726BEARING ASSEMBLIES

726.01Description

This work shall consist of furnishing and installing bearing assemblies in accordance with 105.03. Elastomeric bearings shall include plain bearings consisting of elastomer only, and laminated bearings consisting of layers of elastomer restrained at their interfaces by bonded laminates.

MATERIALS

726.02Materials

The materials shall be in accordance with the following:

Anchor Bolts................................................................ 910.02(g) Elastomer ..................................................................... 915.04 Grout ............................................................................ 707.09 Polytetrafluoroethylene Sliding Surfaces .................... 915.05 Shim and Fill Plates ..................................................... 910.02(a) Side Retainers .............................................................. 910.02(a) Threaded Studs and Hex Nuts ..................................... 910.02(c) 20

CONSTRUCTION REQUIREMENTS

726.03Construction Requirements

Elastomeric bearings without external load plates may be placed directly on a concrete or steel surface provided the surface is flat to within a tolerance of 0.005 of the nominal dimension for steel reinforced bearings or 0.01 of the nominal dimension for other types. Bearings shall be installed on surfaces that are horizontal and parallel between the top of the bearing and the underside of the girder.

The elastomer or the bond shall not be subjected to temperatures higher than 390ºF.

Masonry plates for polytetrafluoroethylene, PTFE, bearings shall be perfectly level. The tolerance between the top face of the masonry plate and the bottom face of the top plate shall be a maximum of 1/16 in., measured at the ends of a diameter of the bottom plate of the bearing assembly. Other dimensional tolerances shall be as shown on the plans or in accordance with 915.04(d).

Immediately prior to setting bearings, the concrete and metal surfaces that are to 40 be in contact shall be cleaned.

726.04Method of Measurement

Elastomeric bearing pads will not be measured for payment. PTFE bearing devices will be measured by the number of devices placed.

726.01

726.05Basis of Payment

Elastomeric bearing pads will not be paid for separately.

PTFE bearing devices will be paid for at the contract unit price per each device, 50 complete and in place.

Payment will be made under:

Pay Item Pay Unit Symbol

Bearing Assembly, PTFE .......................................................... EACH

The cost of the pads, side retainers, anchor bolts, shim plates, and other incidentals shall be included in the cost of the structural member, or for PTFE bearing assemblies. 60