Linking Innovation to Bridge Design and Maintenance
Maintaining bridge deck joints is a persistent and costly maintenance problem, and there is increasing pressure on bridge designers to minimize the number of joints on bridge decks to reduce maintenance and long-term rehabilitation costs. Water, often full of salt and other chemicals, leaking through the joints is a major cause of deterioration of bridge beams and their supporting structural elements.
One method that is gaining popularity in recent years is the use of concrete link slabs, which is a relatively thin reinforced concrete slab that typically connects simply supported deck spans. It is designed to flex due to girder deflections, and transmit compressive and tensile forces through the deck in conjunction with appropriately designed bearings.
Traditional bridge joints are inexpensive to build, but often break down and allow water to leak into and damage the elements below them requiring extensive, costly repairs. Link slabs will sometimes crack, but leakage is minimal, and repairs and maintenance are less expensive. They can be implemented through bridge rehabilitation or preservation activities, or as part of new construction. Link slabs also provide a smoother ride for drivers.
Link slabs have been used successfully in Michigan, West Virginia, New York, and Canada. This innovation was introduced in 2019 by the Design TAG, and an innovation development team has been assembled to further explore this innovation and its potential applications in Pennsylvania.