2020 年 8 巻 1 号 p. 144-153
The steel plate bonding method has been widely adopted as a reinforcing method for deteriorated and damaged reinforced concrete (hereinafter referred to as RC) structures. This research presents a technique for the quantitative estimation of the thickness of water layer that has stagnated on the upper surface of a steel plate, debonded from a RC slab structure due to bonding re-degradation. The proposed technique is a non-destructive inspection that utilizes ultrasonic guided waves on the bottom side of a steel plate. The verification of the proposed technique has been conducted by comparing the results between the theoretical analysis and the experiments. In the verification, we examined various combinations of the thicknesses of steel plate and water layer, considering not only the steel plate bonding slab but also a steel plate-concrete composite slab and a concrete-filled I-beam grid deck, whose bottom surfaces are also covered with steel plates. The comparison provides a good agreement between the theoretical solutions and the experimental results and concludes that our proposed technique is a promising nondestructive testing for the detection and evaluation of the water ponding on the upper surface of the steel plates.