Protecting o stone against weathering

摘要

Weathering of structural stone that is exposed to the environment is brought about by the combined effects of acid rain, salt crystallization and the freeze-thaw cycles of ice. Conventinal coating methods for preventing the degradation of carbonate rock are relatively short-lived and alter the appearance of the material, while contributing very little to improve the structural properties of the stone. We are investigating a new process based on sol-gel methods designed to prevent both chemical and physical degradation and to strengthen or consolidate the existing weathered surface. The sol-gel technique employed facilitates micro-engineering of the protective coating to tailor desirable properties such as hydrophobicity, UV-stability, natural finish or appearance, and added strength.