ASTM C1293-2018 Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction.pdf

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1、Designation: C1293 18Standard Test Method forDetermination of Length Change of Concrete Due to Alkali-Silica Reaction1This standard is issued under the fixed designation C1293; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye

2、ar of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the sus-ceptibility of an aggregate or combination of an aggregate

3、 withpozzolan or slag for participation in expansive alkali-silicareaction by measurement of length change of concrete prisms.1.2 The values stated in SI units are to be regarded as thestandard. No other units of measurement are included in thisstandard. When combined standards are cited, the select

4、ion ofmeasurement system is at the users discretion subject to therequirements of the referenced standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, h

5、ealth, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.(WarningFresh hydraulic cementitious mixtures are causticand may cause chemical burns to skin and tissue uponprolonged exposure.2)1.4 This international standard was developed in accor-dance wi

6、th internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standard

7、s:3C29/C29M Test Method for Bulk Density (“Unit Weight”)and Voids in AggregateC33 Specification for Concrete AggregatesC125 Terminology Relating to Concrete and Concrete Ag-gregatesC138/C138M Test Method for Density (Unit Weight), Yield,and Air Content (Gravimetric) of ConcreteC143/C143M Test Method

8、 for Slump of Hydraulic-CementConcreteC150 Specification for Portland CementC157/C157M Test Method for Length Change of HardenedHydraulic-Cement Mortar and ConcreteC192/C192M Practice for Making and Curing Concrete TestSpecimens in the LaboratoryC227 Test Method for Potential Alkali Reactivity ofCem

9、ent-Aggregate Combinations (Mortar-Bar Method)C294 Descriptive Nomenclature for Constituents of Con-crete AggregatesC295 Guide for Petrographic Examination ofAggregates forConcreteC490 Practice for Use ofApparatus for the Determination ofLength Change of Hardened Cement Paste, Mortar, andConcreteC49

10、4/C494M Specification for Chemical Admixtures forConcreteC511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used in theTesting of Hydraulic Cements and ConcretesC618 Specification for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in ConcreteC702 Pract

11、ice for Reducing Samples ofAggregate toTestingSizeC856 Practice for Petrographic Examination of HardenedConcreteC989 Specification for Slag Cement for Use in Concrete andMortarsC1240 Specification for Silica Fume Used in CementitiousMixtures1This test method is under the jurisdiction of Committee C0

12、9 on Concrete andConcrete Aggregates and is the direct responsibility of Subcommittee C09.50 onAggregate Reactions in Concrete.Current edition approved May 1, 2018. Published July 2018. Originally approvedin 1995. Last previous edition approved in 2015 as C1293 08b(2015). DOI:10.1520/C1293-18.2Secti

13、on on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standards, Vol. 04.02.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the sta

14、ndards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with international

15、ly recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1C1260 Test Method for Potential Alkali Reactivity of Ag-

16、gregates (Mortar-Bar Method)D75 Practice for Sampling Aggregates2.2 CSA Standards:4CSA A23.2-14A Potential Expansivity of Aggregates (Pro-cedure for Length Change due to Alkali-Aggregate Reac-tion in Concrete Prisms at 38 C)CSA A23.2-27A Standard Practice to Identify Degree ofAlkali-Reactivity of Ag

17、gregates and to Identify Measuresto Avoid Deleterious Expansion in ConcreteCSAA23.2-28A Standard Practice for Laboratory Testing toDemonstrate the Effectiveness of Supplementary Cement-ing Materials and Lithium-Based Admixtures to PreventAlkali-Silica Reaction in Concrete3. Terminology3.1 Terminolog

18、y used in this standard is as given in Termi-nology C125 or Descriptive Nomenclature C294.4. Significance and Use4.1 Alkali-silica reaction is a chemical interaction betweensome siliceous constituents of concrete aggregates and hy-droxyl ions (1).5The concentration of hydroxyl ion within theconcrete

19、 is predominantly controlled by the concentration ofsodium and potassium (2).4.2 This test method is intended to evaluate the potential ofan aggregate or combination of an aggregate with pozzolan orslag to expand deleteriously due to any form of alkali-silicareactivity (3,4).4.3 When testing an aggr

20、egate with pozzolan or slag, theresults are used to establish minimum amounts of the specificpozzolan or slag needed to prevent deleterious expansion.Pozzolan or slag from a specific source can be tested individu-ally or in combination with pozzolan or slag from othersources.4.4 When selecting a sam

21、ple or deciding on the number ofsamples for test, it is important to recognize the variability inlithology of material from a given source, whether a deposit ofsand, gravel, or a rock formation of any origin. For specificadvice, see Guide C295.4.5 This test method is intended for evaluating the beha

22、viorof aggregates in portland cement concrete with an alkali (alkalimetal oxide) content of 5.25 kg/m3or in concrete containingpozzolan or slag with an alkali content proportionally reducedfrom 5.25 kg/m3Na2O equivalent by the amount of pozzolanor slag replacing portland cement. This test method ass

23、essesthe potential for deleterious expansion of concrete caused byalkali-silica reaction, of either coarse or fine aggregates, fromtests performed under prescribed laboratory curing conditionsthat will probably differ from field conditions. Thus, actualfield performance will not be duplicated due to

24、 differences inconcrete alkali content, wetting and drying, temperature, otherfactors, or combinations of these (5).4.6 Results of tests conducted on an aggregate as describedherein should form a part of the basis for a decision as towhether precautions should be taken against excessive expan-sion d

25、ue to alkali-silica reaction. Results of tests conducted oncombinations of an aggregate with pozzolans or slag shouldform a part of the basis for a decision as to whether the specificpozzolan or slag, when used in the amount tested, was effectivein preventing excessive expansion. These decisions sho

26、uld bemade before a particular aggregate is used in concrete con-struction. Criteria to determine the potential deleteriousness ofexpansions measured in this test are given in Appendix X1.4.7 When the expansions in this test method are greater thanthe limit shown in X1.2, the aggregate or combinatio

27、n ofaggregate with the tested amount of pozzolan or slag ispotentially alkali-reactive. Supplemental information should bedeveloped to confirm that the expansion is actually due toalkali-silica reaction. Petrographic examination of the concreteprisms should be conducted after the test using Practice

28、 C856to confirm that known reactive constituents are present and toidentify the products of alkali-silica reactivity. Confirmation ofalkali-silica reaction is also derived from the results of the testmethods this procedure supplements (see Appendix X1).4.8 If the supplemental tests show that a given

29、 aggregate ispotentially deleteriously reactive, additional studies may beappropriate to evaluate preventive measures in order to allowsafe use of the aggregate. Preventive measures are mentionedin the Appendix to Specification C33.4.9 This test method does not address the general suitabilityof pozz

30、olans or slag for use in concrete. These materials shouldcomply with Specification C618, Specification C989, or Speci-fication C1240.5. Apparatus5.1 The molds, the associated items for molding testspecimens, and the length comparator for measuring lengthchange shall conform to the applicable require

31、ments of TestMethod C157/C157M and Practice C490, and the molds shallhave nominal 75-mm square cross sections.5.2 The storage container options required to maintain theprisms at a high relative humidity are described in 5.2.1.5.2.1 Recommended ContainerThe recommended con-tainers are 19 to 22-L poly

32、ethylene pails with airtight lids andapproximate dimensions of 250- to 270-mm diameter atbottom, 290 to 310 mm at top, by 355 to 480 mm high. Preventsignificant loss of enclosed moisture due to evaporation withairtight lid seal. Place a perforated rack in the bottom of thestorage container so that t

33、he prisms are 30 to 40 mm above thebottom. Fill the container with water to a depth of 20 6 5mmabove the bottom. A significant moisture loss is defined as aloss greater than 3 % of the original amount of water placed atthe bottom of the pail. Place a wick of absorbent materialaround the inside wall

34、of the container from the top so that thebottom of the wick extends into the water (See Note 1).5.2.2 Alternative ContainersAlternative storage contain-ers may be used. Confirm the efficiency of the alternative4Available from Canadian Standards Association (CSA), 5060 Spectrum Way,Mississauga, ON L4

35、W 5N6, Canada, http:/www.csa.ca.5The boldface numbers in parentheses refer to the list of references at the end ofthis test method.C1293 182storage container with an alkali-reactive aggregate of knownexpansion characteristics.6The expansion efficiency is con-firmed when expansions at one year obtain

36、ed using thealternative container are within 10 % of those obtained usingthe recommended container. Alternative storage containersmust contain the required depth of water. When reportingresults, note the use of an alternative container, if one is used,together with documentation proving compliance w

37、ith theabove.NOTE 1Polypropylene geotextile fabric or blotting paper are suitablematerials for use as the wick.5.3 The storage environment necessary to maintain the 38.0C reaction accelerating storage temperature consistently andhomogeneously is described in 5.3.1.5.3.1 Recommended EnvironmentThe re

38、commended stor-age environment is a sealed space insulated so as to minimizeheat loss. Provide a fan for air circulation so the maximumvariation in temperature measured within 250 mm of the topand bottom of the space does not exceed 2.0 C. Provide aninsulated entry door with adequate seals so as to

39、minimize heatloss. Racks for storing containers within the space are not to becloser than 30 mm to the sides of the enclosure and are to beperforated so as to provide air flow. Provide an automaticallycontrolled heat source to maintain the temperature at 38.0 62.0 C (see Note 2). Record the ambient

40、temperature and itsvariation within the space to ensure compliance.NOTE 2It has been found to be good practice to monitor the efficiencyof the storage environment by placing thermocouples inside dummyconcrete specimens inside a dummy container within the storage area. Thestorage room described in Te

41、st Method C227 generally will be satisfac-tory.5.3.2 Alternative Storage EnvironmentUse of an alterna-tive storage environment is permitted. Confirm the efficiencyof the alternative storage container with an alkali-reactiveaggregate of known expansion characteristics.6The expansionefficiency is conf

42、irmed when expansions at one year obtainedusing the alternative storage environment are within 10 % ofthose obtained using the recommended environment. Whenreporting the results, note the use of an alternative storageenvironment, if one is utilized, together with documentationproving compliance with

43、 the above.6. Reagents6.1 Sodium Hydroxide (NaOH)USP or technical grademay be used. (WarningBefore using NaOH, review: (1) thesafety precautions for using NaOH; (2) first aid for burns; and(3) the emergency response to spills as described in themanufacturers Material Safety Data Sheet or other relia

44、blesafety literature. NaOH can cause severe burns and injury tounprotected skin and eyes. Always use suitable personalprotective equipment including: full-face shields, rubberaprons, and gloves impervious to NaOH (Check periodicallyfor pinholes.).)6.2 Water:6.2.1 Use potable tap water for mixing and

45、 storage.7. Materials7.1 CementUse a cement meeting the requirements for aType I Portland cement as specified in Specification C150. Thecement must have a total alkali content of 0.9 6 0.1 % Na2Oequivalent (Na2O equivalent is calculated as percent Na2O+0.658 percent K2O). Determine the total alkali

46、content of thecement either by analysis or by obtaining a mill run certificatefrom the cement manufacturer. Add NaOH to the concretemixing water so as to increase the alkali content of the mixture,expressed as Na2O equivalent, to 1.25 % by mass of cement(see Note 3).NOTE 3The value of 1.25 % Na2O eq

47、uivalent by mass of cement hasbeen chosen to accelerate the process of expansion rather than toreproduce field conditions. At the 420 kg/m3cement content, thiscorresponds to an alkali level of 5.25 kg/m3.7.2 Aggregates:7.2.1 To evaluate the reactivity of a coarse aggregate, use anonreactive fine agg

48、regate. A nonreactive fine aggregate isdefined as an aggregate that develops an expansion in theaccelerated mortar bar, (see Test Method C1260) of less than0.10 % at 14 days (see X1.6 for interpretation of expansiondata). Use a fine aggregate meeting Specification C33 with afineness modulus of 2.7 6

49、 0.2.7.2.2 To evaluate the reactivity of a fine aggregate, use anonreactive coarse aggregate. Prepare the nonreactive coarseaggregate according to 7.2.3.6A nonreactive coarse aggregateis defined as an aggregate that develops an expansion in theaccelerated mortar bar (see Test Method C1260) of less than0.10 % at 14 days (see X1.6 for interpretation of expansiondata). Use a coarse aggregate meeting Specification C33. Testthe fine aggregate using the grading as delivered to thelaboratory.7.2.3 Sieve the coarse aggregate and recombine in accor-dance with the requireme