||Development of Improved Connection Details for Adjacent Prestressed Member Bridges
Bernard L. Kassner
The objective of this project is to develop new, durable connection schemes for bridges constructed with adjacent precast box beams and adjacent voided slabs to counter deficiencies in present connection designs.
Adjacent prestressed systems are suitable for short structural spans, bridges with low clearance beneath, and accelerated bridge construction. They are economical, allow rapid construction, and provide high torsional stiffness.
However, often reflective cracks occur in the wearing surface or composite slab above the longitudinal joints between adjacent members. The issue of reflective cracks has been prevalent since the details for this type of bridge system were first implemented. Such cracks result from failure of shear keys along longitudinal joints, often in conjunction with shrinkage of deck concrete or connection filler material. This can cause relative movement and water leakage between girders, leading to maintenance and durability problems. Since these problems may ultimately compromise the structural integrity of the bridge, alternative connection designs are sought.