Ultrasonic inspection for water detection in a steel-epoxy-concrete layered medium

摘要

Steel plate bonding method is a repairing method for damaged concrete slabs and has been applied for over 30 years. Recently, the repaired structures have been damaged again due to debonding of adhesive epoxy. To evaluate the integrity of a bonded steel plate, a hammering test has been widely used. This method gives results which depend on the skill of an inspector, and requires works at high elevation. Thus a more efficient method is demanded to be developed. A laser-based inspection system has potential for application to inspections of the damaged structures, because the system can not only generate but also measure oscillation remotely and efficiently. The objective of this study is to develop a remote inspection system based on a laser technology for assessment of bonding conditions between a steel plate and concrete slab. This abstract includes the following contents: setup and concept of our laser-based system for remote inspection, laboratory test results obtained by the developed system for specimens with artificial damages, and some properties of guided waves propagating in layered medium for discriminating water condition.