Unlocking the role of pores in chloride permeability of recycled concrete: A multiscale and a statistical investigation

Chloride ingress is strongly associated with the properties of pores in recycled concrete. To unlock its role in chloride permeability, the pore structures of concrete containing various quantities of recycled coarse (fine) aggregates were analyzed from multi-scales, and the outcomes were further verified by the statistical investigation. The results show that different roles that recycled coarse (fine) played in terms of the pore structures of recycled concrete, as reflected by their volume and diameter of mesopores and micropores, respectively. Meanwhile, Unlike the previous studies, two key pore parameters (i.e., PV < 1 and PT) were put forward, revealing their strong interconnections with chloride diffusion of recycled concrete, as confirmed by the statistical analysis. Further, a model concerning chloride permeability of recycled concrete was proposed on a basis of the probability theory, and the newly proposed factor Rp (relied on the previous two pore parameters) has a great relevance to effective chloride diffusion. Therefore, this work enhances accuracy of prediction for chloride diffusivity and durability associated with recycled concrete.