A review on silane and siloxane materials: enhancing durability of cementitious materials through surface treatments

Cementitious materials, which are extensively utilized in contemporary construction projects, exhibit a vulnerability to deterioration attributed to their inherently porous architecture. The application of surface treatment methodologies presents a practical, efficient, and user-friendly strategy to significantly augment the durability of these materials. Among the diverse surface protection agents utilized, silane and siloxane materials are extensively utilized for hydrophobically modifying and sealing cementitious pore structures. This review provides an overview of the current progress on the application of silane and siloxane materials. It encompasses the hydrophobicity mechanism, various material types, and highlights the advantages and disadvantages associated with each type. Moreover, the effects of silane and siloxane surface treatment on cementitious material properties are examined, including hydrophobicity, resistance to chlorine, freeze–thaw cycles, and salt freezing. While observing substantial effects, the role they play in carbonation resistance remains a topic of debate. Lastly, this review outlines future research directions, aiming to enhance carbonation resistance mechanisms and address the long-term effects.