Seismic performance of shear-dominated concrete walls with carbon fiber-reinforced polymer (CFRP) rebar as internal reinforcement

초록

This paper investigates seismic performance of shear-dominated concrete walls with carbon fiber-reinforced polymer (CFRP) bars compared to concrete walls with conventional steel bars. Three concrete walls with an aspect ratio of 1.0 were tested to failure under cyclic lateral loading in double-curvature. The reference specimen (SSW) was fully reinforced with conventional steel bar. The other two specimens (CSW and CCW) used CFRP bars for vertical reinforcement, while conventional steel and CFRP bars were used for horizontal reinforcement, respectively. Experimental findings indicate that failure mode of all the specimens was governed by shear behavior. CCW exhibited lower initial stiffness compared to SSW. However, for SSW, as drift ratio increased and steel reinforcement yielded, its stiffness decreased, whereas elastic properties of the CFRP bar in CCW reduced stiffness difference between SSW and CCW and promoted linear behavior in CCW up to failure. CCW and CSW exhibited strength and ductility comparable to SSW. Both specimens demonstrated better self-centering performance in comparison to SSW. This self-centering capability is an advantage that helps mitigate excessive residual cracks and displacement that can lead to high repair costs after earthquakes.

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