Seismic Behavior of High-Performance Fiber-Reinforced Cement Composites Beam-Column Connection with High Damage Tolerance

The purpose of this study is to investigate and evaluate the feasibility of using high-performance fiber-reinforced cement composites (HPFRCC) to satisfy the requirement of transverse reinforcement in beam-column joint under seismic loads. The basic mechanical properties of the HPFRCCs are determined by compression, uniaxial tension, and direct shear tests. Four half-scale exterior beam-column connections are cast and tested under cyclic loads. The cracking patterns, hysteresis behavior, ductility, energy dissipation with damping characteristics and joint shear capacity of the HPFRCC beam-column connections are analyzed, investigated, and compared to the cyclic responses of normal concrete connections designed with/without seismic criteria of ACI. The test results revealed that HPFRCC connections considerably enhances shear and flexural capacity and also improved the deformation and damage tolerance behavior in post-cracking stage comparing to normal concrete connections in ultimate stages. Also, the failure mode of HPFRCC specimens changed from shear mode to flexural mode comparing to the connections without seismic details. Severe damages are observed in normal concrete connection designed without considering seismic criteria. Wide diagonal cracking and damage are observed on the designed NC connections under large cyclic displacement at drift 6%. However, in HPFRCC connections, joint remained intact without any cracks and damage until the test end. This implies that the shear stress requirement can be satisfied without any need to the transverse reinforcement in the HPFRCC joint.