bridge bearings & expansion joints

OCEAN RUBBER

®

is

the leading and the

biggest manufacturer and

supplier of Elastomeric

Engineering products and

services in the Middle East

& Africa region, with

products being exported

worldwide. The factory is

ISO 9001:2008 accredited,

with a dedicated quality

assurance and quality

control department monitoring all processes starting from raw

material approval, manufacturing and testing of the finished

products. With almost a quarter century of experience, our

products and services are well known for their quality and

durability. Being an exclusive en gineering products designer and

manufacturer, we have products for many industrial sectors like

the Construction, Marine as well as Oil & Gas. One of our most

accepted products for the construction industry is the PIONEER

bearing pads and Expansion joints series. Backed up by an

equipped testing laboratory and equipment, our products can be

inspected and certified by 3

rd

party inspection agencies like

Germanischer Lloyds, ABS, Velosi, SGS etc.

CO

MP

AN

Y P

RO

FIL

E

PIONEER BEARING PADS

INTRODUCTION

Bridge decks supported by piers are

susceptible to damage due to

vehicle movement and expansion

due to heat. The function of

Elastomeric Bearing Pads is to

provide a connection to control the

interactions of loading and

movements between parts of a

structure, usually between

superstructure & substructure.

Bearing pads provide a uniform

transfer of load from beam to sub-

structure. Bearing pads are used

extensively in bridge structure; Pre-

stressed & Pre-cast concrete

buildings.

Pioneer Bearing pads are manufactured from premium quality Natural Rubber or Neoprene.

All the bearing pads are manufactured in compliance to standards like AASHTO, BS 5400,

EN-1337, DIN 4141 etc hardness ranging from 50 Shore ‘A’ to 70 Shore ‘A’. Specially

designed bearing pads for non-standard application can also be provided including testing

and certification.

BEARING FUNCTION

• Support vertical loads

• Accommodate girder rotation

• Permit lateral movements due to temperature change, traffic movements, wind,

shrinkage & creep, foundation movement, seismic actions, dynamic forces &

resulting vibrations.

• Transmitting load to substructure foundations.

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PIONEER BRIDGE SOLUTIONSPIONEER BRIDGE SOLUTIONS

DESIGN

Bearing pads are designed as per AASHTO LRFD

Bridge Design Specifications-2007. The design rule

is based on the assumption that Rubber is a

viscoelastic material, the deflection of which under

compressive load is influenced by its shape.

Reinforcing plates in the bearing are chemically

bonded to the elastomer to prevent any relative

movement.

Designing of the bearing pads results in achieving

the sizes which would be stable under the

specified loads, translation, and rotations about

the given axis

TYPICAL MATERIAL SPECIFICATIONS

Elastomer Used:

I. PHYSICAL PROPERTIES

S.N DESCRIPTION TEST METHOD UNIT SPECIFICATION

1 Hardness ISO 7619 Shore A 60±5

2 Specific Gravity ISO 2781 - 1.33±0.05

3 Tensile Strength, Min. ISO 37 MPa 15.5

4 Elongation at break, Min. ISO 37 % 350

5 Compression Set, Max. (22hrs @ 1000C ISO 815 % 35

6 Accelerated Ageing Resistance (70 hrs @ 1000C)

6.1 Change in Hardness ISO 7619 Shore A +15

6.2 Change in tensile strength, Max. ISO 37 % -15

6.3 Change in Elongation at break, Max. ISO 37 % -40

II. GENERAL PROPERTIES

1 Resistance to Water Good

2 Resistance to Acids Good

3 Resistance to Alkalis Good

4 Resistance to Weathering Excellent

Inner Reinforcing Plates

The inner reinforcing steel plates shall be of steel grade ASTM A36 or steel of minimum

equivalent elongation at break. The minimum thickness of the plates used shall be 2mm

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LAMINATED ELASTOMERIC BEARING PADS (STEEL REINFORCED)

Laminated elastomeric bearing pads can

accommodate movement in any direction

and rotational movement about any axis by

elastic deformation. Usually used where

bridges are susceptible to high loading, high

translation & rotations. Alternate layers of

Steel & Rubber are vulcanised together to

attain the desired load bearing capacity.

Laminated bearing can be either

rectangular or circular as per the

requirement at the abutments

Bearing pads can also be reinforced with

Cotton duck fabric which is commonly known

as cotton duck pads (CDP). CDP are known to

be quite stiff and to have large compressive

load capacity. Because of this great stiffness,

the rotational capacity and translational

movements of CDP has been severely limited.

The below sizes are nominated as per the

AASHTO Standards and calculations:

SNLength

(mm)

Breadth

(mm)

Thickness

(mm)

Maximum

Load

(kN)

Maximum

Movement

(mm)

Maximum

Rotation

(rad)

1 150 150 15 240 6 0.001

2 200 150 20 320 8 0.001

3 250 250 25 650 9 0.001

4 400 250 30 1050 10 0.001

5 400 300 42 1250 13 0.001

6 400 250 52 1050 18 0.0015

7 400 300 63 1250 21 0.002

8 450 400 129 1850 45 0.004

10 400 500 164 2100 60 0.005

11 400 500 182 2100 70 0.007

12 400 500 200 2100 75 0.008

13 600 400 236 2450 90 0.001

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PLAIN ELASTOMERIC BEARING PADS

Plain elastomeric bearing pads are solid blocks of rubber without any steel reinforcement

plates. They are not generally used in bridges. They are predominantly used where there is

low pressure or loads and static conditions.

Plain elastomeric bearing pads are

simple, low-cost rubber

separation strip capable of

carrying compressive loads, and

providing limited translational

movement and rotational

capacity. They have a varied

application in prefabricated

structures.

The below sizes are nominated as per the AASHTO Standards and calculations:

SNLength

(mm)

Breadth

(mm)

Thickness

(mm)

Maximum Load

(kN)

Horizontal

Movement

(mm)

Maximum

Rotation (rad)

1 150 150 10 120 4 0.0006

2 200 150 10 160 4 0.0006

3 200 200 10 210 4 0.0006

4 150 150 15 120 7 0.0007

5 200 150 15 160 7 0.0007

6 200 200 15 210 7 0.0007

7 150 150 20 120 9 0.0009

8 200 150 20 160 9 0.0009

9 200 200 20 210 9 0.0009

10 1000 150 15 800 4 0.0001

11 1000 200 20 1000 7 0.0001

12 1000 200 25 1300 9 0.0001

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SPECIAL TYPES OF BEARING PADS

POT BEARINGS

Pot bearings are special type of bearing

pads for taking larger loads, translation

& rotation in smaller confined area. Pot

bearings are often regarded as suitable

for use when bridge bearing rotations

are large.

Rotation may occur about any axis and

is accommodated by deformation of the

elastomeric pad. Pot bearings are fixed

against all translations unless they are

used with a PTFE sliding surface. . The

pad is deformable but almost

incompressible and the pot bearing has

large reserve capacity against vertical loads.

Pot bearings are divided in to three types:

1. Fixed pot bearing

• Constrains longitudinal and transversal movements

• Bears longitudinal and transversal horizontal loads

2. Free sliding pot bearing

• Allows longitudinal and transversal movements

• Bears longitudinal and transversal horizontal loads

3. Guided pot bearings

• Allows longitudinal movements

• Constrains transversal movements

• Bears horizontal transversal loads

The basic elements of a pot bearing are

1. Shallow cylinder or pot

2. Elastomeric pad

3. Set of sealing rings

4. Piston

5. PTFE Sliding surface

6. Stainless steel mating surface

7. Sliding plate

8. Anchors 1

4

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2

3


When compared to normal Elastomeric Bearing pads, it has following advantages:

• Takes larger loads where space is a constraint as compared to that of Elastomeric

bearing pads

• It can sustain larger cycles of rotation and movements.

• Maintenance is economical as the replacement is effected only for the rubber disc

• Long term serviceability

• Effect of atmospheric correction is minimal

GUIDED TYPE ELASTOMERIC BEARING PADS

These types of special purpose bearing

pad consists of a top and bottom load

plates with a guide to restrict the

movement to the required direction.

The top and bottom load plates are hot

vulcanised to the rubber. Anchor rods

are also provided in the load plates for

anchoring to the bridges as per the BS

Standards.

The rubber pads could be either plane

or reinforced as per the load conditions

prevailing.

SLIDING TYPE BEARING PADS (FRICTIONLESS BEARING PADS)

Sliding type bearing pads are provided

where there is a requirement of higher

translation with respect to available

area in the abutment, especially in large

malls or airports where spans are very

wide and the relative translations are

more.

PTFE sheets with Mirror finished

stainless steel plates are used for

obtaining the desired result of higher

translations. PTFE is either chemically

bonded or fixed using adhesives to the

top portion of the bearing pads. Bearing

pads are either plain or reinforced with

respect to the loads defined.

STANDARDS & SPECIFICATION

• AASHTO LRFD Bridge Design Specifications

• AASHTO M251 (Standard Specification for Bridge Bearing Materials)

• BS5400

• EN1337

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INSTALLATION PROCEDURE

ELASTOMERIC BEARING PADS (PLAIN & LAMINATED)

STEP 1: CLEAN THE SURFACE STEP 2: CAST THE MORTAR TO LEVEL THE

SURFACE & APPLY THE EPOXY RESIN

STEP 3: LOCATE THE BEARING PAD APPLY STEP 4: PLACE THE UPPER BEAM

ANOTHER LAYER OF EPOXY RESIN

ELASTOMERIC BEARING PADS WITH ANCHOR BARS (PLAIN & LAMINATED)

STEP 1: PREPARE THE CONCRETE SURFACES WITH STEP 2: LOCATE THE BEARING PAD IN THE SPACE

HOLE & CLEAN WITH COMPRESSED AIR PROVIDED & FILL IT WITH RESIN

STEP 3: LOCATE THE UPPER BEAM S UPPORTED BY STEP 4: FILL THE CAVITY WITH RESIN

HYDRAULLIC JACKS AT REQUIREED HEIGHT REMOVE THE JACK AFTER CURING OF RESIN

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PIONEER EXPANSION JOINTS

Pioneer bridge solution offers a variety of expansion joints to suit wide range of movements

and gap between the bridge decks. The complex rubber-metal composite structure of the

Pioneer expansion joints facilitates to accommodate the displacement and rotation of the

concrete structures relative to each other in all directions.

ADVANTAGES

� Long service life

� Corrosion resistance

� Water proof

� Low noise

� Easy installation

MATERIAL

The materials used for the Pioneer Bridge Expansion Joints are completely in compliance with

the relevant bridge standards like AASHTO/BS/DIN/EN. Pioneer bridge expansion joints are

manufactured from virgin polychloroprene based elastomer. The specially formulated rubber

compound helps to meet stringent requirements such as abrasion resistance, extreme

weather conditions, and longer service life.


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Structural steel elements are fabricated from steel grade ASTM A 36 or equivalent. The

fabricated steel plates are blasted to a surface cleanliness of SA2.5 with the surface amplitude

of 50-75 microns.

KERB UNITS AND EXPANSION JOINTS WITH

ARMOUR PLATE

Kerb units can be manufactured with different

angles and lengths based on customer

requirements to suit the structural alignment

of decks. Metal inserts are fabricated in

accordance to the required alignments and are

vulcanized along with the elastomer.

Expansion joints with armour plates are

generally used where heavy traffic flow is

found. Armour plates decreases the wear and

tear due to vehicle flow. Specially designed

aluminum profiles are used as armour plates in

bridge expansion joints.

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DESCRIPTION UNIT TEST METHOD SPECIFICATION

Hardness, max Shore ‘A’ BS 903 Part A26 60 = 5ASTMD 2240 / DIN 5350

Specify gravity ---- BS 903 Part A1 1.15-1.35

2Tensile strength Kg/cm BS 903 Part A2 1.55

ASTM D 412 / DIN 53504

Elongation at break, Min % BS 903 Part A2 450ASTM D 412 / DIN 53504

Tear strength Min KN/m BS 903 A3 / ASTM D624 50

Resistance to Ozone — ASTMD 1149 B No cracks25 pphm, 48hrs, 40°C, 5% strain

Compression set, max % ASTMD 395 30(24hrs. at 70°C, 25% strain) BS 903 Part A6

Bonding of rubber to steel ASTM D429 B >12 N per mm

Change in hardness, max Shore ‘A’ BS 903 Part A 26 +5ASTM D 2240 / DIN 53505

Change in tensile strength, max % BS 903 Part A2 -15ASTM D 412/ DIN 53504

Change in elongation at break, max % BS 903 Part A2 -15ASTM D412/ Din 53504

AFTER AGEING PROPERTIES (22 HRS.AT 70°C

Below table shows the different sizes of exp ansion joints offered by OCEAN PIONEER

BRIDGE SOLUTIONS.

PIONEER EXPANSION JOINT PIONEER EXPANSION JOINT

(XJ-47 to XJ-85) (XJ-105 to XJ-235)

Model Width

mm Total

movement

mm

Gap

btw

deck

mm

Length

per

module

mm

X

mm Y

mm Z

mm l

mm no. of

holes

Per

side

Fastener

size Torque

N-m

PIONEER-XJ-47 240 47(±24) 35 2000 188 334 165 9 6 M12 45

PIONEER-XJ-57 270 57(±29) 46 1830 210 305 152.5 9 6 M14 100

PIONEER-XJ-75 355 75(±38) 62 1830 280 305 152.5 9 6 M14 100

PIONEER-XJ-85 430 85(±43) 74 1830 340 305 152.5 9 6 M16 175

PIONEER-XJ-105 580 105(±53) 94 1830 494 305 152.5 9 6 M16 175

PIONEER-XJ-125 620 125(±63) 98 1830 524 305 152.5 9 6 M18 180

PIONEER-XJ-145 650 145(±73) 105 1830 576 305 152.5 12 6 M18 180

PIONEER-XJ-165 720 165(±83) 110 1830 612 305 152.5 12 6 M20 190

PIONEER-XJ-185 800 185(±93) 125 1830 698 305 152.5 12 6 M22 230

PIONEER-XJ-205 850 205(±103) 134 1830 744 305 152.5 12 6 M24 275

PIONEER-XJ-235 900 235(±118) 145 1830 794 305 152.5 12 6 M24 275

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INSTALLATION PROCEDURE

Before installing an expansion joint it is very important to make sure of the bridge

movements and to check the asphalt thickness in order to conform that it can be installed

correctly.

� Layout a ground plan for the joint and mark the cut width at both side of the axis.

Remove the concrete to obtain the required recess of width and depth for the

respective expansion joints

� In case of aged concrete, prior to installation, the weak, loose, deteriorated or

contaminated concrete must be removed and replaced with new one.

� The joint interface must be dry and clean. It must be completely free from dirt, rust,

grease, oil and other contaminants.

� Prepare block outs to proper dimensions, grade and make sure levels are verified. The

gap will be protected with a polystyrene piece.

� The points are marked and drilled for anchoring and holes are flushed with

compressed air. The bolt sizes are as per the table above. Then it is filled with a fast

curing pour able epoxy grout before inserting the anchor bolts. Care to be taken to

ensure all anchors are set at right angles.

� Install the pioneer expansion joint units starting at the curb over the sealant.

� Proceed until reaching the field cut piece. Apply the sealant to the ends of the field cut

pieces prior to the final placements.

� Nuts will be adjusted with appropriate tightening. Bolt hole cavity may be fi lled with

the sealant.

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QUALITY CONTROL

Quality control department in ocean rubber has highly qualified personnel equipped

with the most modern testing equipments to ensure the quality at every stages of the

production. The function of the quality control starts from the inspection of incoming

raw material continues through the various stages of production and sustains till the

final finished product moving out of the company. The department is highly dedicated

to ensure the product quality to satisfy the customer requirements.

Rubber is compounded in internal mixers; quality is monitored round-the-clock by

continuously testing samples for their physical properties and chemical characteristics.

Every ingredient is checked and monitored regularly; in-process inspection conducted at

various stages of production, performance test and final inspection carried out. The

products of Ocean Rubber are certified to meet the most demanding requirements of

civil construction, oil & gas, infrastructure, marine and military applications.

Laboratory Testing The exclusive in-house laboratory is equipped with computerized facilities to test the

properties of rubber according to ASTM, BS and other international standards. The

laboratory plays a crucial role in implementing quality a s well as developing new

products. Test Certificates are issued on request.

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bridge bearings & expansion joints

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