Recent advance in alkoxysilane-based consolidants for stone

Due to natural effects (stone aging), human factors and other reasons, stone relics, especially open-air stone relics, have suffered varying degrees of damage. Therefore, effective measures should be taken as soon as possible to protect these cultural treasures and their historical heritage. Since ancient times, many stone consolidants have been developed, including alkoxysilanes such as ethyl silicate (TEOS). Alkoxysilanes have the advantages of low viscosity, high chemical stability, etc. However, the silica gel formed by the hydrolysis of TEOS easily cracks under dry conditions. This is not conducive to consolidants. As a result, many studies on the modification of TEOS have appeared. The preparation methods of crack-free silica, including adding drying control chemical additives, adding nanoparticles, adding surfactants and adding organic modifiers are reviewed. We also analyze the advantages and disadvantages of alkoxysilanes as a consolidant. This paper can help researchers understand the use of alkoxysilanes in stone protection. In addition, this article provides suggestions and valuable information for future work in this field, as well as stimulates related studies.