Physical and mechanical properties of sandstones from Southern Zanjan, north-western Iran

In this paper, three groups of quartz-rich sandstone were selected. These three groups include sandstones with low, medium and high quartz content. Three categories of tests including petrography tests, physical and engineering index property tests were performed on 26 samples of sandstones. Physical and engineering index property tests included porosity, density, P-wave velocity, and compressive and tensile strength tests. The purpose of the experiments/article was to find a relationship between different characteristics of the studied sandstone samples. Emphasis was placed on the effect of feldspar content and quartz content on the tensile and compressive strength of specimens. According to the results, significant relationships exist between the engineering index characteristics and the compressive and tensile strength of the samples as well as their elastic properties. The main finding of this research is that due to the presence of micro-mineral cracks in feldspar, increasing feldspar content reduces the compressive and tensile strength of the samples. Packing density, packing proximity, sub-angular and angular grains and quartz content are positively correlated with dry density and P-wave velocity and negatively correlated with porosity. Compressive and tensile strength and Young's modulus increase with increasing dry density, P-wave velocity, packing density, packing proximity, percent sub-angular and angular grains, and quartz content. Feldspar content has a positive correlation with porosity and a negative correlation with dry density and P-wave velocity.