Research on ultrasonic visualization of defects in reinforced concrete beams based on amplitude method

Abstract

This paper mainly studies the use of ultrasonic testing, combined with the ultrasonic amplitude method, to visualize the internal cavity of reinforced concrete so that it can directly judge the size and shape of defects. Through the ultrasonic detection of concrete beams with defects, the amplitude value in the detection result is extracted and processed to make it a characteristic value reflecting the characteristics of the detection area. And by using the phenomenon that the defect background area will produce shadows due to the time difference of diffraction of ultrasound, the characteristic value is visualized, and the imaging effect map of the reinforced concrete beam is obtained. The imaging result mainly has two parts: black and white. Black is a low energy area, there are defects in this area, and white is a high energy area, there is no defect in this area. The results show that using the amplitude as the visualized eigenvalue can realize the imaging problem of reinforced concrete defects. In the imaging results, the abscissa errors of the black-shaded areas are 1%, 0.9%, 4.7%, and 4.8%, and the ordinate errors are 0.7%, 1.9%, 7.5%, and 16.6%. The diameters of the shaded areas are 4.21 cm, 3.34 cm, 4.42 cm, and 3.79 cm, respectively. Therefore, it can better reflect the damage of each area of the reinforced concrete beam and visualize defects.