Evaluation of bridges implementing innovative materials and design.

摘要

Concrete bridge decks exposed to harsh temperatures and a variety of deicing chemicals are suspect to deterioration caused by corrosion of the steel reinforcement. By removing the steel reinforcement within the concrete slab, the life expectancy and durability of the bridge deck can be expected to improve greatly [1]. Researchers at the Bridge Engineering Center at Iowa State University have researched, designed, and tested the first known bridge in the United States that has implemented a steel-free deck (SFD) system. The bridge deck consists of a fiber reinforced deck with no internal reinforcing steel that is composite with the steel superstructure. Transverse steel straps below the slab are attached to the supporting girders to prevent outward lateral displacement and to develop internal arching action within the concrete. This paper describes the design and construction of the SFD bridge, and then presents the results of live load field tests conducted on the completed bridge.;Researchers at the Bridge Engineering Center at Iowa State University have researched, designed, and tested the first known bridge in the United States that has implemented a recently developed material called Ultra-High Performance Concrete (UHPC). UHPC has been shown to have superior material characteristics with compressive strengths up to 30,000 psi and tensile strengths up to 1,700 psi, lending itself to be a desirable construction material. In the fall of 2005, the 110 ft single-span prestressed UHPC girder bridge was constructed in Wapello County, Iowa. This paper describes the design and construction of the UHPC bridge and then presents the results of two live load field tests conducted on the completed bridge to evaluate the structural performance.