部分预制装配型钢混凝土短柱抗震性能试验研究

RESEARCH ON SEISMIC PERFORMANCE OF PARTIALLY PRECAST STEEL REINFORCED CONCRETE SHORT COLUMNS

  • 摘要: 为了充分发挥预制装配结构在施工性能及型钢混凝土结构在抗震性能方面的优势,提出了部分预制装配型钢混凝土柱(PPSRC柱)及预制装配型钢混凝土空心柱(HPSRC柱)。PPSRC柱由高性能混凝土预制部分与普通强度混凝土现浇部分组成;为进一步减轻柱自重,HPSRC柱保持柱横截面空心。结合2个系列10个试件的拟静力试验,对PPSRC短柱与HPSRC短柱的抗震性能进行了研究。通过对试件的破坏形态、滞回曲线、骨架曲线、刚度退化、变形及耗能能力的研究,对柱截面形式、现浇混凝土强度、轴压力、配筋率及配箍率对PPSRC短柱和HPSRC短柱滞回性能的影响进行了分析。研究结果表明:配筋率较低的PPSRC短柱与HPSRC短柱的最终破坏形态为弯剪破坏,其余配筋率较高的试件均发生剪切破坏;所提出的预制高性能混凝土外壳、型钢及现浇混凝土能较好地协同工作,试件柱身未发现明显的纵向黏结裂缝;由于柱芯混凝土的存在,PPSRC短柱比HPSRC短柱表现出更好的耗能及变形能力;轴压力较低、配箍率较大、现浇混凝土强度较高的试件表现出更好的耗能及变形能力。基于试验结果和现行规范,提出了PPSRC短柱与HPSRC短柱的受剪承载力计算式,其计算值与试验值吻合较好。

     

    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.

     

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