High Performance Precast, Pretensioned Concrete Girder Bridges in Washington State

Abstract

The current use of high performance concrete (HPC) in the fabrication of prestressed concrete girders has resulted in improved economy through the use of longer spans, increased girder spacing, and shallower superstructures. HPC also improves durability and resistance to cracking, while decreasing permeability and the effects of volume change due to shrinkage and creep. The design of high performance precast, pretensioned concrete girders has presented several new challenges, including difficulties in the fabrication, shipment, and erection of long, slender girders. This paper presents a parametric study that has been performed by the Washington State Department of Transportation (WSDOT) to demonstrate the effectiveness of HPC in the design of standard pretensioned concrete girders. The results clearly indicate that the use of HPC, along with large diameter strand, increases the span capability of pretensioned concrete girders and, alternatively, can result in fewer girder lines or smaller, less expensive girders. A survey of WSDOT's precast girder design practice is also presented.