Case Studies Using Ultrahigh-Performance Concrete for Prestressed Girder Bridge Design

AbstractUltrahigh-performance concrete (UHPC) develops very high compressive strengths and exhibits improved tensile strength and durability properties that make UHPC a promising material for bridge applications. Through case studies on typical prestressed concrete girder bridges (simple and continuous), the potential impact of implementing UHPC in New Mexico was investigated. Two existing bridges with high-performance concrete girders were redesigned using UHPC with a compressive strength of 155.1 MPa (22,500 psi) and a modulus of rupture of 8.0 MPa (1,160 psi). The redesign used a modified load factor design procedure for the Service III flexure limit state and a modified load and resistance factor design procedure for the ultimate shear limit state that considered the compressive strength, modulus of rupture, and modulus of elasticity of UHPC. Additionally, 15- and 18-mm-diameter (0.6- and 0.7-in.) prestressing strands were investigated. The use of UHPC and 18-mm-diameter (0.7-in.) prestressing strands reduced the required volume of girder concrete by up to 40%. Additionally, the contribution of the steel fibers in the UHPC significantly reduced the required shear reinforcement.