Tensile High Strain-Rate Behavior of Reinforcing Steel from an Existing Bridge

Abstract

Events such accidental or deliberate explosions need to be considered in load design, but this can be difficult due to the uncertainty related to load definition for blast actions. This paper highlights a dynamic characterization that was carried out on reinforcing steel belonging to an existing structure. The steel was from the Tenza Bridge, a reinforced concrete arch bridge in southern Italy. The behavior of both concrete and reinforcing steel under dynamic loading rates at high strain-rate levels was investigated. Tensile failure tests were performed on steel specimens at different strain rates using a modified Hopkinson bar device. Data from the tests were processed to obtain stress-strain relationships under different strain-rate conditions, and the results were compared with existing formulations, providing the dynamic increase factor of yield and ultimate stresses for reinforcing steel. Finding show that the reinforcing steel was strain-rate sensitive in terms of yield stress, ultimate stress and ultimate strain. As the strain rate increased, yield stress increased more than ultimate stress.