CORROSION MONITORING OF STEEL IN CONCRETE USING OPTICAL SENSORS

Abstract

Corrosion of steel in concrete is one of the major reasons for deterioration of concrete structures. It is a complex process involving the diffusion of chlorides and carbon dioxide, followed by active corrosion of rebar leading to cracking and spalling of concrete. There is a need for detection of damage due to corrosion of rebar using sensors in order to adopt an early repair action. This work aims at the development of a sensor system for monitoring rebar corrosion using optical sensors. The sensor system consists of (a) an imaging probe sensor with sacrificial metal foil for monitoring the initiation phase of corrosion, and (b) a lens-based plastic optical fiber (POF) strain sensor and POF crack sensor for monitoring the propagation phase of corrosion. The system offers the possibility for monitoring the entire rebar corrosion process, thereby allowing us to obtain a holistic picture of the health of the structure.