Nanoscale insights on the stress corrosion mechanism of calcium-silicate-hydrate

In this research, the stress corrosion mechanism of cement-based materials is revealed from a nanoscale viewpoint by exploring the evolution of mechanics and structure for calcium-silicate-hydrate (C-S-H) under the external mechanical loads and aqueous environment through the molecular dynamics simulation. It was found that the stress corrosion leads to the reduction of as high as 12% in fracture toughness. This is ascribed to the presence of water, which would attack the interlayer bonding, changes the closely connected Ca-O bonding into weakened hydrogen-bonded hydroxyls, and thus lead to the damage of the model at the crack tip.