Seismic behavior of novel precast concrete shear walls with UHPC in critical areas

초록

To enhance the seismic performance of precast concrete (PC) shear walls, integrating ultra-high performance concrete (UHPC) has emerged as a promising approach. In this study, three novel type of PC shear walls with partial use of UHPC were proposed to improve the seismic performance while satisfying economic feasibility. UHPC was partially applied to the boundary elements, X-shaped bracing, and two vertical columns in the PC wall panel. Three PC shear walls and a control shear wall cast in place were subjected to cyclic loading to evaluate the seismic performance. The crack development and failure modes, hysteretic behavior, deformation components, stiffness degradation, and energy dissipation capacity were analyzed and compared. Three novel PC shear walls exhibited superior seismic performance compared with cast-in-place shear wall. Compared with cast-in-place shear wall, the load-carrying capacity and ductility of three PC shear walls increased by 41.8-46.8 % and 27.9-66.5 %, respectively. The energy dissipation capacity of PC shear walls increased significantly, ranging from 81.8 to 201.2 %. Compared with PC shear wall using UHPC in the boundary element only, the PC shear wall with additional two vertical UHPC columns in the wall panel exhibited the greater load-carrying capacity, ductility, and energy dissipation capacity. The PC shear wall using additional X-shaped bracing exhibited the greatest initial and yield stiffness. Based on a strut-and-tie model, a design equation for shear strength of the proposed PC shear walls was derived. The predictions correlate well with the test results.

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