Degradation and conservation of clay-containing stone: A review

A novel green conservation approach using bacterially-induced formation of CaCO3 cement and exopolymeric substances has shown promise in preventing or controlling clay-related damage to tuff stone at the ancient Maya site of Copán. This method, which inhibits clay swelling, offers a more effective alternative to traditional conservation materials like polymers and alkoxysilanes, often found to be ineffective against such damage. The review discusses the mechanisms behind clay-induced degradation, including scaling, flaking, spalling, exfoliation, and delamination, caused by wetting/drying cycles, while also exploring complementary processes that contribute to stone damage due to expansion/contraction.

Elert, K., & Rodriguez-Navarro, C. (2022). Degradation and conservation of clay-containing stone: A review. Construction and Building Materials, 330, 127226. https://doi.org/10.1016/j.conbuildmat.2022.127226