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Evaporation of colloidal suspension in two-dimensional (2D) porous media leads to the formation of self-assembled clogging structures (SCS). The self-assembly pattern is studied with a hybrid two-phase lattice Boltzmann method incorporating non-isothermal phase change, particle transport and deposition models. During drying, particles accumulate along the liquid–vapor interface while colloidal suspension is evaporating. Upon reaching a certain local concentration threshold, the particles deposit and form a solid structure. The patterns formed by these structures are analyzed in different 2D porous media. In small porous systems of 4 pillars, the self-assembly of C-shaped and X-shaped structures is observed, which compares well with experimental bridge configurations. SCS in porous media of three different initial particle concentrations and of three different porosities are studied in larger porous systems. Simulated self-assembled clogging configurations show good qualitative matches with experimental configuration results. Particle concentration and porosity are both seen to affect the dynamic drying processes as well as the final self-assembled clogging configuration. The liquid configuration and the clogging structure affect each other mutually during drying. With initial concentration increasing from C0 = 0.00 to C0 = 0.16 at a given porosity ϕ 0 = 0.68 , the average evaporation rate and porosity decrease by 21.9% and 1.9%, respectively, due to blockage of pores. With increasing initial porosity from ϕ 0 = 0.53 to ϕ 0 = 0.81 at a given concentration of C0 = 0.16, the average evaporation rate increases by a factor of 2.9 due to larger liquid–vapor interfacial area. Also with the given concentration of C0 = 0.16, the decrease in the porosity (0.94%, 1.9% and 2.7%) is higher for higher initial porosity ( ϕ 0 = 0.53 , 0.68 , and 0.81 ), since more particles (proportional to ϕ 0 · C 0 ) are initially present. This work opens the door for numerically assisted design of colloid-deposition-based clogging patterns. [ABSTRACT FROM AUTHOR]

To assess salt damage risks in building materials and geomaterials, the key components to identify are the accumulation of salts and the damage propagation. Experimental data combining both are scarce but offer an additional richness for understanding the coupling between transport and mechanics in the context of salt crystallization in porous media. Here, we quantify the drying of sodium sulfate and sodium chloride solutions from Savonnières limestone together with the damaging character of anhydrous sodium sulfate and halite precipitation, respectively. Repeated wetting–drying cycles are performed, by using salt solutions in the rewetting phase and by drying at an elevated temperature of 45 °C. The drying and deformation dynamics are characterized by means of high-resolution neutron radiography, with a moisture content resolution of 0.04 kg/m3 and a spatial resolution of 13.5 μm/pixel. Precipitation occurs inside the specimen by treating the upper volume of the specimen hydrophobically. High Peclet numbers are found, representing a long first drying stage leading to salt accumulation in a localized zone, increasing the damage risk. In-pore crystallization of halite during drying of 5.8 molal sodium chloride solutions is particularly damaging for our type of samples. Large deformations are observed already during the first cycle, indicative of crack formation. With 1.4 molal sodium sulfate solutions, no damage is observed upon precipitating the anhydrous sodium sulfate crystal, but the drying rate decreases with every cycle due to augmented pore clogging. [ABSTRACT FROM AUTHOR]