Nondestructive measurement of diameter of reinforcing bars in concrete using an electromagnetic wave radar under the effect of cross bars

A method was proposed previously 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 from the received reflections from the deformed 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.