ASTM C1293-2008b(2015) Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction《测定碱硅反应导致产生的混凝土长度变化的标准试验方法》.pdf

《ASTM C1293-2008b(2015) Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction《测定碱硅反应导致产生的混凝土长度变化的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM C1293-2008b(2015) Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction《测定碱硅反应导致产生的混凝土长度变化的标准试验方法》.pdf（7页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: C1293 08b (Reapproved 2015)Standard 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

2、of revision, the year 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 combinat

3、ion of an aggregate 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 ar

4、e cited, the selection 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 app

5、ro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. (WarningFreshhydraulic cementitious mixtures are caustic and may causechemical burns to skin and tissue upon prolonged exposure.2)2. Referenced Documents2.1 ASTM Standards:3C29/C29M Test Me

6、thod 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 for Slump of Hydra

7、ulic-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 ofCement-Aggregate Combi

8、nations (Mortar-Bar Method)C289 Test Method for Potential Alkali-Silica Reactivity ofAggregates (Chemical Method)C294 Descriptive Nomenclature for Constituents of Con-crete AggregatesC295 Guide for Petrographic Examination ofAggregates forConcreteC490 Practice for Use ofApparatus for the Determinati

9、on ofLength Change of Hardened Cement Paste, Mortar, andConcreteC494/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 As

10、h and Raw or CalcinedNatural Pozzolan for Use in ConcreteC702 Practice 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 Cementitious

11、MixturesC1260 Test Method for Potential Alkali Reactivity of Ag-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 A23.2-27

12、A Standard Practice to Identify Degree ofAlkali-Reactivity of Aggregates and to Identify Measures1This test method is under the jurisdiction of Committee C09 on Concrete andConcrete Aggregatesand is the direct responsibility of Subcommittee C09.26 onChemical Reactions.Current edition approved Aug. 1

13、, 2015. Published October 2015. Originallyapproved in 1995. Last previous edition approved in 2008 as C1293 08b. DOI:10.1520/C1293-08BR15.2Section on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standards, Vol. 04.02.3For referenced ASTM standards, visit the ASTM

14、website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from Canadian Standards Association (CSA), 5060 Spectrum Way,Mississauga, ON L4W 5N6, Canada, htt

15、p:/www.csa.ca.*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 States1to Avoid Deleterious Expansion in ConcreteCSAA23.2-28A Standard Practice for Laboratory Testing toDemonstra

16、te the Effectiveness of Supplementary Cement-ing Materials and Lithium-Based Admixtures to PreventAlkali-Silica Reaction in Concrete3. Terminology3.1 Terminology used in this standard is as given in Termi-nology C125 or Descriptive Nomenclature C294.4. Significance and Use4.1 Alkali-silica reaction

17、is a chemical interaction betweensome siliceous constituents of concrete aggregates and hy-droxyl ions (1).5The concentration of hydroxyl ion within theconcrete is predominantly controlled by the concentration ofsodium and potassium (2).4.2 This test method is intended to evaluate the potential ofan

18、 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 aggregate with pozzolan or slag, theresults are used to establish minimum amounts of the specificpozzolan or slag needed to prevent deleterious

19、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 sample or deciding on the number ofsamples for test, it is important to recognize the variability inlithology of material from a given source,

20、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 behaviorof aggregates in portland cement concrete with an alkali (alkalimetal oxide) content of 5.25 kg/m3or in concrete containingpozzolan or s

21、lag with an alkali content proportionally reducedfrom 5.25 kg/m3Na2O equivalent by the amount of pozzolanor slag replacing portland cement. This test method assessesthe potential for deleterious expansion of concrete caused byalkali-silica reaction, of either coarse or fine aggregates, fromtests per

22、formed under prescribed laboratory curing conditionsthat will probably differ from field conditions. Thus, actualfield performance will not be duplicated due to differences inconcrete alkali content, wetting and drying, temperature, otherfactors, or combinations of these (5).4.6 Results of tests con

23、ducted 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 due to alkali-silica reaction. Results of tests conducted oncombinations of an aggregate with pozzolans or slag shouldform a part of the basi

24、s for a decision as to whether the specificpozzolan or slag, when used in the amount tested, was effectivein preventing excessive expansion. These decisions should bemade before a particular aggregate is used in concrete con-struction. Criteria to determine the potential deleteriousness ofexpansions

25、 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 combination ofaggregate with the tested amount of pozzolan or slag ispotentially alkali-reactive. Supplemental information should bedeveloped to confi

26、rm that the expansion is actually due toalkali-silica reaction. Petrographic examination of the concreteprisms should be conducted after the test using Practice C856to confirm that known reactive constituents are present and toidentify the products of alkali-silica reactivity. Confirmation ofalkali-

27、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 aggregate ispotentially deleteriously reactive, additional studies may beappropriate to evaluate preventive measures in order to allowsafe

28、use of the aggregate. Preventive measures are mentionedin the Appendix to Specification C33.4.9 This test method does not address the general suitabilityof pozzolans or slag for use in concrete. These materials shouldcomply with Specification C618, Specification C989, or Speci-fication C1240.5. Appa

29、ratus5.1 The molds, the associated items for molding testspecimens, and the length comparator for measuring lengthchange shall conform to the applicable requirements of TestMethod C157/C157M and Practice C490, and the molds shallhave nominal 75-mm square cross sections.5.2 The storage container opti

30、ons 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 polyethylene 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

31、. Preventsignificant loss of enclosed moisture due to evaporation withairtight lid seal. Place a perforated rack in the bottom of thestorage container so that the 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

32、 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 of the container from the top so that thebottom of the wick extends into the water (See Note 1).5.2.2 Alternative ContainersAlternative stor

33、age contain-ers may be used. Confirm the efficiency of the alternativestorage container with an alkali-reactive aggregate of knownexpansion characteristics.6The expansion efficiency is con-firmed when expansions at one year obtained using thealternative container are within 10 % of those obtained us

34、ing5The boldface numbers in parentheses refer to the list of references at the end ofthis test method.6The sole source of supply of non-reactive aggregates and alkali-silica reactiveaggregates of known expansion characteristics (6) known to the committee at thistime is The Petrographer, Engineering

35、Materials Office, Ministry of Transportation,1201 Wilson Ave., Downsview, Ontario, Canada, M3M1J8 If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical com

36、mittee1, which you may attend.C1293 08b (2015)2the 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 with theabove.NOTE 1Polypro

37、pylene 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 recommended stor-age environ

38、ment 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 minimize heatloss. Racks f

39、or 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 temperature and itsvariati

40、on 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 Test Method C227 generally w

41、ill 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 confirmed when expansions at o

42、ne 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 the above.6. Reagents6.1

43、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 reliablesafety literature. NaOH

44、 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 storage.7. Materials7.1 C

45、ementUse 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 content of thecement eithe

46、r 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 equivalent by mass of cement

47、 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 aggregate. A nonreactive fine

48、 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 0.2.7.2.2 To evaluate the

49、 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 requirements in Table 1. Select the