Cost-Efficient and Innovative Design for Bridge Approach Slab

Concrete bridge approach slabs (BASs) are used at the interface between bridge abutments and pavements that rest on compacted embankment. The objective of the research presented here was to develop optimal-cost BAS designs for new and replacement slabs. Two solutions presented here included (a) cast-in-place (CIP) design for new construction and (b) novel, precast, prestressed (PCPS) slab designs for new construction and replacement of BASs. The practices of state departments of transportation (DOTs) with respect to BASs were evaluated and compared with those of the Missouri DOT. On the basis of the practices, a 20-ft span was chosen and finite element models were analyzed to consider different slab lengths, thicknesses, and loss of support conditions to calculate maximum moments, deflections, and end slopes. On the basis of predicted values, CIP and PCPS design alternatives were recommended. Recommended alternatives were estimated to have a lower cost and a performance equal to or better than the current Missouri DOT designs. A new study has been initiated in which the recommended BAS designs are to be implemented in the field.