Measurement and monitoring of gap in concrete-metal structures using microwave sensor technologies

This work is in the response of concrete-metal bond problem in structures used in infrastructure engineering such as concrete-filled steel pipes and columns. In this paper the capabilities of near-field microwave waveguide sensors for the purpose of measurement and monitoring of gap between concrete and metal surfaces is demonstrated. It was shown that a microwave dielectric-loaded waveguide sensor provides higher sensitivity to the gap than a conventional open-ended waveguide sensor. The performances of the dielectric-loaded waveguide sensor are studied and optimised.