Effect of pre-cyclic damage and high temperature on residual tensile behavior of concrete

Abstract

In view of devastating outcomes of post-earthquake fires, it is imperative to propose a model for the fire-resistance capacity of a seismically-damaged concrete structure. For this purpose, the effects of cyclic damage and high temperature on residual tensile behavior of normal strength concrete are investigated in this paper. Monotonic tensile tests are performed on cylindrical concrete specimens which have been initially subjected to strain-controlled cyclic tensile load or have been exposed to high temperature. Residual mechanical behaviors are expressed in terms of cyclic damage or high temperature, respectively. Test results indicate that the residual tensile strength and stiffness decrease while residual peak strain and post-peak strain increase with the increase of damage and temperature. Finally, a modified stress-strain model is proposed to describe the residual tensile stress-strain relationship of concrete considering the effect of cyclic damage and high temperature. The modeling results fits well with the experimental curves.