The waterproofing effect and mechanism of graphene oxide/silane composite emulsion on cement-based materials under compressive stress

The influence of the water-to-binder ratio and compressive stress on the waterproofing effect of graphene oxide/ isobutyltriethoxysilane (GS) composite emulsion on cement-based materials was investigated. The results show that GS combines with calcium silicate hydrate to form a hydrophobic film, which prevents the intrusion of external water and carbon dioxide. In addition, after undergoing self-condensation, silanol reacts with calcium hydroxide to generate calcium silicate hydrate gel, which improves the microstructure of cement-based materials. Furthermore, the increase in the water-to-binder ratio and stress ratio leads to the expansion and connection of the pore structure of cement-based materials, resulting in an increase in the capillary water absorption coefficient. Meanwhile, the higher porosity is conducive to the penetration of the emulsion in cement based materials and the formation of a waterproof layer. Thus, the waterproofing effect of GS composite emulsion on the specimen was improved.