Mesoscopic simulation of steel rebar corrosion process in concrete and its damage to concrete cover

Abstract

In atmospheric or chlorine environment, the rebar corrosion process can be initiated by concrete carbonation or chloride penetration, respectively. Along with the rebar corrosion, tensile stress will occur in concrete around rebars, and cracks will be formed when the stress reaches the tensile strength of concrete. This paper mainly studies the uniform and pitting rebar corrosion processes by lattice model at meso-scale. Firstly, the models of uniform and pitting rebar corrosions are developed. Secondly, an integrated procedure based on the lattice model is proposed to identify the crack pattern in the concrete. Published experimental results are adopted to validate the proposed models and method. Thirdly, some typical cases such as the corrosion process of a single rebar and multi-rebars, rebar corrosion process in the corner and pitting corrosion processes are simulated. Finally, the damage of the rebar corrosion to the concrete cover is studied. The results show that the rebar corrosion in the corner and the pitting corrosion can result in a severer damage to the concrete cover compared with the ordinary uniform rebar corrosion. Furthermore, the corrosion of multi-rebar can result in a larger scale of concrete cover spalling due to the firstly formed transverse crack.