Possibility of Applying a Coefficient of Roughness Measurement Device Using Aerial Ultrasonic to Curved Surfaces

Abrasion of concrete is a problem in agricultural canals. It causes an increase in the coefficient of roughness, thereby decreasing the water flow performance. Therefore, abrasion is a factor for repair. Thus, a coefficient of roughness measurement device using aerial ultrasonic technology was developed for use in the inspection of canal concrete. However, this device is designed to measure on a plane surface. In this study, the applicability of this device to curved surfaces such as tunnels and pipelines was investigated. Coefficient of roughness of plane and curved surfaces were compared in model tests and in service canals with curved surfaces. As a result, when the radius of curvature was greater than 1,000 mm, the coefficient of roughness of the plane and curved surfaces were almost the same. When the radius of curvature was less than 1,000 mm, there was a large difference between the coefficient of roughness of the plane and curved surfaces. These results indicate that the device is effective in measuring the coefficient of roughness as an index of roughness on curved surfaces with a radius of curvature of 1,000 mm or more.