A novel lattice model to predict chloride diffusion coefficient of unsaturated cementitious materials based on multi-typed pore structure characteristics

This paper develops a novel lattice diffusive model to quantitatively study the chloride diffusion coefficient in unsaturated cementitious materials, in which the pore voxels are redistributed to make a better representation of a real microstructure of hardened cement paste. Considering the hierarchical microstructure and different drying...

Chloride diffusion of alkali-activated fly ash/slag concrete

The widespread application of alkali-activated fly ash/slag (AAFS) concrete requires satisfaction of a series of performance criteria both from its early age properties (e.g. workability, strength) and long-term stability. In this study, long-term (till 180 days) natural chloride diffusion tests were conducted to evaluate the chloride diffusion...

Dependence of unsaturated chloride diffusion on the pore structure in cementitious materials

Conceptual analysis is performed to examine the effects of pore features on the water continuity in unsaturated porous systems. The roles of pore features in relative chloride diffusion coefficient (D_rc) of mortar specimens at various degrees of water saturation (S_w) were studied based on mercury intrusion porosimetry...

A model for predicting the relative chloride diffusion coefficient in unsaturated cementitious materials

An analytical model for predicting the relative chloride diffusion coefficient in cementitious materials at different degrees of water saturation is presented in this paper. The model is developed based on the Nernst-Einstein equation and conductivity of cementitious electrolyte, as well as on moisture distribution in the pore structure. Good...

Non-saturated Chloride Diffusion in Sustainable Cementitious Materials

Chloride-induced reinforcement corrosion, caused by chloride diffusion in the unsaturated concrete cover, is a major durability problem of concrete structures. Current concepts for concrete mixture design and for service life prediction are generally based on the understanding of the chloride diffusion coefficient of saturated concrete. This...

Experimental study of chloride diffusivity in unsaturated ordinary Portland cement mortar

Experiments are carried out to investigate the chloride diffusivity in partially saturated ordinary Portland cement mortars with water-to-cement (w/c) ratios of 0.4, 0.5 and 0.6. Based on resistivity measurement and Nernst-Einstein equation, the chloride diffusivities of cement mortars at various water saturations are estimated. The pore...