Experimental Study on Seismic Behavior of High-Performance Fiber-Reinforced Cement Composite Coupling Beams

摘要

Current design provisions in the ACI Building Code for reinforced concrete (RC) coupling beams in earthquake-resistant structures require substantial reinforcement detailing to ensure a stable seismic behavior, leading to reinforcement congestion and construction difficulties. As a design alternative, the use of high-performance fiber-reinforced cementitious composites (HPFRCCs) in coupling beams with a simplified reinforcement detailing was experimentally investigated. To validate this alternative, four coupling beam specimens were tested, including an RC control specimen detailed as per the 1999 ACI Building Code. A precast construction process was proposed for the HPFRCC coupling beams in this study. This construction alternative would lead to significant savings in time and workmanship at the job site, and provide good material quality control. Results from large-scale tests demonstrated the superior damage tolerance and stiffness retention capacity of HPFRCC coupling beams. It was also observed that diagonal reinforcement is necessary to achieve large displacement capacity. However, the transverse reinforcement around the diagonal bars was successfully eliminated due to the confinement provided by the HPFRCC material.