Structural Behavior of Debonded Link-Slabs in Continuous Bridge Decks

Abstract

Link-slabs provide continuity in the deck of multispan structures supported by girders. Current practice recommends debonding the link-slab from the girder ends to reduce its stiffness. A simplified method developed based on an analytical study and test program from the late 1990s is available to design the link-slab as an RC beam member. A drawback to this method is that the required deck reinforcement tends to be excessive and, in the absence of more advanced analysis, it has been formally used. This study presents a new method for designing link-slabs based on the exact structural response exhibited by the girders and link-slab under vertical loading. A numerical solution that accurately idealizes the deformed shape of the link-slab and its interaction with the girders in the unbonded zone is developed. Data from the previous test program are then used to show applicability and accuracy of the new solution. Finally, recommendations for designing link-slabs supported by girders are proposed.