AS 1012.20-1992 Methods of Testing Concrete - Concrete and C PDF

 

 

Title   AS 1012.20-1992 1012.20-1992 Methods of testing concrete - Determination Determination of chloride and and sulfate in hardened concrete and concrete aggregates

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AS 1012.20–1992 

Australian Standard

Methods of testing concrete Method 20: Determination of chloride and sulfate in hardened concrete and concrete aggregates PREFACE This Standard has been prepared by the Standards Australia Committee on Methods of  Testing Concrete Testing  Concrete in response to the introduction of limits on chloride and sulfate in AS 3600, Concrete structur ees. s. The method of solution provides aliquots (separate portions) which may be tested in an aggregate concrete laboratory by adetectable quantitative method to indicate whether or sulfides are sulfides  areorpresent above a threshold quantity which will require full chlorides quantitative determination in an analytical laboratory.  .    d   e

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CONTENTS Page

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SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . REFERENCED DOCUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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PRINCIPLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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REAGENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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APPARATUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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SAMPLING AND SAMPLE PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . .

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PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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RECORDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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REPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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METHOD This(including Standard sets out oxidizable a method for the determination of chloride content and 1 SCOPE sulfate content easily sulfide content) of concrete and concrete aggregates. The solutions obtained from the sample may also be used to determine the acid–soluble calcium oxide content of these materials. The method of solution will react with and dissolve any easily oxidizable sulfides which are present and present  and these will be reported as sulfate. Such sulfides have been shown to be deleterious to concrete and the method provides an approach to limiting their inclusion in concrete and concrete aggregates. concrete  aggregates. For compliance with the relevant requirements specified in AS 3600, additional tests and calculations may be required. NOTES: 1 Separate test methods are available for the analysis of the other concrete–making materials, e.g. cementious materials, admixtures, water. 2

Gross var variation iationss in the chloride and su sulfate lfate cont contents ents of concrete concrete and concrete–mak concrete–making ing materials materials can occur

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over distances of even a few millimetres. This can be caused, for example, by leaching with rainwater, surface evaporation and crusting and penetration of salt and ground waters. Sampling technique is of prime importance. As the effect of the use of water during coring, especially small diameter cores, can be significant, the amount of water used should be restricted.

 

AS 1012.20— 1012.20—1992 1992

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The fo foll llow owin ing g docu docume ment ntss ar aree re refe ferr rred ed to in th this is St Stan anda dard rd:: 2 REFE REFERENCE RENCED D DOCUM DOCUMENTS ENTS The AS 1012 Methods of testing concrete 1012.14 Method 14: Method for securing and testing cores from hardened concrete for compressive compre ssive stren strength gth 1152

Test sieves

3600

Concrete structures

BS 1881 Testing concrete 1881.124 Part 124: Methods for analysis of hardened concrete Thee sam ampl plee is diss issolve olved d in hot hot 20% 20% (V (V/V /V)) nitr nitric ic aci cid d to prov provid idee a solu soluti tion on fr fro om 3 PRINC PRINCIPLE IPLE Th wh whic ich h al aliq iquo uots ts ma may y be test tested ed fo forr ch chlo lori ride de an and d su sulf lfat atee co cont nten ent. t. 4 REA REAGEN GENTS TS Anal Analyt ytic ical al qual qualit ity y re reag agen ents ts sh shal alll be used used.. Th Thee fo foll llow owin ing g ar aree re requ quir ired ed:: (a)   Distilled water  Dist Distil ille led d wate waterr sh shal alll be used used fo forr the the prep prepar arat atio ion n of al alll re reag agen ents ts an and d st stan anda dard rd solutions. (b)   Ni Nitr tric ic aci acid d (1 (1:4) :4) Cautiously add 100 mL of nitric acid (15 mol/L or

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1.42 g/mL) to

400 400 mL of wate waterr wh whil ilee stirr tirrin ing. g. (c)   Silve Silverr nitr nitrate ate solution solution Dissolve lve 1 g of silver nitra ratte in 100 mL of water. (d)   Methy Methyll orange solut solution ion Dissolve 0.1 g in 100 mL of water. (e)   Barium chloride solution Dissolve 5 g of bariu rium chloride in 100 mL of water.  .    d   e    t    i    b    i    h   o   r   p    k   r   o   w    t   e   n   n   o   e   s   u   r   o   n   o    i    t   u    i    b   r    t   s    i    d  ,   e   g   a   r   o    t    S  .   y    l   n   o   e   c   e   n   c    i    l   r   e   s   u   e    l   g   n    i    S  .    2    0    0    2   n   u    J    4

(f)   Ammonium Ammonium hydroxide hydroxide soluti solution on Carefully add 100 mL of concentrated (28% (m/m) or 0.89 g/mL g/mL)) ammon mmonia ia solu soluti tion on to 400 400 mL of wate waterr with with st stir irri ring ng.. 20 0.89 (g)   Standard sodium chloride solution. (h)   Standard potassiu potassium m sulfate solution. NO NOTE TE:: Pr Prot otec ecti tive ve glas glasse sess sh shoul ould d be wo worn rn wh when en handl handlin ing g co conc ncent entrat rated ed re reag agent ents. s.

The foll follow owin ing g appa appara ratu tuss is re requ quire ired: d: 5 APPA APPARATUS RATUS The (a) 6.7 mm, 1.18 mm and 150   µm sieve ievess co comp mply lyin ing g with with AS 1152 1152.. (b) A drying oven capable of operating ing in the temperature ra ran nge 100°C to 110°C. (c) A grinder capable of grinding hardened concrete and concrete-m -maaking materials to pass a 150   µm sie sieve. ve. NO NOTE TE:: A ri ring ng grind grinder er is reco recomm mmen ended ded..

6 SAMPLING AND SAMPLE PREPARATION PREPARATION Samplin ling g re requ quir irem emen ents ts shal shalll be full fully y deta detail iled ed by th thee spec specif ifyi ying ng auth author orit ity. y. 6.1 Gen General eral Samp NOTES: 1 It is re reco comm mmen ende ded d that that sa samp mple less from from ha hard rden ened ed co conc ncre rete te be take taken n in ac acco cord rdan ance ce wi with th AS 10 1012 12.1 .14. 4. 2 Wher Wheree th thee mate materi rial alss requ requir iree spec specia iall sa sampl mplin ing g tech techniq nique ues, s, i.e. i.e. dune dune sa sands nds,, ra rain inwa wate terr-le leac ache hed d and and ac acid id-et -etche ched d surf surfac aces es,, co conc ncre rete te su subj bjec ectt to sp spra ray, y, es estu tuar arin inee an and d dred dredge ged d ag aggr greg egat ates es,, gu guid idan ance ce is av avai aila labl blee in BS 18 1881 81:: Part Part 12 124. 4.

ieve ve is re requ quir ired ed,, but but 6.2 Samp Sample le prepara preparation tion Ideally a minimum of 50 g passing the 150   µm sie fo forr in inve vest stig igat atio ions ns of sulf sulfat atee or chlo chlori ride de pene penetr trat atio ion n in co conc ncre rete te,, a to tota tall samp sample le of not not le less ss th than an 20 g shal shalll be prep prepar ared ed.. The The proc proced edur uree is as fo foll llow ows: s: (a) (a) Pr Prog ogre resssi sive vely ly crus rush larg largee sampl amplees unti untill the the sam ampl plee is ab able le to pass pass a 6. 6.7 7 mm sie ieve ve an and d sp spli litt the the sample to not less than 500 g. (b) Further crush the reduced sample until it will pass a 1.18 mm sieve and split the sample to not less than 50 g. (c) lo Grss ind e mple re red dle. uc. ed sample to pass a 150 µm siev sieve. e. Avoi Avoid d ex exce cept ptio iona nall lly y fine fine grin grindi ding ng an and d avoi avoid d loss ofthsamp sa

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(d (d)) Where here nece necess ssar ary, y, grin grind d any ce ceme ment nts, s, fl fly y ashe ashes, s, sla slag or othe otherr powd powder ered ed ad admi mixt xtur ures es to pas pass a 150   µm sie sieve. ve. (e) Dry the sample to a constant mass at a temperature of 100°C to 110°C. 7 PROC PROCEDURE EDURE The proc proced edur uree is as fo foll llow ows: s: 7.1 Prep Preparati aration on of the sa sample mple solutio solution n The (a) Weigh out an accurate mass of the dried sample as given in Table 1 into a 250 mL beaker.

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AS 1012.20—1992

(b (b)) Dis Dispers persee in a fe few w mill millil ilit itre ress of dist distil ille led d water ater (s (see ee Cla laus usee 4(a 4(a) and add the the re rele leva vant nt am amou ount nt of nitric acid (s (seee Clause 4(b)) as shown in Table 1. (c) Bring the solution to the boil in a covered beaker and boil gently for 2 min. NO NOTE TE:: It is im impo port rtan antt that that no sign signif ific ican antt ev evap apor orat atio ion n oc occu curs rs,, as ch chlo lori ride de lo loss ss wi will ll be si sign gnif ific ican antt if th thee ni nitr tric ic ac acid id is co conc ncent entrat rated ed to more more than than 50% 50%..

(d) After cooling, allow the coarse material to settle and decant the solution into a 250 mL grad gradua uate ted d fl flaask. sk. Wa Wassh the the bea beaker ker an and d coar coarse se re ressidue idue sev ever eraal ti time mess wi with th dis disti till lleed wat ater er by decantation. (e) (e) Mak akee up the the deca decan nted ted solu soluti tio on to the the co corr rrec ectt volu volume me and mi mix x thor thorou ough ghly ly,, the then al allo low w to st staand undisturbed for at least 1 h. NO NOTE TE:: The above above proce procedur duree norma normall lly y obvi obviat ates es filt filtra rati tion on for for ca calc lciu ium m oxide oxide and chlo chlori ride de deter determin minat atio ions ns and gr grea eatl tly y re reduc duces es th thee time time requi required red for for pre prefi filt ltra rati tion on for for sulf sulfat atee dete determ rmina inati tion on es espec pecia iall lly y with with sa sampl mples es cont contai aini ning ng hi high gh amoun amounts ts