自愈合混凝土损伤演化声发射监测及其评价技术  

Damage evolution monitoring and evaluation of self-repairing concrete using acoustic emission technique

作　　者：李冬生[1] 匡亚川[2] 胡倩[1] 

机构地区：[1]大连理工大学土木工程学院,辽宁大连116024 [2]中南大学土木工程学院,湖南长沙410083

出　　处：《大连理工大学学报》2012年第5期701-706,共6页Journal of Dalian University of Technology

基　　金：国家自然科学基金资助项目(50808030);教育部博士点新教师基金资助项目(200801411102)

摘　　要：自愈合混凝土能较大程度地提高混凝土的极限承载力.针对自愈合混凝土损伤缺乏有效研究手段的现状,提出用声发射技术来监测它的损伤演化.通过自愈合混凝土梁三点弯曲试验,对它的损伤全过程进行了声发射监测.通过声发射计数能够准确地判断自愈合混凝土裂纹的开裂、扩展及其损伤演化过程,它的包络曲线和荷载曲线具有良好的对应关系.运用凯塞(Kaiser)效应和费利西蒂(Felicity)比能正确判断愈合的优劣情况.最后,对自愈合混凝土损伤演化的各个阶段声发射波形进行小波分析,通过小波奇异检测技术提取出各自的特征波形,并分析其频率分布范围,进一步分析了损伤的内在成因,为自愈合混凝土损伤类型提供了一种新的判据和测试方法.The concrete ultimate load capacity is improved through self-repairing. Because there is a dearth of studies regarding damage evolution of self-repairing concrete, acoustic emission （AE） technology is presented to monitor its evolution process. The full-process damage of self-repairing concrete is monitored under three-point bending beam testing using AE technique. It is found that the initiation, propagation and evolution of self-repairing concrete cracks can be described using AE hits. Firstly, the corresponding relationship between the AE hits and load is testified by comparing with their embraceable curve. Secondly, the repairing effect of self-repairing concrete is judged using Kaiser effect and Felicity ratio. Finally, the different damage types of AE waveforms of self-repairing concrete are extracted and analyzed using wavelet singularity theory. The damage causes are analyzed according to the waveform frequency distribution. The testing results show the AE technique can provide a new testing method for self-repairing concrete damage judgment.

关 键 词：自愈合混凝土 声发射 小波分析 损伤演化 安全评定 

分 类 号：TU528.07[建筑科学—建筑技术科学]