Improved one-phase model of uniform corrosion for predicting the volume of rust

One-phase models of rebar corrosion have been widely used by practising engineers to predict the volume of rust and the time to cracking of the concrete cover, but the models have only considered the deformation of concrete and not the deformation of steel or the rust layer. Neglecting the deformation of the rust layer may result in inaccurate predictions. This study therefore proposes an adjustment factor to take into account the effect of the deformation of the rust layer on predicting the volume of rust with a conventional one-phase model of uniform corrosion. Furthermore, the effects of the material properties of the rust layer and corrosion-induced expansive pressure on the adjustment factor are investigated. To avoid inaccurate predictions of the volume of rust, the proposed adjustment factor should be applied in the conventional one-phase model of corrosion when the Young's modulus of rust is less than 460 MPa.