APPLICATION OF SURFACE WAVE TRANSMISSION MEASUREMENTS FOR CRACK DEPTH DETERMINATION IN CONCRETE
APPLICATION OF SURFACE WAVE TRANSMISSION MEASUREMENTS FOR CRACK DEPTH DETERMINATION IN CONCRETE
复制标题
DOI：
10.14359/815
复制
发表时间：
2000-03
影响因子：
1.7
通讯作者：
J. Popovics;W. Song;M. Ghandehari;K. Subramaniam;J. Achenbach;Surendra P. Shah
中科院分区：
文献类型：
--
作者：
J. Popovics;W. Song;M. Ghandehari;K. Subramaniam;J. Achenbach;Surendra P. Shah
在早期的研究中已经确定，在混凝土上进行的应力波衰减测量对沿着波路径存在的损伤非常敏感。在这项研究中，这一概念的一种修改形式被引入到自补偿测量方案中。在混凝土试件表面的两个感应点之间，获得了在一定频率范围内的表面波传输。所获得的信号透射值与所使用的波发射器和接收器的类型无关。描述了在一系列含有缺口和不同深度的受控裂缝的混凝土板上进行的实验测试。裂缝是通过使用闭环加载程序使楼板受弯而产生的。每个产生的裂纹的实际深度是用基于激光的相位测量干涉技术确定的。对不连续面(缺口、开放裂纹和闭合裂纹)进行了自补偿波传播测量，结果表明，该测量对缺口甚至闭合裂纹的存在是可重复的，并且很敏感。指出了波的透射率与裂纹深度之间的关系，该关系相对于传播波长归一化。这种关系似乎在很大程度上不受混凝土类型和不连续性质的影响。结果表明，自补偿波透过率测量在混凝土结构表面裂缝的敏感检测和尺寸确定方面具有很好的潜力。
It has been established in earlier studies that stress wave attenuation measurements performed on concrete are very sensitive to the presence of damage located along the wave path. In this study, a modified form of this concept is introduced in a self-compensating measurement scheme. Surface wave transmission is obtained, across a range of frequencies, between two sensing points on the surface of a concrete specimen. The obtained signal transmission values are independent of the type of wave transmitter and receiver used. An experimental test series on a range of concrete slabs containing notches and controlled cracks of varying depths is described. The cracks are generated by subjecting the slabs to flexure using a closed-loop loading procedure. The actual depth of each generated crack is determined with the laser-based phase measurement interferometry technique. Self-compensating wave transmission measurements are performed across the discontinuities, (notches, open cracks, and closed cracks) and are shown to be repeatable and sensitive to the presence of notches and even tightly closed cracks. A relationship between the wave transmission and the crack depth normalized with respect to propagating wavelength is noted. This relationship appears to be largely unaffected by the type of concrete and the nature of the discontinuity. The results demonstrate that self-compensating wave transmission measurements show excellent potential for sensitive detection and sizing of surface-breaking cracks in concrete structures.