Experimental investigations on reinforced concrete shear walls strengthened with basalt fiber-reinforced polymers under cyclic load

Abstract

Reinforced concrete (RC) shear walls are common lateral load resisting systems used in many RC structures. In the seismic region, the effectiveness of fiber-reinforced polymer (FRP) externally bonded reinforcement is today widely recognized with respect to enhancing the behavior of RC shear walls, particularly of those not satisfying the requirements of modern seismic codes. Although a number of studies have been concentrated on the RC shear walls strengthened with FRP, the investigations on the RC shear walls strengthened with basalt FRP (BFRP) are relatively limited compared with RC shear walls strengthened with carbon FRP or glass FRP. Six RC shear wall specimens with an aspect ratio of 1.6, characterized as medium-rise, were subjected to cyclic load to investigate failure modes, displacement ductility ratio, stiffness characteristic, energy dissipation capacity, and load carrying capacity. One of them was tested without any strengthening as a reference specimen and the other five specimens were strengthened using BFRP strips with different configurations. The theoretical load carrying capacity was also calculated and compared with the test results. The test and theoretical results show that: (1) use of BFRP strips significantly improved the seismic performance of RC shear wall under cyclic load; (2) the final secant stiffness of specimens SHW1-SHW5 increased by 55.2%, 10.3%, 13.8%, 17.2%, and 37.9% compared with that of reference specimen SHW0; (3) the final cumulative dissipated energies of specimens SHW1-SHW5 increased by 37.5%, 175.3%, 134.2%, 153.7%, and 95.2% compared with that of reference specimen SHW0; (4) the calculated load carrying capacity of the RC shear walls based on the Li’s method showed a good agreement with the test results.