Seismic behavior of reinforced concrete sacrificial exterior shear keys of highway bridges

Shear keys as sacrificial members are widely used in cap beams and abutments of highway bridges, to limit the transverse displacement of superstructures and control damage to substructures. An experimental program to study the seismic behavior of reinforced concrete (RC) sacrificial exterior shear keys was presented. The influence of reinforcement ratios and construction joint types on the mechanical behavior of the shear keys was investigated, and three failure modes of the exterior shear keys under reversed loads were observed during testing. Two analytical models for predicting the force-displacement backbone curves of the exterior shear keys with sliding shear failure and sliding friction failure were developed, respectively. The analytical models proposed in this paper were in good agreement with the experimental data, indicating that they can be used as a reliable tool for predicting the response of exterior shear keys of highway bridges.