METHOD OF TEST FOR THE DETERMINATION OF POTENTIAL ALKALI-CARBONATE REACTIVITY OF. CARBONATE ROCKS BY CHEMICAL COMPOSITION

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1 Labratry Testing Manual Date., Page 1 f 5 METHOD OF TEST FOR THE DETERMINATION OF POTENTIAL ALKALI-CARBONATE REACTIVITY OF. CARBONATE ROCKS BY CHEMICAL COMPOSITION 1. SCOPE 1.1 This methd cvers a prcedure fr testing quarried carbnate aggregates t determine whether r nt they are ptentially alkali- carbnate expansive. 1.2 Alkali-carbnate reactive aggregates are dlmitic limestnes with a high clay cntent. Other carbnate rcks are nt alkali- carbnate reactive. Dlmitic limestne may be recgnized by determining CaO : MgO rati. Clay cntent may be determined by measuring alumina (AI 23) cntent. 1.3 Carbnate rcks which are nt alkali-carbnate reactive may be alkali-silica reactive. This test prcedure des nt determine the ptential fr alkali-silica reactivity. 2. RELEVANT DOCUMENTS 2.1 ASTM C 72, Methds f Reducing Field Samples f Aggregate t Testing Size. 2.2 CSA-A A, Sampling Aggregates fr Use in Cncrete. 2.3 CSA-A A, Determinatin f Ptential Alkali-Carbnate Reactivity f Quarried Carbnate Rcks by Chemical Cmpsitin. 3. APPARATUS 3.1 Crushing Equipment - a small jaw crusher r ther suitable equipment capable f crushing apprximately 2 kg f aggregate t pass a 2. mm sieve. 3.2 Grinding Equipment - a chatter bx r ther suitable equipment capable f grinding apprximately 3 g f aggregate t pass a 15 pm sieve. 4. SELECTION AND PREPARATION OF TEST SAMPLES 4.1 The prcedures utlined in CAN/CSA-A23.2-1A shuld be fllwed t btain a representative sample f the aggregate t be tested. The sample, if pssible, shuld be btained frm a stckpile f aggregate prduced in a manner identical t that which will be used in subsequent prductin The prcedures utlined in ASTM C 72 shuld be fllwed t btain representative test specimens f the aggregate sample. The mass f the test specimens is determined by the particle size f the aggregate as shwn in Table 1.

2 Ministry f Transprtatin, Ontari Test Methd LS-615, Rev. N. 16 Labratry Testing Manual Date: Page 2 f 5 Table 1 Pass Retain Apprx. Mass g 19. mm 13.2 mm mm 9.5 mm mm 6.7 mm mm 4.75 mm N attempt shuld be made t btain the required test specimen mass by adding r subtracting individual pieces. When preparing test specimens f aggregates larger in size than 2 mm, the mass f the sample shuld be such that a minimum f 2 particles will be btained f each sieve size. 4.3 The varius test specimens shall be cmbined and crushed, using a small bench crusher, r ther suitable means, s that the entire sample passes a 2. mm sieve. Care shuld be taken that the jaw crusher is clean, and that n material is lst. 4.4 The crushed test specimen shall be mixed thrughly, and further separated, using a sample splitter t btain a specimen f abut 3 g. This 3 g test specimen shall be pulverized, using suitable equipment s that it passes a 15 pm sieve. Any material retained n the 15 lam sieve shall be further treated t pass the sieve. Care shuld be taken that n material is lst. 4.5 The pass 15 tam sieve specimen shall be mixed thrughly, and split t btain specimens f a suitable size fr chemical analysis. 5. TEST PROCEDURE 5.1 Where analytical data btained in accrdance with this methd are required, any methd may be used that meets the requirements f 5.2. A methd is cnsidered t cnsist f the specific prcedures, reagents, supplies, equipment, instrument, etc., selected and used in a cnsistent manner by a specific labratry. Nte 1 : Examples f methds used successfully fr analysis f carbnate rcks are given in references 1, 2, and If mre than ne instrument, even thugh substantially identical, is used in a specific labratry fr the same analyses, use f each instrument shall cnstitute a separate methd, and each shall be qualified separately. 5.2 Qualificatin f a Methd - Prir t use fr analysis f aggregate, the methd chsen must be qualified fr such analysis Using the methd chsen, make single determinatins fr each xide n the Standard Reference Materials (see nte). Cmplete tw runds f tests n nn-cnsecutive days, repeating

3 Labratry Testing Manual Date: Page 3 f 5 all steps f sample preparatin. Calculate the differences between values and averages f the values fr the tw rund f tests. Nte 2: The Standard Reference Materials are Natinal Institute f Standards and Technlgy, Gaithersburg, Maryland, Reference Materials Ns. 1C and 88A The differences between duplicates shall nt exceed the limits shwn in clumn 3 f Table The average fr each cmpnent shall nt differ frm the certified cncentratins by mre than the value shwn in clumn 4 f Table REPORT 6.1 The reprt shall include the fllwing: Surce f aggregate including a descriptin f the elevatin and lcatin f the quarry face that was sampled Any relevant infrmatin cncerning the preparatin f the sample Maximum size f the aggregate The weight percentage f the varius xides t the nearest.1 percent The type f analytical methd used, tgether with data t shw that the methd used meets the precisin and accuracy limits shwn in Table 2. Table 2 Maximum Pennissable Variatin in Results Clumn 1 Clumn 2 Clumn 3 Clumn 4 Standard reference Cmpnent Maximum difference Maximum difference f material (S.R.M.) between duplicates the average f duplicates frm the S.R.M. certificate values N.I.S.T. 1C Ca.6% t.5 % MgO.1% ±.1% A123.1 % +.2% N.I.S.T. 88A CaO.5% ±.5 MgO.4% ±.5 % A63.1 % ±.1 7. INTERPRETATION OF RESULTS 7.1 A crrelatin between data btained by this methd, expansin f cncrete prisms, rck cylinders, and perfrmance f aggregates in cncrete structures has been published (4). On the basis f this data, an area n the graph in Figure 1 has been established where ptentially expansive

4 Labratry Testing Manual Date: Page 4 f 5 alkali-carbnate reactive rcks are fund. Aggregates that fall in this area shuld be cnsidered t be ptentially deleterius until the inncuus character f the aggregate is demnstrated by service recrds r by a supplementary test in accrdance with CSA-A23.14A. 8. PRECISION Preliminary data indicate that the mufti-labratry cefficient f variatin (fr experienced labratries) is dependent upn the element being analyzed. Mufti-labratry cefficient f variatin, fr an alkali-carbnate reactive rck, btained in a study with twelve participants is given in Table 3. The D2S values are the limits that shuld nt be exceeded by the difference between the results f tw prperly cnducted test, in different labratries, expressed as a percent f their mean. These values are nly applicable t carbnate rck with a chemical cmpsitin similar t that given in Table 3. Table 3 Mufti-Labratry Variatin Ca Mg CaO : Mg AI23 Value C. Of V.' 1.5% 6.9% 7.6%, 13% D2S" 4.3% 2% 22% 37 ' Cefficient f variatin " D2S = acceptable maximum difference between tw results (see ASTM C 67). 9. REFERENCES 9.1 SHAPIRO, L. ; 1975, Rapid Analysis f Silicate, Carbnate and Phsphate Rcks - Revised Editin ; United States, Gelgical Survey, Bulletin 141, 76 p. 9.2 NORRISH, K., and CHAPPELL, B.W. ; 1977, X-ray Flurescence Spectrmetry ; in Physical Methds in Determinative Mineralgy, Ed by J. ZUSSMAN, Academic Press, Lndn, Chapter 5, pp ASTM C25-83 Standard Methds f Chemical Analysis f Limestne, Quicklime and Hydrated Lime ; Annual Bk f ASTM Standards, Vl ROGERS, C.A. ; 1985 Evaluatin f the Ptential fr Expansin and Cracking Due t the Alkali-Carbnate Reactin ; Ontari, Ministry f Transprtatin and Cmmunicatins, Engineering Materials Office, Reprt EM-75, 38 p., Feb. Als published in Cement, Cncrete and Aggregates, CCAGDP, Vl. 8, N. 1, Summer 1986, pp

5 r Q 1 ROCK CYLINDER EXPANSION TEST (ASTM C-586) CONCRETE PRISM EXPANSION TEST (C5A A232-14A) 2 1 s 1 2 f O 1 u 1 O <.17. E.pnnn at 4 Weeks 6 <.251. E.pn.in f I Yea, O <.17. f 4 Weeks but >27. at 16 Wl, in N 2 Equivalent Curant " >.17. E.pmin f 4 Wlf " > E.pnun at I Yew in Na2 Equivalent Cement O GGREGATES CONSIDERED 6 & NON-EXPANSIVE ~ 12.~. O d) a " AGGREGATES CONSIDERED -. a POTENTIAItV q e --- n EXPANSIVE " " 4 4 _--- "!-._."" P ill ~O ON AGGREGATES CONSIDERED NON E XPA NSIVE.J 4 s a A123 IN PERCENT r 1 y d J Elf f IIf O G O v U1 Figure 1 :111ustratin Of The Divisin Between Nn-Expansive And c Ptentially Expansive Aggregates On Basis Of Chemical Cmpsitin, -. ~