复相导电混凝土应用于损伤诊断的试验研究

Experimental studies of diphasic electric conduction concrete applying in the diagnosis of the damnification

为了研究含有纳米炭黑或碳纤维的导电混凝土梁受荷过程中电阻变化规律与混凝土损伤之间的关系,通过比拟与试验数据回归分析方法,先建立混凝土梁电阻变化率与梁几何中性轴处应变的曲线关系,再结合损伤力学理论,建立损伤度与电阻变化率的函数关系,为导电混凝土材料或构件自身电阻诊断其内部损伤提供了新途径。研究表明:开裂前,混凝土梁的电阻变化率与梁几何中性轴处应变的关系用一次衰减指数函数方程拟合较好,通过拟合曲线的斜率可以直接反映出导电混凝土用于检测损伤的灵敏度,从而间接反映出混凝土损伤的程度。

In order to study the relationship between concrete damage and the electric resistance change of electric conductive concrete,concrete beams containing nano-meter carbon black or carbon fiber subjected to loading were investigated.The relationship between the resistance change rate of concrete beams and the strain of geometrical neutral axis was established using an analogy method and a experimental data regression.Based on the damaging mechanics theory and the relationship above,the expression between degree of damnification and the rate of resistance change was set up.This self-diagnosis of conductive concrete material provides a new way for the measurement of the internal damage.The results show that the relationship between the rate of resistance change of concrete beams and the strain of the geometrical neutral axis can be well fitted by the exponential decay first order curve before cracking.The sensitivity of the electric conduction concretes can be reflected directly by the slope of the fitted curve,and the degree of concrete damage can be also indirectly responded.