1、Designation: C 1646/C 1646M 07Standard Practice forMaking and Curing Test Specimens for Evaluating FrostResistance of Coarse Aggregate in Air-Entrained Concreteby Rapid Freezing and Thawing1This standard is issued under the fixed designation C 1646/C 1646M; the number immediately following the desig
2、nation indicates theyear of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers procedure
3、s for making and curingtest specimens for evaluating frost resistance of normal-weightcoarse aggregates in air-entrained concrete in accordance withTest Method C 666/C 666M, Procedure A or B.1.2 The values stated in either inch-pound or SI units shallbe regarded separately as standard. The SI units
4、are shown inbrackets. The values stated in each system may not be exactequivalents; therefore each system shall be used independentlyof the other. Combining values from the two systems mayresult in nonconformance with the standard.1.3 This practice does not purport to address all the safetyconcerns,
5、 if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use. (WarningFresh hydraulic cementi-tious mixtures are caustic and may cause chemical burns to
6、skin and tissue upon prolonged use.2)2. Referenced Documents2.1 ASTM Standards:3C33 Specification for Concrete AggregatesC 39/C 39M Test Method for Compressive Strength of Cy-lindrical Concrete SpecimensC 143/C 143M Test Method for Slump of Hydraulic-Cement ConcreteC 150 Specification for Portland C
7、ementC 173/C 173M Test Method for Air Content of FreshlyMixed Concrete by the Volumetric MethodC 192/C 192M Practice for Making and Curing ConcreteTest Specimens in the LaboratoryC 231 Test Method for Air Content of Freshly MixedConcrete by the Pressure MethodC 490 Practice for Use of Apparatus for
8、the Determinationof Length Change of Hardened Cement Paste, Mortar, andConcreteC 494/C 494M Specification for Chemical Admixtures forConcreteC 666/C 666M Test Method for Resistance of Concrete toRapid Freezing and ThawingD75 Practice for Sampling Aggregates2.2 ACI Standard:4211.1 Practice for Select
9、ing Proportions for Normal,Heavyweight, and Mass Concrete3. Significance and Use3.1 This practice provides standard requirements for evalu-ating frost-susceptible coarse aggregate in air-entrained con-crete subjected to freezing and thawing in accordance with TestMethod C 666/C 666M.3.2 Concrete con
10、taining frost-resistant paste may not beresistant to freezing and thawing if it contains coarse aggregatethat becomes critically saturated. An aggregate particle isconsidered to be critically saturated when there is insufficientunfilled pore space to accommodate the expansion of water thataccompanie
11、s the freezing.3.3 The potential of the coarse aggregate to cause damagedue to cycles of freezing and thawing is evaluated by TestMethod C 666/C 666M.4. Apparatus4.1 Equipment for mixing concrete and procedures formaking and curing test specimens shall be in accordance withPractice C 192/C 192M.5. C
12、oarse Aggregate Preparation5.1 SamplingSample in accordance with Practice D75.5.2 GradingWhen coarse aggregates are to be comparedusing this practice, standardize the coarse aggregate gradingsby recombining individual size fractions in accordance with1This practice is under the jurisdiction of ASTM
13、Committee C09 on Concreteand ConcreteAggregates and is the direct responsibility of Subcommittee C09.67 onResistance to the Environment.Current edition approved Jan. 15, 2007. Published February 2007.2Section on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standar
14、ds, Volume 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 standards Document Summary page onthe ASTM website.4Available from American Concrete Institute
15、(ACI), P.O. Box 9094, FarmingtonHills, MI 48333-9094, http:/www.aci-int.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Table 1 for the appropriate size aggregate being tested. Bringthe as-received sample to a saturated-surface-d
16、ry (SSD) con-dition or drier prior to sieving. Do not oven-dry the coarseaggregate sample. If necessary, air drying of the sample toachieve this condition is permitted. The nominal-maximum-aggregate size shall not exceed one-third the least dimension ofthe test specimen to be used. Fine aggregate sh
17、all meet therequirements of Specification C33 and the grading shallconform to Table 1.5.3 ConditioningCondition fine and coarse aggregates asfollows:5.3.1 Fine AggregateUniformly wet the fine aggregate 24h prior to mixing of concrete so that the moisture contentexceeds the saturated-surface-dry cond
18、ition but there is notendency for loss of surface water by draining. Keep the fineaggregate covered to prevent evaporation prior to use.5.3.2 Coarse AggregateImmerse the coarse aggregate inwater 24 h prior to mixing of concrete. On the day of mixing,decant the water from the coarse aggregate.6. Conc
19、rete Mixture6.1 IngredientsThe portland cement shall meet the re-quirements of Specification C 150, Type I or Type II. Batchesfor a particular test series shall use cement, fine aggregate, andair-entraining admixture taken from the same lot.6.2 Air-entraining admixtureAs described in Specifica-tion
20、C 494/C 494M, section on Air-Entraining Admixture.6.3 ProportionsExcept when tests are being made wheremixture proportions are those proposed for the work, propor-tion all concrete using ACI 211.1 conforming to the followingrequirements:6.3.1 The cement content shall be 517 6 5 lb/yd3307 6 3kg/m36.3
21、.2 The air content used in the computation of mixtureproportions shall be in accordance with Table 2. The amount ofair-entraining admixture used shall be such as to give an aircontent as prescribed in Table 2, 6 1 %, when tested accordingto Test Method C 231 or Test Method C 173/C 173M.6.3.3 The mix
22、ture shall contain the amount of coarseaggregate shown in the “Volume of Coarse Aggregate Per Unitof Volume of Concrete” table of ACI 211.1 for the nominal-maximum size of aggregate and for the fineness modulus of thefine aggregate being used.6.3.4 Adjust the water content and fine aggregate content
23、 toobtain a slump of 3 6 1 in. 75 6 25 mm when tested inaccordance with Test Method C 143/C 143M.6.4 MixingMachine mix the concrete as prescribed inPractice C 192/C 192M.7. Specimen Preparation and Conditioning7.1 Specimen PreparationThe type and size of the testspecimen and the method for molding s
24、hall be in accordancewith the Test Specimen section of Test Method C 666/C 666M,unless otherwise specified. If length change testing is to beperformed as a permitted option in Test Method C 666/C 666M, fit the specimens with axially centered stainless steelgauge studs in accordance with Practice C 4
25、90.7.2 Number of SpecimensMake at least three freezing-and-thawing test specimens from each batch. In addition, makeat least three cylindrical specimens from each batch forstrength verification. The cylindrical specimens shall be madein accordance with Practice C 192/C 192M and tested inaccordance w
26、ith Test Method C 39/C 39M.7.3 CuringComplete initial storage and remove frommolds in accordance with Practice C 192/C 192M. After re-moval from the molds, inspect for defects and store in saturatedlimewater at 73.5 6 3.5 F 23.0 6 2.0 C to an age of 14days.8. Method of Test8.1 After the specimens ha
27、ve cured, test in accordance withProcedure A or Procedure B of Test Method C 666/C 666M.9. Keywords9.1 aggregate; coarse aggregate; freezing and thawing; frostresistanceTABLE 1 Grading RequirementsAmounts Finer Than Each Laboratory Sieve, Mass PercentSize No. NominalMax. Size112 in.37.5 mm1in.25.0 m
28、m34 in.19.0 mm12 in.12.5 mm38 in.9.5 mmNo. 44.75 mmNo. 82.36 mmNo. 161.18 mmNo. 50300 mNo. 100150 m467 112 in. 37.5 mm 100 70 50 30 20 056 1 in.25.0 mm 100 60 25 057 1 in. 25.0 mm 100 75 40 0634 in.19.0 mm 100 35 06734 in. 19.0 mm 100 60 35 0712 in. 12.5 mm 100 55 0838 in. 9.5 mm 100 20 08938 in. 9.
29、5 mm 100 35 15 0Fine Aggregate No. 4 4.75 mm 100 65-75 12-20 2-5TABLE 2 Target Total Air ConentNominal Maximum Size of Aggregate, in. mm38 9.512 12.534 19.0 1 25.0 112 37.5Total Air Content, % 7.5 7.0 6.0 6.0 5.5C 1646/C 1646M 072ASTM International takes no position respecting the validity of any pa
30、tent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revisio
31、n at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your com
32、ments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyright
33、ed by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C 1646/C 1646M 073
