Combined Punctual and Diffused Monitoring of Concrete Structures Based on Dielectric Measurements

This work presents a microwave reflectometry-based system for monitoring large concretestructures (during the curing process and also while the structure is in use), through the combineduse of punctual and diffused sensing elements. In particular, the adoption of punctual probes ona reference concrete specimen allows the development of an innovative and accurate calibrationprocedure, useful to obtain the value of the water content on a larger structure made of the samematerial. Additionally, a wire-like diffused sensing element can be permanently embedded inbuildings and used to monitor the structure along the entire length of the sensing element. Theadopted diffused sensing element can be used not only to detect dielectric variation during the curingprocess, but also throughout the service life of the structure. The combined use of punctual anddiffused sensing elements represents an important innovation from a procedural point of view, ableto provide detailed and quantitative information on the health status of the structure both duringand after construction.