On the variability of chloride diffusion in modelled recycled aggregate concrete

This paper proposes a new model to describe effects of recycled coarse aggregate (RCA) distribution on chloride diffusion from four modelled recycled aggregate concrete (RAC) with different RCA replacement ratios (RRA). Chloride diffusivities of each type of the modelled RAC are experimentally investigated using a rapid chloride migration (RCM) equipment and are simulated by a finite element method (FEM). The results show that the chloride diffusivities of the modelled RAC generally increase with the increase of RRA; while for the same RRA, the chloride diffusivities and the chloride concentration distribution in the modelled RAC are still different due to the effect of different aggregate arrangements; the chloride concentration distribution characteristics in the FEM model are verified using RCM testing; the variability of the modelled RAC for both chloride migration and compressive strength show consistent tendency, which can provide insights into RAC mix design.