冲击回波法对混凝土内部损伤检测的试验研究

通过预加荷载给混凝土试件内部引入一定程度的损伤,分别测量了损伤前后试件内部弹性波的传播速度以及抗压强度,探讨了弹性波波速的降低程度与抗压强度劣化之间的关系。研究表明:在MEM卓越周期图中,主要峰值数量增加和底部边界面反射信号周期加长可作为判别损伤产生的依据;弹性波波速与混凝土内部的损伤程度具有很好的相关性,混凝土损伤程度越大,波速降低值越大;弹性波波速降低程度与抗压强度劣化之间具有线性相关性。根据试验数据拟合出了线性方程。说明采用冲击回波法对混凝土内部损伤程度检测是可行的,在混凝土结构的可靠性与安全性分析方面具有广阔的应用前景。

Experimental study on the detection of internal damage of concrete by impact-echo method

Through the preloading on the concrete specimen,the internal propagation velocity of elastic waves and the compressive strength between initial state and failure state can be measured,then the relationship between the reduction of elastic wave velocity and deterioration of compressive strength can be researched.The research shows that the increase of the number of main peaks and the extension of the reflection signal period of the bottom boundary surface can be used as the basis for the identification of damage in the MEM superior cycle diagram.Elastic wave velocity has a good correlation with the damage degree inside concrete,the greater the damage degree of concrete,the greater the reduction value of wave velocity.According to the experimental data between the linear correlation with the decrease of elastic wave velocity and the deterioration of compressive strength,a linear equation is fitted.It is possible to detect internal damage to the concrete in the impact echo,and the reliability and safety analysis of concrete structures has a broad application prospect.