混凝土动态破坏过程超声波测试研究

混凝土在荷载作用下会产生损伤或破坏,用超声波的方法可测量损伤或破坏的程度。但在荷载作用下混凝土的破坏是一个动态过程,由于测试面发生变形,使常规超声波测试无法完成。本文研制了一个混凝土材料破坏过程超声波测试辅助装置,结合原有的非金属材料超声波检测仪,使测试混凝土材料动态破坏过程成为可能。同时通过辅助装置还可消除试件在破坏过程中由于变形带来的测试误差,可方便、快捷、准确地测试混凝土在荷载作用下的动态破坏过程。采用常规混凝土和冻融混凝土为试件,在材料万能试验机上进行了破坏实验,得到了不同荷载作用下超声波的波速。实验结果表明,混凝土的超声波波速随混凝土的破坏程度不断增大而减小,由此表示可采用超声波测试的方法确定混凝土的动态破坏过程。

Study of Concrete Dynamic Failure Process Based on Supersonic Detection

Damage or failure of concrete under loading can be detected by supersonic method. The conventional supersonic detection of concrete is impossible to be accomplished due to the dynamic failure process which results in the deformation of tested surface. An auxiliary testing equipment of supersonic detection developed by authors, together with previous nonmetal material supersonic detector was applied to carry out detection of concrete dynamic failure process. Meanwhile the auxiliary equipment may eliminate the measurement error due to specimen deformation, and provide a convenient, quick and accurate measurement of concrete dynamic failure process under loading. Conventional and freeze-thawed concrete specimens were detected by a universal test machine. The relationship between supersonic velocity and loading was obtained. Experimental results show that the descent of supersonic velocity accelerates along with the concrete damage increase, which indicates that supersonic detection is applicable to estimate concrete dynamic failure process.