In this research, ultrasonic pulse echo measurements are used to quantify through thickness chemical degradation in thin mortar specimens. The degradation level is predicted using the time of travel of the acoustic wave through the thickness of the structure. The front and back wall interaction reflections are used to obtain additional information from very early stage degradation. The pulse-velocity of sound waves as a function of the thickness of the layers within the structure is described. With knowledge of the pulse-velocity in pristine and fully degraded conditions, it is possible to determine the complete range of degradation length over the layer thickness. The method is applicable for leaching of calcium and acidic attack. The acoustic measurements were verified with destructive testing. The correlation between the acoustic and non-acoustic experiments agree with the described pulse-velocity and degraded depth function. The method based on ultrasonic measurements can be implemented in other thin-layered structures.

中文翻译：

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一种基于脉冲速度测量来量化薄砂浆试样中化学降解水平的方法

在这项研究中，超声波脉冲回波测量用于量化薄砂浆试样中的厚度化学降解。使用声波穿过结构厚度的传播时间来预测退化水平。前壁和后壁相互作用反射用于从非常早期的退化中获取额外信息。描述了作为结构内层厚度的函数的声波脉冲速度。通过了解原始和完全退化条件下的脉冲速度，可以确定整个层厚度上的退化长度的完整范围。该方法适用于钙的浸出和酸蚀。声学测量通过破坏性测试进行了验证。声学和非声学实验之间的相关性与所描述的脉冲速度和退化的深度函数一致。基于超声波测量的方法可以在其他薄层结构中实施。