1、Designation: C1262 09Standard 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 Freezing-and-Thawing ChamberUse a chamber thathas:5.1.1 Forced air circulation,5.1.2 A programmable air
9、-temperature 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 tempera
10、tureranges 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 i
11、n. (38 mm) 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 suppor
12、t rods.5.3 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 t
13、helongitudinal 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 Dec. 15, 2009. Published De
14、cember 2009. Originallyapproved in 1994. Last previous edition approved in 2008 as C1262 08a. DOI:10.1520/C1262-09.2For 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 t
15、he standards Document 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-t
16、ions including placing the supports in the I, Z, or box configurations.5.4 Temperature-Measuring Equipment:5.4.1 Reference Temperature-Measuring Device, shall bereadable and accurate to 60.5F (0.2C) within the range ofuse. A certificate or report that verifies the accuracy shall beavailable in the l
17、aboratory for review. Verify the accuracy ofliquid-in-glass reference temperature measuring devices atleast once. Verify the accuracy of direct-reading resistancereference temperature-measuring devices every twelve months.The certificate or report shall provide documentation that thereference standa
18、rd used in the verification is traceable to theNational Institute of Standards and Technology (NIST).5.4.2 Temperature-Measuring Devices, capable of measur-ing the temperature at various points within the test chamber towithin 2F (1C). Verify the accuracy of the temperature-measuring devices at leas
19、t every six months.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. Close thedoor and leave undisturbed for at least 5 min. Read the
20、temperature immediately after opening the chamber door.Record the temperature readings of both devices. If thetemperature readings differ by more than 2F, adjust or replacethe temperature-measuring device.5.5 ScalesScales for weighing full-size specimens shallhave a capacity of at least 50 % greater
21、 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 required 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 UnitsSele
22、ct 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 Freezing-and-Thawing Test SpecimensTest specimensshall consist of solid coupons saw-cut from full sized units. Donot saw-cut test specimens from units
23、 that have been previ-ously oven-dried. Do not subject test specimens to oven-dryingprior to completion of freezing-and-thawing testing.6.2.1 Cut one coupon from each of the five sampled units.Using a water-cooled saw, cut the coupon from the exposedsurface of the unit as the unit is used in service
24、 unless theexposed surface is an architectural or other nonplanar surface(see Note 4). In the case of a unit with an exposed architecturalor other nonplanar surface, cut the coupon from another flatmolded surface ideally as far as possible from the architecturalor other nonplanar face and in no case
25、 less than 2 in. (50 mm)from that surface. Immediately following saw-cutting, removeloose particles and residue from the coupon by rinsing in tapwater and brushing with a soft bristle brush. Do not fullyimmerse coupons in water. Each specimen shall be markedwith a unique identification number on the
26、 non-molded surfaceof the specimen.NOTE 4Split-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 similar architectural effects liketumbling, grinding, and slumping.6.2.2 Place the coupons
27、 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 15F(24 6 8C) and a relative humidity of less than 80 %.6.2.3 The thickness of each coupo
28、n shall be 114 in. (32 mm)6116 in. (2 mm), 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).6.2.4 The area of the submerged surface of t
29、he test specimenshall be at least 25 in.2(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 no
30、t exceed35 in.2(225 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) for each test from each of five SRW units to facilitatecorrelation among t
31、he 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 specimens in accordance with Test Methods C140. Speci-mens used for Test
32、 Methods C140 tests shall not be used asspecimens for freeze-thaw tests.NOTE 5While 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 from a given se
33、t of materials.7. Procedure7.1 Specimen Conditioning:7.1.1 After preparation of the freezing-and-thawing testspecimens in accordance with Section 6, place the specimen inthe container face down on the specimen supports such that thenon-saw-cut surface of the specimen is in contact with thespecimen s
34、upports. Add a sufficient amount of test solution at3Chan, C., Hover, K. C., Folliard, K. J., Hance, R. M., Trejo, D., Durability ofSegmental Retaining Wall Blocks: Final Report, Federal Highway AdministrationReport No. FHWA HRT-07-021, April 2007, pp. 4255.Available from http:/www.tfhrc.gov/structu
35、r/pubs/07021/index.htm.FIG. 1 Test Specimen in Freezing-and-Thawing ContainerC1262 092a temperature of 60 to 80F (16 to 27C) to the container toachieve a test solution depth of12 6116 in. (13 6 2 mm) (seeNote 6 and Note 7). Do not pour test solution directly onto thespecimen. The test solution shall
36、 be either potable tap water ora36 0.1 % (by weight) sodium chloride saline solution (seeNote 8). Close the container lid tightly and store the containeron a level surface in laboratory air as defined in 6.2.2.NOTE 6The submerged portion of the specimen is38 in. (10 mm) ofits thickness. There is18 i
37、n. (3 mm) of test solution between the bottomof the container and the face of the specimen.NOTE 7One 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.NOT
38、E 8The 3 % saline solution 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
39、 the test solution and allow 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 9The weight Wpas determined in 7.1.2 is not required to bereport
40、ed 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-weight of the specimen is not determined until thecompletion of freezing-and-thawing testing by adding the dry-weight ofthe collected residue to
41、the dry-weight of the remains of 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
42、as required in 7.1.1.7.1.4 Test 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 i
43、n. (13 mm) on allsides. During testing 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 ai
44、r temperature in the chamberto reach 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
45、that all test solution is frozen solid.NOTE 10Temperature 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 temper
46、ature of theair within the chamber 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 thec
47、ycle requirements. The same procedures 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 aperio
48、d 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 the air surrounding the containers is
49、 notcontinuously circulated during the thawing cycle, the contain-ers shall be laid out in a single layer without stacking in thevertical direction. Periodically, at the end of a thawing cycle,open the containers and visually inspect the specimens todetermine if no ice remains. If ice is still present, extend thelength of the thawing cycle to ensure that all ice has thawed.7.2.3 One freezing-and-thawing cycle is defined as a com-pleted freezing cycle followed by a completed thawing cycle.7.2.4 At 20 cycle intervals for those spec
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