Coupling effect of concrete cracks and stray current on chloride-induced corrosion of rebar

Abstract

Either concrete cracking or stray current promotes the corrosion of rebars; however, the coupling effects of concrete cracking and stray current on the rebar corrosion are still unknown. In this work, the effect of concrete cracking patterns coupled with stray current on rebar corrosion is presented by both experimental and finite element simulation. Specifically, there is a strong coupling effect when crack width is less than 100 μm, which manifests that ion concentration and electric field intensity increase pronouncedly with decreasing crack width. Simulation shows that the coupling effect leads to an asymmetric distribution of ions and electric fields at the crack tip, which in turn causes the asymmetric corrosion of rebars. Under the coupling effect, the highest corrosion rate reaches 3 μA/cm2 and is more than three times higher than that in a natural environment. Our findings contribute to understanding and evaluating accurately rebar corrosion in practical application.