1、Designation: D 6924 03Standard Specification forPreformed Thermoplastic Vulcanizate Elastomeric JointSeals for Bridges1This standard is issued under the fixed designation D 6924; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the material requirements forpreformed thermoplastic vulcanizate (TPV) elastomeric
3、jointseals for bridges. The seal consists of a multiple-web designcomposed of a TPV and functions only by compression of theseal between the faces of the joint with the seal folding inwardat the top to facilitate compression. The seal is installed with alubricant adhesive and is designed to seal the
4、 joint and rejectincompressibles.NOTE 1This specification may not be applicable for seals whoseheight is less than 90 % of its nominal width.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are providedfor information only.1.3 This standard
5、 does not 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 requirements prior to use.2. Referenced Documents2.1 ASTM
6、 Standards:D 395 Test Methods for Rubber PropertyCompressionSet2D 412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTension2D 518 Test Method for Rubber DeteriorationSurfaceCracking2D 573 Test Method for RubberDeterioration in an AirOven2D 575 Test Methods for Rubber Properties in
7、Compression2D 1149 Test Method for Rubber DeteriorationSurfaceOzone Cracking in a Chamber2D 2240 Test Method for Rubber PropertyDurometerHardness2D 4483 Practice for Determining Precision for Test MethodStandards in the Rubber and Carbon Black Industries2D 6338 Classification System for Highly Cross
8、linked Ther-moplastic Vulcanizates (HCTPVs)33. Marking and Ordering Information3.1 Each lot of seal shall be marked with characters of notless than 0.25 in. (6.35 mm) in height on the top of the seal ata maximum of 4 ft (1.22 m) intervals showing the lot number,date of manufacture, and the manufactu
9、ring seal designation.3.2 The purchaser shall specify the anticipated requiredminimum acceptable joint movement, and either the minimumjoint opening, or the nominal width of seal.4. Materials and Manufacture4.1 The seals shall be preformed, and the material shall bevulcanized elastomeric compound us
10、ing a thermoplastic vul-canizate as the compound. A thermoplastic vulcanizate is ablend of a crosslinked rubber and a thermoplastic polymer thatcan be processed on conventional thermoplastic processingmachinery and has the properties of a crosslinked elastomer.Highly crosslinked thermoplastic elasto
11、mers are classifiedaccording to Classification System D 6338. TPV materials aremade in the dynamic vulcanization process. One example of atypical TPV is crosslinked ethylene propylene diene rubberblended with polypropylene. The TPV material can alsocontain processing oils, antioxidants, fillers, or
12、other additives.5. Physical Requirements5.1 The materials shall conform to the physical propertiesprescribed in Table 1.5.2 In the applicable requirements of Table 1 and the testmethods, all deflection shall be based on the nominal width.6. Dimensions and Working Parameters6.1 The size, shape and di
13、mensional tolerances shall be asoutlined in 6.1.1.6.1.1 Measurements used for laboratory testing shall betaken to the nearest 0.01 in. (0.3 mm) and reported/recorded tothe nearest 0.1 in. (3 mm) as the average of three measure-ments. The measured width shall be greater than or equal to thenominal wi
14、dth. The seal height shall not be less than 90 % of1This specification is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.34 onPreformed Joint Fillers and Sealers.Current edition approved July 10, 2003. Published October 2
15、003.2Annual Book of ASTM Standards, Vol 09.01.3Annual Book of ASTM Standards, Vol 08.031Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the nominal width unless joint recess dimensions or specialdesign considerations dictate the geome
16、try.6.2 Compression Deflection PropertiesThe contact pres-sure expressed in pounds-force per square inch (or pascals)when the seal is compressed to any particular width indicatesthe stress-strain relationship that exists in the seal. Thisrelationship is dependent on both the properties of the elas-t
17、omer and the cross-sectional configuration of the seal. There-fore, for a predetermined allowable pressure, a definitiverelationship will exist and the working limits of the seal may bedefined.6.2.1 The working limits (minimum and maximum degreesof compression) of the seal shall be determined on the
18、 basis ofthe minimum and maximum limits of compressibility (LC minand LC max), and the movement range as specified herein.Seals with nominal width differing from that specified areacceptable, providing the compressed width at LC max is lessthan the minimum anticipated joint opening, and the movement
19、range requirement is met.6.2.2 The minimum limit of compressibility (LC min) isdefined as the compressed width (expressed in terms of percentof nominal width) corresponding to a contact pressure of 3 psi(20.68 kPa). The LC min shall be determined in accordancewith 9.3. For the purpose of calculating
20、 movement range, avalue at 85 % of nominal width shall be used for LC min whenthe measured value of LC min exceeds 85 %.NOTE 2If the seal generates a pressure of 3 psi at 90 % of nominalwidth, LC min equals 85 %. However, if the seal generates 3 psi at 70 %of nominal width, the LC min equals 70 %.6.
21、2.3 The maximum limit of compressibility (LC max) isdefined as the compressed width (expressed in terms of percentof nominal width) corresponding to a contact pressure of 35 psi(241.32 kPa). The LC max shall be determined in accordancewith 9.3. LC max has been designated at 35 psi (241.32 kPa)in ord
22、er to mitigate the tendencies toward pressure decay of theseal during use. A reading of 35 psi is considered an absolutemaximum pressure which should not be exceeded.6.2.4 The movement range of the seal is defined as thenumerical difference between the LC min and the LC maxexpressed in inches (mm).
23、For the purpose of calculating themovement range, a value at 85 % shall be used for LC minwhen the measured value of LC min exceeds 85 %. Forpurposes of acceptance testing, the calculated movement rangeof the seal shall not be less than the specified value.7. Sampling7.1 A lot shall consist of the q
24、uantity for each cross sectionagreed upon between the purchaser and the supplier.7.2 Samples shall be taken at random from each shipment ofmaterial. If the shipment consists of more than one lot, each lotshall be sampled.7.3 The minimum lengths of samples for testing purposesshall be as prescribed b
25、y the purchaser or as prescribed in Table2.8. Specimen Preparation8.1 All test specimens shall be cut, buffed, or both from thesample of preformed seal. Care should be taken not to overheatthe test specimen during buffing. The cut shall be square towithin 2 and smooth, with no roughness visible to t
26、he nakedeye. The use of a tooth blade device or a guillotine-type cutter,or both, is not acceptable. This process will eliminate irregu-larities.8.2 Specimens for determining tensile strength and elonga-tion (Test Methods D 412) shall be prepared using Die C whenpossible. Die D may be used when the
27、flat sections of a seal aretoo small for Die C. However, the requirement of Table 1 shallapply regardless of the die used. Buffing should be carefullyperformed and kept to a minimum.8.3 Specimens for low-temperature and high-temperaturerecovery tests and for pressure deflection tests shall consist o
28、f6-in. (150-mm) lengths of the preformed seal.TABLE 1 Physical Requirements for Preformed ElastomericJoint SealsRequirementsASTMTest MethodTensile strength, min, psi (MPa) 730 (4.4) D 412Elongation at break, min, % 300 D 412Hardness, Type A durometer, points 50 to 70 D 2240(modified)AOven aging, 168
29、 h at 212F (100C)Tensile strength, max, % loss 10Elongation, max, % loss 10Hardness, Type A durometer,points change0to5Ozone resistanceBno cracks D 1149C20 % strain, 300 pphm in air, 70 h,at 104F (40C) (wiped with tolueneto remove surface contamination)Low-temperature recovery,72 h at 14F (-10C), 50
30、 %:Deflection, min, % 80 Section 7DLow-temperature recovery,22 h at -20F (-29C), 50 %:Deflection, min, % 70 Section 7DHigh-temperature recovery,70 h, at 212F (100C), 50 %:Deflection, min, % 75 Section 7DCompression-deflection properties:LC min in. (mm) 9.3 D 575 Method ALC max in. (mm) 9.3 (modified
31、)EMovement range, in. (mm) 9.3AThe term “modified” in the table relates to the specimen preparation. The useof the joint seal as the specimen source requires that more plies than specified ineither of the modified test procedures be used. Such specimen modification shallbe agreed upon between the pu
32、rchaser and the supplier prior to testing. Thehardness test shall be made with the durometer in a durometer stand asrecommended in Test Method D 2240.BSample prepared in accordance with Method A of Test Method D 518.CCracking, splitting, or sticking of a specimen during a recovery test shall meantha
33、t the specimen has failed the test.DThe reference section and subsections are those of this specification. Thevalues found in 6.2.2, 6.2.3, and 6.2.4 shall be within the range specified by thepurchaser in 3.2.ESpeed of testing shall be 0.5 6 0.05 in. (13 6 1.3 mm), min at roomtemperature of 73 6 4F
34、(23 6 2.2C). The sheets of sandpaper are not used.TABLE 2 Minimum Lengths of Seal SamplesSeal Size,in. (mm)Length of Sample,in. (m)Less than 2 (51) 96 (2.44)2 (51) to less than 3 (76) 72 (1.83)3 (76) and larger 60 (1.52)D69240329. Test Methods9.1 Compliance with the requirements of Table 1 shall bed
35、etermined by tests conducted in accordance with the methodsspecified.9.2 Recovery Tests:9.2.1 Determine the low-temperature and high-temperaturerecovery test values using specimens prepared in accordancewith Section 8. Two specimens shall be used for each test.9.2.2 Deflect the specimen between para
36、llel plates to 50 %of the nominal width using the compression set clamp assem-bly described in Method B of Test Methods D 395. Prior tocompression, place the specimen in a horizontal position, suchthat the plane through both edges of the top surface of the jointseal is perpendicular to the compressi
37、on plate. As the specimenis being compressed, the top surface of the joint seal shouldfold inward toward the center of the specimen.9.2.3 Place a clamp assembly containing the compressedspecimen in a refrigerated box capable of maintaining atemperature of 14 6 2F (-10 6 1.1C) for 72 h. Unclamp theas
38、sembly and remove the upper compression plate, or carefullyremove the specimen from the assembly and transfer it to awooden surface in the refrigerated box. Allow the specimen torecover for1hat146 2F (-10 6 1.1C). Measure therecovered width in the center of the 6-in. (150-mm) length atthe top longit
39、udinal edge of the specimen. Measurements maybe made with either a dial caliper or a platform-mounted dialgage graduated in thousandths of an inch (0.025 mm). Theplatform-mounted gage shall have a14-in. (6-mm) diameterpressure foot with a force of 0.18 6 0.02 lbf (0.80 6 0.09 N).Measurements with th
40、e platform-mounted gage should betaken with the pressure foot centered on the longitudinal edgeof the seal. Calculate the recovery as follows:Recovery, % 5recovered width 3 100!nominal width!(1)Report the least value of recovery to the nearest 1 %.NOTE 3The use of a desiccant, such as calcium chlori
41、de, in therefrigerated box should be used to minimize frosting. The desiccant shouldbe changed or reactivated as frequently as necessary to keep it effective.9.2.4 Place a clamp assembly containing the compressedspecimen in a refrigerated box capable of maintaining atemperature of -20 6 2F (-29 6 1.
42、1C) for 22 h (see Note 3).Unclamp the assembly and remove the upper compressionplate, or carefully remove the specimen and transfer it to awooden surface in the refrigerated box. Allow the specimen torecover for1hat-206 2F (-29 6 1.1C). Measure therecovered width and calculate the recovery as in 9.2
43、.3.9.2.5 Place a clamp assembly containing the compressedspecimen in an oven conforming to Test Method D 573. Thetemperature shall be maintained at 212 6 2F (100 6 1.1C)for 70 h. Do not preheat the clamp assembly. Unclamp theassembly, carefully remove the specimen, and allow it torecover at 73 6 4F
44、(23 6 2.2C) on a wooden surface for 1h. Measure the recovered width and calculate the recovery as in9.2.3.9.3 Compression-Deflection Tests:9.3.1 Determine compression-deflection values using speci-mens prepared in accordance with Section 8. Measure thelength of each specimen at the top, center, and
45、bottom using arule graduated in thirty seconds of an inch (or millimetres).Average the three measurements and record as the length of thespecimen to the nearest132 in. (0.8 mm). Measure the height ofthe contact area on both sides and at both ends (four measure-ments) with a dial caliper or suitable
46、rule. Average and recordto the nearest132 in. (0.8 mm).9.3.2 Calculate the contact area of the specimen by multi-plying the average length times the average height of thecontact area as determined above.9.3.3 Calculate the forces required to compress the speci-men to LC min and LC max by multiplying
47、 the contact areatimes 3 psi (20.68 kPa) and 35 psi (241.32 kPa), respectively.9.3.4 Place the specimen on its side in such a manner that aplane through both edges of the top surface of the seal shall beperpendicular to the platens. Close the platens until thedistance between them is slightly larger
48、 than the actual widthof the seal. Test in accordance with Method A of Test MethodsD 575, except that the speed shall be 0.5 6 0.05 in. (13 6 1.3mm)/min, and the sheets of sandpaper are not used.9.3.5 Compress the specimen to LC max by observing theforce calculated in 9.3.3. Immediately reverse at t
49、he same rateto the original distance between the platens. Repeat this cycletwo times for a total of three cycles. Record the compressedwidth of the seal obtained at both the LC min and LC max onthe compression portion of the third cycle by measuring thecompressed width of the seal at those forces calculated in 9.3.3.9.3.6 During the course of running the test described in9.3.4, the tendency of the top surface of the seal to becomemisaligned shall be observed. Misalignment of more than14 in.(6.3 mm) shall be reason for rejection of the seal.9.3.7 Ca
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