TY - EJOU AU - Yan, Hua AU - Song, Bo AU - Wang, Mansheng TI - Comparison of Fuzzy Synthetic Evaluation and Field Measurement of Internal Defects in Assembled Concrete Detected by Ultrasonic Waves T2 - Structural Durability \& Health Monitoring PY - 2020 VL - 14 IS - 3 SN - 1930-2991 AB - Analyze and compare the basic principles of ultrasonic detection of voids in concrete, choose ZBL-U520/510 non-metallic ultrasonic detector, and use the opposite detection method to test the void size in the joints of prefabricated concrete structures. The results show that: ultrasonic method by testing the waveform, sound, and speed of sound analysis can effectively determine the position of the defect, and through the conversion formula can estimate the void size. Ultrasonic parameters are used to distinguish the internal defects of Assembly concrete. Sometimes there are different results with different parameters. It is difficult for engineers to directly determine the internal defects. Fuzzy comprehensive evaluation can establish an overall evaluation of things or objects controlled by multiple factors by establishing membership functions. Through the inspection of engineering examples: the fuzzy comprehensive judgment method has no difference between the judgment of some good quality points and the judgment results of the original criteria, but for some abnormal points or points near the critical value, the advantages of fuzzy criteria can be achieved. The judgment process will be more scientific by considering several parameters in a comprehensive manner and digitizing the original subjective judgments. KW - Ultrasonic wave; assembly type; internal defects; fuzzy comprehensive evaluation DO - 10.32604/sdhm.2020.06403