ASTM D4014-03(2007)

Standard Specification for Plain and Steel-Laminated Elastomeric Bearings for Bridges

ABSTRACT
This specification covers bearings, which consist of all elastomer or of alternate laminates of elastomer and steel, when the function of the bearings is to transfer loads or accommodate relative movement between a bridge superstructure and its supporting structure, or both. The bearings are furnished in four types as follows: plain elastomeric bearing pad; plain elastomeric sandwich bearing; steel-laminated elastomeric bearing; and steel-laminated elastomeric bearing with external load plate. The elastomer for the manufacture of the bearing is furnished in two types: Type CR and Type NR. The elastomer for the manufacture of the bearing is furnished in four grades of low-temperature properties: Grade 0; Grade 2; Grade 3; and Grade 5. The elastomeric compound used in the construction of a bearing shall contain only either natural rubber or chloroprene rubber as the raw polymer. Internal steel laminates shall be of rolled mild steel. Plain bearing pads shall be molded individually, or cut from previously molded strips or slabs, or extruded and cut to length. A steel-laminated bearing or a plain sandwich bearing shall be molded as a single unit under pressure and heat. All bonding of elastomer to steel laminates and to external load plates shall be carried out during molding. Bearing compression tests, compression stiffness, visual inspection, quality control properties, shear modulus, ozone resistance, and low-temperature grade tests shall be performed to conform to the specified requirements.
SCOPE
1.1 This specification covers bearings, which consist of all elastomer or of alternate laminates of elastomer and steel, when the function of the bearings is to transfer loads or accommodate relative movement between a bridge superstructure and its supporting structure, or both.
1.2 The values stated in SI units are to be regarded as the standard.
Note 1—The words “elastomer” or “elastomeric” will be used interchangeably with the word “rubber” in this specification.  
1.3 The following safety hazards caveat pertains only to the test methods portion, Section B, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Nov-2007
• ICS: 93.040 - Bridge construction
• Technical Committee: D04 - Road and Paving Materials
• Drafting Committee: D04.32 - Bridges and Structures

Relations

• Replaces: ASTM D4014-03 - Standard Specification for Plain and Steel-Laminated Elastomeric Bearings for Bridges
• Effective Date: 01-Dec-2007
• Replaced By: ASTM D4014-03(2012) - Standard Specification for Plain and Steel-Laminated Elastomeric Bearings for Bridges
• Effective Date: 15-Jul-2012

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4014 −03(Reapproved 2007)
Standard Specification for
Plain and Steel-Laminated Elastomeric Bearings for
Bridges
This standard is issued under the fixed designation D4014; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D1149TestMethodsforRubberDeterioration—Crackingin
an Ozone Controlled Environment
1.1 This specification covers bearings, which consist of all
D1415Test Method for Rubber Property—International
elastomer or of alternate laminates of elastomer and steel,
Hardness
when the function of the bearings is to transfer loads or
D1418 Practice for Rubber and Rubber Latices—
accommodate relative movement between a bridge superstruc-
Nomenclature
ture and its supporting structure, or both.
D2000Classification System for Rubber Products in Auto-
1.2 The values stated in SI units are to be regarded as the
motive Applications
standard.
D2137TestMethodsforRubberProperty—BrittlenessPoint
of Flexible Polymers and Coated Fabrics
NOTE 1—The words “elastomer” or “elastomeric” will be used inter-
changeably with the word “rubber” in this specification.
D2240TestMethodforRubberProperty—DurometerHard-
ness
1.3 The following safety hazards caveat pertains only to the
D3183Practice for Rubber—Preparation of Pieces for Test
test methods portion, Section B, of this specification: This
Purposes from Products
standarddoesnotpurporttoaddressallofthesafetyconcerns,
E4Practices for Force Verification of Testing Machines
ifany,associatedwithitsuse.Itistheresponsibilityoftheuser
of this standard to establish appropriate safety and health
3. Terminology
practices and determine the applicability of regulatory limita-
tions prior to use.
3.1 Definitions:
3.1.1 design load—the mean compressive stress applied to
2. Referenced Documents
the area of the steel laminate.
2.1 ASTM Standards:
3.1.2 external load plate—a steel plate bonded to the top or
A36/A36MSpecification for Carbon Structural Steel
bottom elastomeric surface of a bearing, or both.
D395Test Methods for Rubber Property—Compression Set
3.1.3 lot—unless otherwise specified in the contract or
D412TestMethodsforVulcanizedRubberandThermoplas-
purchaseorder,alotshallconsistofasingletypeofbearing,of
tic Elastomers—Tension
the same design and material, submitted for inspection at the
D518 Test Method for Rubber Deterioration—Surface
same time.
Cracking (Withdrawn 2007)
3.1.4 plainelastomericbearingpad—abearingthatconsists
D573Test Method for Rubber—Deterioration in an Air
only of elastomeric material.
Oven
D832Practice for Rubber Conditioning For Low Tempera- 3.1.5 plain elastomeric sandwich bearing—a bearing that
consistsofasinglelayerofelastomericmaterialbondedtoone
ture Testing
or two external load plates (3.1.2).
3.1.6 steel-laminated elastomeric bearing—a bearing
This specification is under the jurisdiction ofASTM Committee D04 on Road
molded of elastomeric material with one or more steel lami-
and Paving Materialsand is the direct responsibility of Subcommittee D04.32 on
nates embedded in and bonded to it, and to which one or two
Bridges and Structures.
Current edition approved Dec. 1, 2007. Published January 2008. Originally external load plates (3.1.2) may be bonded.
approved in 1981. Last previous edition approved in 2003 as D4014–03. DOI:
10.1520/D4014-03R07.
4. Classification
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4.1 The bearings are furnished in four types as follows:
Standards volume information, refer to the standard’s Document Summary page on
4.1.1 Plain Elastomeric Bearing Pad.
the ASTM website.
4.1.2 Plain Elastomeric Sandwich Bearing.
The last approved version of this historical standard is referenced on
www.astm.org. 4.1.3 Steel-Laminated Elastomeric Bearing.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4014−03 (2007)
NOTE 5—The abbreviations for the elastomer types are taken from
4.1.4 Steel-Laminated Elastomeric Bearing with External
Practice D1418.
Load Plate(s).
4.3 The elastomer for the manufacture of the bearing is
NOTE2—Examplesofthetypesofelastomericbearingconstructionare
given in Fig. 1. furnished in four grades of low-temperature properties. The
NOTE3—Theadjectiveelastomericisomittedinthisspecificationwhen
grades and typical operating temperature conditions for each
referring to bearing types.
grade are as follows:
4.2 The elastomer for the manufacture of the bearing is
4.3.1 Grade 0—Suitable for continuous use down to+5°C.
furnished in two types as follows:
4.3.2 Grade 2—Sub-zero temperatures occur at night and
4.2.1 Type CR—Chloroprene rubber.
occasionally persist for no more than one or two days.
4.2.2 Type NR—Natural rubber.
4.3.3 Grade 3—Same as Grade 2 but occasional periods of
4.2.3 Ifnoneisspecifiedthenthemanufacturershalluseone
up to two weeks continuously below zero.
of those types.
4.3.4 Grade 5—Sub-zero temperatures down to−40°C per-
NOTE 4—Appendix X1 relates to elastomeric materials which do not
sisting for several months each year with up to two months
havefullydocumentedin-servicerecordsorsufficientlywidespreaduseor
both. continuously below−15°C.
FIG. 1 Examples of the Construction of Elastomeric Bearings
D4014−03 (2007)
4.3.5 If a grade is not specified Grade 0 shall be furnished. thickness of the outer steel laminates may differ if not adjacent
An elastomer of a higher grade number may be substituted for to an external load plate (see Fig. 1).
any lower grade.
7.3 The minimum thickness of internal steel laminates shall
be1.5mmor0.060in.(16gage)whenthegreaterofthelength
NOTE 6—A discussion of low-temperature properties of elastomeric
materials is given in Practice D832.
or width of a rectangular bearing or the diameter of a circular
NOTE 7—The grade numbers for the low-temperature properties corre-
bearing is less than 450 mm or 18 in. In all other cases, the
spond to those in Table6 of Classification D2000.
minimum thickness shall be 2 mm or 0.075 in. (14 gage).
7.4 Externalloadplatesshallbeofuniformthicknessunless
5. Ordering Information
otherwise specified in the contract or purchase order.
5.1 Orders for each type of bearing under this specification
7.5 Bearing dimensions and elastomer layer thicknesses
shall include the following:
shallsatisfythetolerancesinTable1,inwhich Disthelength,
5.1.1 Quantity,
width or diameter as appropriate, and T is the total elastomer
5.1.2 Bearing design,
thickness.
NOTE 8—An example of the design information required is given in
7.6 Variation from a plane parallel to a design surface shall
Appendix X2. Working drawings may be substituted.
not exceed an average slope of 0.005 for the upper surface and
5.1.3 Design load,
0.006 for a side surface.
5.1.4 Shear modulus of the elastomer,
5.1.5 Rubber type,
8. Test Methods and Acceptance Requirements
5.1.6 Rubber grade,
8.1 BearingCompressionTests—Allbearingssampledfrom
5.1.7 Ozone test partial pressure, if higher than 50 mPa
a lot shall be subjected to the compression tests. The cost of
(formerlyreferredtoasaconcentrationof50partsperhundred
replacement bearings and of testing them shall be borne by the
million (pphm)).
supplier.
8.1.1 Thebearingsshallbebroughttoatemperatureof23 6
6. Materials and Manufacture
6°C and shall be tested at this temperature.
6.1 Theelastomericcompoundusedintheconstructionofa
8.1.2 CompressionStiffness—Loadthebearingtothedesign
bearing shall contain only either natural rubber or chloroprene
load (3.1.1) by increments of one fifth of the design load. For
rubber as the raw polymer. No reclaimed rubber shall be used.
eachloadincrement,theloadingtimeshallbewithintherange
of 1.4 to 2.6 min. When the increment has been applied the
6.2 Internal steel laminates shall be of rolled mild steel.
load or deflection (depending on the type of testing machine)
6.3 External load plates shall conform to the requirements
shall be maintained constant for 30 s then the load and
of Specification A36/A36M unless otherwise specified in the
deflectionmeasured.Fromaplotofloadagainstdeflection,the
contract or purchase order.
compression stiffness shall be determined as the slope of the
6.4 Plain bearing pads shall be molded individually, or cut
best straight line through the points, ignoring the first point at
from previously molded strips or slabs, or extruded and cut to
zero load. Record the compressive stiffness for each bearing.
length. Cutting shall produce a smooth surface and no heating
8.1.3 Visual Inspection—Increase the load to 1.5 times the
of the elastomer.
design load then maintain either load or deflection constant
while the bearing is inspected for visual faults, as follows:
6.5 A steel-laminated bearing or a plain sandwich bearing
8.1.3.1 If lack of elastomer to steel bond is indicated, the
shall be molded as a single unit under pressure and heat.
bearing shall be rejected.
6.6 All bonding of elastomer to steel laminates and to
8.1.3.2 If laminate placement faults are observed which
external load plates shall be carried out during molding. The
resultinelastomerlayerthicknessthatexceedthetolerancesin
elastomer at the outer edges of bonds to external load plates
7.5, the bearing shall be rejected.
shall be shaped to avoid serious stress concentrations (see Fig.
8.1.3.3 If there are at least three separate surface cracks
1).
whichareeachatleast2mmwideand2mmdeep,thebearing
6.7 Internal steel laminates shall be free of sharp edges. shall be rejected.
6.8 External load plates shall be protected from rusting
TABLE 1 Tolerances for Bearing Dimensions and Elastomer
when supplied by the manufacturer.
Layer Thicknesses
6.9 All molds shall have a standard shop-practice mold Tolerance
Dimension
finish.
Minimum Maximum
Length, width or diameter of 0 5 (0.2) + 0.005D
bearing, mm (in.)
7. Dimensions and Permissible Variations
Height of bearing, mm (in.) 0 2 (0.1) + 0.04T
Thickness of elastomer 0 3 (0.1)
7.1 All elastomeric layers, for example, plain-bearing pads,
cover
laminates, and covers, shall be of uniform thickness unless
at top, bottom or side,
otherwise specified in the contract or purchase order.
mm (in.)
Thickness of internal elas- ±20 % of design
7.2 All internal steel laminates shall be of uniform thick-
tomer laminate, % value
ness. When specified in the contract or purchase order, the
D4014−03 (2007)
TABLE 2 Quality Control Properties of Elastomer
8.1.4 Record the median compressive stiffness (K)ofthe
bearing of median stiffness. The compressive stiffness of each Rubber NR CR
bearing tested shall not differ from (K) by more than 10%. Hardness limits (Test 45 to 75 45 to 75
Method D1415 or Test
8.1.5 For each bearing that fails to meet the requirements in
Method D2240)
8.1,twoadditionalbearingsmaybesampledandshallmeetall
Physical properties
(Test Methods D412):
the requirements in 8.1 or the lot shall be rejected.
Tensile strength, 15.5 (2250) 15.5 (2250)
8.1.6 If the lot is not rejected, the bearing of median
min, MPa (psi)
stiffness(K)shallbesubjectedtotheelastomericmaterialtests
Ultimate elongation:
in 8.2. 45 to 55 400 400
hardness, min, %
8.2 Elastomeric Material Tests:
56 to 65 400 350
hardness, min, %
8.2.1 All test specimens used for the determination of the
66 to 75 300 300
propertiesofthevulcanizedelastomericmaterialshallbetaken
hardness, min, %
from bearings (see Practice D3183). Tensile and hardness
High-temperature re-
sistance (Test
specimens for the quality control tests in 8.2.3, specimens for
Method D573)
the ozone resistance test in 8.2.5, and strips for the low-
Aging time, h 168 70
temperature brittleness test in 8.2.6.1, if applicable, shall
Aging tempera- 70 100
ture, °C
includeanoutersurfaceofabearing.Allotherspecimensshall
Change in +10 +15
be taken from within the middle one third of a bearing.
hardness, max, %
Compression set specimens shall be as specified in Test Change in tensile −25 −15
strength, max, %
Methods D395, Method B, Type 1.
Change in ultimate −25 −40
8.2.2 The temperature at which the tests shall be carried out
elongation, max, %
shall be 23 6 2°C except where otherwise specified in this Compression set (Test
Methods D395,
specification.
Method B)
8.2.3 Quality Control Properties—Thequalitycontrolprop-
After 22 h at 70°C, 25 .
max, %
erties of the elastomer shall meet the requirements of Table 2
After 22 h at 100°C, . 35
for the hardness and type of rubber used.
max, %
8.2.4 Shear Modulus—The shear modulus of the elastomer
determined in accordance with Annex A1 shall not differ by
more than 615% from the required shear modulus of the
elastomer.
8.2.5 Ozone Resistance—An ozone resistance test shall be 9.1.1 For acceptance purposes, bearing from within the lot
carriedoutonteststripsmountedinaccordancewithprocedure shall be selected at random as samples for inspection and
A of Test Method D518. The test shall be carried out in testing.
accordance with Test Methods D1149 at 20% strain and at 40 9.1.2 Aminimum of three bearings shall be taken from the
6 2°C for 100 h.The ozone test partial pressure shall be 50 6
lot for testing. If the number of bearings in the lot exceeds 50
5 mPa formerly referred to as a concentration of 50 6 5 pphm thenforeach50,orpartthereof,oneadditionalbearingshallbe
unlessahighertestpartialpressurehasbeenspecified.Thetest
taken for testing.
strips shall be examined for cracks using a 7× magnification
lens. The elastomer has adequate ozone resistance if no 10. Product Marking
perpendicular cracks are observed on that surface of the strip
10.1 Every bearing shall be marked in indelible ink or
corresponding to the outer surface of the bearing.
flexible paint. The marking shall consist of the order number,
8.2.6 Low-Temperature Grade Tests:
lot number, bearing identification number and elastomer type
8.2.6.1 When Low-Temperature Grade 2, 3, or 5 is
and grade reference number.
specified,alow-temperaturebrittlenesstestshallbecarriedout
10.2 Unless otherwise specified in the contract or purchase
in accordance with Test Methods D2137, MethodAusing five
order, the marking should be on a side face visible after
test strips. The temperature at which the strips shall be
erection of the bridge.
conditioned and tested shall be−10°C for Grade 2,−25°C for
Grade 3, and−40°C for Grade 5. To meet the requirements of
11. Precision and Bias
this specification, none shall fail.
11.1 No user is currently interested in participating in a
9. Sampling
...

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D4014–89(Reapproved 1995) Designation: D 4014 – 03 (Reapproved 2007)
Standard Specification for
Plain and Steel-Laminated Elastomeric Bearings for
Bridges
This standard is issued under the fixed designation D4014; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers bearings, which consist of all elastomer or of alternate laminates of elastomer and steel, when the
functionofthebearingsistotransferloadsoraccommodaterelativemovementbetweenabridgesuperstructureanditssupporting
structure, or both.
1.2 The values stated in SI units are to be regarded as the standard.
NOTE 1—The words “elastomer” or “elastomeric” will be used interchangeably with the word “rubber” in this specification.
1.3 Thefollowingsafetyhazardscaveatpertainsonlytothetestmethodsportion,SectionB,ofthisspecification:Thisstandard
does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this
standardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
2. Referenced Documents
2.1 ASTM Standards:
A36/A36MSpecification for Structural Steel 36/A36M Test Method for Measuring the Longitudinal Profile of Traveled
Surfaces with an Accelerometer Established Inertial Profiling Reference
D395Test Methods for Rubber Property—Compression Set Test Method for Measuring the Longitudinal Profile of Traveled
Surfaces with an Accelerometer Established Inertial Profiling Reference
D412TestMethodsforVulcanizedRubberandThermoplasticRubbersandThermoplasticElastomersinTension TestMethod
for Measuring the Longitudinal Profile of Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
D518Test Method for Rubber Deterioration—Surface Cracking Test Method for Measuring the Longitudinal Profile of
Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
D573TestMethodforRubber—DeteriorationinanAirOven TestMethodforMeasuringtheLongitudinalProfileofTraveled
Surfaces with an Accelerometer Established Inertial Profiling Reference
D832Practice for Rubber Conditioning for Low-TemperatureTesting Test Method for Measuring the Longitudinal Profile of
Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
D1149Test Method for Rubber Deterioration Surface Ozone Cracking in a Chamber Test Method for Measuring the
Longitudinal Profile of Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
D1415Test Method for Rubber Property—International Hardness Test Method for Measuring the Longitudinal Profile of
Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
D1418Practice for Rubber and Rubber Latices—Nomenclature Test Method for Measuring the Longitudinal Profile of
Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
D2000Classification System for Rubber Products in Automotive Applications Test Method for Measuring the Longitudinal
Profile of Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
D2137Test Methods for Rubber Property—Brittleness Point of Flexible Polymers and Coated Fabrics Test Method for
Measuring the Longitudinal Profile of Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
D2240Test Method for Rubber Property—Durometer Hardness Test Method for Measuring the Longitudinal Profile of
Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
This specification is under the jurisdiction ofASTM Committee D-4 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.32 on Bridges
and Structures.
Current edition approved Oct. 27, 1989. Published December 1989. Orginally published as D4014–81. Last previous edition D4014–87.
This specification is under the jurisdiction ofASTM Committee D04 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.32 on Bridges
and Structures.
Current edition approved Dec. 1, 2007. Published January 2008. Originally approved in 1981. Last previous edition approved in 2003 as D4014–03.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,[e-mail]ards
, Vol 01.04.volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 4014 – 03 (2007)
D3183Practice for Rubber—Preparation of Pieces for Test Purposes from Products Test Method for Measuring the
Longitudinal Profile of Traveled Surfaces with an Accelerometer Established Inertial Profiling Reference
E4Practices for Force Verification of Testing Machines Test Method for Measuring the Longitudinal Profile of Traveled
Surfaces with an Accelerometer Established Inertial Profiling Reference
3. Terminology
3.1 Definitions:
3.1.1 design load—the mean compressive stress applied to the area of the steel laminate.
3.1.2 external load plate—a steel plate bonded to the top or bottom elastomeric surface of a bearing, or both.
3.1.3 lot—unlessotherwisespecifiedinthecontractorpurchaseorder,alotshallconsistofasingletypeofbearing,ofthesame
design and material, submitted for inspection at the same time.
3.1.4 plain elastomeric bearing pad—a bearing that consists only of elastomeric material.
3.1.5 plain elastomeric sandwich bearing—a bearing that consists of a single layer of elastomeric material bonded to one or
two external load plates (3.1.2).
3.1.6 steel-laminated elastomeric bearing—a bearing molded of elastomeric material with one or more steel laminates
embedded in and bonded to it, and to which one or two external load plates (3.1.2) may be bonded.
4. Classification
4.1 The bearings are furnished in four types as follows:
4.1.1 Plain Elastomeric Bearing Pad.
4.1.2 Plain Elastomeric Sandwich Bearing.
4.1.3 Steel-Laminated Elastomeric Bearing.
4.1.4 Steel-Laminated Elastomeric Bearing with External Load Plate(s).
NOTE 2—Examples of the types of elastomeric bearing construction are given in Fig. 1.
NOTE 3—The adjective elastomeric is omitted in this specification when referring to bearing types.
4.2 The elastomer for the manufacture of the bearing is furnished in two types as follows:
4.2.1 Type CR—Chloroprene rubber.
4.2.2 Type NR—Natural rubber.
4.2.3 If none is specified then the manufacturer shall use one of those types.
NOTE 4—Appendix X1 relates to elastomeric materials which do not have fully documented in-service records or sufficiently widespread use or both.
NOTE 5—The abbreviations for the elastomer types are taken from Practice D1418.
4.3 The elastomer for the manufacture of the bearing is furnished in four grades of low-temperature properties.The grades and
typical operating temperature conditions for each grade are as follows:
4.3.1 Grade 0—Suitable for continuous use down to+5°C.
4.3.2 Grade 2—Sub-zero temperatures occur at night and occasionally persist for no more than 1one or 2two days.
4.3.3 Grade 3—Same as Grade 2 but occasional periods of up to 2two weeks continuously below zero.
4.3.4 Grade 5—Sub-zero temperatures down to−40°C persisting for several months each year with up to 2two months
continuously below−15°C.
4.3.5 If a grade is not specified Grade 0 shall be furnished.An elastomer of a higher grade number may be substituted for any
lower grade.
NOTE 6—A discussion of low-temperature properties of elastomeric materials is given in Practice D832.
NOTE 7—The grade numbers for the low-temperature properties correspond to those in Table 5Table6 of Classification D2000.
5. Ordering Information
5.1 Orders for each type of bearing under this specification shall include the following:
5.1.1 Quantity,
5.1.2 Bearing design,
NOTE 8—An example of the design information required is given in Appendix 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 concentration of 50 parts per hundred million
(pphm)).
6. Materials and Manufacture
6.1 The elastomeric compound used in the construction of a bearing shall contain only either natural rubber or chloroprene
D 4014 – 03 (2007)
FIG. 1 Examples of the Construction of Elastomeric Bearings
rubber as the raw polymer. No reclaimed rubber shall be used.
6.2 Internal steel laminates shall be of rolled mild steel.
6.3 ExternalloadplatesshallconformtotherequirementsofSpecificationA36/A36M/A36Munlessotherwisespecifiedinthe
contract or purchase order.
6.4 Plainbearingpadsshallbemoldedindividually,orcutfrompreviouslymoldedstripsorslabs,orextrudedandcuttolength.
Cutting shall produce a smooth surface and no heating of the elastomer.
6.5 A steel-laminated bearing or a plain sandwich bearing shall be molded as a single unit under pressure and heat.
6.6 All bonding of elastomer to steel laminates and to external load plates shall be carried out during molding. The elastomer
at the outer edges of bonds to external load plates shall 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 rusting when supplied by the manufacturer.
6.9 All molds shall have a standard shop-practice mold finish.
7. Dimensions and Permissible Variations
7.1 All elastomeric layers, for example, plain-bearing pads, laminates, and covers, shall be of uniform thickness unless
otherwise specified in the contract or purchase order.
7.2 All internal steel laminates shall be of uniform thickness. When specified in the contract or purchase order, the thickness
of the outer steel laminates may differ if not adjacent to an external load plate (see Fig. 1).
D 4014 – 03 (2007)
7.3 The minimum thickness of internal steel laminates shall be 1.5 mm or 0.060 in. (16 gage) when the greater of the length
orwidthofarectangularbearingorthediameterofacircularbearingislessthan450mmor18in.Inallothercases,theminimum
thickness shall be 2 mm or 0.075 in. (14 gage).
7.4 External load plates shall be of uniform thickness unless otherwise specified in the contract or purchase order.
7.5 Bearing dimensions and elastomer layer thicknesses shall satisfy the tolerances in Table 1, in which D is the length, width
or diameter as appropriate, and T is the total elastomer thickness.
7.6 Variationfromaplaneparalleltoadesignsurfaceshallnotexceedanaverageslopeof0.005fortheuppersurfaceand0.006
for a side surface.
8. Test Methods and Acceptance Requirements
8.1 Bearing Compression Tests—All bearings sampled from a lot shall be subjected to the compression tests. The cost of
replacement bearings and of testing them shall be borne by the supplier.
8.1.1 The bearings shall be brought to a temperature of 23 6 6°C and shall be tested at this temperature.
8.1.2 Compression Stiffness—Loadthebearingtothedesignload(3.1.1)byincrementsofonefifthofthedesignload.Foreach
load increment, the loading time shall be within the range of 1.4 to 2.6 min. When the increment has been applied the load or
deflection (depending on the type of testing machine) shall be maintained constant for 30 s then the load and deflection measured.
From a plot of load against deflection, the compression stiffness shall be determined as the slope of the best straight line through
the points, ignoring the first point at zero load. Record the compressive stiffness for each bearing.
8.1.3 Visual Inspection—Increase the load to 1.5 times the design load then maintain either load or deflection constant while
the bearing is inspected for visual faults, as follows:
8.1.3.1 If lack of elastomer to steel bond is indicated, the bearing shall be rejected.
8.1.3.2 Iflaminateplacementfaultsareobservedwhichresultinelastomerlayerthicknessthatexceedthetolerancesin7.5,the
bearing shall be rejected.
8.1.3.3 If there are at least three separate surface cracks which are each at least 2 mm wide and 2 mm deep, the bearing shall
be rejected.
8.1.4 Recordthemediancompressivestiffness(K)ofthebearingofmedianstiffness.Thecompressivestiffnessofeachbearing
tested shall not differ from ( K) by more than 10%.
8.1.5 For each bearing that fails to meet the requirements in 8.1, two additional bearings may be sampled and shall meet all the
requirements in 8.1 or the lot shall be rejected.
8.1.6 If the lot is not rejected, the bearing of median stiffness (K) shall be subjected to the elastomeric material tests in 8.2.
8.2 Elastomeric Material Tests :
8.2.1 All test specimens used for the determination of the properties of the vulcanized elastomeric material shall be taken from
bearings (see Practice D3183). Tensile and hardness specimens for the quality control tests in 8.2.3, specimens for the ozone
resistance test in 8.2.5, and strips for the low-temperature brittleness test in 8.2.6.1, if applicable, shall include an outer surface
of a bearing.All other specimens shall be taken from within the middle one third of a bearing. Compression set specimens shall
be as specified in Test Methods D395, Method B, Type 1.
8.2.2 The temperature at which the tests shall be carried out shall be 23 6 2°C except where otherwise specified in this
specification.
8.2.3 Quality Control Properties —The quality control properties of the elastomer shall meet the requirements of Table 2 for
the hardness and type of rubber used.
8.2.4 Shear Modulus— The shear modulus of the elastomer determined in accordance withAnnexA1 shall not differ by more
than 615% from the required shear modulus of the elastomer.
8.2.5 Ozone Resistance—An ozone resistance test shall be carried out on test strips mounted in accordance with procedureA
of Test Method D518. The test shall be carried out in accordance with Test Methods D1149 at 20% strain and at 40 6 2°C for
100h.Theozonetestpartialpressureshallbe50 65mPaformerlyreferredtoasaconcentrationof50 65pphmunlessahigher
test partial pressure has been specified. The test strips shall be examined for cracks using a 73 magnification lens. The elastom
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