ASTM C1293-2006 Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction《测定由于碱-硅石反应引起的混凝土长度变化的标准试验方法》.pdf

《ASTM C1293-2006 Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction《测定由于碱-硅石反应引起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 C1293-2006 Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction《测定由于碱-硅石反应引起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: C 1293 06Standard Test Method forDetermination of Length Change of Concrete Due to Alkali-Silica Reaction1This standard is issued under the fixed designation C 1293; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the

2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 aggreg

3、ate withpozzolan or slag for participation in expansive alkali-silicareaction by measurement of length change of concrete prisms.1.2 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

4、 appro-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)1.3 The values stated in SI units are to be regarded as

5、 thestandard. The inch-pound values in parentheses are for infor-mation only.2. Referenced Documents2.1 ASTM Standards:3C33 Specification for Concrete AggregatesC 125 Terminology Relating to Concrete and ConcreteAggregatesC 138/C 138M Test Method for Density (Unit Weight),Yield, and Air Content (Gra

6、vimetric) of ConcreteC 143/C 143M Test Method for Slump of Hydraulic-Cement ConcreteC 150 Specification for Portland CementC 157/C 157M Test Method for Length Change of Hard-ened Hydraulic-Cement Mortar and ConcreteC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC

7、 227 Test Method for Potential Alkali Reactivity ofCement-Aggregate Combinations (Mortar-Bar Method)C 289 Test Method for Potential Alkali-Silica Reactivity ofAggregates (Chemical Method)C 294 Descriptive Nomenclature for Constituents of Con-crete AggregatesC 295 Guide for Petrographic Examination o

8、f Aggregatesfor ConcreteC 490 Practice for Use of Apparatus for the Determinationof Length Change of Hardened Cement Paste, Mortar, andConcreteC 494/C 494M Specification for Chemical Admixtures forConcreteC511 Specification for Mixing Rooms, Moist Cabinets,Moist Rooms, and Water Storage Tanks Used i

9、n theTesting of Hydraulic Cements and ConcretesC 618 Specification for Coal Fly Ash and Raw or CalcinedNatural Pozzolan for Use in ConcreteC 702 Practice for Reducing Samples of Aggregate toTesting SizeC 856 Practice for Petrographic Examination of HardenedConcreteC 989 Specification for Ground Gran

10、ulated Blast-FurnaceSlag for Use in Concrete and MortarsC 1240 Specification for Silica Fume Used in CementitiousMixturesC 1260 Test Method for Potential Alkali Reactivity ofAggregates (Mortar-Bar Method)D75 Practice for Sampling Aggregates2.2 CSA Standards:4CSA A23.2-14A Potential Expansivity of Ag

11、gregates (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 Aggregates and to Identify Measuresto Avoid Deleterious Expansion in ConcreteCSA A23.2-28A Standard Practice for Laboratory Te

12、sting1This test method is under the jurisdiction of Committee C09 on Concrete andConcrete Aggregates and is the direct responsibility of Subcommittee C09.26 onChemical Reactions.Current edition approved Sept. 1, 2006. Published September 2006. Originallyapproved in 1995. Last previous edition approv

13、ed in 2005 as C 1293 05.2Section on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standards, Vol. 04.02.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume

14、 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, http:/www.csa.ca.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100

15、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.to Demonstrate the Effectiveness of Supplementary Ce-menting Materials and Lithium-Based Admixtures to Pre-vent Alkali-Silica Reaction in Concrete3. Terminology3.1 Terminology used in this standard is as given in Termi-

16、nology C 125 or Descriptive Nomenclature C 294.4. 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 is predominantly controlled by the concent

17、ration 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 aggregate with pozzolan or slag, theresults are

18、 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 sample or deciding on the number ofsamples for

19、 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 C 295.4.5 This test method is intended for evaluating the behaviorof aggregates in portland cement concr

20、ete with an alkali (alkalimetal oxide) content of 5.25 kg/m3(8.85 lb/yd3) or in concretecontaining pozzolan or slag with an alkali content proportion-ally reduced from 5.25 kg/m3(8.85 lb/yd3)Na2O equivalent bythe amount of pozzolan or slag replacing portland cement. Thistest method assesses the pote

21、ntial for deleterious expansion ofconcrete caused by alkali-silica reaction, of either coarse orfine aggregates, from tests performed under prescribed labora-tory curing conditions that will probably differ from fieldconditions. Thus, actual field performance will not be dupli-cated due to differenc

22、es in concrete alkali content, wetting anddrying, temperature, other factors, 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 due to alk

23、ali-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 should bemad

24、e 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 combination ofaggre

25、gate 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 C 856to

26、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 aggrega

27、te 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 pozzolans or

28、 slag for use in concrete. These materials shouldcomply with Specification C 618, Specification C 989,orSpecification C 1240.5. Apparatus5.1 The molds, the associated items for molding test speci-mens, and the length comparator for measuring length changeshall conform to the applicable requirements

29、of Test MethodC 157/C 157M and Practice C 490, and shall have square crosssections of 75.0 6 0.7 mm (3.00 6 0.03 in.).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 2

30、2-L (5 to 5.8-gal) polyethylene pails withairtight lids and approximate dimensions of 250- to 270-mm(9.8- to 10.6-in.) diameter at bottom, 290 to 310 mm (11.4 to12.2 in.) at top, by 355 to 480 mm (14.0 to 18.9 in.) high.Prevent significant loss of enclosed moisture due to evapora-tion with airtight

31、lid seal. Place a perforated rack in the bottomof the storage container so that the prisms are 30 to 40 mm(1.2-1.6 in.) above the bottom. Fill the container with water toa depth of 20 6 5 mm (0.8 6 0.2 in.) above the bottom. Asignificant moisture loss is defined as a loss greater than 3 % ofthe orig

32、inal amount of water placed at the bottom of the pail.Place a wick of absorbent material around the inside wall of thecontainer from the top so that the bottom of the wick extendsinto the water (See Note 1).5.2.2 Alternative ContainersAlternative storage contain-ers may be used. Confirm the efficien

33、cy 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 usingthe recommended container. Alternative storage

34、 containersmust contain the required depth of water. When reporting5The 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) know

35、n to the committee at thistime is The Petrographer, Engineering 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 ca

36、reful consideration at a meeting of theresponsible technical committee1, which you may attend.C1293062results, note the use of an alternative container, if one is used,together with documentation proving compliance with theabove.NOTE 1Polypropylene geotextile fabric or blotting paper are suitablemat

37、erials for use as the wick.5.3 The storage environment necessary to maintain the 38.0C (100.4 F) reaction accelerating storage temperature con-sistently and homogeneously is described in 5.3.1.5.3.1 Recommended EnvironmentThe recommended stor-age environment is a sealed space insulated so as to mini

38、mizeheat loss. Provide a fan for air circulation so the maximumvariation in temperature measured within 250 mm (9.8 in.) ofthe top and bottom of the space does not exceed 2.0 C (3.6F). Provide an insulated entry door with adequate seals so asto minimize heat loss. Racks for storing containers within

39、 thespace are not to be closer than 30 mm (1.2 in.) to the sides ofthe enclosure and are to be perforated so as to provide air flow.Provide an automatically controlled heat source to maintain thetemperature at 38.0 6 2.0 C (100.4 6 3.6 F) (see Note 2).Record the ambient temperature and its variation

40、 within thespace 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 C 227 generally wil

41、l 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 one

42、 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 So

43、dium 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 c

44、an 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 Cem

45、entUse a cement meeting the requirements for aType I Portland cement as specified in Specification C 150. Thecement must have a total alkali content of 0.9 6 0.1 % Na2Oequivalent (Na2O equivalent is calculated as percent Na2O+0.658 3 percent K2O). Determine the total alkali content of thecement eith

46、er 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 cemen

47、t hasbeen chosen to accelerate the process of expansion rather than toreproduce field conditions. At the 420 kg/m3(708 lb/yd3) cement content,this corresponds to an alkali level of 5.25 kg/m3(8.85 lb/yd3).7.2 Aggregates:7.2.1 To evaluate the reactivity of a coarse aggregate, use anonreactive fine ag

48、gregate. A nonreactive fine aggregate isdefined as an aggregate that develops an expansion in theaccelerated mortar bar, (see Test Method C 1260) of less than0.10 % at 14 days (see X1.6 for interpretation of expansiondata). Use a fine aggregate meeting Specification C33with afineness modulus of 2.7

49、6 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 C 1260) 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 all coarse aggregates to which this test methodis applied and grade