NON-DESTRUCTIVE INSPECTION METHOD FOR MECHANICAL TYPE REINFORCING BAR COUPLER AND ULTRASONIC PROBE FOR INSPECTION

摘要

PROBLEM TO BE SOLVED: To easily measure fitting length L of a reinforcing bar fitted with a sleeve and then evaluate performance of a coupler jointed with a mechanical type reinforcing bar coupler. SOLUTION: The mechanical type reinforcing bar coupler is formed by joining end edges 1a, 2a of two reinforcing bars 1, 2 to connect with a sleeve 3. A probe 5 of an ultrasonic wave is contacted to the surface of the reinforcing bar 2 at a distance L0from the end edge 3b of the sleeve 3. The ultrasonic wave (surface SH wave) is transmitted from the probe 5 towards the end edge 2a, and then echo reflected with the end edge 2a of the reinforcing bar 2 is received and displayed on a flaw detector 4. A distance L1 from the probe 5 to the end edge 2a of the reinforcing bar 2 is calculated and length L from the end edge 3b to the end edge 2a of the reinforcing bar 2 is measured by analyzing the time-of-arrival of the echo. The analyzing of the time-of-arrival of the echo determines with either 'the time-of-arrival of a pulse firstly reaching' or 'the time-of-arrival of pulse with maximum amplitude among pulses reaching' as the time-of-arrival. COPYRIGHT: (C)2004,JPO