Rhim Hong Chul, Kim Dae You, Cho Chang Shik, Kim Do Hyun
Department of Architectural Engineering, Yonsei University, Seoul 03722, Korea.
Korea Fire Safety Association, Cheongju-Si, Chungcheongbuk-Do, Seoul 28620, Korea.
Materials (Basel). 2020 Feb 17;13(4):887. doi: 10.3390/ma13040887.
The presence of embedded steel affects the estimates obtained for the compressive strength of concrete during ultrasonic testing, as it increases the ultrasonic wave velocity. Thus, if the presence of steel in concrete is inevitable, then a correction factor is required for an accurate estimation of the concrete strength. While previous studies focused on the effect of steel reinforcing bars on the speed of ultrasonic waves in concrete, this work expands on the significance of embedded steel from steel bars to include steel plates. The wave velocity was measured for varying dimensions of embedded steel plates from 15 mm to 150 mm using 54-kHz ultrasonic testing equipment. Through experiments, the effect of steel plates on the ultrasonic testing of concrete was quantified to derive proper correction factors. It was found that the thickness, depth, and height of the steel plates significantly affected the test results. These findings can be applied to ultrasonic testing to estimate the compressive strength of concrete consisting of a significant volume of steel, such as in steel-reinforced concrete structures.
嵌入式钢材的存在会影响超声检测时所获得的混凝土抗压强度估算值，因为它会提高超声波速度。因此，如果混凝土中钢材的存在不可避免，那么就需要一个校正系数来准确估算混凝土强度。虽然先前的研究聚焦于钢筋对混凝土中超声波速度的影响，但这项工作拓展了嵌入式钢材的意义，从钢筋扩展到包括钢板。使用54千赫的超声检测设备，对尺寸从15毫米到150毫米不等的嵌入式钢板测量了波速。通过实验，量化了钢板对混凝土超声检测的影响，以得出合适的校正系数。结果发现，钢板的厚度、深度和高度对测试结果有显著影响。这些发现可应用于超声检测，以估算含有大量钢材的混凝土的抗压强度，比如在钢筋混凝土结构中。
