1、Designation: D6924 03 (Reapproved 2012)Standard Specification forPreformed Thermoplastic Vulcanizate Elastomeric JointSeals for Bridges1This standard is issued under the fixed designation D6924; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f 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. Scope1.1 This specification covers the material requirements forpreformed thermoplastic vulcanizate (TP
3、V) elastomeric 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 desig
4、ned to seal the 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.
5、3 This standard 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 Do
6、cuments2.1 ASTM Standards:2D395 Test Methods for Rubber PropertyCompression SetD412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTensionD518 Test Method for Rubber DeteriorationSurfaceCracking3D573 Test Method for RubberDeterioration in an AirOvenD575 Test Methods for Rubber Prope
7、rties in CompressionD1149 Test Methods for Rubber DeteriorationCrackingin an Ozone Controlled EnvironmentD2240 Test Method for Rubber PropertyDurometerHardnessD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD6338 Classification S
8、ystem for Highly Crosslinked Ther-moplastic Vulcanizates (HCTPVs) Based on ASTM Stan-dard Test Methods3. 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 sho
9、wing the lot number,date of manufacture, and the manufacturing 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, a
10、nd the material shall bevulcanized elastomeric compound using 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 cro
11、sslinked elastomer.Highly crosslinked thermoplastic elastomers are classifiedaccording to Classification System D6338. TPV materials aremade in the dynamic vulcanization process. One example of atypical TPV is crosslinked ethylene propylene diene rubberblended with polypropylene. The TPV material ca
12、n alsocontain processing oils, antioxidants, fillers, or other additives.5. Physical Requirements5.1 The materials shall conform to the physical propertiesprescribed in Table 1.1This specification is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsib
13、ility of Subcommittee D04.34 onPreformed Joint Fillers, Sealers and Sealing Systems.Current edition approved June 1, 2012. Published June 2012. Originallyapproved in 2003. Last previous edition approved in 2003 as D6924 03R07. DOI:10.1520/D6924-03R12.2For referenced ASTM standards, visit the ASTM we
14、bsite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM
15、 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 dimensional tolerances
16、 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 width. The seal height
17、 shall not be less than 90 % ofthe nominal width unless joint recess dimensions or specialdesign considerations dictate the geometry.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 in
18、dicatesthe stress-strain relationship that exists in the seal. Thisrelationship is dependent on both the properties of the elasto-mer and the cross-sectional configuration of the seal. There-fore, for a predetermined allowable pressure, a definitiverelationship will exist and the working limits of t
19、he seal may bedefined.6.2.1 The working limits (minimum and maximum degreesof compression) of the seal shall be determined on the 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 spec
20、ified areacceptable, providing the compressed width at LC max is lessthan the minimum anticipated joint opening, and the movementrange 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) correspondin
21、g 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 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
22、90 % of nominalwidth, LC min equals 85 %. However, if the seal generates 3 psi at 70 %of nominal width, the LC min equals 70 %.6.2.3 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
23、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 order 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
24、 The movement range of the seal is defined as thenumerical difference between the LC min and the LC maxexpressed in inches (mm). 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
25、, the calculated movement rangeof the seal shall not be less than the specified value.7. Sampling7.1 A lot shall consist of the quantity 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 consis
26、ts of more than one lot, each lotshall be sampled.7.3 The minimum lengths of samples for testing purposesshall be as prescribed by 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 tak
27、en not to overheatthe test specimen during buffing. The cut shall be square towithin 2 and smooth, with no roughness visible to the nakedeye. The use of a tooth blade device or a guillotine-type cutter,or both, is not acceptable. This process will eliminate irregu-larities.TABLE 1 Physical Requireme
28、nts for Preformed ElastomericJoint SealsRequirementsASTMTest MethodTensile strength, min, psi (MPa) 730 (4.4) D412Elongation at break, min, % 300 D412Hardness, Type A durometer, points 50 to 70 D2240(modified)AOven aging, 168 h at 212F (100C)Tensile strength, max, % loss 10Elongation, max, % loss 10
29、Hardness, Type A durometer,points change0to5Ozone resistanceBno cracks D1149C20 % 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 %:Deflection, min, % 80 Section 7DLow-temperature recovery,22 h at -20F (-2
30、9C), 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 D575 Method ALC max in. (mm) 9.3 (modified)EMovement range, in. (mm) 9.3AThe term “modified” in the table relates to th
31、e 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 purchaser and the supplier prior to testing. Thehardness test shall be made wit
32、h the durometer in a durometer stand asrecommended in Test Method D2240.BSample prepared in accordance with Method A of Test Method D518.CCracking, splitting, or sticking of a specimen during a recovery test shall meanthat the specimen has failed the test.DThe reference section and subsections are t
33、hose 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 (23 6 2.2C). The sheets of sandpaper are not used.TABLE 2 Minimum Lengths of Se
34、al 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)D6924 03 (2012)28.2 Specimens for determining tensile strength and elonga-tion (Test Methods D412) shall be prepared using Die C whenpossible. Die D may be use
35、d when the 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 shal
36、l consist of6-in. (150-mm) lengths of the preformed seal.9. Test Methods9.1 Compliance with the requirements of Table 1 shall bedetermined 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
37、specimens prepared in accordancewith Section 8. Two specimens shall be used for each test.9.2.2 Deflect the specimen between parallel plates to 50 %of the nominal width using the compression set clamp assem-bly described in Method B of Test Methods D395. Prior tocompression, place the specimen in a
38、horizontal position, suchthat the plane through both edges of the top surface of the jointseal is perpendicular to the compression 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 t
39、he compressedspecimen in a refrigerated box capable of maintaining atemperature of 14 6 2F (-10 6 1.1C) for 72 h. Unclamp theassembly 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 specim
40、en torecover for 1 h at 14 6 2F (-10 6 1.1C). Measure therecovered width in the center of the 6-in. (150-mm) length atthe top longitudinal 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). Theplatfo
41、rm-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 the platform-mounted gage should betaken with the pressure foot centered on the longitudinal edgeof the seal. Calculate the recovery as follows:Recovery, % 5recovered wid
42、th 3 100!nominal width!(1)Report the least value of recovery to the nearest 1 %.NOTE 3The use of a desiccant, such as calcium chloride, 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 Plac
43、e a clamp assembly containing the compressedspecimen in a refrigerated box capable of maintaining atemperature of -20 6 2F (-29 6 1.1C) 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 refrige
44、rated box. Allow the specimen torecover for1hat-206 2F (-29 6 1.1C). Measure therecovered width and calculate the recovery as in 9.2.3.9.2.5 Place a clamp assembly containing the compressedspecimen in an oven conforming to Test Method D573. Thetemperature shall be maintained at 212 6 2F (100 6 1.1C)
45、for 70 h. Do not preheat the clamp assembly. Unclamp theassembly, carefully remove the specimen, and allow it torecover at 73 6 4F (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-de
46、flection values using speci-mens prepared in accordance with Section 8. Measure thelength of each specimen at the top, center, and 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. (
47、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 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 th
48、econtact area as determined above.9.3.3 Calculate the forces required to compress the speci-men to LC min and LC max by multiplying 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 th
49、e top surface of the seal shall beperpendicular to the platens. Close the platens until thedistance between them is slightly larger than the actual widthof the seal. Test in accordance with Method A of Test MethodsD575, 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 the same rateto the original distance between the platens. Repeat this cycletwo times for a total of three cycles. Recor
