Corrosion of reinforcing steel in reinforced and prestressed concrete bridges

Abstract

The corrosion of reinforcing steel has led to the premature deterioration of many concrete bridges in countries throughout the World, such as Libya, before their design life is attained. This has placed tremendous financial burden on such countries and local transportation organizations in their attempts to halt ongoing reinforcing steel corrosion in the existing structures that are still functional and to replace those structures that have already deteriorated to the point that it does not make any economic sense to keep on maintaining them. In addition, badly deteriorated bridges have considerable adverse effects on the nation's economic output and also place the safety of motorists at risk. In this study the effects of several factors on the corrosion behavior of steel have been studied. These factors are chloride ion concentrations and environmental variables such as temperature and relative humidity. The interactions of chloride ion concentration, temperature, and relative humidity on the corrosion behavior of steel are complex. In addition, the effect of the concrete mix components, such as water/cement ratio and proper selection of cement type, mineral admixture, and fine aggregate, coarse aggregate, and air content on the corrosion rate of reinforcing steel are studied.