ABSTRACT
Corrosion of reinforcing bars in concrete is one of the main causes of structural deterioration and is one of the greatest maintenance challenges (Du et al. 2006, Beaudette 2001). Corrosion reduces the strength, durability, and service life of reinforced concrete structures. As the reinforcement corrodes, it expands causing cracking of concrete and spalling. Chloride concentration, carbonation, temperature, relative humidity, cover depth, and concrete quality are the major factors affecting the rate of corrosion. The transformation of metallic iron to rust can result in an increase in volume of up to 600%, depending on the final rust form (Mehta & Monteiro 1993). For corrosion initiated by chloride ions, the presence of both oxygen and chloride is required for the corrosion activity to continue, and corrosion may slow down considerably if a barrier could reduce the diffusion of moisture and harmful ions like chloride through the concrete.
