which have previously been usedfor the drying shrinkage test (see Annex E) shall afterthe completion of that test be immersed in water for4 days, the temperature being maintained at 27 ± 2°Cfor at least 4 h prior to the removal of the specimenand the wet length measured. The moisture movementshall be determined as the difference between the dryand wet lengths and expressed as a percentage of thedry length for each specimen.
ANNEXH
(Foreword)
COMMITTEE COMPOSITION
Cement Matrix Products Sectional Committee, CED 53
Organization
Gammon India Limited. Mumbai
All India A.C. Pipe Manufacturers' Association, Secunderabad
Asbestos Information Centre. New Delhi
Central Building Research Institute. Roorkee
Central Pollution Control Board. Delhi
Central Public Works Department. New Delhi
Directorate General of Factory Advise Services and LabourInstitute. Mumbai
Engineer-in-Chief's Branch. New Delhi
Eternit Everest Limited. New Delhi
Fly Ash Utilization Programme (TIFAC). New Delhi
Gammon India Ltd. Mumbai
Gujarat Ambuja Cement Ltd. Ahmedabad
Housing & Urban Development Corporation Limited.New Delhi
Representativeis)
SHRI S. A. REDDI (Chairman)
SHRI N. KISHAN REDDY
SHRI P. S. KALANI (Alternate)
BRIG AAROON K. SETHI
SHRI V. PATIABHI (Alternate)
DR B. K. RAO
DR S. K. AGARWAL (Alternate)
SHRI J. S. KM!YUfRA
SHRI P. K. GUPTA (Alternate)
SHRI P. SUBRAMANIAN
SHRI K. P. ABRAHAM (Alternate)
SHRI V. S. SASIKUMAR
SHRI S. C. SHARMA (Alternate)
SHRI V. K. MANGLlK
SHRI P. K. GUPTA (Alternate)
SHRI S. P. BOLAR
SHRI Y. S. RAO (Alternate)
DR VIMAL KUMAR
SHRI MUKESH MATHUR (Alternate)
SHRI R. K. MALHarRA
SHRI M. U. SHAH (Alternate)
SHRI J. P. DESAI
SHRI B. K. JAGETIYA (Alternate)
CHAIRMAN & MANAGING DIRECTOR
SHRI DEEPAK BANSAL (Alternate)
II
-IS 2185 (Part 4) : 2008
Organization
Hyderabad Industrie s Limited. Hyderab ad
Industrial Toxicology Research Centre, Lucknow
Ministry of Environment and Forest . New Delhi
Municipal Corporat ion of Delhi, New Delhi
National Council for Cement & Building Material s, Ballabg arh
National Institute of Occupational Health, Ahmedabad
National Test House. Kolkata
Rural Electrification Corporation Lim ited, New Delhi
Small Scale Industrie .• Services Institute, Bangalore
Spun Pipes Manufacturer's Assoc iation of Maharashtra, Nanded
Structural Engineering Research Centre (CSIR), Chennai
Tamil Nadu Water Supply & Drainage Board , Chennai
The Indian Hume Pipe Company Limited, Mumbai
BIS Directorate General
Representative!s)
SHRI D. B. MUNDRASHRI P. K. ANAND (Alterna te )
DR (SHRIMATI) Q. REHMAN
REPRESENTATIVE
SUPERINTENDING ENGINEER (PLANNING)EX.ECUTIVE ENGINEER (PLANNING) (Alternote)
SIIRI H. K. JlILKADR S. HARSHA (A lternate)
DR H. N. SAIYEDDR ASIM SAIIA (Alternate)
SIIRf D. K. KAN UNGOSHRI T. CHOUDHURY (Alternate)
SHRI S. K. SETIIISHRI F. C. BHAGIA (A lternate v
SHRI C. H. SUBRAMANIANSIIRI A. DUTTA (Alternate)
SIIRI C. y. GAVHANESIIRI D. N. JOSHI (Alt ernate)
SHRI A. CHELLAPPAN
SIIRI S. HARIRAMASAMY
SHRI P. D. KELKARSIIRI S. J. SHAH (Alt ernate )
SIIRl A. K. SAINI. Scient ist 'F ' and Head (CED)[Representing Director General (Ex-offi cio )]
Member Secretary
J. Roy CIIOWDIIURY
Scientist 'E' (CED), BIS
Precast Concrete Products Subcommittee, CED 53 : 3
In personal capacity (C-2/2220. Vasant Kunj. Ne..... Delhi 110070)
B.G. Shirke Construction Technology PVt Ltd. Pune
Central Building Research Institu te. Roorkee
Central Electricity Authority. New Delhi
Central Public Works Department. Chandigarh
Central Soil and Materials Research Station, New Delhi
Delhi Development Authority , New Delhi
Engineer-in-Chief's Branch. Mumbai
12
SIIRI SUDDHODAN Roy (Convener)
SIIRI V. G. JANASIIRI Y. P. KAJALE (A lternate s
SHRI M. S. KALRASIIRI D. K. GAL,AM iAlternate t
DIRECTOR (RE)DEPUTY DIRECTOR (RE) (A lternate )
SUPERINTENDING ENGINEER (PlANNING)EXECVTlVE ENGINEER (PlANNING) (Alternate)
SHRI N. CIIANDER SHEKH .~RAN
SIIRI N. SHIV KUMAR (Alternatev
SIIRI S. K. BHATIASIIRI P. K. AGARWAl. (Alt ernate)
SIIR I YASH"'N<T KUMARSIIR' K. G. DUA (A lternate )
Organization
Fly Ash Utilization Programme (TI FAC ). New Delhi
Gammon India Limited . Ne w Delhi
Hindustan Prefab Limit ed. New Delhi
Housing & Urban Development Corporation Lim ited . New Delhi
Hyderabad Indu stries Limited. Hyderabad
Institution of Engineers . New Delh i
Larsen & Toubro Ltd. ECC Group. Chennai
K.K. Manhole & Grating Co (P) Ltd . New Delhi
Maharashtra State Electricity Board. Mumbai
National Council for Cement & Building Materials . Ballabgarh
Public Worles Department, Haryana
Siporex India Limited. Pune
Structural Engineering Research Centre. Chennai
System Building Technologists . New Delhi
The Indian Hume Pipe Company Limited. Mumbai
U.P. Electricity Board. Luclenow
Unitech Prefab Limited. Mumbai
13
IS 2185 (Part 4) : 2008
Representative!s)
DR VIMAL K UMAR
SHRt M UKESH MATHUR (Altemate)
SHRI R. K. MALHarRA
SHRI G . P. JOSHI (Altemate)
SHRI M . K UNDU
SHRI H. C. G UPTA (Alternate)
CHAIRMAN & MANAGING DIRECTOR
SHRJ DEEPAK BANSAL (Alternate)
SHRI D . B. M UNDRA
SHRI K . V . RA O (Altemate)
SHRI C. R . ALiMCHANDANI
SHRJ N . C. JAIN (Altemate)
SHRI S . R . KUMAR
SHRI STHALADIPTI SAHA (Alternate)
SHRI P. S. GUPTA
SHRI C . G. GUPTA (Alternate)
SHRI C. B. R UNWAL
SHRI H. K . JULKA
SHRI V . V. ARORA (A/remate)
REPRESENTATIVE
SHRJ D . N. DHONGDE
SHRI D . V. KULKARNI (Alternate)
DR M. NEELAMGAM
SHRI J. PRABHAKAR (Alternate)
SHRI G . B. SINGH
SHRI P. D. KELKAR
SHRI S. J. SHAH (Altemate)
CHIEF ENGINEER
SHRI DEVENDRA KUMAR PANDEY
Bureau of Indian Standards
BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification of goodsand attending to connected matters in the country.
Copyright
BIS has the copyright of all its publications. No part of these publications may be reproduced in any formwithout the prior permission in writing of BIS. This does not preclude the free use, in the course ofimplementing the standard, of necessary details, such as symbols and sizes, type or grade designations.Enquiries relating to copyright be addressed to the Director (Publications), BIS.
Review of Indian Standards
Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewedperiodically; a standard along with amendments is reaffirmed when such review indicates that no changes areneeded; if the review indicates that changes are needed, it is taken up for revision. Users of Indian Standardsshould ascertain that they are in possession of the latest amendments or edition by referring to the latest issue of'BIS Catalogue' and 'Standards: Monthly Additions'.
This Indian Standard has been developed from Doc : No. CED 53 (7289).
Ameudments Issued Since Publication
Amend No. Date of Issue Text Affected
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