Seismic shear strength and deformation of RC columns failed in flexural shear

Abstract

This paper investigates the seismic shear strength and deformation capacity of flexural shear critical columns in the post-yield range of longitudinal reinforcement. In total, 24 reinforced concrete (RC) column specimens with span-to-depth ratios ranging from 1·63 to 6·16 and volumetric ratios of transverse reinforcement of 0·77% and 1·54% were tested under constant axial load ratios of 0·2 and 0·5 and cyclically reversed horizontal load. Of these 24 RC column specimens, seven failed in flexure, two failed in shear and 15 failed in flexural shear. Based on the test results, simple models are proposed to predict the shear strength and displacement capacity of columns failed in flexural shear mode. The proposed shear model includes the effects of span-to-depth ratio, axial load ratio, transverse reinforcement and displacement ductility. Analytical results from the proposed model were compared with test data and consistent agreement was achieved.