Analysis and modeling of corrosion of steel in prestressed concrete

Abstract

Development of conceptual and mathematical models describing the corrosion of steel in prestressed concrete is outlined. The application of the principles of stress corrosion and general corrosion to understanding the mechanisms involved in corrosion of steel in prestressed concrete is discussed. The first step in estimating the failure time of a prestressed concrete structural system because of corrosion of the reinforcing steel is to estimate corrosion rates under various realistic conditions. A simplified approach based on mathematical modeling of concrete properties for estimating corrosion rates is proposed.Before the proposed mathematical model can be applied to practical problems information is needed on the specific mechanisms of corrosion cell processes of steel in prestressed concrete.In addition, well designed corrosion tests need to be performed in which the important factors affecting the corrosion rates are considered.

Computational models developed for the corrosion of prestressing steel

“…The corrosion of steel in prestressed concrete (PC) may cause a potential threat to the-integrity of the structure or pipeline of which it is a part even though the concrete in PC is generally of high quality (Treadway, 1971;Szilard, 1969). The major problems in assessing the threat have been identified as the lack of methods for estimating the corrosion rates and for evaluating the effects due to stress corrosion (e.g., Galligo and Climent (1980); Wu and Clifton, 1981).…”

“…The Analytical Model Diffusion and electrochemical reactions are the major processes involved in the corrosion of steel. Due to the complicated conditions existing near the electrodes, it was proposed (Wu and Clifton, 1981 ) to use the following simplified equations in evaluating the rates for general corrosion:…”