Abstract:
In order to combine the advantage of constructional performance in prefabricated structures and that of seismic performance in steel reinforced concrete structures, this paper presents two novel precast steel reinforced columns, namely the partially precast steel reinforced concrete (PPSRC) column and the hollow precast steel reinforced concrete (HPSRC) column. The PPSRC column consisted of a precast high-performance concrete outer part and a cast-in-place conventional concrete inner-part, and the HPSRC column keeped the column core hollow to further reduce the column deadweight. With the aim to investigate the seismic behavior of PPSRC and HPSRC short columns, quasi-static tests of ten short column specimens were conducted. The failure patterns, hysteretic loops, skeleton curves, stiffness degradation, deformability and energy dissipation of the test specimens were analyzed and the effects of the section shape, concrete strength of inner-part, axial compression and longitudinal and transverse reinforcement ratio on the cyclic behavior of PPSRC and HPSRC short columns, were then critically investigated. The test results indicated that the PPSRC and HPSRC short columns with lower longitudinal reinforcement ratios failed in flexural-shear mode and the rest specimens all suffered typical shear failure. Meanwhile, no obvious longitudinal bond cracks were found on the column specimens, indicating the precast high-performance concrete outer-part could work compatibly with steel shape and cast-in-place part. Due to the solid column core, the PPSRC columns exhibited more favorable deformability and energy dissipation capacity than the HPSRC columns. Better cyclic performance can be found in the specimens with lower axial compression, higher stirrup ratio or higher concrete strength of cast-in-place inner-part. Based on the test results and current design codes, formulas to calculate the shear capacity of PPSRC and HPSRC short columns were proposed, and the predicted shear strengths of the specimens agreed well with the test results.