ASTM C1262 C1262M-2016 Standard Test Method for Evaluating the Freeze-Thaw Durability of Dry-Cast Segmental Retaining Wall Units and Related Concrete Units《评价干硬性混凝土挡墙砌块与相关混凝土砌块冻融耐久.pdf

1、Designation: C1262/C1262M 16Standard Test Method forEvaluating the Freeze-Thaw Durability of Dry-CastSegmental Retaining Wall Units and Related Concrete Units1This standard is issued under the fixed designation C1262/C1262M; the number immediately following the designation indicates theyear of origi

2、nal 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 test method covers the resistance to freezing andthawing o

3、f dry-cast segmental retaining wall (SRW) units (seeSpecification C1372) and related concrete units. Units aretested in a test solution that is either potable tap water or 3 %saline solution depending on the intended use of the units inactual service.NOTE 1Related concrete units include units such a

4、s hollow and solidconcrete masonry units, concrete brick, and concrete roof pavers.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of

5、 the other. Combiningvalues from the two systems may result in non-conformancewith this standard. Some values have only SI units because theinch-pound equivalents are not used in practice.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is

6、theresponsibility of the user of this 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:2C140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related UnitsC1

7、093 Practice for Accreditation of Testing Agencies forMasonryC1232 Terminology of MasonryC1372 Specification for Dry-Cast Segmental Retaining WallUnits3. Terminology3.1 Terminology defined in Terminology C1232 shall applyfor this test method.4. Significance and Use4.1 The procedure described in this

8、 test method is intendedto determine the effects of freezing and thawing on SRW andrelated units in the presence of potable tap water or salinesolution.4.2 The procedure is not intended to provide a quantitativemeasure to determine an expected length of service for aspecific type of concrete unit.NO

9、TE 2The testing laboratory performing this test method should beevaluated in accordance with Practice C1093.5. Apparatus5.1 Freeze-Thaw ChamberUse a chamber that has:5.1.1 Forced air circulation,5.1.2 A programmable air-temperature controller capable ofautomatically performing at least two freezing

10、and thawingcycles per 24-h period during testing,5.1.3 A temperature range of at least 10 to 100F 25 to40C, and5.1.4 The capability of maintaining the air temperaturethroughout the chamber within the specified temperatureranges for the duration of the test cycle.5.2 ContainersUse containers that are

11、:5.2.1 Made of non-rigid plastic,5.2.2 Of sufficient size to contain each test specimen andspecimen supports as illustrated in Fig. 1,5.2.3 Of sufficient size to provide a minimum of18 in. 3mm and a maximum of 112 in. 40 mm of test solutionsurrounding the sides of the specimen,5.2.4 Supplied with a

12、tightly-fitting lid to reduceevaporation, and5.2.5 Flat enough so that the specimen will not deviate fromlevel by more than116 in. 2 mm from one end of thespecimen to the opposite end when placed on the support rods.5.3 Specimen SupportsSupport the specimen above thecontainer bottom. Use supports th

13、at are:1This test method is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and is the direct responsibility of SubcommitteeC15.03 on Concrete Masonry Units and Related Units.Current edition approved Dec. 15, 2016. Published January 2017. Originallyapproved in 1994. Last pr

14、evious edition approved in 2010 as C1262 10. DOI:10.1520/C1262_C1262M-16.2For 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 A

15、STM website.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standard

16、ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.3.1 Rods having a thickness of18 6124 in. 3 6 1 mmand a width of the portion that contacts

17、 the specimens of nogreater than the rod thickness (see Note 3),5.3.2 Made of a solid, non-corrosive, non-absorptive mate-rial (brass, plastic, and so forth), and5.3.3 Capable of supporting the specimen in both thelongitudinal and transverse directions (see Note 4).NOTE 3The rods can be of any cross

18、-sectional shape (for example,round, square, or triangular) as long as the specimen is held off the bottomof the container by the required rod thickness and the width of the portionof the rod that contacts the specimen is no greater than the rod thickness.NOTE 4Examples of longitudinal and transvers

19、e support configura-tions including placing the supports in an I, Z, or box configurations.5.4 Temperature-Measuring Equipment:5.4.1 Reference Temperature-Measuring DeviceThe refer-ence temperature-measuring device shall be readable andaccurate to 60.5F 0.2C within the range of use. Acertificate or

20、report that verifies the accuracy shall be availablein the laboratory for review. Verify the accuracy of referencetemperature-measuring devices at intervals not exceedingtwelve months. The certificate or report shall provide docu-mentation that the reference standard used in the verification istrace

21、able to the National Institute of Standards and Technology(NIST).5.4.2 Temperature RecorderEquip the chamber with adevice to record the air temperature every 15 min or less; thisdevice shall be accurate and readable to 2F 1C. Verify theaccuracy of the temperature measuring device at least every sixm

22、onths. During testing, evaluate the data from the temperaturerecording device at least once every twenty cycles to ensurethat cycles meet the temperature requirements of 7.3.1 and7.3.2. A record of this evaluation documenting the datechecked, a confirmation that the data is within the requiredtemper

23、ature range, and the name of the individual performingthis evaluation shall be maintained in the laboratory.NOTE 5This requirement may be satisfied by an initialed and datedtemperature recorder chart. Brief changes in the temperature due to dooropenings should be ignored.NOTE 6A convenient time to e

24、valuate the temperature results is whenthe chamber is stopped for residue collection.5.4.3 To verify the accuracy of the temperature-measuringdevices, position the reference temperature-measuring devicein the chamber in a readable position as near to thetemperature-measuring device probe as possible

25、. Close thedoor and leave undisturbed for at least 5 min. Read thetemperature immediately after opening the chamber door.Record the temperature readings of both devices. If thetemperature readings differ by more than 2F 1C, adjust orreplace the temperature-measuring device.5.5 ScalesScales for weigh

26、ing full-size specimens shallhave a capacity of at least 50 % greater than the weight of thelargest specimen tested and shall be accurate to at least 1 g.Scales for weighing the filter paper and specimen residue(spall), as required in 7.3.3, shall be accurate to at least 0.2 g.5.6 OvenA ventilated o

27、ven of appropriate size capable ofmaintaining a uniform temperature of 230 6 9F 110 6 5C.Ovens shall be verified in accordance with Practice C1093.6. Sampling and Preparation of Test Specimens6.1 Selection of UnitsSelect five whole SRW units repre-sentative of the lot from which they are selected. T

28、he unitsshall be free from visible cracks or structural defects.6.2 Freeze-Thaw Test SpecimensTest specimens shallconsist of solid coupons saw-cut from full sized units. Do notsaw-cut test specimens from units that have been previouslyoven-dried. Do not subject test specimens to oven-drying priorto

29、completion of freeze-thaw testing.6.2.1 Cut one coupon from each of the five sampled units.Cut the coupon from the exposed surface of the unit as the unitis used in service unless the exposed surface is an architecturalor other nonplanar surface (see Note 7). In the case of a unitwith an exposed arc

30、hitectural or other nonplanar surface, cutthe coupon from another flat molded surface ideally as far aspossible from the architectural or other nonplanar face and inno case less than 2 in. 50 mm from that surface. Immediatelyfollowing saw-cutting, remove loose particles and residue fromthe coupon by

31、 rinsing in tap water and brushing with a softbristle brush. Do not fully immerse coupons in water. Eachspecimen shall be marked with a unique identification numberon the non-molded surface of the specimen.NOTE 7Split-faced surfaces are the most common surfaces used toprovide an architectural appear

32、ance to segmental retaining walls.However, other means could be used to obtain similar architectural effectslike tumbling, grinding, and slumping.6.2.2 Sawing shall be performed in an accurate, competentmanner, subjecting the specimen to as little saw vibration aspossible. Use a diamond saw blade of

33、 proper hardness.6.2.3 Place the coupons on edge on a38 in. 10 mm orcoarser mesh such that there is an air space of not less than 1 in.25 mm between coupons. Allow the coupons to dry for notless than 48 h in laboratory air at a temperature of 75 6 15F24 6 8C and a relative humidity of less than 80 %

34、.6.2.4 The thickness of each coupon shall be 114 in. 6116 in.32 mm 6 2 mm, unless the unit does not permit thisthickness, in which case the thickness shall be the maximumthickness that can be obtained from the unit. The thickness ofthe coupon shall not be less than34 in. 20 mm.6.2.5 The area of the

35、submerged surface of the test specimenshall be at least 25 in.2160 cm2and shall not exceed 35 in.2225 cm2, unless the unit does not permit a coupon meetingthe minimum area, in which case the test specimen shallconsist of two coupons. The combined area of the two couponsshall be at least 25 in.2160 c

36、m2and shall not exceedFIG. 1 Test Specimen in Freeze-Thaw ContainerC1262/C1262M 16235 in.2225 cm2. These two coupons shall be tested as andconsidered to be a single specimen.6.3 When compression and absorption testing will be con-ducted in addition to freeze-thaw testing, obtain a specimen(coupon) f

37、or each test from each of five SRW units to facilitatecorrelation among the properties. If this is not possible, thenobtain compressive strength and absorption specimens fromdifferent units manufactured in the same production lot as thefreeze-thaw specimens. Take compressive strength and absorp-tion

38、 specimens in accordance with Test Methods C140. Speci-mens used for Test Methods C140 tests shall not be used asspecimens for freeze-thaw tests.NOTE 8While compressive strength and absorption values by them-selves have been shown by research3to not be reliable indicators ofdurability, they have bee

39、n shown to be good reference values for unitsmanufactured from a given set of materials.7. Procedure7.1 Test Solution:7.1.1 The test solution shall be either potable tap water or a3 6 0.1% (by weight) sodium chloride saline solution (seeNote 9).NOTE 9The 3 % saline solution can be prepared by adding

40、 0.03 lb 3g of sodium chloride to each 0.97 lb 97 g water.7.1.2 The test solution shall be at a temperature of 60 to80F 16 to 27C when added to the container or when usedto rinse the specimens or residue.7.2 Specimen Conditioning:7.2.1 After preparation of the freeze-thaw specimens inaccordance with

41、 Section 6, weigh each specimen to the nearest1 g and record as Wstart.NOTE 10 The weight Wstartas determined in 7.2.1 is not required tobe reported at the conclusion of the test, nor is it used to calculate thereported weight loss of the specimen throughout the test. However,because the initial dry

42、-weight of the specimen is not determined until thecompletion of freeze-thaw testing by adding the dry-weight of thecollected residue to the dry-weight of the remains of the specimen (see8.2), this Wstartweight is needed as a reference weight to be used duringthe testing to estimate percentage weigh

43、t loss and to predict relativeperformance among test specimens.7.2.2 Place the specimen in the container face down on thespecimen supports such that the non-saw-cut surface of thespecimen is in contact with the specimen supports. Add asufficient amount of test solution at a temperature of 60 to 80F1

44、6 to 27C to the container to achieve a test solution depth of12 6116 in. 13 6 2 mm (see Note 11 and Note 12). Do notpour test solution directly onto the specimen. Close thecontainer lid tightly and store the container on a level surfacein laboratory air as defined in 6.2.3.NOTE 11The submerged porti

45、on of the specimen is38 in. 10 mm ofits thickness. There is18 in. 3 mm of test solution between the bottomof the container and the face of the specimen.NOTE 12One way to repeatedly achieve the specified test solutiondepth is to add a consistent volume of test solution, which has beencalibrated for a

46、 given specimen and container size combination to yieldthe specified depth.7.2.3 After 1 h 6 15 min, open the container and add testsolution as necessary to maintain the test solution levelrequired in 7.2.2. Reseal the container. Continue storing for atleast an additional 23 h prior to starting the

47、test.Adjust that testsolution level as required in 7.2.2 prior to starting the test.7.3 Cyclical Testing:7.3.1 Begin the test with a freezing cycle. Place the con-tainers into the freezing test chamber such that each containeris surrounded by a minimum air space of12 in. 13 mm on allsides. During te

48、sting the container shall be level within116 in.2 mm. During the freezing cycle, maintain the air temperaturein the chamber at 0 6 10F 18 6 5C for a period of not lessthan 4.0 h and not more than 5.0 h. The cycle time does notinclude the time required for the air temperature in the chamberto reach t

49、he prescribed temperature. Periodically, at the end ofa freezing cycle, open the containers and visually inspect thespecimens to determine if all the test solution surrounding thespecimen is frozen solid. If not, extend the length of thefreezing cycle to ensure that all test solution is frozen solid.NOTE 13Temperature probes should be used to monitor the airtemperature throughout the chamber. If warm units are placed into afreezing chamber, the air temperature within t