Mechanical and microstructural properties of stone units in the masonry building stock of Urla peninsula

This experimental study focuses on two most commonly used stone types in masonry building stock on the Urla Peninsula of İzmir: sandstone and limestone. The compressive behavior of these stones, which is critical to the structural integrity of historic and contemporary stone masonry buildings in the region, was analyzed in detail. To assess their mechanical performance under compressive stress, uniaxial compressive loads were applied to the stone samples, which were gathered after an extensive field survey. Scanning Electron Microscopy (SEM) and Brunauer-Emmett-Teller (BET) analyses were leveraged to characterize their microstructure. SEM analysis provided detailed insights into the surface morphology and microstructural composition of the stones, revealing differences in grain size and bonding. BET analysis was used to determine the specific surface area and pore size distribution, which are key factors influencing the stones' mechanical strength and durability. The results demonstrated that limestone exhibits significantly superior mechanical properties under compressive stress compared to sandstone. Specifically, the denser and more homogeneous microstructure of limestone, characterized by smaller pores and fewer micro-cracks, contributes to its higher compressive strength. This was corroborated by BET analysis, which showed that limestone has a larger surface area and less porous structure, enhancing its load-bearing capacity. In contrast, sandstone, with its relatively higher porosity, displayed lower resistance to compressive forces, making it more susceptible to deformation and failure under axial loads. The study underscores the importance of microstructural characteristics in determining the mechanical performance of natural building materials.