1、Designation: C1262/C1262M 18Standard 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on stan
7、dard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C140/C140M Test Methods for Sampling and Test
8、ing Con-crete Masonry Units and Related UnitsC1093 Practice for Accreditation of Testing Agencies forMasonryC1232 Terminology for MasonryC1372 Specification for Dry-Cast Segmental Retaining WallUnits3. Terminology3.1 Terminology defined in Terminology C1232 shall applyfor this test method.3.2 Defini
9、tions of Terms Specific to This Standard:3.2.1 chamber capacity, nthe number of specimens con-tained within the test chamber during verification of chambertemperatures and cycling.3.2.1.1 DiscussionThe number of specimens in the cham-ber must remain the same at all times during testing. Chambertempe
10、rature cycling verification must be performed at thechamber capacity that will be used during testing. If at any timeduring testing the actual number of test specimens is less thanthe chamber capacity, dummy specimens must be used tomaintain the same thermal load. A change in chamber capacityrequire
11、s verification of temperature cycling.3.2.2 dummy specimen, na specimen with the same ap-proximate mass as actual test specimens which is used tomaintain a consistent thermal load in a test chamber.3.2.2.1 DiscussionDummy specimens could be leftoverspecimens from previous testing, additional specime
12、ns cutfrom manufactured concrete products, or even a measuredamount of sand approximately equal to the mass of the testedunits. The dummy specimen is placed in a sample containerwhich contains an equivalent amount of test solution as used inthe other test containers in order to maintain approximatel
13、y thesame thermal load in the whole test chamber.4. Significance and Use4.1 The procedure described in this 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 prov
14、ide a quantitativemeasure to determine an expected length of service for aspecific type of concrete unit.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.C
15、urrent edition approved July 15, 2018. Published August 2018. Originallyapproved in 1994. Last previous edition approved in 2016 as C1262 16. DOI:10.1520/C1262_C1262M-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annu
16、al Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM 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 internat
17、ional standard was developed in accordance with internationally recognized principles on standardization 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) Commit
18、tee.1NOTE 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 fr
19、eezing 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.5.1.5 The chamber shall comply
20、 with the temperature re-quirements for cycling contained in 7.2.1 and 7.2.2 at chambercapacity. When testing is conducted, the total number of testspecimens and dummy specimens combined shall equal thechamber capacity used when the temperatures are verified.5.2 ContainersUse containers that are:5.2
21、.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 tigh
22、tly-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 that a
23、re:5.3.1 Rods having a thickness of18 6124 in. 3 6 1 mmand a width of the portion that contacts 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
24、 both thelongitudinal and transverse directions (see Note 4).NOTE 3The rods can be of any cross-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
25、 the specimen is no greater than the rod thickness.NOTE 4Examples of longitudinal and transverse 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-measuri
26、ng device shall be readable andaccurate to 60.5F 0.2C within the range of use. Acertificate or 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 r
27、eport shall provide docu-mentation that the reference standard used in the verification istraceable 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 an
28、d readable to 2F 1C. Verify theaccuracy of the temperature measuring device at least every sixmonths. 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 ev
29、aluation documenting the datechecked, a confirmation that the data is within the requiredtemperature 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. Brie
30、f changes in the temperature due to dooropenings should be ignored.NOTE 6A convenient time to evaluate 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
31、the chamber in a readable position as near to thetemperature-measuring device probe as possible. 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 b
32、y more than 2F 1C, adjust orreplace the temperature-measuring device.5.5 ScalesScales for weighing 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 r
33、esidue(spall), as required in 7.3.3, shall be accurate to at least 0.2 g.5.6 OvenA ventilated oven 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
34、 of UnitsSelect five whole SRW units repre-sentative of the lot from which they are selected. The 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 u
35、nits that have been previouslyoven-dried. Do not subject test specimens to oven-drying priorto 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
36、 architecturalFIG. 1 Test Specimen in Freeze-Thaw ContainerC1262/C1262M 182or other nonplanar surface (see Note 7). In the case of a unitwith an exposed architectural or other nonplanar surface, cutthe coupon from another flat molded surface ideally as far aspossible from the architectural or other
37、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 rinsing in tap water and brushing with a softbristle brush. Do not fully immerse coupons in water. Eachspecimen shall be marked with a unique i
38、dentification numberon the non-molded surface of the specimen.NOTE 7Split-faced surfaces are the most common surfaces used toprovide an architectural appearance to segmental retaining walls.However, other means could be used to obtain similar architectural effectslike tumbling, grinding, and slumpin
39、g.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 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 bet
40、ween 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 %.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 thic
41、kness 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 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 cou
42、pon 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 cm2and shall not exceed35 in.2225 cm2. These two coupons shall be tested as andconsidered to be a single specimen.6.3 When compression and absorp
43、tion testing will be con-ducted in addition to freeze-thaw testing, obtain a specimen(coupon) for 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
44、 the same production lot as thefreeze-thaw specimens. Take compressive strength and absorp-tion specimens in accordance with Test Methods C140/C140M.Specimens used for Test Methods C140/C140M tests shall notbe used as specimens for freeze-thaw tests.NOTE 8While compressive strength and absorption va
45、lues by them-selves have been shown by research3to not be reliable indicators ofdurability, they have been 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 we
46、ight) sodium chloride saline solution (seeNote 9).NOTE 9The 3 % saline solution can be prepared by adding 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
47、 residue.7.2 Specimen Conditioning:7.2.1 After preparation of the freeze-thaw specimens inaccordance with 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
48、to calculate thereported weight loss of the specimen throughout the test. However,because the initial dry-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), th
49、is Wstartweight is needed as a reference weight to be used duringthe testing to estimate percentage weight 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 80F16 to 27C to the container to achieve a test solution depth of12 6116 in. 13 6 2 mm (
