Experimental investigation of the seismic performance of precast post-tensioned segmental bridge piers with stainless energy-dissipating bars

The seismic performance of seven precast post-tensioned segmental (PPS) bridge piers is investigated by quasi-static tests in this work. Five piers are reinforced by stainless energy-dissipating bars. Two piers are reinforced by conventional carbon energy-dissipating bars as control specimens. Different reinforcement ratios of energy-dissipating bars are considered. The specimens are tested under different axial loads and prestressing levels. The experimental results are analysed in terms of hysteresis characteristics, damping (energy dissipation), re-sidual displacement, the opening width of the bottom joint and variation of prestressing tendons. With optically measured strain data based on digital image correlation (DIC) theory, the deformation components of the segmental bridge pier are calculated to evaluate the contribution ratios of deformation components to the total top displacement of the pier. It is found that the PPS piers with stainless reinforcement have the comparable seismic capacity, larger deformation capacity and smaller residual displacement compared to the control spec-imen. The top displacement of the column obtained by deformation component analysis is in agreement with the directly measured displacement. The bottom joint opening contributes the most of the total top displacement (about 70%).