ASTM C666 C666M-2003 Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing《混凝土抗快速冷冻和解冻特性的标准试验方法》.pdf

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1、Designation: C 666/C 666M 03Standard Test Method forResistance of Concrete to Rapid Freezing and Thawing1This standard is issued under the fixed designation C 666/C 666M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of

2、last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers the determin

3、ation of the resis-tance of concrete specimens to rapidly repeated cycles offreezing and thawing in the laboratory by two differentprocedures: Procedure A, Rapid Freezing and Thawing inWater, and Procedure B, Rapid Freezing inAir and Thawing inWater. Both procedures are intended for use in determini

4、ng theeffects of variations in the properties of concrete on theresistance of the concrete to the freezing-and-thawing cyclesspecified in the particular procedure. Neither procedure isintended to provide a quantitative measure of the length ofservice that may be expected from a specific type of conc

5、rete.1.2 The values stated in either inch-pound units or SI unitsshall be regarded seperately as standard. The SI units areshown in brackets. The values stated may not be exactequivalents; therefore each system must be used independentlyof the other. Combining values from the two units may resultin

6、nonconformance.1.3 All material in this test method not specifically desig-nated as belonging to Procedure A or Procedure B applies toeither procedure.1.4 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

7、 standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:C 157/C 157M Test Method for Length Change of Hard-ened Hydraulic-Cement Mortar and Concrete2C 192C/ 192M Practice for Mak

8、ing and Curing ConcreteTest Specimens in the Laboratory2C 215 Test Method for Fundamental Transverse, Longitu-dinal, and Torsional Frequencies of Concrete Specimens2C 233 Test Method for Testing Air-Entraining Admixturesfor Concrete2C 295 Guide for Petrographic Examination of Aggregatesfor Concrete2

9、C 341 Test Method for Length Change of Drilled or SawedSpecimens of HydraulicCement Mortar and Concrete2C 490 Practice for Use of Apparatus for Determination ofLength Change of Hardened Cement Paste, Mortar, andConcrete2C 494/C 494M Specification for Chemical Admixtures forConcrete2C 670 Practice fo

10、r Preparing Precision and Bias Statementsfor Test Methods for Construction Materials2C 823 Practice for Examination and Sampling of HardenedConcrete in Constructions23. Significance and Use3.1 As noted in the scope, the two procedures described inthis test method are intended to determine the effect

11、s ofvariations in both properties and conditioning of concrete in theresistance to freezing and thawing cycles specified in theparticular procedure. Specific applications include specifieduse in Specification C 494/C 494M, Test Method C 233, andranking of coarse aggregates as to their effect on conc

12、retefreeze-thaw durability, especially where soundness of theaggregate is questionable.3.2 It is assumed that the procedures will have no signifi-cantly damaging effects on frost-resistant concrete which maybe defined as (1) any concrete not critically saturated withwater (that is, not sufficiently

13、saturated to be damaged byfreezing) and (2) concrete made with frost-resistant aggregatesand having an adequate air-void system that has achievedappropriate maturity and thus will prevent critical saturation bywater under common conditions.3.3 If as a result of performance tests as described in this

14、test method concrete is found to be relatively unaffected, it canbe assumed that it was either not critically saturated, or wasmade with “sound” aggregates, a proper air-void system, andallowed to mature properly.3.4 No relationship has been established between the resis-tance to cycles of freezing

15、and thawing of specimens cut fromhardened concrete and specimens prepared in the laboratory.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.67 on Resistance to the Environment.Current edition app

16、roved June 10, 2003. Published August 2003. Originallyapproved in 1971. Last previous edition approved in 1997 as C 666 97.2Annual Book of ASTM Standards, Vol 04.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Apparatus4.1 Free

17、zing-and-Thawing Apparatus:4.1.1 The freezing-and-thawing apparatus shall consist of asuitable chamber or chambers in which the specimens may besubjected to the specified freezing-and-thawing cycle, togetherwith the necessary refrigerating and heating equipment andcontrols to produce continuously, a

18、nd automatically, reproduc-ible cycles within the specified temperature requirements. Inthe event that the equipment does not operate automatically,provision shall be made for either its continuous manualoperation on a 24-h a day basis or for the storage of allspecimens in a frozen condition when th

19、e equipment is not inoperation.4.1.2 The apparatus shall be so arranged that, except fornecessary supports, each specimen is: (1) for Procedure A,completely surrounded by not less than132 in. 1 mm normore than18 in. 3 mm of water at all times while it is beingsubjected to freezing-and-thawing cycles

20、, or (2) for ProcedureB, completely surrounded by air during the freezing phase ofthe cycle and by water during the thawing phase. Rigidcontainers, which have the potential to damage specimens, arenot permitted. Length change specimens in vertical containersshall be supported in a manner to avoid da

21、mage to the gagestuds.NOTE 1Experience has indicated that ice or water pressure, duringfreezing tests, particularly in equipment that uses air rather than a liquidas the heat transfer medium, can cause excessive damage to rigid metalcontainers, and possibly to the specimens therein. Results of tests

22、 duringwhich bulging or other distortion of containers occurs should be inter-preted with caution.4.1.3 The temperature of the heat-exchanging medium shallbe uniform within 6F 3C throughout the specimen cabinetwhen measured at any given time, at any point on the surfaceof any specimen container for

23、ProcedureAor on the surface ofany specimen for Procedure B, except during the transitionbetween freezing and thawing and vice versa.4.1.3.1 Support each specimen at the bottom of its containerin such a way that the temperature of the heat-exchangingmedium will not be transmitted directly through the

24、 bottom ofthe container to the full area of the bottom of the specimen,thereby subjecting it to conditions substantially different fromthe remainder of the specimen.NOTE 2A flat spiral of18-in. 3-mm wire placed in the bottom of thecontainer has been found adequate for supporting specimens.4.1.4 For

25、Procedure B, it is not contemplated that thespecimens will be kept in containers. The supports on whichthe specimens rest shall be such that they are not in contactwith the full area of the supported side or end of the specimen,thereby subjecting this area to conditions substantially differentfrom t

26、hose imposed on the remainder of the specimen.NOTE 3The use of relatively open gratings, metal rods, or the edgesof metal angles has been found adequate for supporting specimens,provided the heat-exchanging medium can circulate in the direction of thelong axis of the rods or angles.4.2 Temperature-M

27、easuring Equipment, consisting of ther-mometers, resistance thermometers, or thermocouples, capableof measuring the temperature at various points within thespecimen chamber and at the centers of control specimens towithin 2F 1C.4.3 Dynamic Testing Apparatus, conforming to the require-ments of Test M

28、ethod C 215.4.4 Optional Length Change Test Length Change Compara-tor, conforming to the requirements of Specification C 490.When specimens longer than the nominal 1114 in. 285 mmlength provided for in Specification C 490 are used for freeze-thaw tests, use an appropriate length reference bar, which

29、otherwise meets the Specification C 490 requirements. Dialgage micrometers for use on these longer length changecomparators shall meet the gradation interval and accuracyrequirements for Specification C 490 for either the inch ormillimetre calibration requirements. Prior to the start of mea-surement

30、s on any specimens, fix the comparator at an appro-priate length to accommodate all of the specimens to bemonitored for length change.4.5 Scales, with a capacity approximately 50 % greater thanthe mass of the specimens and accurate to at least 0.01 lb 0.5g within the range of 610 % of the specimen m

31、ass will besatisfactory.4.6 Tempering Tank, with suitable provisions for maintain-ing the temperature of the test specimens in water, such thatwhen removed from the tank and tested for fundamentaltransverse frequency and length change, the specimens will bemaintained within 2F and +4F (1C and +2C) o

32、f thetarget thaw temperature for specimens in the actual freezing-and-thawing cycle and equipment being used. The use of thespecimen chamber in the freezing-and-thawing apparatus bystopping the apparatus at the end of the thawing cycle andholding the specimens in it shall be considered as meeting th

33、isrequirement, provided the specimens are tested for fundamen-tal transverse frequency within the above temperature range. Itis required that the same target specimen thaw temperature beused throughout the testing of an individual specimen since achange in specimen temperature at the time of length

34、measure-ment can affect the length of the specimen significantly.5. Freezing-and-Thawing Cycle5.1 Base conformity with the requirements for the freezing-and-thawing cycle on temperature measurements of controlspecimens of similar concrete to the specimens under test inwhich suitable temperature-meas

35、uring devices have been im-bedded. Change the position of these control specimens fre-quently in such a way as to indicate the extremes of tempera-ture variation at different locations in the specimen cabinet.5.2 The nominal freezing-and-thawing cycle for both pro-cedures of this test method shall c

36、onsist of alternately loweringthe temperature of the specimens from 40 to 0F 4 to 18Cand raising it from 0 to 40F 18 to 4C in not less than 2 normore than 5 h. For Procedure A, not less than 25 % of the timeshall be used for thawing, and for Procedure B, not less than20 % of the time shall be used f

37、or thawing (Note 4).At the endof the cooling period the temperature at the centers of thespecimens shall be 0 6 3F 18 6 2C, and at the end of theheating period the temperature shall be 40 6 3F 4 6 2C,with no specimen at any time reaching a temperature lowerthan 3F 19C nor higher than 43F 6C. The tim

38、eC 666/C 666M 032required for the temperature at the center of any singlespecimen to be reduced from 37 to 3F 3 to 16C shall benot less than one half of the length of the cooling period, andthe time required for the temperature at the center of any singlespecimen to be raised from 3 to 37F 16 to 3C

39、shall be notless than one half of the length of the heating period. Forspecimens to be compared with each other, the time required tochange the temperature at the centers of any specimens from 35to 10F 2 to 12C shall not differ by more than one sixth ofthe length of the cooling period from the time

40、required for anyspecimen and the time required to change the temperature atthe centers of any specimens from 10 to 35F 12 to 2Cshall not differ by more than one third of the length of theheating period from the time required for any specimen.NOTE 4In most cases, uniform temperature and time conditio

41、ns canbe controlled most conveniently by maintaining a capacity load ofspecimens in the equipment at all times. In the event that a capacity loadof test specimens is not available, dummy specimens can be used to fillempty spaces. This procedure also assists greatly in maintaining uniformfluid level

42、conditions in the specimen and solution tanks.The testing of concrete specimens composed of widely varying mate-rials or with widely varying thermal properties, in the same equipment atthe same time, may not permit adherence to the time-temperaturerequirements for all specimens. It is advisable that

43、 such specimens betested at different times and that appropriate adjustments be made to theequipment.5.3 The difference between the temperature at the center ofa specimen and the temperature at its surface shall at no timeexceed 50F 28C.5.4 The period of transition between the freezing-and-thawing p

44、hases of the cycle shall not exceed 10 min, exceptwhen specimens are being tested in accordance with 8.3.6. Sampling6.1 Constituent materials for concrete specimens made inthe laboratory shall be sampled using applicable standardmethods.6.2 Samples cut from hardened concrete are to be obtainedin acc

45、ordance with Practice C 823.7. Test Specimens7.1 The specimens for use in this test method shall beprisms or cylinders made and cured in accordance with theapplicable requirements of Practice C 192/C 192M and Speci-fication C 490.7.2 Specimens used shall not be less than 3 in. 75 mm normore than 5 i

46、n. 125 mm in width, depth, or diameter, and notless than 11 in. 275 mm nor more than 16 in. 405 mm inlength.7.3 Test specimens may also be cores or prisms cut fromhardened concrete. If so, the specimens should not be allowedto dry to a moisture condition below that of the structure fromwhich taken.

47、This may be accomplished by wrapping in plasticor by other suitable means. The specimens so obtained shall befurnished with gage studs in accordance with Test MethodC 341.7.4 For this test the specimens shall be stored in saturatedlime water from the time of their removal from the molds untilthe tim

48、e freezing-and-thawing tests are started. All specimensto be compared with each other initially shall be of the samenominal dimensions.8. Procedure8.1 Molded beam specimens shall be cured for 14 days priorto testing unless otherwise specified. Beam specimens sawedfrom hardened concrete shall be mois

49、ture-conditioned byimmersing in saturated lime water at 73.4 6 3F 23.0 62.0C for 48 h prior to testing unless otherwise specified.8.2 Immediately after the specified curing or conditioningperiod, bring the specimen to a temperature within 2Fand +4F 1C and +2C of the target thaw temperature thatwill be used in the freeze-thaw cycle and test for fundamentaltransverse frequency, determine the mass and average lengthand cross section dimensions of the concrete specimen withinthe toler