Axial behavior of precast segmental hollow bridge columns confined by grouted steel tubes

Abstract

To avoid the problems of the conventional precast segmental bridge columns (PSBCs) such as the concrete crushing at column ends, joint openings between segments, and torsional deformation under seismic attacks, a novel type of precast segmental bridge column confined by a grouted steel tube (TPSBC) was proposed, and herein the axial compressive behavior of the TPSBCs was investigated by testing of 14 specimens. The main parameters of the tested specimens included the diameter-thickness ratios of the steel tubes, the number of the precast segments, reinforcement arrangements in the precast hollow segments, initial prestress levels, sandwich concrete strengths, and loading forms. The effects of the parameters on the failure modes, loading bearing capacity, ductility, and steel strain development of the specimens were evaluated. The test results indicate that the proposed TPSBCs with proper configurations exhibited desirable compressive behavior with significantly improved load bearing capacity and deformability compared with the PSBCs. Based on the analysis of the confinement effects, analytical models were developed for predicting the axial bearing capacity of the TPSBCs under the different loading forms.