含水缺陷混凝土受压破坏红外辐射与声发射特征试验研究  

Experimental study on infrared radiation and AE characteristics of concrete with water-containing defects under compression

作　　者：郑艾辰 何兆益[1] 黄锋[1,2] 周洋 杨康[1] ZHENG Aichen;HE Zhaoyi;HUANG Feng;ZHOU Yang;YANG Kang(School of Civil Engineering,Chongqing Jiaotong University,Chongqing,400074,China;State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing,400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学省部共建山区桥梁及隧道工程国家重点实验室,重庆400074

出　　处：《混凝土》2021年第11期1-5,共5页Concrete

基　　金：国家重点研发计划(2018YFB1600200);重庆市研究生科研创新项目(CYB20177);国家自然科学基金面上项目(52078090)。

摘　　要：研究含水缺陷对混凝土受压破坏过程中红外辐射特征影响及声发射特征影响,以期为类似隧道衬砌结构含水缺陷裂损状态的监测提供理论依据.预制不同形状及尺寸的含水缺陷混凝土试件并开展无侧限单轴压缩试验,期间进行声发射-红外摄像联合监测分析.结果表明:(1)与无缺陷试件相比,含水缺陷混凝土试件抗压强度明显降低,同一形状下,峰值强度随空洞体积的增加而降低,峰值应变随空洞体积增加而增大.(2)变形破坏过程中应力、红外辐射特征和声发射特征具有较好的对应关系,根据混凝土的损伤状态红外辐射特征和声发射特征可大致分为三个阶段.(3)无缺陷混凝土声发射能量较大值在应力峰值附近持续时间较含缺陷试件更长,且含水缺陷体积越大,能量幅值衰减越明显,声发射事件衰减规律可作为含水缺陷开裂源定位的重要依据。Study the influence of water-containing defects on the infrared radiation characteristics and acoustic emission characteristics in the process of concrete compression failure,in order to provide a theoretical basis for monitoring the cracking state of water-containing defects in similar tunnel lining structures.Prefabricated concrete specimens of different shapes and sizes with water-containing defects and carried out unconfined uniaxial compression tests,during which joint monitoring and analysis of acoustic emission and infrared cameras were carried out.The test results show that(1)Compared with non-defect specimens,the compressive strength of concrete specimens with water-containing defects is significantly reduced.Under the same shape,the peak strength decreases with the increase of the cavity volume,and the peak strain increases with the increase of the cavity volume.(2)In the process of deformation and failure,the stress,infrared radiation characteristics and acoustic emission characteristics have a good corresponding relationship.According to the damage state of concrete,the infrared radiation characteristics and acoustic emission characteristics can be roughly divided into three stages.(3)The larger value of acoustic emission energy of non-defective concrete lasts longer near the stress peak than the specimen containing defects,and the larger the volume of water-containing defects,the more obvious the energy amplitude attenuation.The attenuation law of acoustic emission events can be used as an important basis for the location of cracking sources of water-bearing defects.

关 键 词：含水缺陷 混凝土 红外热成像 声发射 单轴压缩 

分 类 号：TU528.01[建筑科学—建筑技术科学]