Variables Affecting Cyclic Behavior of Reinforcing Steel

Abstract

A reasonable understanding of the cyclic behavior of reinforcing steel is required to accurately estimate the performance of reinforced concrete members subjected to cyclic deformations beyond the elastic range such as those expected from large earthquakes. Although the cyclic behavior of reinforcing steel has been extensively studied, very little is known about the effects that factors such as the bar deformations, strain rate, and strain aging have on the cyclic behavior. The effects of strain aging on the cyclic behavior of reinforcing steel can be very relevant when considering postearthquake retrofitting of reinforced concrete structures. A series of cyclic uniaxial tests were conducted at the University of Canterbury on the two commercially available grades of New Zealand reinforcing steel, where the effects of cyclic loading, bar deformations, strain rate, and strain aging on the stress‐strain behavior of reinforcing steel were investigated. The emphasis of the tests was to observe the material behavior, and hence buckling was restricted. The present paper describes the test setup and discusses the results of the investigation.