Simulating the response of CFRP strengthened shear-keys in composite concrete bridges

摘要

The reduction in the integral action between cast-in-situ slab and precast prestressed concrete girders in composite concrete bridges can be attributed to the increase in truck loads; increase in the allowable stress at service loads; exposure to aggressive environments; and the increase in traffic flow. It is a necessity to restore this integral action by strengthening against horizontal shear. In this paper, a finite element analysis (FEA) was performed considering 32 push off specimens using ANSYS software package to evaluate the behavior of shear-keys of composite concrete bridges. The studied parameters include: the concrete compressive strength, spacing of the shear stirrups, the carbon fiber reinforce polymer (CFRP) sheet spacing, and CFRP plate spacing, fiber angle, and anchorage length. The FEA results show that the reduced crack opening and slip in the strengthened shear-keys compared with the control specimen reflect the efficiency of the CFRP strengthening scheme. Moreover, the FEA results indicate that the CFRP composites anchorage length and angle had a notable impact on the longitudinal shear force and corresponding slip, failure mode, stiffness, and toughness. Finally, an empirical model was proposed for predicting the bond-slip behavior of shear-keys based on reliable experimental results available in literature.