摘要
为了从细观角度了解不同强度等级,以及不同碳化龄期的混凝土的损伤演化特征,对强度等级分别为C20、C30、C40以及碳化龄期分别为0、28、56、77、90 d的混凝土棱柱体试件进行了单轴受压试验;并利用声发射(AE)技术对试验全过程进行了动态监测,获得了表征混凝土损伤演化过程的典型声发射事件累积计数(burst line cumulate,BLC)曲线;以及声发射事件数-相对应力水平关联曲线。结果显示:1 BLC曲线的三个部分分别反映出材料损伤演化过程的三个阶段,曲线的两个转折点分别对应混凝土材料内部的起裂点和失稳点;2在低应力时,不同强度等级以及不同碳化龄期的混凝土试件的声发射特征没有明显区别;随着应力的增加,高强度等级和碳化龄期长的混凝土试件的声发射事件数增长较快,并且声发射活性急剧增加点明显前移。
In order to understand the characteristics of the damage evolution of concrete,witch have different strength grade and different age of carbonation in the microscopic angle,concrete prism specimens which strength grade was C20 、C30 and C40,and carbonization time were 0,28,56,77,90 days respectively were tested under uniaxial compression,the whole process of destruction under uniaxial compression of the concrete prism was monitored dynamically by acoustic emission systems.The burst line cumulate which represent the concrete damage evolution and the curve of the number of acoustic emission events vs the stress level.Results shows：（①The three parts of the BLC curve reflects the three stages of material damage evolution,two turning points of the curve corresponds the cracking point and the instability point of the concrete; ②At low stresses,acoustic emission characteristics of the concrete prisms of various strength and various carbonization time has no significant difference,with the increase of stress,acoustic emission events of the concrete prisms of higher strength and longer carbonization time increase faster,furthermore,the dramatic increase in acoustic emission points clear forward.
出处
《科学技术与工程》
北大核心
2015年第1期279-284,共6页
Science Technology and Engineering
基金
2014年度广西高校科研项目(YB2014169)
广西自然科学基金项目(2011GXNSFA018031)资助
关键词
声发射
混凝土
损伤
碳化
累积计数曲线
acoustic emission （AE）
concrete
damage
carbonize
burst line cumulate （BLC）
