Analytical method for the behaviour of a reinforced concrete flexural member at elevated temperatures

Abstract

SUMMARYAn analytical method is proposed for the thermal behaviour of a reinforced concrete flexural member subjected to fire. The analysis procedure can be subdivided into two different steps; sectional analysis and member solution. A segmentation scheme is employed in the analysis for a section. It implicates uniform sectional properties and temperature distribution through the longitudinal axis of the member. The mechanical changes at the segmented section such as strain changes and corresponding stresses due to temperature increase are integrated into the member behaviour at the member solution step. According to the analysis results, there exist very severe nonlinear strain changes with the depth measured from the fireexposed surface, which are caused by a nonlinear temperature distribution at the section. Self-equilibrating stresses are manifested during heating just to let the section remain plane after deformation.