Strength anisotropy in building granites

Abstract

Throughout history, natural stones have been used as building materials in the architectural heritage. The purpose of this research is to assess the influence of anisotropy on building granites’ behavior. This article deals with San Giovanni in Fiore granite (Italy). Samples are subjected to several tests, namely: petrographic analysis; ultrasonic P-waves velocity; uniaxial compressive, flexural and indirect tensile strength; and point load, with respect to different angles between splitting planes and loading directions. Good strength values indicate that this granite is to be considered as adequate as building material, even though it exhibits an anisotropic behavior. The microcrack systems and their different orientation along the spatial directions, influence the petrophysical and mechanical behavior. The highest strength values are registered for the anisotropic XY plane (Z-direction), for all performed tests. Thus, it can be used in construction whilst considering the anisotropic directions to improve its strength properties and its resistance to decay processes.