Shear strength model of large-scale reinforced concrete rectangular columns with light transverse reinforcement

Abstract

Columns with low transverse reinforcement due to poor detail, small rebar size, and wide spacing were commonly used in old buildings. These types of columns often fail in shear with the brittle mode that could lead to a sudden collapse of the entire building. Thus, the accurate determination of the shear strength is significant for estimating the response of reinforced concrete (RC) columns under earthquake events. Numerous experiments were conducted to investigate the shear strength, however, there is a lack of tests on large-scale lightly RC columns under high axial compression load. Therefore, this study tested four large-scale RC columns with dimensions of 800 mm × 800 mm × 3200 mm. The paper highlights the main factors that influence the shear strength of the RC columns and based on the test results, an equation with high predictive power is established. In addition to the experimental results, the analytical/empirical models’ predictions from design codes or other researchers were evaluated. Furthermore, the interaction diagram between bending moment (M)—shear force (V)—axial compression force (N) was conducted to estimate the strength ability of RC columns. It was found that the simple processes to build the backbone curves and the hysteresis loops that were recommended had good agreement with the tested results and experimental database.