1. ( Reaffirmed 1997 )

2. _ .________~ -__
IS I 6441( Part VI ) - 1973
hidian Standard
METHODS OF TESTS FOR AUTOCLAVED
CELLULAR CONCRETE PRODUCTS
PART VI STRENGTH, DEFORMATlbN AND CRACKING OF
FLEXURAL MEMBERS SUBJECT TO BENDING-
SHORT DURATION LOADING TEST
Cement and Concrete Sectional Committee, BDC 2
Ckairtnm RrpIumting
DR H. C. V~svrsvr~A~~ Cement Research Institute of India, New Delhi
Members
DR A. S. BH~DURI National Test Ho&, Calcutta
SXRXE. K. RAYACHANDRAN( Alternate 1
DR S. 5. REHSI( .-llrrmate ;
DIRECTO.P
DR R. K. GHOSX ( Alternate )
DIRECTOR( CSMRS )
Ds~un DIRECTOR ( CSMRS )
( Alternate )
SHRlK. H. CANOWIJ.
Ccnt~~orkB~ilding Research Institute (CSIR ),
Central Road Research Institute ( CSIR ), New Delhi
Central Water & Power Commission, New Delhi
SHRIK. C. GHO~AL
Sxsu A. K. Buw~s ( Ahmote)
DR R. K. GHOSH
DR R. R. HATTIAN~ADI
SWRl P. J. JAOVS ( AI&mate )
TOINT DIRECWR. STANDARDS
* ( :I$% DIRECXORSTAND~UW
(B&S)(Al&c)
SHRIS’.B. JOSH:
SXIU hi. T. KASSB
SHRI S. L. KATHURIA
SHRI S. R. KULMRSI
SHRI Al. A. MEHTA
SHRI 0. MuTHhCNE~
SUPERINTEXDINOE N o I N B E R,
2r;D &cur ( Altematr )
Hyderabad Asbestos Cement Products Ltd,
Hyderabrd
hlokudyog Services Ltd, New Delhi
Indian Roads Congress, New Delhi
Associated Cement Companies Ltd, Bombay
Research, Designs & Standards Organization,
Lucknow
S. B. Joshi & Co Ltd, Bombay
Directorate General of Supplies & Disposals
Roads Wing, Ministry of Transport 8; Shipping
M. N. Dastur 8; CO ( Private ) Ltd, Calcutta
Concrete Association of India. Bombay
Central Public Works Dcparment
( Cbntinucdonpage 2 )
@ Copyrigkr 1973
INDIAN STANDARDS INSTITUTION
This publication is protected under the Indian Copyright Act ( XIV of 1957 ) and
reproduction in whole or in part by ifn~ means except with written permission of the
publisher shall be deemed to be an lnfnngement of copyright under the said Act.

3. 15:6441(PartvI)-1973
(C0&wdJfm puge1)
Mcmbcrs R@I&titlE
SHRI ERACHA. NADIRSHAH Institution of Engineers ( India ), Calcutta
Sum K. K. NAMXAR In personal capacity ( ’ Ramnnalaya ‘, I1 First Crsscmt
Park Road, Gandhinagar, A&ar, Madras )
BRIQNARESHPRASAD Engineer-in-Chief’s Branch, Army Headquarters
COL J. M. TOLANI ( Alkrnak)
PROPG. S. &laASWAbfY StructRx--ake~inecring Research Ccntre ( CSIR ),
0
DR N. S. BHAL ( Alkrnak )
DR A. V. R. RAO National Buildines Omanization. New DelhiY 1
SHRI RAV~NDERLAL ( Alkmak )
SHRI G. S. M. RAO Geological Survey of India, Nagpur
SHRI T. N. S. RAO Gammon India Ltd, Bombay
SHRI S. R. PINIIE~O ( Alternate )
SECRETARY Central Board of Irrigation & Power, New Dclhl
SHRI R. P. SHARMA Irrigation and Power Research Institute, Amritsar
SHRI MOHINDERSINGH( Alkrnak ) _
SHRI.G. B. SINGH Hindustan Housing Factory Ltd, New Delhi
SHRI c. I_,. tiSLlWAL [ Alkrnak j
’SHRIJ. S. SINGEIOTA
SHRI T. C. GARG ( Alfemate)
‘Beas Designs Organization, Nangal Township
SWRI R. IL. SXNHA
SHRI IL A. SU~RAMAN~AM
Indian Bureau of Mines, Nagpur
India Cements Ltd. Madras
SHRI P. S. RAMAMANDRAN ( Alkmak )
SHRI L. SWAROOP
Srrnr A. V. RAMANA ( A!temak)
Dalmia Cement ( Bharat ) Ltd, New Delhi
Smu D. AJITHA S~MHA, Director General, IS1 (&-o&o Member )
Director ( Civ Engg )
Smtr Y..R. T~NEJA
Deputy Director ( Clv Engg ), IS1
precast Concrete Products Subcommittee, BDC 2 : 9
SHRIM. A. MEHTA Concrete Association .of India, Bombay .
iucmbcr#
SHRI E. T. ANTIA ( Alirmats to
Shri M. A. Mehta )
SBRI V. A. ARTHANOOR Neyveli Lignite Corporation Ltd, Neyveli
SHRI T. RAMACHANDRAN ( Alkmak ) .
SHRI H. B. CHAYTERJEE
SHRI S. K. CHATTERJEE
Hindustan Block Manufacturing Co Ltd, Calcutta
DEPUTY DIRECZTOR,
Hindustan Housing Factory Ltd, New Delhi
(B&S)
STANDARDS R-L;&oDwQigns and Standards Organiaation,
ADJUTANTDIRECMR. STANDARDS
(M/C ) ( A-‘)
bRECTOR( CSMRS )
Dapurv DIWXOR (CSMRS)
Central Water& Power Commission, New Delhi
( BItema&)
2

4. _.
IS:6441(PadVI)-1973
lndian Standard
METHODS OF TESTS FOR AUTOCLAVED
CELLULAR CONCRETE PRODUCTS
PART VI STRENGTH, DEFORMATION AND CRACKING OF
FLEXURAL MEMBERS SUBJECT TO BENDING-
SHORT DURATION LOADING TEST
0. FOREWORD
0.1 This Indian Standard ( Part VI) was adopted by the Indian
Standards Institution on 22 March 1973, after the draft finalized by the
Cement and Concrete Sectional Committee had been approved by the
Civil Engineering Division Council.
0.2 Autoclaved cellular concrete is a class of material, which has .been
developed commercially abroad and is in the process of development in
this country also. A series of Indian Standards on cellular concrete is
being formulated so as to provide guidance in obtaining reliable products
in auroclaved celiular concrete. The Sectional Committee has considered
it desirable to issue a standard for the methods of test for autoclnvcd cellu-
lar concrete products for the guidance of manufacturers and users.
0.3 In the formulation of this standard due weightage has been given to
international co-ordination among the standards and practices prevailing
in different countries in addition to relating it to the practices in the field
in this country.
0.4 For convenience of reference, ‘ Indian Standard methods of test
for autoclaved cellular concrete products’ has been grouped into the
following nine
Part I
Part II
Part III
Part IV
Part V
Part VI
parts:
Determination of unit weight or bulk density and moisture
content
Determination of drying shrinkage
Determination of thermal conductivity
Corrosion protection of steel reinforcement in autoclaved
cellular concrete
Determination of compressive strength
Strength, deformation and cracking of flexural members
subject to bending-short duration loading test
3
jw
1.

5. IS:6441(PartVI)-1973
Part VII Strength, deformation and cracking of flexural members
subject to bending-sustnined loading test.
Part VIII Loading tests fw flextlral members in diagonal tension
Part IX Jointing of autoclaved cellular concrete elements
05 In reporting the result of a test or analysis made in accordance with
this standard, if the final value, observed or calculated, is to be rounded off,
it shall be dane in accordance with IS : 2-1960*.
1. SCOPE
1.1 This standard ( Part VI ) covers the method of test for the strength,
deformation and cracking ( under short duration load ) af flexural
members such as floor or roof slabs of cellular concrete subject to bending.
Z TEST SPECIMEN
2.1 Size of the Specimen - The test specimen. shall be the full size
member as to be actually used in construction satisfying the requirements
of the relevant Indian Standard (or the requirements specified by the
manufacturer ) in respect of shape and dimensions.
2.2 Condition of the Test Specimen
2.2.1 Moisture Content -The moisture content of the concrete during
the test should be indicated and should be not less than 10 percent,by
weight, when determined in accordance with IS : 6441 ( Part I )-1972t.
2.2.2 Te&fierature of Specimen - The temperature of the concrete shall
not be materially different from the ambient temperature in which it is
being tested and in any case not less than 0°C.
3. TEST ARRANGEMENTS
3.1 The member to be tested shall be simply supported at the ends.
The supports shall consist of 25-mm thick horizontal mild steel plates
bedded on rigid supports of steel or concrete. The ends of the member shall
be fully in contact with the steel plate over the whole width of the
member. The bearing width and the span used for the test shall be the
same as those indicated by the manufacturer and to be actually used in
construction practice ( see Fig. 1 ).
*Rules for rounding off numerical values(recirud).
th4ethods of tests for autoclaved cellular concrete products : Part I Determb&ou of
unit weight or bulk density and moisture content,

6. XSt6441(Pa*VI )-1973
~ J;
t $ +-.4 +
~25mfn
-,..,’. ,. ..,..,’ .. . . . .. “,.,’. ,. ?.,..*.
. “”,’’.:*. “’.~l2”mm:,’,. ’..,. . . . .’.
“’’’1.’? .’.”. ,. ,’; ; ..,, ,,.. ,., .:. . . . .
., -.”., ... .,. ._F.’.’... ,,, .,, ,., :, ,
.. . . . . . . . . ,.. .
./.
b/ /MI?WUM PERMISSIBLE Sil’EB. PLATE EMBEDDED
BEARING WIDTH Ihl STFELOR CUNCRETE
RIGID SUPPORT
i = effectivespan of unit,
t = steel pIatc of thickness not less than 25 mm and length
equal to width of the unit,
t E porow fibre board thickness not less than 12 mm and
length equal to width of the unit, and
Q= applied load.
Fm. 1 MSTZiODFOR BENDING TEST OF REINFORCED CELLIJLAR
CONCRETE UNITS ( SHORT DURATION LOADING TEST)
4. LOADING
4.1 The test specimen member shall be subjected tO loads placed at + span
points through steel platens not lCSSthan 25 mm *U the load extending
over the entire widtil of the member. The steel platens shall be bedded
on soft fibre board packing, not less than 12 mm thick and of the same
plan dimensions as the steel pIatens. The packing shaU be placed between
each steel loading platen and the top of the member. The span shall be
taken as the distance between the centms of the bearing ( see Fig. 1 ).
4.2 The loads at the two ~ span po.iII.~ shall be equal and evenly
distributed over the steel loading platens The wxdth of the steel platen
shall not be less than 100 mm and shall be inme=edj where necessaty, in
multiples of 50 mm, so that We contact pr=ure under the applied load
is not more than 20 p~rcent of the compr=slve stiengds of the concrete.
4.3 The weight of the Ioadlng equipment siall be taken into account in
calculating the applied load.
5. MEASU’RE~NTS
5S Loada — The loads shall be measured to an accuracy of not less
than + 1q5 percent of the applied load.
5.2 Deflection — The deflection of the member shall be measured at
mid-span and th~ least count of the dial gauge shall be at least 0.01 mm.
5

7. IS: 6441 ( Part VI) -1973
5.3 Stt-aiss — Strain measurements may be made, where required, prefer-
ably at mid-span, cm the main tension reinforcement and on the extreme
compression fibre of the concrete,
5.4 Crack Widths — Crack widths shall be measured with an accuracy
of * 0“05 mm.
6. TEST PROCEDURE
6.1 Zero for the deflection measurements shatl be taken immediately
after the member had been placed in position.
6.2 The loading apparatus shall then be fixed and the load applied in
Stages. At the end of this stage the load, including the self weight of the
m~mber and the weight of the Ioading apparatus, shall be equal to the
design dead load for the member.
6.2.1 After an interval of about 5 min loading shall be increased
gradually until the load equals the combined dead and design live loads
for the member.
6.2,2 After a further intcrwd of about 5 min loading shall be increased
at-adually until the Ioad equals the combined dead and twice the design
five loads. At that load, the deflection shall be noted.
6.2.3 After a further interval of about 5 min loading shail bc increased
at a rate of about + of the design live load per minute until failure occurs
or the mid-span d~fkction is 1/60 of the span, M$hichever is earlier. If
the member is not tested [o failure: then a hypothetical failure load shall
be assumed w be Lhat Ioad for wh]ch the red-span deflection is 1/60 of
the span.
6.2.4 Defection and strain measurements ( see 5.3 ) shall be recorded
at the beginning and where applicable at the end of each of the loading
stages; intermediate measurements may also be made if required.
7. REPORT
7.1 The test report shall state:
a) moisture content of the specimen;
b) temperature of the specimen; and
c) measured Ioads, deflcctions~ strains and crack widths for all load
conditions..
6

8. ( Coatissdfrom @gt 2 )
Memlw
StSax K. c. GSSOSAL
SHRI A. K. BISWM ( .4Msafe )
%su k’. G. GOKHALE
SHRI M. K. GUPTA
SHRI B. D. JAYARAMAK
SXRSB. K. JIXD~L
DR S. S. RESSSI( Ahcrrrats)
SHSU L. C. LAI
SHRI G. C. MATHSJR
Rsfmssstting
Alokudvog Services Ltd, New Delhi
Bombay Chemicals Private Lknited, Bombay’
Himalayan Tiles & Marble Pvt Ltd, Bombay
%~~~””~~~~~~dk%$% Institute ( CSIR ),
Roorkce
In personal CR acity ( BI17 U’eStEnd,Arm’Dtlhi23)
1National Bud mm Organizaliorr, New Delhi_--.
SHR: A. C. GUPTA ( Msnsals )
--
&IR1 S. ~AMROY Engineering Construction Corporation Ltd, Madras
SHRI A. ~AXRtSIWA ( Aitsrn& )
SHRI K. K. NASSZIAR In personal capaci ~{ ’kmenalqa’. 11 First (%atort
Perk Road, Gan hwagar, A&ar, it~adras)
Sr+m RADHrtY SHIAU Engineer-in-Chief’s Branoh, Army Headquarters
SSSRIB. G. SSSIRKE B. G. Shirke& Co, Poona
SHRI R. A. DaSHSi’UKH ( Akraate )
SHRSc. N. SRINIVMAN C. R. KRravana Road, Madras
SStRI C. N. RAOSIAVENDRAN ( Ahcrnafe)
SURVEYOR OF WORKS ( I ) Central Public Works Department
Dz H. C. VSSVE.WARAYA Cement Research Institute of India. !few Dclbi
7