1、Designation: C 1646/C 1646M 08Standard 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 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 SI units or inch-pound unitsare to be regarded separately as standard. The va
4、lues stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This practice does not purport to address all the safetyconcerns, if any, associated with it
5、s 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 toskin and tissue upon prolon
6、ged 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 125 Terminology Relating to Concrete and ConcreteAggregatesC 143/C 143M Test Method for Slump of Hydraulic-Cement Concrete
7、C 150 Specification for Portland CementC 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
8、Practice for Use of Apparatus for 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 S
9、tandard:4211.1 Practice for Selecting Proportions for Normal,Heavyweight, and Mass Concrete3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this specification, referto Terminology C 125.4. Significance and Use4.1 This practice provides standard requirements for evalu-ating frost-
10、susceptible coarse aggregate in air-entrained con-crete subjected to freezing and thawing in accordance with TestMethod C 666/C 666M.4.2 Concrete containing frost-resistant paste may not beresistant to freezing and thawing if it contains coarse aggregatethat becomes critically saturated. An aggregat
11、e particle isconsidered to be critically saturated when there is insufficientunfilled pore space to accommodate the expansion of water thataccompanies the freezing.4.3 The potential of the coarse aggregate to cause damagedue to cycles of freezing and thawing is evaluated by TestMethod C 666/C 666M.1
12、This practice is under the jurisdiction of ASTM Committee C09 on Concreteand ConcreteAggregates and is the direct responsibility of Subcommittee C09.67 onResistance to the Environment.Current edition approved Aug. 1, 2008. Published September 2008. Originallyapproved in 2007. Last previous edition a
13、pproved in 2007 as C 1646/C 1646M 07.2Section on Safety Precautions, Manual of Aggregate and Concrete Testing,Annual Book of ASTM Standards, 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 ASTMS
14、tandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American Concrete Institute (ACI), P.O. Box 9094, FarmingtonHills, MI 48333-9094, http:/www.aci-int.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Inter
15、national, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Apparatus5.1 Equipment for mixing concrete and procedures formaking and curing test specimens shall be in accordance withPractice C 192/C 192M.6. Coarse Aggregate Preparation6.1 SamplingSample in accorda
16、nce with Practice D75.6.2 GradingWhen coarse aggregates are to be comparedusing this practice, standardize the coarse aggregate gradingsby recombining individual size fractions in accordance withTable 1 for the appropriate size aggregate being tested. Bringthe as-received sample to a saturated-surfa
17、ce-dry (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 aggregat
18、e shall meet therequirements of Specification C33 and the grading shallconform to Table 1.6.3 ConditioningCondition fine and coarse aggregates asfollows:6.3.1 Fine AggregateUniformly wet the fine aggregate 24h prior to mixing of concrete so that the moisture contentexceeds the saturated-surface-dry
19、condition but there is notendency for loss of surface water by draining. Keep the fineaggregate covered to prevent evaporation prior to use.6.3.2 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.7.
20、Concrete Mixture7.1 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.7.2 Air-entraining admixtureAs described in Specifica-t
21、ion C 494/C 494M, section on Air-Entraining Admixture (SeeNote 1).NOTE 1As stated in Specification C 494/C 494M, note that “neutral-ized Vinsol resin” is required if no material is designated by the person oragency for whom the testing is being performed.7.3 ProportionsExcept when tests are being ma
22、de wheremixture proportions are those proposed for the work, propor-tion all concrete using ACI 211.1 conforming to the followingrequirements:7.3.1 The cement content shall be 307 6 3 kg/m3517 6 5lb/yd37.3.2 The air content used in the computation of mixtureproportions shall be in accordance with Ta
23、ble 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.7.3.3 The mixture shall contain the amount of coarseaggregate shown in the “Volume of Coarse Aggregate Per U
24、nitof 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.7.3.4 Adjust the water content and fine aggregate content toobtain a slump of 75 6 25 mm 3 6 1 in. when tested inaccordance with Test Method C 143/C 143
25、M.7.4 MixingMachine mix the concrete as prescribed inPractice C 192/C 192M.8. Specimen Preparation and Conditioning8.1 Specimen PreparationThe type and size of the testspecimen and the method for molding shall be in accordancewith the Test Specimen section of Test Method C 666/C 666M,unless otherwis
26、e 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 490.8.2 Number of SpecimensMake at least three freezing-and-thawing test specimens from each bat
27、ch. 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 with Test Method C 39/C 39M.8.3 CuringComplete initial storage and remove frommolds in accordanc
28、e with Practice C 192/C 192M. After re-moval from the molds, inspect for defects and store in saturatedlimewater at 23.0 6 2.0 C 73.5 6 3.5 F to an age of 14days.9. Method of Test9.1 After the specimens have cured, test in accordance withProcedure A or Procedure B of Test Method C 666/C 666M.10. Key
29、words10.1 aggregate; coarse aggregate; freezing and thawing;frost resistanceTABLE 1 Grading RequirementsAmounts Finer Than Each Laboratory Sieve, Mass PercentSize No. NominalMax. Size37.5 mm112 in.25.0 mm1 in.19.0 mm34 in.12.5 mm12 in.9.5 mm38 in.4.75 mmNo. 42.36 mmNo. 81.18 mmNo. 16300 mNo. 50150 m
30、No. 100467 37.5 mm 112 in. 100 70 50 30 20 056 25.0 mm 1 in. 100 60 25 057 25.0 mm 1 in. 100 75 40 06 19.0mm34 in. 100 35 067 19.0 mm 34 in. 100 60 35 07 12.5mm12 in. 100 55 08 9.5 mm 38 in. 100 20 089 9.5 mm 38 in. 100 35 15 0Fine Aggregate 4.75 mm No. 4 100 65-75 12-20 2-5C 1646/C 1646M 082SUMMARY
31、 OF CHANGESCommittee C09 has identified the location of selected changes to this practice since the last issue,C 1646/C 1646M 07, that may impact the use of this practice. (Approved August 1, 2008)(1) Revised 1.2 and put SI units first throughout the standard tocomply with C09s policy addressing SI
32、units.(2) Added new Section 3 Terminology and renumbered subse-quent sections.(3) Added new Note 1 after 7.2.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised
33、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 revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reap
34、proved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you
35、 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 copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual
36、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).TABLE 2 Target Total Air ContentNominal Maximum Size of Aggregate, mm in.9.5 38 12.5 12 19.034 25.0 1 37.5 112 Total Air Content, % 7.5 7.0 6.0 6.0 5.5C 1646/C 1646M 083
