Molecular Dynamics Simulations of Chloride and Sulfate Ion Transport in C-S-H gel and γ-FeOOH Nanopores

Interactions between Cl-, SO42- and cementitious materials, reinforcement passive films influence the durability of reinforced concrete structures. Transport three solutions (NaCl, Na2SO4, mixed) in calcium silicate hydrate (C-S-H) gel, γ-FeOOH nanopores was investigated using molecular dynamics. Solution transport is slower than C-S-H gel because lesser hydrophilicity surface. can form ion clusters to hinder solution atomic motion, appear more frequently at interface. Temporary adsorption on substrate surfaces occurs during Ca-Cl, Ca-SO4 ionic bonds surface Ho (hydroxyl hydrogen atoms) -Cl, Ho-SO4 surface, these are influenced by local structure. Two substrates interact with water, via distinct microscopic mechanisms.