Study on concrete cracking caused by non-uniform corrosion of steel bar

Abstract

In this paper, the cracking of concrete cover caused by steel bar corrosion was discussed and studied based on the three-period model of steel bar corrosion in concrete. In the analysis, the contour of the corrosion layer was simplified into a semi-ellipse according to the non-uniformity of steel bars in reinforced concrete under a natural environment. The steel bar corrosion was divided into three different periods by two corrosion points, namely, the void to be filled was exactly filled and the concrete cover was exactly cracked. Different assumptions are made for each corrosion period. Before the concrete cover cracks, it is developed into an elastic plate. Based on the theory of elastic mechanics, the maximum corrosion depth of steel bar when concrete cover cracks is predicted. After the concrete cover cracks, a model of the relationship between the crack width of the concrete cover and the maximum corrosion depth of steel bar was established by considering the filling of cracks by corrosion products. The rationality of the model was tested by employing experimental data from the literature, and it was found that the calculated value of the model was in good agreement with the experimental data in the literature.