Seismic performance of fiber-reinforced concrete interior beam-column joints

Abstract

Fiber-reinforced concrete (FRC), as an advanced alternative to normal concrete, has been increasingly used to construct beam-column joints which is one of the most congested parts of reinforcements in reinforced concrete (RC) structures because of its potentially beneficial properties. The present work aims to investigate the seismic performance of FRC beam-column joints experimentally and numerically. A total of eight beam-column joints, including both FRC beam-column joints and RC beam-column joint, were conducted to explore its seismically important features under quasi-static reversed cyclic load, mainly including the failure modes, hysteretic response, energy dissipation, stiffness degradation. It was found that the application of FRC can effectively improve the seismic performance of beam-column joints because it leads to higher load-carrying capacity and a greater deformation capability prior to the formation of the major diagonal cracks in the joint core zone. A numerical study, using the Open System for Earthquake Engineering Simulation (OpenSEES), was also conducted to study the seismic performance of beam-column joints deeply after its applicability and accuracy being validated with test data. The prediction from the proposed numerical model shows a good agreement with test data. Furthermore, a parametric study was generated to address and evaluate the effects on the seismic performance of FRC beam-column joints from different parameters, including the axial load ratios, transverse reinforcement ratios and FRC compressive strength. The results indicate that the increment of axial load ratios and FRC compressive strength can enhance the load-carrying capacity.