高温作用后钢筋混凝土短柱轴压力学性能试验研究  

Experimental study on axial mechanical behavior of reinforced concrete stub columns with pre-load after exposure to high temperatures

作　　者：张家广[1,3] 霍静思[1,4] 肖岩[1,2] 

机构地区：[1]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082 [2]南加州大学,加利福尼亚洛杉矶CA90089 [3]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090 [4]华南理工大学亚热带建筑科学国家重点实验室,广东广州510640

出　　处：《建筑结构学报》2011年第4期117-124,共8页Journal of Building Structures

基　　金：长江学者和创新团队发展计划教育部创新团队(IRT0619);国家自然科学基金项目(50778069);亚热带建筑科学国家重点实验室开放基金(2009KB23)

摘　　要：采用高温抗压试验炉对有初始荷载作用的钢筋混凝土短柱进行了升温、降温及冷却全过程作用后轴压力学性能试验。试验测试了截面温度场、轴向变形发展规律,考察了温度、轴压比和降温效应对高温后有初始荷载作用的钢筋混凝土短柱轴压承载力、刚度和延性等力学指标的影响规律。试验结果表明:初始荷载作用使试件产生明显的残余压缩变形,且残余变形主要是在降温阶段产生;与无初始荷载作用的试件相比,初始荷载作用对钢筋混凝土短柱的高温后轴压承载力、刚度和延性影响较大,承载力和刚度提高,但延性明显降低;初始荷载作用对试件高温后轴压短柱刚度和延性系数的影响明显大于对承载力的影响。建议进行火灾后钢筋混凝土结构性能评估时,需考虑初始荷载作用的影响。The reinforced concrete（RC） stub columns with sustained pre-load were heated and cooled using a specially-built electrical furnace.The temperature fields of the cross-sections and axial deformations of the columns were measured.After the entire period of high temperature tests,the axially mechanical behavior of the fire-damaged RC stub columns were experimentally studied.The effects of high temperature,axial load level and cooling phase on the compressive carrying capacity,axial stiffness and ductility of RC stub columns were discussed.The test results show that specimens with sustained pre-load after exposure to high temperature remarkable suffer residual deformations,which are accumulated during the cooling phase.The sustained axial load has significant effects on the compressive carrying capacity,axial stiffness and ductility of RC stub columns.The carrying capacity and axial stiffness are found to be improved and the post-fire ductility is found to be deteriorated.However,the sustained axial load has more significant effects on axial stiffness and ductility than carrying capacity.It is recommended that the effect of pre-load should be taken into consideration in assessing the behavior of fire-damaged RC structures.

关 键 词：钢筋混凝土短柱 高温全过程 初始荷载 轴压 高温试验 力学性能 

分 类 号：TU375.3[建筑科学—结构工程] TU317.1