A study of reinforced concrete corner columns after fire

Abstract

This study investigated the behavior of corner columns under axial loading, biaxial bending and asymmetric fire loading. It is found that, under a longitudinal stress ratio of 0.1f'(c), the residual strength ratios of the columns after fire loading show: (a) the 2 and 4 h fire loadings result in residual strength ratios of 67% and 57%, respectively; a 10% reduction on residual strength results as the duration changes from 2 to 4 h; (b) reductions in reinforcing steel ratio cause lower residual strength ratios; and (c) increasing the thickness of concrete cover causes lower residual strength ratios. It was also found that the temperature distribution across the cross-section is not affected by concrete cover thickness and steel ratio. The residual strengths can be used for future evaluation, repair and strengthening. (C) 2007 Elsevier Ltd. All rights reserved.