水泥基保护层锈胀开裂阶段声发射信号特征  

Acoustic emission characteristics in stage of corrosion-induced cement-based cover cracking

作　　者：徐港[1] 张萌 张瑞[1] 王青[1] XU Gang;ZHANG Meng;ZHANG Rui;WANG Qing(College of Civil Engineering and Architecture,China Three Gorges University,Yichang 443002,Hubei China)

机构地区：[1]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《华中科技大学学报（自然科学版）》2021年第6期116-120,共5页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51379111);湖北省自然科学基金资助项目(2020CFB272)。

摘　　要：以水泥基材料锈胀开裂过程中释放的应力波为对象,对保护层胀裂阶段进行声发射信号特征提取.采用参数分析、小波分析、双谱分析对采集到的声发射信号进行处理.研究发现:累计计数曲线出现陡增的起点,可视为保护层出现锈胀裂缝的信号;在试件锈蚀期间双谱熵值(BIE)的减小可作为保护层开裂的前兆;非高斯性强度(NGI)中的两个极值点可分别作为保护层内裂和表面出现宏观裂缝的标志;采用声发射技术可以有效地监测到保护层锈胀开裂全过程.Taking the stress wave released during the corrosion-induced cracking process of cement-based materials as the object,the acoustic signal characteristics of the cover were extracted in stage of corrosion-induced cement-based cover cracking.Parameter analysis,wavelet analysis,and bispectrum analysis were used to process the collected acoustic emission signals.The study finds:the starting point of a sharp increase in the cumulative counting curve can be regarded as a signal of corrosion-induced cracking in the cover;the decrease of the bispectral entropy(BIE) during the corrosion of the specimen can be used as a precursor to the cracking of the cover;the two extreme points in the non-Gaussian intensity(NGI) can be used as signs of internal cracks in the cover and macro cracks on the surface;the whole process of corrosion-induced cracking of the cover can be effectively monitored by acoustic emission technology.

关 键 词：水泥基材料 锈胀开裂 声发射 保护层 耐久性 

分 类 号：TU375[建筑科学—结构工程]