ASTM C1262-2008a Standard Test Method for Evaluating the Freeze-Thaw Durability of Dry-Cast Segmental Retaining Wall Units and Related Concrete Units.pdf

1、Designation: C 1262 08aStandard Test Method forEvaluating the Freeze-Thaw Durability of Dry-CastSegmental Retaining Wall Units and Related Concrete Units1This standard is issued under the fixed designation C 1262; the number immediately following the designation indicates the year oforiginal adoptio

2、n or, 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

3、segmental retaining wall (SRW) units (seeSpecification C 1372) 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 solidconc

4、rete 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 n

5、ot purport 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 Standar

6、ds:2C 140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related UnitsC 1093 Practice for Accreditation of Testing Agencies forMasonryC 1209 Terminology of Concrete Masonry Units and Re-lated UnitsC 1372 Specification for Dry-Cast Segmental RetainingWall Units3. Terminology3.1 Termi

7、nology defined in Terminology C 1209 shall 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 intende

8、d to provide a quantitativemeasure to determine 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 C 1093.5. Apparatus5.1 Freezing-and-Thawing ChamberUse a chamber thathas:5.1.1 For

9、ced air circulation,5.1.2 A programmable air-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 temperaturethrough

10、out the chamber within the specified temperatureranges 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 m

11、inimum of18 in. (3mm) and a maximum of 112 in. (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 t

12、o the opposite end when placed on the support 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

13、Capable of supporting the specimen in both thelongitudinal 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

14、edition approved Nov. 1, 2008. Published December 2008. Originallyapproved in 1994. Last previous edition approved in 2008 as C 1262 08.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in

15、formation, refer to the 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 transvers

16、e support configura-tions 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

17、 beavailable in the laboratory 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 tha

18、t thereference standard 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-meas

19、uring devices at least 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

20、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 replacethe temperature-measuring device.5.5 ScalesScales for weighing full-size specimens shallhave a capacity of

21、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 required in 8.2.3, shall be accurate to at least0.2 g (0.0005 lb).6. Sampling6.1 Selection of Test SpecimensSelect

22、 whole units repre-sentative of the lot from which they are selected. The unitsshall be free from visible cracks or structural defects.6.2 Number of SpecimensSelect five SRW units forfreeze-thaw tests.6.2.1 When compression and absorption testing will beconducted in addition to freeze-thaw testing,

23、obtain a specimenfor 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 streng

24、th and absorp-tion specimens in accordance with Test Methods C 140.Specimens (coupons) used for Test Methods C 140 tests shallnot be used as specimens for freeze-thaw tests.NOTE 4While compressive strength and absorption values by them-selves have been shown by research to not be reliable indicators

25、 ofdurability, they have been shown to be good reference values for unitsmanufactured from a given set of materials.6.3 IdentificationMark each freezingandthawing speci-men so that it is identifiable at any time.7. Preparation of Test Specimens7.1 FreezingandThawing Test SpecimensTest speci-mens sha

26、ll consist of solid coupons saw-cut from full sizedunits. Do not saw-cut test specimens from units that have beenpreviously oven-dried. Do not subject test specimens to oven-drying prior to completion of freezingandthawing testing.7.1.1 Cut one coupon from each of the five sampled units.Using a wate

27、r-cooled saw, cut the coupon from the exposedsurface of the unit as the unit is used in service unless theexposed surface is an architectural or other nonplanar surface(see Note 5). In the case of a unit with an exposed architecturalor other nonplanar surface, cut the coupon from another flatmolded

28、surface ideally as far as possible from the architecturalor other non-planar face and in no case 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 fullyi

29、mmerse coupons in water.NOTE 5Split-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.7.1.2 Place the coupons on edge on

30、 a38 in. (10 mm) orcoarser mesh such that there is an air space of not less than 1in. (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 %.7.1.3 The thickness of each coupon shall be 1

31、14 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).7.1.4 The area of the submerged surface of the test spec

32、imenshall 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 not exceed 35i

33、n.2(225 cm2). These two coupons shall be tested as andconsidered to be a single specimen.8. Procedure8.1 Specimen Conditioning:8.1.1 After preparation of the freezingandthawing testspecimens in accordance with Section 7, place the specimen inthe container face down on the specimen supports such that

34、 thenon-saw-cut surface of the specimen is in contact with thespecimen supports. Add a sufficient amount of test solution ata temperature of 60 to 80F (16 to 27C) to the container toFIG. 1 Test Specimen in FreezingandThawing ContainerC 1262 08a2achieve a test solution depth of12 6116 in. (13 6 2 mm)

35、 (seeNote 6 and Note 7). Do not pour test solution directly onto thespecimen. The test solution shall 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 define

36、d in 7.1.2.NOTE 6The submerged portion 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 7One way to repeatedly achieve the specified water depth is toadd a consistent volume of water which ha

37、s been calibrated for a givenspecimen and container size combination to yield the specified depth.NOTE 8The 3 % saline solution can be prepared by adding 0.03 lb ofsodium chloride to each 0.97 lb of water.8.1.2 After 1 h 6 15 min, open the container and add testsolution as necessary to maintain the

38、water level required in8.1.1. Reseal the container. After another 23 h 6 1 h, removethe specimen from 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

39、 1 g (0.002 lb) and record asWp.NOTE 9The weight Wpas determined in 8.1.2 is not required to bereported 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 unt

40、il thecompletion of freezingandthawing testing by adding the dry-weight ofthe collected residue to the dry-weight of the remains of the specimen (see8.3.5), this Wpweight is needed as a reference weight to be used duringthe testing to estimate percentage weight loss and to predict relativeperformanc

41、e between test specimens.8.1.3 Return the specimens to the container and adjust testsolution level as required in 8.1.1.8.1.4 Test solution added to the containers shall be at atemperature of 60 to 80F (16 to 27C).8.2 Cyclical Testing:8.2.1 Begin the test with a freezing cycle. Place the con-tainers

42、 into the freezing test chamber such that each containeris surrounded by a minimum air space of12 in. (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

43、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 the prescribed temperature. Periodically, at the end ofa freezing cycle, open the containers and visually inspect thespecimens to determine if all the test solution

44、 surrounding thespecimen is frozen solid. If not, extend the length of thefreezing cycle to ensure 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 temperatur

45、e within the chamber rises. The startof the freezing cycle time period begins only after the temperature 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

46、 the specimens remain in thefreezing chamber for the appropriate length of time to comply with thecycle requirements. The same procedures should also be used to verifycompliance with thawing cycle requirements in 8.2.6.8.2.2 After the freezing cycle, immediately begin the thaw-ing cycle. During the

47、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 b

48、e surrounded by a minimum air space of12 in. on all sides. If the air surrounding the containers is 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

49、 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.8.2.3 One freezingandthawing cycle is defined as a com-pleted freezing cycle followed by a completed thawing cycle.8.2.4 At 20 cycle intervals for those specimens tested inwater and at 10 cycle intervals for those specimens tested insaline solution, remove containers from the test chamber andcollect residue in accordance with 8.3. Open containe