In the present paper, the addition of silane to improve the properties of mortar was experimentally investigated. The morphology and microstructure of mortar were investigated by using both scanning electron microscopy (SEM) and polarizing microscopy (PM). The results show that silane significantly alters the microstructure of mortar, reduces the crystallization, restricts the degree of hydration of cement-based materials, and decreases micro-voids. As a result, silane effectively improves the chemical and carbonation resistance, as well as the...