Study of Physico-Mechanical Characteristic of Jurassic Rock Unit from the Serki and Sehkaniyan Formations for a Dimension Stone, Sulaimaniyah City, NE-Iraq

Natural stones are widely used for paving, crushing, building, and dimensioning purposes worldwide. There are plenty of natural stone resources in the Sulaimaniyah governorate of north-eastern Iraq that can be used for a range of architectural and ornamental purposes. The aim of this study is to evaluate the suitability of dolomitic limestone from the Serki and Sehkaniyan formations for use as dimension stone based on their physical and mechanical properties. In this study, 21 samples of the Serki and Sehkaniyan dolomitic limestone rock were collected in outcropped rock units within the quarry sites. The physical testing of rocks includes assessments of total porosity, water absorption, saturation coefficient, apparent specific gravity, and bulk density. Based on Iraqi standard specification 1989, 1387 and American standards 2004, C568, all tested characteristics were classified as having very high density, and the rock units were frost-resistant. The uniaxial compressive strength (UCS) of the rock samples indicated a strength range of 60 to 80 MPa, these values are higher than the strength in the parallel orientation tested samples which are 43 to 56 MPa. Based on different classifications and standards, the majority of the tested samples were rated as strong to very strong, while only a few were considered moderately strong. Notably, there are significant relation between the UCS values and the physical parameters of the rock units, also strong relation with the point load index were observed in both perpendicular and parallel testing modes, yielding R² values of 0.85 and 0.76, respectively. Excavatability assessment shows most samples need hard ripping or blasting due to high strength and wide fractures. Standard excavation tools may not be effective for these rocks. The results reveal that the Serki and Sehkaniyan formations examined are of high quality and suitable for use as dimension stone for both exterior and interior applications, as well as for paving and construction materials.