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B ~ " I ' 2 ' . ,'1l0Qoo . ~_'U,_.JU~)C (jl:rj,U{12 : GD\'})"L: . U.: _.' :O (J I : '1 '

British Standurds lnstitution. Nopart of thi . publication may bophotocopied or othervvise ruproducad without tho prio: permission in writin9 .:.';8SJ

: 1ritish Standard Specification forortland cements

pecif icati on des cim ents Por tlaridsezif ik ation flit' Poni

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BS 12 : 1989

Foreword

This Britist: S tandard has been pr e par ed under the d irectionof the Cement, Gypsum , Aggregates and Quarry ProductsStandards Policy Comm ittee. I t was revised to bring it in toline w ith curren t practices fo llowed in the production andt e s t.nq of Portland cem ents. This standard supersedesBS i2 1978 which is w ithdrawn.'Fer m any years thure has been a dem and by specia list userstur a cem ent which m akes it easier to rem ove excess w aterIre ::~ the c on cre te durinq' compaction . M oreover, in som eappli ca tioris the fineness of the cem ent is m ore critica lth;JI its cornpr cssive strength. A contro lled finenessI)o~tianci cem ent has therefore been in troduced, w ith thes arne strength lim its as were given for ord inary PortlandCI;"1,,_nt in BS 12 1978. Consequently the specifiedstr" tlgth m in im a for ord inary Portland and rapid- hardening"or rland cem ents have now been revised . Furtherm ore,

. . , 1 Older to em phasize the d istinction between these cem entty:;" s, the early m inimum strength for rap id- harden ingPcr~:~H \(J cernen t is now specified to have at 2 days the sam e

v" ,ut.: as ord inary Portl;nd cem ent at 3 days.USC" 5 have expressed concern that im provem ents in m anu-t~!_ ",re have lecl to ord inary Portland cem ents develop inqhic;h~ r strengths at earlier ages, thus enabling specified-co .rc .e te strengths to be achieved w ith insufficien t cem entto cusureadequate durability . A maxim um value for thes u ." ,n~Jth of or d inarv Por tland cem ent at 28 days .has there-Ior c ilucn in tr oduccd as a contro l m easure.T I- .is s t andar d m akes reference to BS 4550 : Part 2 forch er n i ca l test m ethods. BS 4550 : Part 2 :1970 was" r" t.:: lded in 1983 t o include, in 16.2, a m ethod which gives;]1:';"1: values tha: canbe L1sed when ca.cula ti.u j the alkalic tJ '1 :~rlt of concr c tu. BS 45S0 : Part 2 : 1970 was Iurthercn,~;;deJ in 1988 to include, as clause 17, a new testr(,.-:i 'od for rne.rsurinq the 'vurv low levels of chloride found

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in Portland cem ent. This new test m ethod ' ep laced one thatw as less sen sitiv e.In this revision , a lim it fo r the chloride conten t has beenin troduced . A lso in this revision , the lim e saturation factorr e q u ir e rn en t has been om itted ; this was ori jinallv in troducedesser-tia llv as a safeguard against unsoundness which isadequate ly covered by the soundnessrequ:rem ents specifiedin clause 6, The lim e satura tion factor provides noguidance on strength-giving properties. . ..Guidance on the use of cem ent has been tn-:luded inappendix A , and atten tion is drawn to the safe ty pre-cautions recomm ended therein when worklllg.w ith cem entPortland cem ents w ill partia lly hydrate whenexposed tow ater vapour, and appendix A also includes guidance onstorage. ..The U I( is partic ipating actively in the work of TechnicalComm ittee TC 51, Cem ent and build ing lim es,ofthaEuropean Comm ittee for Standard ization (,~EN ) on thepreparation of a European Standard specifica tion forcem ents. One of the typesof cem ent to be included in theEuropean Standard is in tended for use in ,: e sam e wayas ord inary Portland cem ent complying w ith B S 12, It isexpected that BS 12 w ill even tually form r.srto f a newBritish. Standard that w ill be published in crder toim plem ent the European Standard , once the la tter hasbeen approved , as required by the CEN rer,!Jlations.Assessed copebilitv. Users of this B ritish Srmdard areadvised to consider the desirability of assessm ent and 'registra tion of a supplier's quality system s ,gainst theappropriate Part o f O S 5750 by a third party cer titica tio r.body.Com pliance w ith a British Standard does n.it o f itse lfconfer imm unity from legal obligation .

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"." ...Contents

Foreword,C om m ittee s res po nsible ':Specification1 Scope2 D ef in it io ns3 Com position and manufacture

~: . :B S !:.2 19 8 9

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Inside TrUI:c coverSJC!, cover

22222233334

4 Fineness5 Settin g tim es'6 Soundness ,7 C om pressive stren gih '8 Chemica l composition ;9 Sam pling and tests.for complir r ice~ '10 Marking '"11 I n fo rm ation to be p rovidedAppendixA Product gu idanceTable

Com pressive streng th o f cem cn" s" '

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r~. 1 3 5 'i 2 1 9 8 9

's pacification~- .

1 ScopeT his B ritish Standard specifies requirem en ts fo r thecom position , the m anufacture and the physical andchem ical p roperties of con trolled fineness, o rd inary andrapid- harden ing Portland cem en ts. .NOTE. The .titles of the publications referred to in this standard'arc listed on the inside 'back cover.

!2 Definitions. for the purposes of th is B ritish S tan da rd th e defin itio ns~n BS 6100 ; Section 6.1 apply toqether w ith the fo llow ing. 'pontrotled fineness Portland cem en t. Portland cem en traving a specific surface con tro lled w ith in a sm all agreedan . 'iat u sually lies b elow th at fo r o '" fdin ary P ortlan d-en1cllt. I.:~~~otE. This range is usually agreed between the manufacturer~nd, the purchaser,

S Compositionand manufacture~ > ,3.1 Control led fin eness P ortlan d cem en t {C FP Cl. ord inaryPortland cem en t {O PC l. or rapid-hardeninq Portland; ~el1len t {R HP Cl. sh all b e ob tain ed b y g rin din g P ortlan d!~el1\~nt clinker.3.2 The .cernents shall con tain no o ther added m aterialsexcept a s f ol low s:

(a ) gypsum or anhydrite o r o ther fo rm s of calciumsulphate. or (lilY com bination of them (sec 8. 4 fo rl.m it ):(b) not m ore than 0.10 % o y m ass of p ropylene glyco lwhen determ ined in accordance w ith clause 18 ofBS4550: Part 2 : 1970. "~,~ ;; iron or w ater rernaininq after the g rin din g p rocess1;lIll1ot be regarded as additions (see 8 .5 fo r loss 011nirion Iimit) .

.~: Ta '? l~ 1. C om pressive stren gth o f cem ents

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3.3 Pigm en ted Portland cem en ts shall com ply v/ith th isB ritish S tandard provided that: . . ( :; .(a) the pigm en ts com ply w ith BS 1014; , , , : ; ; ; >(b) the ch em ical co mp osition of the P ~;tl~!1 ci c~irIen tco nstituen t, ex clud ing pig men t, co mp lies w ith C l'h lse 8of this 'B ritish Standard ; ':- , , . . . ~ t ~ , \ ~. .(c) the cem en t as a w ho le, includ ing pigm ent c~m lpliesw ith this B ritish Standard, w ith the excep tion o r : 'clause 8,.

4 FinenessW hen tested for fineness in accordance w ith BS .155.0 :Section 3.3, the cem en ts shall have the fo llowhg m in im umspecific surfaces:' ;~'. . '.-~~~\~.~.

c on tro lle d. fin en es s P ortla nd c em en t :225 Ir,2 i k i i :ord in ary P ortlan d cem ent: 275 r , , 2 / k 9 : rapid-hardeninq Portland cem ent: . 350 1:12/ k g .

5 Setting timesW hen determ ine 'd in accordance w ith _ .SS4550 : Section 3.6,the Setting tim es of cem en t pastes o f standard co.islstence(us determ ined in accordance w ith BS 4550 : Section 3.5)shall be: , ,_

in itia l se tting tim e: no t less than 45 min :final setting tim e: no t m ore than 10 h.

6 Soundness6.1 T he c em en ts shall have en expansion of no t.:;,lo re than '10 mm when tested for soundness in accordance NittiBS 4550 : Section 3.7. '

Test age

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28I . R : ~ dhardeninq PO"':Od.~'--=::::---'-,-~::-:-.-._--:-:--""",,-_-=_ ..,...J.-~~_ ~. ~~ __J-- ,l_ -;;"._---

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Co nt ro ll ed f in en es s P or tl an ddays3 (72 1 h)

-'r'\~.:,:':l;~Strength

N/mm 2 .

N ot less than 25'

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Concrete Mortar

Ordi na ry P o rt la n d 3 (72 1 h)

N ot less than 13N ot less than 29 . . , ' - , i . - ; i 'N ot less than 41 " ,.';:';/' '

28 Not less than 34 Not less than 47and not m ore than 52 and not m ore thlm 67 .---_-.....---.--.-.---.:.._~-+--------+----------'--+-------~--..,2 (48 lh)~-~'"~,-~~.---~+---------~~r--~---------~.~.-~.

N ot iess than 52 ,',.;...

N ot less than 15 N ot less than 25 , S , : ; ~

N ot less than 15Not less than 38

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6.2 If tile cem ent fa ils to comply w ith 6.1, a further testshall be made by the som e method on another portion ofthe sam e sam ple after it has been aerated by being spreadout to a depth o f 7.0 rnrn to 80 rnrn at a re la tive hum idityof 50% to 80 % tor a to ta l period of 7 days:.6.3 If the expansion of this aera ted portion as describedin 6.2 does no t exceed 5 mrn, th e cement shall be deem edto comply w ith 6.1.

7 Coineressive strength7.1 C oncrete specim ensWhen tested in accordance w ith BS 4550 : Section 3.4 :1978, using concrete of m ix C1 of that standard ,the comp ressive strength of the cem en t shall be as givenin table 1.7.2 -M ortar specim ensW I1en 1e~ted in accordance w ith BS4550 : Section 3.4 :1978, using mortar of m ix V1 .of thatstandard,~he com pressive strength of the cem ent shall be as givenin ta ble 1 ..

,.8 Chemical composition8.1 In so lu ble r es id ueWhen determ ined in accordance w ith clause 3 of BS 4550 :Par t 2 : 1970, the proportion of inso luble residue shall

" no t exceed 1.5 %by mass.-8.2 M agnesium oxide

W h en d ete rm in ed in-accordance w ith 9.2 o f BS 4550 :Part 2 : 1970, the proportion of m agnesium oxid e shallno t exceed 4.0,% by m ass.8.3 ChlorideW hen det~1m ined in accordance with clause 17 ofBS 4550 : P art 2 : 1970, the chlo ride ion conten t shallno t exceed 0.10 o/c,' by m ass.8.4 T o t,,1 s ulp h urW hen tle tf:rm ined ill accordance w ith clause 12 ofOS 4550: Part 2 : 1970, the proportion of to ta l sulphurIexpressed as 503) shall no t exceed 3.0 % by m ass forcontrolled fineness Portland cem ent and 3.5 % by massfor o rd inary Portland cem ent and rap id- harden ingPo rtland C l)m ent. .W hen the trica lc ium alum inate con ten t (C3 A) is less then3. 5 % by m ass, the proportion of te-al su lp hu r (e xp re sse das SOJ ishall not exceed 2.5 % by rTHlS~ f or c on tr oll edfineness, o rd inary and rapid- harden ing Portland cem ents ..------_

B S 1 2 19S9

The 'trica lc ium alum inate conten t i;calcula ted Iro rn ,h efollowing:

(CJA) =2.65A - 1.69Fwhere

A is the prop 'o rtion (in %by' rr:assY "of alum in ium oxide(All 03) of the to ta l cernentdetermlned-ln accoro ancew ith 7~2 of BS 4550 :Part 2: 1970 exclud ing anyalum in ium oxide inthe insoluble resid ue (see 8.1:.

, '.,.~.,. .F is th e p ro po rtio n (In'% by mass) of Iron (II I) oxideof the to ta l cem ent determ ined lnaccordance Wi1hclause 8 of BS4550 : P art 2 : 1 9 7 6 . :

8.5 Loss on ign itionWh 'e n d et er ~in ed in accordance v.~ith ;3 .2 of BS 45SJ :Par t 2 : 1970, th e lo ss o n ig nitio n shall not exceed 3. 0 %by mass. " . .

9 Sampling and tests for.ccrnpliance .::-- .. '.rt; ,.'. : "J;:~: . .'~':'9 ..1 If required bythepurcnaser,;om pliance shall be

assessed by t~king a represen tativ" sa'rr.ip leo t'the cem ent -in accordance w ith BS 4550: Part 1 e ith er b efo re , C at ,-the tim e of, del iverv. A certifica te o iiam pli[19. as i i!u; tra ted in figure 3 of BS4550 : Pan 1 : :1978 Shad becom pleted at the tim e of sam pling and shall accorncanvthe sam ple . This certiflcateshall also confirm that thesam ple was stored in a clean dry afrtight rigid cont a.neim ade of p lastics, m etal o r g l.ass irrunediatelv after it V". 'JSt aken .9.2 Testing m ay be delayed for IJ P t~ '5weeks from ~hetim e of sam pling provided that there is confirm ation that::the sam ple has been stored continr ouslv in the m annerdescribed in 9.1. c9.3 When the cem ent is to be tesr- dtor chemical composi-tion (see clause 8) th e sa mp le s shall b e p re pa re d bv them ethod described in 1.2 .1 o f B S 4350 :. Part 2 1970.

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10 MarkingCon tro lled fineness, o rd inary ' o r repid-hardeninq Portland'cem ent shall be m arked on the bag, the certifica te .thedeliverv note or the invoice witnthe fol lowingparticulars: '

(a) the nam e, trade mark or other m e an s o f id cn tiiic atio 'nof the m anufacturer to facilita te traceabilitv to the ..works in which the Cement was -uanutacturcd: :.~.(b) the nam e of the m ateria l, i.e . ccn trc lled-tinencss,o rd inary or rapid- harden ing Por. Iand cement ,(c) the num ber and date of this ,d ritish S tandard ,i.e . BS 12 : 1989t. .

a s 811~ rc.~.?mm.~r.~d~s,I~Jaxi(r1Y":l.o~~.lrhloride' content: of the concrete-mix of 0.4 % chloride b y mass o f ceme~(inA_he m ix to (1:reduce the risk of corrosion of embedded metal. For prestressed concrete BS8110 also recommends a maximum value.of 0.1% .;,.'chloride kin- b y ' mass.' -', ,. " .~ . , , . . . ,~:--~ ." , . - . .~: .t rvia~king BS ',2 . : .1.9.8~pn or if) relaJion toe.oroduct.reorcsenrs a manufacturer's declaration of confermltv, i.e. aci;i'im by or on, behalf : ~:,:.of' Ihc m?n~\ J,cture_r_iha,t,thC"I?.ro'o,u,S~:.e~\~ the requir~~'\1,~Jl\5of the standard. The accur acv olth.e clalm l~ th'ere'or~' solely the re'PO")ibil!~~01,lhe~fl~lso!l niilRihg th~ 'claim.S"uc~ a dcciaration is not to be confused with third party certification of conloirolity;'which rnav ~"~ be' .F f; .d~sirablr, .

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6512 : 1989

11 Information t~ b~provided.~::1 1.1 C e rti fi ca te .\'1-:;;~ ~If req ueste d. th e m anu factu rer sh all p ro vId e a ce rtif ic ate .to aU irm that the cem en t com plie s w i t h . t hi s s ta n da rd .The ccn i::c ,,!,; sha ll s ta te that the C em en t con tains riOaddition~ O\11Cr th en th ose p erm itted by ,3.2 an d 3.3 and

I in c! ut Jl ! r es ul ts o f t he ! ': Jl lo w in g te ~t s':

50 .:lC!"l'55 (se e c la us e 6 );) cen1pressive strength at 2 days o r 3 d ays a s ap pro -

.7 GJYS { i f reques te l ): and~? dllYS, a nd w h eth erdtJ or m ortar specim ens w eretested (seeclause 7);

C hlo ri(!e c on ten t (see S 3); :~"\he con ten t o f alka li soluble in 'n itric acld determ ined

dunce w ith 16.2 ',axcep t 16.2.4.2) of as 4550 :2 . 1970, or by a n X ra y f lu ore ~c en ce te cn niq ue... ed " ga in st th e B ritl'.h S tan dard m eth od,ex pre sse d as th e ce rtif ie d so diu m o xid e e qu iv alen t

"'IIl":ltll,d OVCI th e m an ufac tu rer's la test 2 5 co nsecu uv e

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11.2 Add itional in fo rm ation :,.:h e fo llo wing info rr:n atio n sh ~1 I a lso b e m ad e ~v :~rl~ ble ,If r equested at the tim e of o rdering : . . .; ~ , , >.' . . ~~;

(a) the con ten ts o f silica , alum in ium oxide , Iron !III)oxide a nd c alcium oxide ; .(b) the conten t o f to tal sulphur (expressed as S03)(see 8 .4); .'(c) fo r p iqrnen tcd cem en ts, the tarqc t m ean p igm en tcon tent; . "(d ) an ind ication of the va riab ility o f the chlo ride'con ten t w hen its m ean level exceeds 0,05 % ~ Y m a ss;(e) ~n ind ication of the variab ility o f the sod ium oxide 'equivalen t for the m anufacturer's la test 25 com posite 'sam ples. ..,.

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. .Appendix

Appendix A. Product guidanceA.1 Safety warningDry cem en t in norm al use has no harm ful effec t on dryskin . W hen cem en t is m ixed w ith w ater. a lkali is re leased .P recautions should the refo re be taken to avo id dry cem en ten tering the eyes, m outh and nose and to preven t sk inco nta ct w ith . w et cem en t.Repeated skin con tac t w ith w et cem en t ove r a pe riod m aycause irritan t con tact derm atitis . T he abrasiveness o f thepertlc lcs o f cem en t and aggregate in m orta r o r concre tecan con tribute to th is effec t. Con tinued con tact during aw orking day can lead to cem en t burns w ith ulce ration,but th is is no t com mon. Som e peop le are sensitive to thesm all am oun ts o f chrom ate w hich m ay be presen t I nc em e .C lts a nd c an d ev elo p a lle rg ic c on ta ct d erm atitis,b ut th is . i , ~t ar e ..Wh e n wo rk in g i1 1 p laces w here dry cem en t becom esa irborne, p ro tection fo r the eyes, m outh an d n os e sh ou ldb e w orn .W he n w ork inqwith w et m ortar o r concrete , su itab lep ro tective clo t~ ing should be w orn such as long sleevedsh irts, fu ll len gth tro users , w ate r p ro of g l,o vesan d w ellin gto nboo ts . C lo th ing con tam inated w ith w et cem en t, m ortar o rconc rete should be ' rem oved and w ashed befo re furthe r use.If cem en t en ters the eye it should irnm ed la telv be w ashedout tho roughly w ith clean w ater and m edical treatm en tshould be sought w ithout delay. W et m ortar o r concreteon the skin should be w ashed of.' im rned iate lv ,

A.2 StorageTo pro tec t cem en t from prem ature hydra tion afterdelivery , bulk silo s should be w aterp roof and in ternalco nd on s atio nsh ou ld b e m in im iz ed .Pape r baas should be sto red c lear o f the ground , no t m ore 'than eight bags high and pro tec ted by a w ate rp roofstruc ture . A s sign ifican ,t strength losses begin after 4 to 6w eeks of sto rage in bags in norm al cond itions, and consider-ably sooner under adverse w ea ther cond itions o r highhum id ity , deliveries should be con tro lled and used in ordero f receip t. M anufac turers are able to p rovide a system ofmark inq a high proportion of the bags in each delivery toinch:at.; w hen they w ere [illcd. ' .

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BS 12 :'.1f)89

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A.3 Test temperature",~:+;~.:

.'.'~." ...BS 4550 requires that-the c oh l;x ei;iv es tr 'e ng th a nd s etti'n gtim e tests are carriedoutat atem p '~ rature o f 20 lOe.W hen cem en t is tested a t a d ifiere l1 i tem pera ture theresults a re likely to be affec ted , A 'ppr6pria te advice m ay be obtained from the m anufacture rs', ..

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A.4 Grouting and rendering. ,~ . -. ' . .;;J :\,. ,". . "W here cem en t is to be used in ~routs o r renders tha t are 'pum ped through sm all ape rtur~ ;:s 'u 'ch as sp ray nozz les;'it is recom mended tha t the cel(,en~orsuspension is passed through a sc reen of suitab lem esh: '~pertu[e to reta in any ' occasiona l coarse partic les ,.j;_ ;-' .' . ':~ ',

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A.5 Heat generation - \T he cem en t hydration process causes siqn if ican t generationof heat, This m ay be an advarnsqewhen sm all concrete ..sec tio ns are b ein g ca st o r w he n, cO ,ricretin g.is u nd erta ke n ..in co lde r w eathe r. This m ay be a d isadvan tage w hen large rconc rete sections are cast becausecf the tem perature ~ ..grad ien ts w hich can be set up ," > .,. . . . ?

' ~ . . , ~ \ ; . , ' . . ' . ' 1 " ~ When higher heat generation is required , rap id - ha rden ing 'cem en ts com plying w ith th is sr: n~~rdm ay be used , -:~tWhe n lo wer h ea t g en eratio n is ,'q q\.lired , co ntro l leo fin ~rie sscem en ts com plying w ith th is standard rnav be used , and-Inth es e c ir cum sta nc es .s ur fa ce a re il s: lie lo w : : 3 " 0 0 m~ Ik g wouldn o rm a ll y b e a p pr op ri at e :~>W: :'X : {; ,'BS 1370 sp ec 'ifie s re qu ire m en ts f9 Ei.~ w h ea t P ortla nd :'.. cem en t and BS 4246: P art 2 sj:e 'c1 fiesreq uirem en ts fo 'r; .low heat Portland- blastfur~ace c :eO len t. 'O ther cem en ts w hich m ay be be,)~fi~ial w ,hen low er heatso f h yd ratio n are req uired , are th ',)s~ ~co m.p ly in g w ;th 8S'146,. B S 4027 BS 6588 and a s 661'l.:~~(':, ', - . .. . . . . . :~:. , :, ~'"

': ,~ i " " : : : ':~ : . .. ..

A.6 Pigmented cements':The quan tity o f p igm en ted cem en t used in a COil';' cte o rm orta r m ix m ay need to be grC i.)ter than that o f i~'1,unp igm en ted cem en t to take accoun t o f the a rno .rn t o fp ig m en t p re se nt.

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8 rh is !l S ta n_ cj~ j, 1~i .1Vln9 been prepLJied uncJ'(~r the direction ofC~I neru, Gypsum. A~grcgates and Ouarry Products Standards

Cornmittce,cw.,s nubl ,ishcd, uncer tbc authority of the Bour d'SldllU conics i"t'~'i!lf':ct orl 28 Anr;1 1989'-itish Siunuarus lnsti tui ion, 1989published December 1904revision June 1907d revision AU9llst 1910revision March 19,15

h revision August 19:10revision October 1925revision November 1931

th revision July .1940 ,h revision November 1947

re vis io n March 1958hed in'metriC units as Part 2 July 1971nih revision as 6S 12 June 1978fth rl!V~sion April 1\)89

580~1nOl 5.,. ".;.....19 ;13~r reference,s relate to the work on t hi: standard:refl:rtlncc CASH Dr.,1t for comment 87/13451 DC'o ~u - - -_

JIT1 8 2 2 0 0 2 2and for telex 825777, " i > , : ' 1 i / i,' 'Contract requirements. A British Standard do~s,ncii purp'ort toinclude all 'he necessary provisions of a cOIVrfct. L~~rs'6J BritishStandards arc responsible for their correct ap~licaticf', ,-":", ,. ... . .....Revision of British Standards, Br itish St andnrds are .(!vi~~d; whennecessarv , by the issue either of amendments or of r nvised ediricns.II is Important thatusers o(Uri tish Standards shoulc' rscertain thatthey are in p ossession of tho latust amendmentsor eclltions,Automatic updating service. BSI provides an cconorruc, 'individua'!and automatic standards updating service called PLUS:Oetails areavailable from SSI Enquiry Section at Millon Keynes" telephone0908 221166, tl!lex 825777, '~i?',Information on all BSI nubticaticns is in the aSI Catil/o9~e,suoplemerued each month by BSI News which is available tosubscribin'g members of OSI and gives details of new publications,revisions, amendments and withdrawn standards. Any person who,when making us e of a Br itisn Standard, encounters an inaccuracy 01ambiguity, is r equest ed to uo nlv BSI without dclav ;'r order thatthe matter may be lnvest iqated and appropriate acuo.: taken"

mmittees responsibletor this British Standardpreparution of this British Standard was entrusted by theent, Gypsum, Aggrc9aies and Quarry Products StandardscyCom(n'itlce (CAB/,) to Technical Committee CAB/1,n which the following bodies were represented:of Consul tinq Engineers

Development AssociationtishAggregate Construction Materials Industriestish'Cement Associat iontiSh Precast Concrete FederationtiS,h Ready Mixed Concrete Association

Steel Industry "Slag Makur s' Association

~rcte soc.ew '

rnendrnent s issued since publication

County Surveyors' SocietyDepartment of the Environment (Building Hesear ch Gstablishment)Department of the Environment (Property Services "ge(lcyl ,Department of Transport .'.,::::Electricity Supply Industry in England and WalesFederation of Civil Engineering ContractorsInstitution of Civil EngineersInstitution of Structural EngineersMortar Producers' AssociationRoyal Institution of Chartered SurveyorsSociety of Chemical IndustryWater Authorities Association

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No, T ext affected J . , , ;r ~ ~ - : \i " ; 'Date of issue

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riush Stan,dmcls!nstitLitioin . 2,parkStreet LondonW1A 2BS', Telephone01629 9000 Telex,,266933