1、Designation: D 4014 03Standard Specification forPlain and Steel-Laminated Elastomeric Bearings forBridges1This standard is issued under the fixed designation D 4014; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、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 bearings, which consist of allelastomer or of alternate laminates of elastomer and steel,when th
3、e 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-changeably with t
4、he 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 the userof this
5、standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:A 36/A 36M Specification for Carbon Structural Steel2D 395 Test Methods for Rubber PropertyCompressionSet3D 412 Test Methods
6、for Vulcanized Rubber and Thermo-plastic ElastomersTension3D 518 Test Method for Rubber DeteriorationSurfaceCracking3D 573 Test Method for RubberDeterioration in an AirOven3D 832 Practice for Rubber Conditioning for Low-Temperature Testing3D 1149 Test Method for Rubber Deterioration SurfaceOzone Cra
7、cking in a Chamber3D 1415 Test Method for Rubber PropertyInternationalHardness3D 1418 Practice for Rubber and Rubber LaticesNomenclature3D 2000 Classification System for Rubber Products in Auto-motive Applications4D 2137 Test Methods for Rubber PropertyBrittlenessPoint of Flexible Polymers and Coate
8、d Fabrics3D 2240 Test Method for Rubber PropertyDurometerHardness3D 3183 Practice for RubberPreparation of Pieces for TestPurposes from Products3E 4 Practices for Force Verification of Testing Machines53. Terminology3.1 Definitions:3.1.1 design loadthe mean compressive stress applied tothe area of t
9、he 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, submitted for inspectio
10、n at thesame time.3.1.4 plain elastomeric bearing pada bearing that con-sists only 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 elastomeric beari
11、nga 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.4.1.2 Plain Elastom
12、eric Sandwich Bearing.4.1.3 Steel-Laminated Elastomeric Bearing.4.1.4 Steel-Laminated Elastomeric Bearing with ExternalLoad Plate(s).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 S
13、tructures.Current edition approved Feb. 10, 2003. Published May 2003. Orginallyapproved in 1981. Last previous edition approved in 1995 as D 4014-89 (1995).2Annual Book of ASTM Standards, Vol 01.04.3Annual Book of ASTM Standards, Vol 09.01.4Annual Book of ASTM Standards, Vol 09.02.5Annual Book of AS
14、TM Standards, Vol 03.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 2Examples of the types of elastomeric bearing construction aregiven in Fig. 1.NOTE 3The adjective elastomeric is omitted in this specificationwhen referring
15、 to bearing types.4.2 The elastomer for the manufacture of the bearing isfurnished in two types as follows: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
16、 do nothave fully documented in-service records or sufficiently widespread use orboth.NOTE 5The abbreviations for the elastomer types are taken fromPractice D 1418.4.3 The elastomer for the manufacture of the bearing isfurnished in four grades of low-temperature properties. Thegrades and typical ope
17、rating temperature conditions for eachgrade are as follows:4.3.1 Grade 0Suitable for continuous use down to + 5C.4.3.2 Grade 2Sub-zero temperatures occur at night andoccasionally persist for no more than 1 or 2 days.4.3.3 Grade 3Same as 2 but occasional periods of up to 2weeks continuously below zer
18、o.4.3.4 Grade 5Sub-zero temperatures down to 40C per-sisting for several months each year with up to 2 monthscontinuously below 15C.4.3.5 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-tempe
19、rature properties of elastomericmaterials is given in Practice D 832.NOTE 7The grade numbers for the low-temperature properties corre-spond to those in Table 5 of Classification D 2000.5. Ordering Information5.1 Orders for each type of bearing under this specificationshall include the following:FIG.
20、 1 Examples of the Construction of Elastomeric BearingsD40140325.1.1 Quantity,5.1.2 Bearing 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 gra
21、de,5.1.7 Ozone test partial pressure, if higher than 50 mPa(formerly referred to as a concentration 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
22、 raw polymer. No reclaimed rubber shall be used.6.2 Internal steel laminates shall be of rolled mild steel.6.3 External load plates shall conform to the requirementsof Specification A 36/A 36M unless otherwise specified in thecontract or purchase order.6.4 Plain bearing pads shall be molded individu
23、ally, or cutfrom previously molded strips or slabs, or extruded and cut tolength. Cutting 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 st
24、eel laminates and toexternal load plates shall be carried out during molding. Theelastomer 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
25、 protected from rustingwhen supplied by the manufacturer.6.9 All molds shall have a standard 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
26、the contract or purchase order.7.2 All internal steel laminates shall be of uniform thick-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 lam
27、inates shallbe 1.5 mm or 0.060 in. (16 gage) when the greater of the lengthor width of a rectangular 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 t
28、hickness unlessotherwise specified in the contract or purchase order.7.5 Bearing dimensions 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
29、a design surface shallnot exceed an average slope of 0.005 for the upper surface and0.006 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 test
30、ing them shall be borne by thesupplier.8.1.1 The bearings shall be brought to a temperature 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
31、shall be within the rangeof 1.4 to 2.6 min. When the increment has been applied theload or 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 determ
32、ined as the slope of thebest straight line through the points, ignoring the first point atzero 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 f
33、or visual faults, as follows:8.1.3.1 If lack of elastomer to steel bond is indicated, thebearing 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
34、three separate surface crackswhich are each at least 2 mm wide and 2 mm deep, the bearingshall be rejected.8.1.4 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 bea
35、ring that fails to meet the requirements 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 Elastomeri
36、c Material Tests:8.2.1 All test specimens used for the determination of theproperties of the vulcanized elastomeric material shall be takenfrom bearings (see Practice D 3183). Tensile and hardnessTABLE 1 Tolerances for Bearing Dimensions and ElastomerLayer ThicknessesDimensionToleranceminimum maximu
37、mLength, 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)Thickness of internal elas-tomer laminate, %620 % of designvalueD4014033specimens for the quality control tests in 8.2.3, sp
38、ecimens forthe ozone resistance test in 8.2.5, and strips for the low-temperature brittleness 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
39、 TestMethods D 395, Method B, Type 1.8.2.2 The temperature at which the tests shall be 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 hard
40、ness and type of rubber used.8.2.4 Shear ModulusThe shear modulus of the elastomerdetermined 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 acc
41、ordance with procedureA of Test Method D 518. The test shall be carried out inaccordance with Test Method D 1149 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
42、been specified. The teststrips shall be examined for cracks using a 73 magnificationlens. 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 Lo
43、w-Temperature Grade 2, 3 or 5 is specified,a low-temperature brittleness test shall be carried out inaccordance with Test Methods D 2137, 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. T
44、o meet the requirements ofthis specification, none shall fail.9. Sampling9.1 Unless otherwise 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
45、.9.1.2 A minimum of three bearings shall be taken from thelot for testing. If the number 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 m
46、arking shall consist of the order number,lot number, bearing identification number and 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 use
47、r is currently interested in participating in around robin test to verify precision and bias. As an alternative,two producers have agreed to run repeatability in their ownlaboratories.TABLE 2 Quality Control Properties of ElastomerRubber NR CRHardness limits (TestMethods D 1415 orD 2240)45 to 75 45
48、to 75Physical properties(Test Methods D 412):Tensile strength,min, MPa (psi)15.5 (2250) 15.5 (2250)Ultimate elongation:45 to 55hardness, min, %400 40056 to 65hardness, min, %400 35066 to 75hardness, min, %300 300High-temperatureresistance (TestMethods D 573)Aging time, h 168 70Agingtemperature,C70 1
49、00Change inhardness, max, %+10 +15Change in tensilestrength, max, %25 15Change in ultimateelongation, max, %25 40Compression set (TestMethods D 395Method B)After 22 h at 70C,max, %25 .After 22 h at 100C,max, %. 35D4014034ANNEX(Mandatory Information)A1. DETERMINATION OF SHEAR MODULUSA1.1 ScopeA1.1.1 This method determines the shear modulus of thebearing elastomer from the shear force-extension curve afterfive conditioning cycles to 50 % strain as four times the stressat 25 % strain.NOTE A1.1If the shear stress-strain curve is
