Transition Slabs of Integral Abutment Bridges

Over the past decades, an increasing number of bridges with integral abutment have been built in Switzerland. This type of bridge offers various advantages over standard bridges with abutments, equipped with expansion joints and bearings that require regular inspection and maintenance. One main concern of integral abutment bridges is related to the soil-structure interaction, in particular between the transition slab and the embankment. To avoid any expansion joints, transition slabs are directly connected to the end of integral abutment bridges. They are therefore subjected to large displacements of the bridge deck due to temperature effects and to creep and shrinkage for concrete bridges. Consequently, detailing of transition slabs needs to be carefully considered. This paper investigates the behaviour of transition slabs focusing on the settlement of the pavement at the end of the transition slab and on the cracking of the pavement between bridge deck and transition slab. On that basis, a modified geometry of the transition slab and a new detail for the connection between the bridge deck and the transition slab are proposed. If these propositions are considered at an early stage in the design process, they result in an improved long term performance of bridges with integral abutments without increasing the construction costs.