Читать книгу Monument Future - Siegfried Siegesmund - Страница 62

Volcanic tuff was of great importance in the ancient culture of Zapotecs and Mixtecs as a construction material. The historical buildings in both Mitla and the historical center of Oaxaca were erected with a great variety of volcanic tuff rocks, many of which are not quarried anymore. These tuffs were compared and evaluated regarding their petrophysical properties and weathering behavior. Analyses of the petrography, pore space, water transport and water storage as well as mechanical properties were performed.

The results of the investigations show that the rocks have high sensitivity to water, linked to high porosities and high amounts of capillary pores. Additionally, very variable behavior towards hydric expansion and salt bursting provokes different responses to weathering and decay. To protect the historical buildings in Oaxaca, it is therefore necessary to control the exposure to water or to find suitable conservation measures for the stones.