1、Designation: D 6924 03 (Reapproved 2007)Standard 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
2、 of revision, the 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
3、(TPV) 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 de
4、signed 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
5、.1.3 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
6、 Documents2.1 ASTM Standards:2D 395 Test Methods for Rubber PropertyCompressionSetD 412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTensionD 518 Test Method for Rubber DeteriorationSurfaceCrackingD 573 Test Method for RubberDeterioration in an AirOvenD 575 Test Methods for Rubber
7、 Properties in CompressionD 1149 Test Methods for Rubber DeteriorationCrackingin an Ozone Controlled EnvironmentD 2240 Test Method for Rubber PropertyDurometerHardnessD 4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD 6338 Classi
8、fication System for Highly Crosslinked Ther-moplastic Vulcanizates (HCTPVs)3. 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
9、 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, and the material shall bevul
10、canized 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 crosslinked elastomer.Highly c
11、rosslinked thermoplastic elastomers 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 o
12、ils, antioxidants, fillers, or 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.1This specification is under th
13、e jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.34 onPreformed Joint Fillers, Sealers and Sealing Systems.Current edition approved Dec. 1, 2007. Published January 2008. Originallyapproved in 2003. Last previous edition approved in
14、 2003 as D 6924 03.2For 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 Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Ha
15、rbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Dimensions and Working Parameters6.1 The size, shape and dimensional 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
16、 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 shall not be less than 90 % ofthe nominal width unless joint recess dimensions or specialdesign considerations dictate the geometry.6.2 Compress
17、ion 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-tomer and the cro
18、ss-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 basis ofthe min
19、imum 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 movementrange requiremen
20、t 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 movement range,
21、 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 %.6.2.3 The maximum
22、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 order to mitigate t
23、he 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). For the purpose
24、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 quantity for each
25、 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 by the purchaser
26、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 the nakedeye. The
27、 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 flat sections of
28、 a seal areTABLE 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 h at 212F (100C)Tensile strength,
29、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 %:Deflection, min, % 80 Section 7D
30、Low-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)EMovement range, in. (mm) 9.3AThe
31、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 purchaser and the supplier prior to t
32、esting. 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 meanthat the specimen has failed the test.
33、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 (23 6 2.2C). The sheets of sandpape
34、r 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)D 6924 03 (2007)2too small for Die C. However, the requirement of Table 1 shallapply regardless of the die used. Bu
35、ffing 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 of6-in. (150-mm) lengths of the preformed seal.9. Test Methods9.1 Compliance with the requirements of Table 1 shall bedetermin
36、ed 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 parallel pl
37、ates 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 compression plat
38、e. 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 theassembly
39、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 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 longitud
40、inal 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 the
41、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 chloride
42、, 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 1.1C
43、) 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 9.2.3
44、.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 (2
45、3 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 bo
46、ttom 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 ru
47、le. 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 t
48、he 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 t
49、han 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 the 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 th
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1