Abstract
Ultrasonic testing of a reinforced concrete member is affected by the rebars embedded in the concrete. With the surface transmission of the pulse, there is some uncertainty regarding the exact length of the transmission path. An investigation of the pulse velocity of the rebar, the effects of the rebar and the exact transmission path length of the pulse has been made, using the bar diameter and the water/cement ratio as the variables. It is found that the pulse velocity of the rebar is under the diameter of the rebar, and the rebar appears to act compositely with surrounding concrete in transmitting ultrasonic pulse. If there is no effect of the rebar on the transit time of the pulse, the slope of the time-distance line is the mean pulse velocity. A method that examines the presence of an effect of the rebar is proposed.
