Bridges

Modular bridge expansion joints (MBEJs) are utilised when the movement range at a bridge expansion gap exceeds around 300 mm, with the largest MBEJ installed to date accommodating a movement range in excess of 2100 mm. Traditionally MBEJs have been specified on a performance basis, with the detailed design of the MBEJ being undertaken by the successful supplier. Some MBEJs have given problems in-service, related to both design and construction deficiencies.

In Australia the RTA carried out research into the behaviour of MBEJs on a number of their bridges, and published RTA QA Specification B316 which sets out the requirements for the design, fabrication, testing, supply, and installation of MBEJs. This specification enables bridge authorities in Australia to specify MBEJs to an appropriate level of detail, and avoid the high-level performance specification that has given rise to some inservice problems in the past.

This paper will make some observations from the design of new MBEJs recently installed in Australia, and the refurbishment of existing MBEJs, with particular reference to RTA Specification B316 and to the current state of knowledge with regard to this type of expansion joint.