Experimental investigation of the uniaxial compressive behavior of thin building granite

Abstract

To investigate the uniaxial compressive behavior of a thin granite material, three groups of thin granite cylinders with the same length-to-diameter ratio (L/D) of 0.5 but with different lengths were manufactured. An additional group of standard cylinders was made to compare the mechanical properties with those of cylinders with smaller lengths. Uniaxial compressive tests were carried out, and the resulting stress–strain diagrams were obtained. Brittle columnar fracture failure was the typical damage mode. The geometrical shape of the pre-peak stress–strain diagrams was nonlinear in the four groups of specimens. The post-peak branches were nonlinear for the diagrams of groups with lengths of 25 mm and 30 mm, while the branches were linear in the other two groups. The resulting compressive strength ranged between 119 N/mm2 and 167 N/mm2, and it varied with the geometries. A representative stress–strain diagram of each group of specimens was fitted based on the obtained diagrams. The resulting two types of diagrams matched the experimental diagrams closely compared to those in the reference literature. The mechanical properties such as the elastic modulus and threshold stresses of each stress–strain diagrams were obtained, and their relationships were analyzed and fitted mathematically. The size effects of the specimens were discussed through the relationships between the strength (or elastic modulus) and the diameter. The strength modification formulas were evaluated in terms of the L/D ratio. It was found that these formulas did not apply to the tested specimens.