A method of identifying the diameters of deformed bars nondestructively in concrete structures using an electromagnetic wave radar

We previously proposed a method to measure the diameter of the deformed reinforcing bars in concrete structures nondestructively using an electromagnetic wave radar. The method estimated the periodicity of the knots of the inspected bar and utilized the standard relationship between the knot´s pitch and the diameter of the bar to measure the diameter indirectly. The effectiveness of the method was verified using test specimens where the bars were placed parallel to each other. However, in practical case, where other reinforcing bars cross the inspected bar perpendicularly, the stronger reflections from the cross bars influence the reflection from the inspected bar. The paper thus proposes a general method which eliminates such unwanted influences from the cross bars and measures the diameter accurately even in practical environment.