1、Designation: D4014 03 (Reapproved 2012)Standard Specification forPlain and Steel-Laminated Elastomeric Bearings forBridges1This standard is issued under the fixed designation D4014; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he 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 bearings, which consist of allelastomer or of alternate laminates of elastomer an
3、d steel,when the function of the bearings is to transfer loads oraccommodate relative movement between a bridge superstruc-ture and its supporting structure, or both.1.2 The values stated in SI units are to be regarded as thestandard.NOTE 1The words “elastomer” or “elastomeric” will be used inter-ch
4、angeably with the word “rubber” in this specification.1.3 The following safety hazards caveat pertains only to thetest methods portion, Section B, of this specification: Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of t
5、he userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:2A36/A36M Specification for Carbon Structural SteelD395 Test Methods for Rubber PropertyCompression SetD412 Te
6、st Methods for Vulcanized Rubber and Thermoplas-tic ElastomersTensionD518 Test Method for Rubber DeteriorationSurfaceCracking (Withdrawn 2007)3D573 Test Method for RubberDeterioration in an AirOvenD832 Practice for Rubber Conditioning For Low Tempera-ture TestingD1149 Test Methods for Rubber Deterio
7、rationCracking inan Ozone Controlled EnvironmentD1415 Test Method for Rubber PropertyInternationalHardnessD1418 Practice for Rubber and Rubber LaticesNomenclatureD2000 Classification System for Rubber Products in Auto-motive ApplicationsD2137 Test Methods for Rubber PropertyBrittleness Pointof Flexi
8、ble Polymers and Coated FabricsD2240 Test Method for Rubber PropertyDurometer Hard-nessD3183 Practice for RubberPreparation of Pieces for TestPurposes from ProductsE4 Practices for Force Verification of Testing Machines3. Terminology3.1 Definitions:3.1.1 design loadthe mean compressive stress applie
9、d tothe area of the steel laminate.3.1.2 external load platea steel plate bonded to the top orbottom elastomeric surface of a bearing, or both.3.1.3 lotunless otherwise specified in the contract orpurchase order, a lot shall consist of a single type of bearing, ofthe same design and material, submit
10、ted for inspection at thesame time.3.1.4 plain elastomeric bearing pada bearing that consistsonly of elastomeric material.3.1.5 plain elastomeric sandwich bearinga bearing thatconsists of a single layer of elastomeric material bonded to oneor two external load plates (3.1.2).3.1.6 steel-laminated el
11、astomeric bearinga bearingmolded of elastomeric material with one or more steel lami-nates embedded in and bonded to it, and to which one or twoexternal load plates (3.1.2) may be bonded.4. Classification4.1 The bearings are furnished in four types as follows:4.1.1 Plain Elastomeric Bearing Pad.4.1.
12、2 Plain Elastomeric Sandwich Bearing.4.1.3 Steel-Laminated Elastomeric Bearing.1This specification is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.32 onBridges and Structures.Current edition approved July 15, 2012. Publ
13、ished July 2012. Originallyapproved in 1981. Last previous edition approved in 2007 as D4014 03(2007).DOI: 10.1520/D4014-03R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information
14、, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.4 Steel-Laminated Elastomeric Be
15、aring with ExternalLoad Plate(s).NOTE 2Examples of the types of elastomeric bearing construction aregiven in Fig. 1.NOTE 3The adjective elastomeric is omitted in this specification whenreferring to bearing types.4.2 The elastomer for the manufacture of the bearing isfurnished in two types as follows
16、:4.2.1 Type CRChloroprene rubber.4.2.2 Type NRNatural rubber.4.2.3 If none is specified then the manufacturer shall use oneof those types.NOTE 4Appendix X1 relates to elastomeric materials which do nothave fully documented in-service records or sufficiently widespread use orboth.NOTE 5The abbreviati
17、ons for the elastomer types are taken fromPractice D1418.4.3 The elastomer for the manufacture of the bearing isfurnished in four grades of low-temperature properties. Thegrades and typical operating temperature conditions for eachgrade are as follows:4.3.1 Grade 0Suitable for continuous use down to
18、 +5C.4.3.2 Grade 2Sub-zero temperatures occur at night andoccasionally persist for no more than one or two days.4.3.3 Grade 3Same as Grade 2 but occasional periods ofup to two weeks continuously below zero.4.3.4 Grade 5Sub-zero temperatures down to 40C per-sisting for several months each year with u
19、p to two monthscontinuously below 15C.FIG. 1 Examples of the Construction of Elastomeric BearingsD4014 03 (2012)24.3.5 If a grade is not specified Grade 0 shall be furnished.An elastomer of a higher grade number may be substituted forany lower grade.NOTE 6A discussion of low-temperature properties o
20、f elastomericmaterials is given in Practice D832.NOTE 7The grade numbers for the low-temperature properties corre-spond to those in Table 6 of Classification D2000.5. Ordering Information5.1 Orders for each type of bearing under this specificationshall include the following:5.1.1 Quantity,5.1.2 Bear
21、ing design,NOTE 8An example of the design information required is given inAppendix X2. Working drawings may be substituted.5.1.3 Design load,5.1.4 Shear modulus of the elastomer,5.1.5 Rubber type,5.1.6 Rubber grade,5.1.7 Ozone test partial pressure, if higher than 50 mPa(formerly referred to as a co
22、ncentration of 50 parts per hundredmillion (pphm).6. Materials and Manufacture6.1 The elastomeric compound used in the construction of abearing shall contain only either natural rubber or chloroprenerubber as the raw polymer. No reclaimed rubber shall be used.6.2 Internal steel laminates shall be of
23、 rolled mild steel.6.3 External load plates shall conform to the requirementsof Specification A36/A36M unless otherwise specified in thecontract or purchase order.6.4 Plain bearing pads shall be molded individually, or cutfrom previously molded strips or slabs, or extruded and cut tolength. Cutting
24、shall produce a smooth surface and no heatingof the elastomer.6.5 A steel-laminated bearing or a plain sandwich bearingshall be molded as a single unit under pressure and heat.6.6 All bonding of elastomer to steel laminates and toexternal load plates shall be carried out during molding. Theelastomer
25、 at the outer edges of bonds to external load platesshall be shaped to avoid serious stress concentrations (see Fig.1).6.7 Internal steel laminates shall be free of sharp edges.6.8 External load plates shall be protected from rustingwhen supplied by the manufacturer.6.9 All molds shall have a standa
26、rd shop-practice moldfinish.7. Dimensions and Permissible Variations7.1 All elastomeric layers, for example, plain-bearing pads,laminates, and covers, shall be of uniform thickness unlessotherwise specified in the contract or purchase order.7.2 All internal steel laminates shall be of uniform thick-
27、ness. When specified in the contract or purchase order, thethickness of the outer steel laminates may differ if not adjacentto an external load plate (see Fig. 1).7.3 The minimum thickness of internal steel laminates shallbe 1.5 mm or 0.060 in. (16 gage) when the greater of the lengthor width of a r
28、ectangular bearing or the diameter of a circularbearing is less than 450 mm or 18 in. In all other cases, theminimum thickness shall be 2 mm or 0.075 in. (14 gage).7.4 External load plates shall be of uniform thickness unlessotherwise specified in the contract or purchase order.7.5 Bearing dimension
29、s and elastomer layer thicknessesshall satisfy the tolerances in Table 1, in which D is the length,width or diameter as appropriate, and T is the total elastomerthickness.7.6 Variation from a plane parallel to a design surface shallnot exceed an average slope of 0.005 for the upper surface and0.006
30、for a side surface.8. Test Methods and Acceptance Requirements8.1 Bearing Compression TestsAll bearings sampled froma lot shall be subjected to the compression tests. The cost ofreplacement bearings and of testing them shall be borne by thesupplier.8.1.1 The bearings shall be brought to a temperatur
31、e of 23 66C and shall be tested at this temperature.8.1.2 Compression StiffnessLoad the bearing to the designload (3.1.1) by increments of one fifth of the design load. Foreach load increment, the loading time shall be within the rangeof 1.4 to 2.6 min. When the increment has been applied theload or
32、 deflection (depending on the type of testing machine)shall be maintained constant for 30 s then the load anddeflection measured. From a plot of load against deflection, thecompression stiffness shall be determined as the slope of thebest straight line through the points, ignoring the first point at
33、zero load. Record the compressive stiffness for each bearing.8.1.3 Visual InspectionIncrease the load to 1.5 times thedesign load then maintain either load or deflection constantwhile the bearing is inspected for visual faults, as follows:8.1.3.1 If lack of elastomer to steel bond is indicated, theb
34、earing shall be rejected.8.1.3.2 If laminate placement faults are observed whichresult in elastomer layer thickness that exceed the tolerances in7.5, the bearing shall be rejected.8.1.3.3 If there are at least three separate surface crackswhich are each at least 2 mm wide and 2 mm deep, the bearings
35、hall be rejected.TABLE 1 Tolerances for Bearing Dimensions and ElastomerLayer ThicknessesDimensionToleranceMinimum MaximumLength, width or diameter ofbearing, mm (in.)0 5 (0.2) + 0.005DHeight of bearing, mm (in.) 0 2 (0.1) + 0.04TThickness of elastomercoverat top, bottom or side,mm (in.)0 3 (0.1)Thi
36、ckness of internal elas-tomer laminate, %20 % of designvalueD4014 03 (2012)38.1.4 Record the median compressive stiffness (K)ofthebearing of median stiffness. The compressive stiffness of eachbearing tested shall not differ from (K) by more than 10 %.8.1.5 For each bearing that fails to meet the req
37、uirements in8.1, two additional bearings may be sampled and shall meet allthe requirements in 8.1 or the lot shall be rejected.8.1.6 If the lot is not rejected, the bearing of medianstiffness (K) shall be subjected to the elastomeric material testsin 8.2.8.2 Elastomeric Material Tests:8.2.1 All test
38、 specimens used for the determination of theproperties of the vulcanized elastomeric material shall be takenfrom bearings (see Practice D3183). Tensile and hardnessspecimens for the quality control tests in 8.2.3, specimens forthe ozone resistance test in 8.2.5, and strips for the low-temperature br
39、ittleness test in 8.2.6.1, if applicable, shallinclude an outer surface of a bearing.All other specimens shallbe taken from within the middle one third of a bearing.Compression set specimens shall be as specified in TestMethods D395, Method B, Type 1.8.2.2 The temperature at which the tests shall be
40、 carried outshall be 23 6 2C except where otherwise specified in thisspecification.8.2.3 Quality Control PropertiesThe quality control prop-erties of the elastomer shall meet the requirements of Table 2for the hardness and type of rubber used.8.2.4 Shear ModulusThe shear modulus of the elastomerdete
41、rmined in accordance with Annex A1 shall not differ bymore than 615 % from the required shear modulus of theelastomer.8.2.5 Ozone ResistanceAn ozone resistance test shall becarried out on test strips mounted in accordance with procedureA of Test Method D518. The test shall be carried out inaccordanc
42、e with Test Methods D1149 at 20 % strain and at 406 2C for 100 h. The ozone test partial pressure shall be 50 65 mPa formerly referred to as a concentration of 50 6 5 pphmunless a higher test partial pressure has been specified. The teststrips shall be examined for cracks using a 7 magnificationlens
43、. The elastomer has adequate ozone resistance if noperpendicular cracks are observed on that surface of the stripcorresponding to the outer surface of the bearing.8.2.6 Low-Temperature Grade Tests:8.2.6.1 When Low-Temperature Grade 2, 3, or 5 isspecified, a low-temperature brittleness test shall be
44、carried outin accordance with Test Methods D2137, Method A using fivetest strips. The temperature at which the strips shall beconditioned and tested shall be 10C for Grade 2, 25C forGrade 3, and 40C for Grade 5. To meet the requirements ofthis specification, none shall fail.9. Sampling9.1 Unless oth
45、erwise specified in the contract or purchaseorder, sampling shall consist of the following.9.1.1 For acceptance purposes, bearing from within the lotshall be selected at random as samples for inspection andtesting.9.1.2 A minimum of three bearings shall be taken from thelot for testing. If the numbe
46、r of bearings in the lot exceeds 50then for each 50, or part thereof, one additional bearing shall betaken for testing.10. Product Marking10.1 Every bearing shall be marked in indelible ink orflexible paint. The marking shall consist of the order number,lot number, bearing identification number and
47、elastomer typeand grade reference number.10.2 Unless otherwise specified in the contract or purchaseorder, the marking should be on a side face visible aftererection of the bridge.11. Precision and Bias11.1 No user is currently interested in participating in around robin test to verify precision and
48、 bias. As an alternative,two producers have agreed to run repeatability in their ownlaboratories.TABLE 2 Quality Control Properties of ElastomerRubber NR CRHardness limits (TestMethod D1415 or TestMethod D2240)45 to 75 45 to 75Physical properties(Test Methods D412):Tensile strength,min, MPa (psi)15.
49、5 (2250) 15.5 (2250)Ultimate elongation:45 to 55hardness, min, %400 40056 to 65hardness, min, %400 35066 to 75hardness, min, %300 300High-temperature re-sistance (TestMethod D573)Aging time, h 168 70Aging tempera-ture, C70 100Change inhardness, max, %+10 +15Change in tensilestrength, max, %25 15Change in ultimateelongation, max, %25 40Compression set (TestMethods D395,Method B)After 22 h at 70C,max, %25 .After 22 h at 100C,max, %. 35D4014 03 (2012)4ANNEX(Mandatory Information)A1. DETERMINATION OF SHEAR MODULUSA1.1 Scope
