Physical-mechanical characterization of limestones from Yucatan churches, Mexico

Abstract

Churches in Yucatan region in Mexico are considered a built heritage legacy of great cultural interest. Some of these churches exhibit some pathologies with deformation mainly located at the stone masonry vaults. The churches are mostly built with ruble stone masonry walls and vaults in which limestone and lime mortar predominate. The design of any intervention on this type of structure requires the knowledge on the masonry materials, but very scarce information exist on the properties of limestone and lime mortar used in the construction of the churches. Therefore, the characterization of the existing materials, namely the limestone is considered to be of great interest.This research aims at the characterization of limestones found in masonry churches from sixteenth to eighteenth centuries located in Yucatan region in Mexico. To achieve the objectives, an experimental campaign was designed with the following steps: (1) identification of churches under ruins and in situ collection of stone specimens, (2) characterization of physical and mechanical properties on the collected specimens; (3) evaluation of the mineralogical composition of limestones and petrography description; (4) assessment of correlation between physical and mechanical properties.It was found that the limestones studied were mainly composed of calcium carbonate (CaCO3) and based on the physical properties, it was possible to group them in three different groups. It was also found that different ranges for the compressive strength and modulus of elasticity were obtained for the limestone belonging to each group defined. The relation between physical and mechanical properties was analyzed by a set of statistic correlations, for which very reasonable coefficients of determination were found.