Effects of Coarse Aggregates on the Corrosion of Steel Bars in Cement Paste

Testing steel in concrete pore solution has the advantage of avoiding the long time necessary for chlorides to penetrate the concrete cover. However, the time to corrosion of steel immersed in pore solution is different from that in actual concrete. The objective of this work was to study the impact of the presence of the steel and the distance between coarse aggregates and steel bars on the corrosion of the steel bars. Three distances between steel and the coarse aggregates were investigated in this study. Results clearly showed that the presence and the position of coarse aggregates with respect to the steel bars can significantly affect the access of steel to chloride ions and consequently, corrosion initiation on the surface of steel. It was determined that decreasing the distance between the coarse aggregates and steel had adverse impact on the corrosion initiation on the steel.