Impacts of anisotropy coefficient and porosity on the thermal conductivity and P-wave velocity of calcarenites used as building materials of historical monuments in Morocco

Abstract

It is essential to study the porosity, thermal conductivity, and P-wave velocity of calcarenites, as well as the anisotropy coefficients of the thermal conductivity and P-wave velocity, for civil engineering, and conservation and restoration of historical monuments. This study focuses on measuring the thermal conductivity using the thermal conductivity scanning (TCS) technique and measuring the P-wave velocity using portable equipment. This was applied for some dry and saturated calcarenite samples in the horizontal and vertical directions (parallel and perpendicular to the bedding plane, respectively). The calcarenites were selected from some historical monuments in Morocco. These physical properties were measured in the laboratory to find a reliable relationship between all of these properties. As a result of the statistical analysis of the obtained data, excellent linear relationships were observed between the porosity and both the thermal conductivity and porosity. These relationships are characterized by relatively high coefficients of determination for the horizontal and vertical samples. Based on the thermal conductivity and P-wave velocity values in these two directions, the anisotropy coefficients of these two properties were calculated. The internal structure and the pore fabric of the calcarenite samples were delineated using scanning electron microscopy (SEM), while their chemical and mineral compositions were studied using the energy dispersive X-ray analysis (EDXA) and X-ray diffraction (XRD) techniques.