摘要 为研究高温喷水冷却后圆钢管再生混凝土的轴压性能及剩余承载力评估方法,以再生粗骨料取代率、历经最高温度和冷却方式为变化参数,设计了27个圆钢管再生混凝土试件,对其进行高温喷水冷却后单调轴心受压加载试验,观察了试件的受力全过程和破坏形态,获取其应力-应变曲线并分析了不同变化参数对峰值应力、峰值应变、轴压位移延性以及耗能的影响,结合试件的刚度退化曲线分析其性能退化过程,并参考各规程对高温喷水冷却后试件的剩余承载力进行计算。研究结果表明:高温喷水冷却后,随着历经最高温度的升高,试件的峰值应力显著降低,峰值应变却逐渐增大,轴压位移延性和耗能均呈先增大后减小的变化趋势;随再生骨料取代率的增大,试件的峰值应力、峰值应变变化不大,轴压位移延性先减小后增大,耗能逐渐减小;与自然冷却相比,温度较高时喷水冷却试件的峰值应力、峰值应变、轴压位移延性及耗能均较大。另外,历经最高温度的升高会使喷水冷却试件的刚度退化速率减缓,而不同再生粗骨料取代率试件的刚度退化速率较为接近,且与自然冷却试件相比,喷水冷却试件的刚度退化速率更快。经过理论分析,建议采用日本AIJ规程的计算方法,并引进高温后钢管和混凝土的系数折减,对高温喷水冷却后圆钢管再生混凝土的剩余承载力进行评估。 In order to study the axial compression performance and residual bearing capacity evaluation method of recycled concrete filled circular steel tube(RCFCST)after elevated to high temperatures and water cooling,27 RCFCST short columns were designed for axial compression test,with the variable parameters of recycled coarse aggregate replacement percentage,temperature and cooling method considered.By the experiment,the whole mechanical process and failure mode of all specimens were observed,and stress-strain curves of specimens were obtained,and the influence of different variation parameters on peak stress,peak strain and axial displacement ductility and energy dissipation were analyzed.The performance degradation process was analyzed by combining the rigidity degradation curves of the specimen.And referring to each regulation,the residual bearing capacity of the specimen after exposure to high temperatures and water coolingwas calculated.The results indicate that with the increase of the maximum temperature,the peak stress of the specimen subjected to high temperatures and water cooling decreases significantly,but the peak strain increases gradually,and the ductility and energy dissipation are the trend of increasing first and then decreasing.With the increase of the replacement percentage of recycled aggregate,the peak stress and strain of the specimen change little,the axial displacement ductility decreases first and then increases,and the energy dissipation decreases gradually.When the temperature is higher,the peak stress,strain,ductility and energy dissipation of specimens subjected to water cooling are larger than those of natural cooling specimens.In addition,the rigidity degradation rate of water cooling specimens will slow down with the increase of the highest temperature,while the rigidity degradation rate of specimens with different replacement percentage is close,and the rigidity degradation rate of water cooling specimens is faster than that of natural cooling specimens.After theoretical analysis,it is
出处 《材料导报》 EI CAS CSCD 北大核心 2021年第7期7033-7041,共9页 Materials Reports
基金 国家自然科学基金项目(51578163) 八桂学者专项经费资助项目([2019]79号) 广西重点研发计划项目(桂科AB17292083)。
关键词 喷水冷却 圆钢管再生混凝土 轴压性能试验 剩余承载力评估 water cooling recycled concrete filled circle steel tube axial compression performance test residual bearing capacity assessment
