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Laminated Elastomeric Bearing
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To Contact Us
Tele: + 971 50 6268246
Fax: + 971 6 534 7707
....please copy and
paste this email id...
pretread@eim.ae
Site Translation
Neoprene is Registered Trademark of DupontDow
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Bridge Bearings - Frequently Asked Questions.
Many of the general Frequently asked questions (FAQ) on
laminated bearings, slide bearings and pot bearings are answered
in this page. Your suggestions and comments about this page will
be highly appreciated so we could serve you better.Please email
us comments and suggestions. (use the right side task bar to go
to next Question)
Neoprene bridge bearings - plain or laminated - elastomeric
bearings are much easier to install in a bridge than compared to
other types of bearing used and elastomeric bearings require nil
maintenance. Unlike most other elastomer, Neoprene rubber
under-goes no marked stiffening at low temperature when the
thermal contraction of the bridge deck is at maximum. Such
stiffening could be deleterious to bearing and / or structure.
Correctly-designed and suitably-compounded laminated Neoprene
Rubber bridge bearings can be confidently expected to function
efficiently for at least a decade even at different high
variances of temperature.
As efficient bearing plates for pre-cast, pre-stressed
concrete or steel beams in bridges and buildings, Neoprene Pads -
plain and laminated - manufactured by us permits a smooth and
uniform transfer of load from the beam to the substructure and
allow beam rotation at the bearing due to deflect ion of the beam
under load. They further allow lateral and longitudinal movement
of the beam caused by thermal forces. Neoprene Pads have no
movable parts and thermal expansion and contraction are absorbed
by the pad's ability to give and take in shear. There is no
sliding motion between pad and beam or between pad and
abutment.
The material specifications for the elastomeric bearing shall
meet all the current requirements of AASHTOM M 251.Bearing pads
and elastomeric bearings will comply with Articles 18.2.3 through
18.2.6 of Section 18, Bearing Devices, Division II, Construction,
of the AASHTO Standard Specifications for Highway Bridges.
Bearing pads and laminated bearings shall be of the compound
known as neoprene and shall be cast in molds under pressure and
heat. A plain elastomeric bearing pad and steel load distribution
plate combination shall be classified as a laminated elastomeric
bearing. Test specimens shall be in accordance with ASTM D 3182
or D 3183. Where test specimens are cut from the finished
product, a 20 percent variation from the original physical
properties is allowed.
Elastomeric bearings shall be composed of multiple laminates
of elastomeric material separated by steel reinforcing. The
overall size of the bearing, the number of laminate and thickness
of laminates are designed in accordance to the requirement of
Load to be Transferred. Bearings having steel plates as
reinforcement shall be cast/compression moulded/vulcanized as a
single unit in a mould under pressure and heat.
Internal plates shall be ASTM A 36/A 36M or A 570/A 570M,
Grade 36 or Grade 40. All plates shall be deburred. The internal
plates shall not be less than 1.88 mm (0.074 inch) thick.The
steel plates separating the elastomeric layers will be completely
bonded by vulcanization to the elastomeric material on all
surfaces using special metal to rubber bonding adhesive. All
external load bearing steel plate(s) if present, shall be factory
vulcanized to the elastomeric bearings during the primary molding
process.
Acceptance Tests of the pads and bearings shall be according
to Level I acceptance criteria of Article 18.2.5. This testing
shall be included in the price bid for the bearings.
Yes, Mechanical bearings are also manufactured and supplied
by us and further investments for plant up-gradation is under
way.Please send us your requirement for Pot Bearings
In house Quick Production Test of all bearings shall be done
at Clients/Representative presence. Tests confirming to AASHTO
specification in accordance with Acceptance Testing on either
Level I or Level II or Short/Long-Duration Compression Test up to
3400 kN with horizontal shear up to 180kN can be carried out in
our facility.
Neoprene or Polychloroprene Rubber Compounds are used where
Laminated Elastomeric bearings are designed, manufactured and
tested in accordance to requirements with AASHTO M 251 .
Natural Rubber Compounds are used where Laminated Elastomeric
bearings are designed, manufactured and tested in accordance to
requirements with BS 5400 Part 9.
www.pretread.com you have your single relayable source for
all your requirements of sliding bearing,expansion joints
neoprene pads, manufactured from polychloroprene. Even for
building bearings, expansion joints, elastomeric bearings, shock
absorber mountings,and custom bridge bearings, manufactured to
your specification, with approval from American Association of
State Highway and Transportation Officials. Our PTFE laminated
elastomeric bearings,bridge bearings, isolation pads,seismic
isolators, and pot bearings are manufactured complying to US road
transportation authority specifications.
Yes, we could assist you in verify load calculations for your
bearings. Send us sizes, construction and load details of your
bearings and we will send results on design parameters compared
to AASHTO LRFD.
Click to see sample report
Yes, we are the first manufacture to produce ptfe -TEFLON
sliding bearings successfully in the middle east.Various projects
have been supplied with our ptfe -teflon sliding bearings.
When horizontal movements are expected at high values over 50
mm and the vertical shear is low instead of using a thicker
lamianted bearing, it would be ideal to use a ptfe sliding
bearing with SS 316 mirror finish for a smoother long term
application.
Yes, we will be happy to do designing of ptfe sliding
bearings for you, and please send us the details.
Yes we have in house facility to design and manufacture pot
bearings,Fixed pot bearings, Guided Sliding pot bearings and Free
Sliding pot bearings.These are designed and manufactured to
AASHTO standards.
Yes we can supply you with additional accessories and
fixtures for installation of pot bearings like temporary
bearings, ptfe sliding bearings, studs, base plates, masonry
plates etc to AASHTO specifications.
Yes we do design,manufacture and support in installations of
ptfe -TEFLON sliding bearings.
When the lateral movements required for structure are of
greater values than the height of bearing it would be ideal to
use a ptfe-TEFLON sliding bearing which and the friction
coefficient between ptfe and Stainless Steel surface is less than
0.05 the service life of the bearings will be normally over 50
years.
Yes, we are the only manufacturer in Middle East who has
in-house facility to test Laminated Bearings / Pot Bearings
applying Vertical Load and Lateral Shear to confirm that Shear
Modules confirms to specified for bearing designing.
Yes on our in-house Bearing Testing Machine can be used to
test Teflon Sliding Bearing to note lateral sliding on required
vertical loads.
Internal Lamination construction of Elastomeric Bearings are
designed based on required Vertical Load /Lateral Shear, keeping
Shear Modules value of rubber compound as required by Client /
Bearing designer. Only through results obtained from Stress
Strain Tests and graph plotted will prove that bearing
manufactured meets the required values for Lateral Shear under
vertical load. We are the only manufacturer in Middle East who
has in-house facility to carry out these tests and confirm that
Laminated Bearings manufactured by us meets the design
parameters.
Clients / Consultants are welcomed to witness these tests and
see our facility to test Laminated Bearings up to 3400 kN
Vertical Load and Lateral Shear Load of 180 kN and a lateral
movement of 100 mm.
Let us help you to design your requirements of elastomeric
bearings. Please click on the links to
visit our form fill up page and we can design bearings to
your requirement
Thank you very much for visiting us.
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Country Managers
we are seeking enterprising individuals with strong regional
experiences to represent us in your country or area for our
products. Please contact us with your product of interests.
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Expansion Projects
For our up coming new expansion Project we are seeking
partnership with any renowned Elastomeric Bearing or other rubber
products manufacturer. Interested manufacturers please contact
us.
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Bearing Load Testing.
We are the first and only laminated bearing manufacturing
facility in Middle East to have an in-house bearing testing
facility to carry out tests confirming to AASHTO
specification in accordance with Acceptance Testing on either
Level I or Level II as well as Short/Long-Duration Compression
Test. Our bearing testing machine can test bearings to Vertical load of 4200
kN with horizontal shear load up to 400kN and movement to 100
mm.
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Bearing Load Calculations
Let us verify ..load
calculations.. for your bearings. On receipt of corbel
size, and load details of your requirements, and we can provide
calculations and bearings sizes based on results on design
parameters compared to AASHTO LRFD - FREE.
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Dealer-ship
Dealer ship and agency offered, please contact us with
details on your organization,current activities and area of
interest.Send us an email to:
pretread@eim.ae
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Bearing Design
Let us help you to design your requirement of
elastomeric bearings click on the links to visit Design a Bearing
Form- - we can support you to design elastomeric bearings to
requirement
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Picture Gallery
Installed Bridge Bearing
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