Moisture expansion associated to secondary porosity: an example of the Loseros Tuff of Guanajuato, Mexico

Research on the Loseros Tuff, a volcanic rock used extensively in Guanajuato's UNESCO-listed colonial buildings, reveals that moisture expansion—driven by secondary porosity and high clay mineral content—is a key factor in its deterioration. The study found that once liquid water penetrates the rock, it triggers matrix dissolution, creating additional pores that amplify expansion. This process is influenced by pore radius distribution, which affects water transport and porosity effectiveness. To uncover these mechanisms, scientists analyzed the tuff's petrographic, mineralogical, geochemical, and petrophysical properties, providing critical insights into its weathering behavior and potential conservation strategies for historic structures.

López-Doncel, R., Wedekind, W., Dohrmann, R., & Siegesmund, S. (2012). Moisture expansion associated to secondary porosity: an example of the Loseros Tuff of Guanajuato, Mexico. Environmental Earth Sciences, 69(4), 1189–1201. https://doi.org/10.1007/s12665-012-1781-1