The Sensitivity of Acoustic-Laser Technique for Detecting the Defects in CFRP-Bonded Concrete Systems

This paper presents an experimental study to evaluate the sensitivity of acoustic-laser technique in defect detection. The technique is particularly useful towards the detection of near-surface defects in fiber reinforced polymer-bonded concrete by vibrating the material with an acoustic excitation and measuring the vibration signals with a laser beam. However, relatively little is known about the sensitivity of acoustic-laser technique. More research work should be conducted to evaluate the effectiveness of the technique when adopted for defect detection. It is also important to investigate the limits of the technique performance with respect to varying operational conditions so as to determine ways of improving the detectability. For this purpose, operational conditions in terms of acoustic excitation and laser beam incidence are investigated for their effectiveness in detecting near-surface defects and a reliable defect detection scheme using our portable equipment is therefore recommended. This work provides a basis for further improving such technique which can be used in other engineering applications including quality control of materials and product development process.