Photothermal Radiometry Characterization of Limestone Rocks from the Península of Yucatán

Abstract

Limestone is a sedimentary rock composed of calcium carbonate with minor amounts of silica, iron oxide, clay, dolomite, and organic material. These types of stones have been used extensively as building materials. Due to this, determination of their thermal properties is of the utmost importance. These properties depend on the microstructure and composition of each type of rock. In this study, the effect of the thermal treatment of three different limestone rocks from the Peninsula of Yucatán were studied, in the range from 100 • C up to 600 • C, using photothermal radiometry. These studies were complemented by the characterization of the crystalline phases using X-ray diffraction and effective porosity measurements performed by the saturation technique. It is shown that the thermal diffusivity, thermal conductivity, and specific heat of the limestone decrease as the temperature increases. This behavior can be related to increases in microcracks and effective porosity due to thermal treatments.

Thermal effects on the physical properties of limestones from the Yucatan Peninsula

“…The value of the bulk density of the four rocks is between 1.98 g/cm 3 and 2.36 g/cm 3 (Table 1), which are lower than other values reported for limestone rocks [16,26,27]. A comprehensive study of porosity can provide valuable information to determine whether a given type of rock is susceptible to thermal stress or not.…”

Antifungal Coatings Based on Ca(OH)2 Mixed with ZnO/TiO2 Nanomaterials for Protection of Limestone Monuments

“…These results clearly show the effect of stone porosity on the susceptibility for fungal attack: although the visual inspection method of the surface and the averaging method of X-ray diffraction seemed to indicate that limestone B was more susceptible to fungal deterioration, most likely related to a different mineralogical composition, the SEM images demonstrate that the more porous limestone A is more prone to fungal deterioration up to much greater depths. It has been found that fungi are able to penetrate up to a depth of 4 to 9 mm, through cracks and microfissures of rock samples in stone buildings after 6 months of culture . In summary, limestone A has a higher porosity, hence, a high incidence of fractures and cavities was generally present, leading to more pronounced hyphae penetration.…”

“…It has been found that fungi are able to penetrate up to a depth of 4 to 9 mm, through cracks and microfissures of rock samples in stone buildings after 6 months of culture. 51 In summary, limestone A has a higher porosity, hence, a high incidence of fractures and cavities was generally present, leading to more pronounced hyphae penetration. In addition, because the TiO 2 -based coatings were characterized by a higher incidence of cracking, their performance in terms of hyphae penetrations was generally worse than for the ZnO-based coatings.…”