Study of the residual axial capacities of shear-damaged reinforced concrete columns: Part 1—development of an evaluation model

Abstract

This is the first of two companion papers addressing the residual axial capacities of shear-damaged reinforced concrete columns. To evaluate the residual axial capacity, this article presents an arch resistance model that is based on the theory of mechanics and can reasonably explain the collapse mechanism of shear-damaged reinforced concrete columns. In the proposed model, the residual axial capacity of the column is evaluated by considering the interaction between the contributions of the longitudinal bars and the concrete core rather than by simply adding the two contributions together. The proposed model is also verified using an experimental database of shear-damaged reinforced concrete column specimens compiled from previous studies. The result shows that the proposed arch resistance model has an improved level of accuracy for evaluating the residual axial capacities of most column specimens. However, because the available information about column specimens in the compiled experimental database is limited, it is difficult to further verify the proposed model, and a new experimental program will be presented in Part 2.

Study of the residual axial capacities of shear-damaged reinforced concrete columns: Part 2—experimental verification of an evaluation model

“…In part 1 (Yang et al, 2018) of the companion papers, it is confirmed that the proposed model can accurately evaluate the residual axial capacities of the columns with transverse reinforcements ratio of less than 5%; however, for the columns with transverse reinforcement ratios of greater than 5%, the proposed model overestimates the residual axial capacities. The reason is believed to be related to the assumption that transverse reinforcements within the shear-damaged region can fully develop their strength at axial collapse.…”

“…One is to obtain the experimental results of stress state of transverse reinforcements to investigate the applicable scope of the proposed model; the other is to obtain the experimental results of the axial forces carried by the longitudinal bars and concrete core to further verify the accuracy of the proposed model. Based on the experimental database in part 1 (Yang et al, 2018) of this study, the specimens are designed with different transverse reinforcement and axial load ratios.…”

“…To evaluate the residual axial capacities of shear-damaged RC columns, the authors also proposed the arch resistance model in part 1 (Yang et al, 2018) of the companion papers. In the proposed model, the interaction between the concrete core and longitudinal bars is considered for the first time.…”