R 2-20-98

MODULAR EXPANSION JOINTS

    These joints shall be prefabricated modular assemblies of the type consisting of multiple elastomeric seals, separator beams and support bars. The joints furnished and installed shall be in accordance with these specifications, the plans, and the manufacturer's recommendations, subject to approval by the Engineer.

GENERAL FEATURES

    The joint shall be designed for HS-20 truck loading and impact in accordance with AASHTO Specifications and shall accommodate the movements shown in the plans.

    The elastomeric seals shall as a minimum:

  1. Be held in place by compressive forces throughout the normal limits of joint movement.

  2. Be supplied and installed in one piece.

  3. Have corner locked edges for a watertight fit.

  4. Not be any part of the load bearing riding surface.

  5. Be installed using seal lubricant-adhesive.

  6. Have a shape which promotes self removal of foreign material during normal joint operation.

  7. Be recessed 13 mm (1/2 in.) or more below the riding surface throughout the normal limits of joint movement.

  8. Be held in position by the separator beams.

    The separator beams shall as a minimum:

  1. Provide the riding surface across the joint.

  2. Have an extruded shape suitable to hold the seals.

  3. Be stable against tipping, tilting or lifting during application of traffic loads. This shall be done by use of a suitable shape and connection to the support bar.

  4. Be supported individually on their own independent support bars.

  5. Maintain equidistant spacing through use of suitable equilibrium type spacers which work counter force to the compression forces of the seals.

    The support bars shall as a minimum:

  1. Incorporate stainless steel sliding surfaces to minimize resistance to joint movements.

  2. Be supported above, below, and laterally as required to prevent lifting, transmit bearing loads, and maintain positioning of bar.

    If support bar boxes are required to accommodate support bar movements, they shall be made of steel plate with 13 mm (1/2 in.) minimum thickness.

    Anchorages shall be of the type of a looped No. 19 (#5) rebar welded to a 13 mm (1/2 in.) steel plate, spaced at 230 mm (9 in.) centers.

    To limit noise propagation, no unwelded steel to steel contact will be permitted.

    Bearings above and below the support bar shall be of a urethane compound with teflon riding surfaces.

    All components of the system shall be accessible to periodic inspection and component replacement if necessary.

MATERIALS

    Materials shall conform to the following:

Structural Steel    - ASTM A-36, A-570, A-242, or Merchant Quality 1010, 1020.
Sealant and Grouts - Federal Specification TT-S-00230 or as recommended by the joint manufacturer.
Elastomer          - Shall be 100% virgin polychloroprene (neoprene) and conform to the properties specified by the joint manufacturer, subject to approval by the Engineer.

    The structural steel and sealant shall be covered by a Type C certification and the elastomer by a Type B certification in accordance with 915.04(f).

CONSTRUCTION REQUIREMENTS

    The joint shall be constructed in accordance with the details shown on the shop drawings as prepared by the manufacturer of the expansion joint assembly. Tolerance requirements shall be in accordance with Article 2.25.4 of AASHTO Specifications.

    The profile of the joint in the roadway area shall conform to the roadway cross section. Where changes in direction are required, such as at curbs or concrete rails, the sections shall be cut to the bevel required to produce the same cross section on each piece being joined. Slider plates shall be provided at curbs, walkways and concrete rails as part of the completed joint assembly.

    The manufacturer of the prefabricated expansion joint assembly shall prepare shop drawings showing details of the assembly. Three sets of the shop drawings, manufacturer's specifications and joint setting data shall be submitted for approval. This information shall be approved prior to manufacture of the joint.

    The joint, including anchor assembly, shall be shop fabricated, delivered and installed as a continuous unit for lengths up to 13 m (44 ft). Joints longer than 13 m (44 ft) shall be furnished in continuous units or in appropriate shorter sections as shown on the shop drawings and approved by the Engineer. Joints used in stage construction shall be furnished in sections appropriate to accommodate the work. Any joint furnished in sections shall be spliced with welds, with ends prepared for welding in the shop. All work, both shop and field, shall be in accordance with 711.03.

    All welding shall be done by certified welders only. All splice welds shall develop full strength. All welds in contact with the elastomeric seals shall be ground smooth. Metal surfaces in direct contact with the elastomeric seal shall be clean and properly treated in accordance with the manufacturer's recommendations to provide a high strength bond between elastomeric seal and mating metal surfaces. The elastomeric seals shall be clean and free of foreign materials. All exposed structural steel surfaces, except stainless steel or teflon coated, shall be painted in accordance with 619.

    The modular expansion joint assembly shall be prefabricated and preset by the manufacturer in accordance with the approved shop drawings, joint setting data and specifications. The assembly shall be properly secured for shipping and contain provision for final field adjustment at the time of installation. Final adjustment of the assembly shall be made at the direction of the Engineer. All movements due to factors such as shrinkage, creep and midslab deflection shall be properly accounted for prior to this final adjustment.

    The method of installation of the joint, including all items incidental to the installation, shall be in accordance with the recommendations of the manufacturer. In all cases, excess sealant shall be removed before it has set. The Contractor shall submit for approval the manufacturer's recommendations for the installation of the joint. This information shall be approved before installation begins.

MEASUREMENT AND PAYMENT

    The work will be measured in meters (linear feet) parallel to the plane of the finished joint surface and will be paid for at the contract unit price bid per meter (linear feet) for "Modular Expansion Joint", which payment shall include and be full compensation for all materials, labor, tools, equipment, and incidentals necessary to complete the item.