1、Designation: C1262 10Standard 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; the number immediately following the designation indicates the year oforiginal adoption o
2、r, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the resistance to freezing andthawing of dry-cast seg
3、mental retaining wall (SRW) units (seeSpecification C1372) and related concrete units. Units aretested in a test solution that is either water or 3 % salinesolution depending on the intended use of the units in actualservice.NOTE 1Related concrete units include units such as hollow and solidconcrete
4、 masonry units, concrete brick, and concrete roof pavers.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not p
5、urport to address all of thesafety concerns, if any, associated with its use. It is 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:2
6、C140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related UnitsC1093 Practice for Accreditation of Testing Agencies forMasonryC1232 Terminology of MasonryC1372 Specification for Dry-Cast Segmental RetainingWall Units3. Terminology3.1 Terminology defined in Terminology C1232 shall
7、applyfor this test method.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 water or saline solution.4.2 The procedure is not intended to provide a quantitativemeasure to deter
8、mine an expected length of service for aspecific type of concrete unit.NOTE 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-tempera
9、ture controller capable ofautomatically performing at least two freezing and thawingcycles per 24-h period during testing,5.1.3 A temperature range of at least 10 to 100F (24 to38C), and5.1.4 The capability of maintaining the air temperaturethroughout the chamber within the specified temperaturerang
10、es for the duration of the test cycle.5.2 ContainersUse containers that are: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. (38 m
11、m) of test solutionsurrounding the sides of the specimen,5.2.4 Supplied with a tightly-fitting lid to reduce evapora-tion, 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
12、.3 Specimen SupportsSupport the specimen above thecontainer bottom. Use supports that are:5.3.1 Rods having dimensions of18 6124 in. (3 6 1 mm),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 thelongit
13、udinal and transverse directions (see Note 3).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 June 1, 2010. Published June 2010.
14、Originallyapproved in 1994. Last previous edition approved in 2009 as C1262 09. DOI:10.1520/C1262-10.2For 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 D
15、ocument Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 3Examples of longitudinal and transverse support configura-tions including
16、 placing the supports in the I, Z, or box configurations.5.4 Temperature-Measuring Equipment:5.4.1 Reference Temperature-Measuring DeviceThe ref-erence temperature-measuring device shall be readable andaccurate to 60.5F (0.2C) within the range of use. Acertificate or report that verifies the accurac
17、y shall be availablein the laboratory for review. Verify the accuracy of liquid-in-glass reference temperature measuring devices at least once.Verify the accuracy of direct-reading resistance referencetemperature-measuring devices every twelve months. Thecertificate or report shall provide documenta
18、tion that thereference standard used in the verification is traceable to theNational 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
19、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 7.2.1 and7.2.2. A record of this evaluation documenting the dat
20、echecked, 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 4This requirement may be satisfied by an initialed and datedtemperature recorder chart. Brief changes in the temperature
21、 due to dooropenings should be ignored.NOTE 5A 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 the chamber in a readable po
22、sition 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 by more than 2F, adjust or re
23、placethe 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(0.002 lb). Scales for weighing the filter paper and specimenresidue (spall), as re
24、quired in 7.2.3, shall be accurate to at least0.2 g (0.0005 lb).6. Sampling and Preparation of Test Methods6.1 Selection 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
25、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 completion of freeze-thaw testing.6.2.1 Cut one coupon from each of the five sampled
26、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 6). In the case of a unitwith an exposed architectural or other nonplanar surface, cutthe coupon from another flat molded surface
27、 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 rinsing in tap water and brushing with a softbristle brush. Do not fully immerse c
28、oupons in water. Eachspecimen shall be marked with a unique identification numberon the non-molded surface of the specimen.NOTE 6Split-faced surfaces are the most common surfaces used toprovide an architectural appearance to segmental retaining walls. How-ever, other means could be used to obtain si
29、milar architectural effects liketumbling, 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 proper hardness.6.2.3 Place the coupons on edge on a38 in. (10 mm) orcoarser mes
30、h 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 15F(24 6 8C) and a relative humidity of less than 80 %.6.2.4 The thickness of each coupon shall be 114 in. (32 mm)6116 in. (2 mm)
31、, unless the unit does not permit this minimumthickness, 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. (19 mm).6.2.5 The area of the submerged surface of the test specimenshall be at least 25 in.2
32、(161 cm2) and shall not exceed 35 in.2(225 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.2(161 cm2) and shall not exceed35 in.2(225 cm2). These two coupo
33、ns 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) for each test from each of five SRW units to facilitatecorrelation among the properties. If this is not possible, t
34、henobtain compressive strength and absorption specimens fromdifferent units manufactured in the same production lot as thefreeze-thaw specimens. Take compressive strength and absorp-tion specimens in accordance with Test Methods C140. Speci-mens used for Test Methods C140 tests shall not be used ass
35、pecimens for freeze-thaw tests.FIG. 1 Test Specimen in Freeze-Thaw ContainerC1262 102NOTE 7While compressive strength and absorption values by them-selves have been shown by research3to not be reliable indicators ofdurability, they have been shown to be good reference values for unitsmanufactured fr
36、om a given set of materials.7. Procedure7.1 Specimen Conditioning:7.1.1 After preparation of the freeze-thaw test specimens inaccordance with Section 6, place the specimen in the containerface down on the specimen supports such that the non-saw-cutsurface of the specimen is in contact with the speci
37、mensupports. Add a sufficient amount of test solution at a tempera-ture of 60 to 80F (16 to 27C) to the container to achieve a testsolution depth of12 6116 in. (13 6 2 mm) (see Note 8 andNote 9). Do not pour test solution directly onto the specimen.The test solution shall be either potable tap water
38、 or a 3 6 0.1% (by weight) sodium chloride saline solution (see Note 10).Close the container lid tightly and store the container on a levelsurface in laboratory air as defined in 6.2.3.NOTE 8The submerged portion of the specimen is38 in. (10 mm) ofits thickness. There is18 in. (3 mm) of test solutio
39、n between the bottomof the container and the face of the specimen.NOTE 9One way to repeatedly achieve the specified water depth is toadd a consistent volume of water which has been calibrated for a givenspecimen and container size combination to yield the specified depth.NOTE 10The 3 % saline soluti
40、on can be prepared by adding 0.03 lb ofsodium chloride to each 0.97 lb of water.7.1.2 After 1 h 6 15 min, open the container and add testsolution as necessary to maintain the water level required in7.1.1. Reseal the container. After another 23 h 6 1 h, removethe specimen from the test solution and a
41、llow to drain for 1 minby placing it on a38-in. (10-mm) or coarser sieve, removingvisible surface test solution with a damp cloth. Immediatelyweigh the specimen to the nearest 1 g (0.002 lb) and record asWp.NOTE 11The weight Wpas determined in 7.1.2 is not required to bereported at the conclusion of
42、 the test, nor is it used 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
43、 the specimen (see7.3.5), this Wpweight is needed as a reference weight to be used duringthe testing to estimate percentage weight loss and to predict relativeperformance between test specimens.7.1.3 Return the specimens to the container and adjust testsolution level as required in 7.1.1.7.1.4 Test
44、solution added to the containers shall be at atemperature of 60 to 80F (16 to 27C).7.2 Cyclical Testing:7.2.1 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 t
45、esting 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 r
46、each the 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
47、 solid.NOTE 12Temperature probes should be used to monitor the airtemperature throughout the chamber. If warm units are placed into afreezing chamber, the air temperature within the chamber rises. The startof the freezing cycle time period begins only after the temperature of theair within the chamb
48、er is within the permissible range. Typically, constanttemperature monitoring is not necessary, but it should be preformedthrough the first several cycles to ensure that the specimens remain in thefreezing chamber for the appropriate length of time to comply with thecycle requirements. The same proc
49、edures should also be used to verifycompliance with thawing cycle requirements in 7.2.6.7.2.2 After the freezing cycle, immediately begin the thaw-ing cycle. During the thawing cycle, maintain the air tempera-ture around the containers at 75 6 10F (24 6 5C) for aperiod of not less than 2.5 h and not more than 96 h. The cycletime does not include the time required for the air temperaturearound the specimens to reach the prescribed temperatures.Each container shall be surrounded by a minimum air space of12 in. on all sides. If th
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