高温下混凝土SHPB动态力学性能试验研究  

IMPACT TESTS ON DYNAMIC BEHAVIOR OF CONCRETE AT ELEVATED TEMPERATURES

作　　者：何远明[1] 霍静思[1] 陈柏生[1] 黄政宇[1] 

机构地区：[1]湖南大学建筑安全与节能教育部重点实验室,长沙410082

出　　处：《工程力学》2012年第9期200-208,共9页Engineering Mechanics

基　　金：国家自然科学基金项目(50778069;50678065);教育部长江学者和创新团队发展计划创新团队项目(IRT0619)

摘　　要：采用霍普金森压杆（Split Hopkinson pressure bar，SHPB）试验装置和高温炉进行了高温下普通混凝土的抗冲击性能试验研究，通过比较实测动态强度和应力．应变曲线，揭示了温度和应变率对高温下混凝土动态力学性能的影响规律。试验结果表明：除200℃～300℃范围外，高温下混凝土具有显著的应变率效应，且温度越高动态应变率效应越显著；温度和应变率对混凝土归一化应力．应变关系曲线上升段的形状影响很小，可采用统一的函数形式。200℃～300℃低温区混凝土不仅无明显动态效应，且存在静力强度衰减现象，此特性需引起注意并有待进一步研究。A Split Hopkinson pressure bar （SHPB） and a purpose-developed electrical furnace were used to experimentally study the dynamic behaviors of normal concrete at elevated temperatures. The dynamic strength and stress-strain relation curves of concrete at elevated temperatures were measured to discover the effects of high temperature and the strain rate on the dynamic behavior of concrete at elevated temperature. Test results show that concrete at elevated temperature except the temperature range from 200℃ to 300℃ experienced a remarkable strain rate effect, the higher the temperature was and the greater the strain rate effect was. There are no obvious effects of temperature and the strain rate on the shape of ascending branch of normalized stress-strain relation curves of concrete at elevated temperatures. Thus a uniform formula can be used to express the ascending branch of normalized stress-strain relation curves. Much attention should be paid not only to the mechanical property of no significant strain-rate effect of concrete at the lower temperature range from 200℃ to 300℃, but also to the strength degradation under static loading at such a temperature range. Additionally, further research on the dynamic behavior of concrete at elevated temperature is necessary.

关 键 词：混凝土 SHPB 高温下 动力性能 抗冲击性能 

分 类 号：TU528.1[建筑科学—建筑技术科学]