Techniques to Overcome the Obstruction of Attachments and Improve the Antiseepage Effectiveness of Grouting in Protecting Stone Carvings

Water seepage is the primary cause of corrosion of stone carvings in caverns. At present, grouting is commonly accepted by conservators as an effective technique to reduce leakage and help preserve carvings. However, because cracks are often narrow and deep, there can be attachments on the surface of rocks that affect the bonding between the grouting materials and rocks and that cannot be cleared completely. This will eventually cause the failure of accepted techniques to seal against leakage. In this work, four kinds of modifiers were applied to improve the bonding between the grouting material and rock under laboratory conditions. The results show that dried moss and dried fungus will significantly increase the hydrophobicity of rock and inhibit the spread of grouting material on the surface of rock. Mud and calcium sulfate will immensely increase the water absorption of rock and cause the grouting material to lose fluidity. All four kinds of modifiers tested improved the diffusion and penetration depth of grouting materials on the surfaces of specimens. Among these, the 3-glycidoxypropyl trimethoxy silane (KH560) had the best overall effect. It could help to increase by 40%–55% the diffusion and penetration depth of grouting materials on the four kinds of mimic surfaces.