Investigating the effects of porosity on the strength and mechanical behaviors of geo-materials’ specimens

Porosity plays a crucial role in both natural and man-made materials, serving as a fundamental microstructural characteristic that has a significant impact on their physical properties. Soils and rocks in nature are porous materials that are usually saturated with different fluids such as water, oil and gas. Therefore, it is very important to investigate the properties of porous materials and a better understanding of porous materials properties can lead to progress in oil, mining, and civil industries. In this research, porous samples with different porosity percentages were made and analyzed. The laboratory generation of actual porosity within the rock-like material samples was one of a significant aspect of this research. ۵ groups of samples with different percentage of porosities were prepared including: ۲۰%, ۱۵%, ۱۰%, ۵%, ۲% porosity and classified in ۵ groups of A, B, C, D and E, respectively. Various experimental tests were performed with loading rate .۵ MPa per second on the samples and the mechanical parameters of the samples were determined. These experiments show that the uniaxial compression and tensile strengths and elastic modulus of the rock-like specimens decrease with increasing their porosity. The mechanical parameters' maximum values were associated with group E samples (with ۲-۳% porosity). This group demonstrated a strength of approximately ۳۴ MPa, an elastic modulus of ۳۶ GPa, and a tensile strength of ۷.۳ MPa. The minimum values were observed in group A (with ۲۰% porosity), which exhibited a strength of approximately ۱۳ MPa, an elastic modulus of ۱۶ GPa, and a tensile strength of ۲.۷ MPa. The study also investigated the Poisson’s ratio. The results indicate that Poisson's ratio increases with increasing porosity. The maximum Poisson's ratio was found in group A, which had ۲۰% porosity and ۱۱% Poisson's ratio, while the minimum value was found in group E, which had ۲-۳% porosity and ۲۶% Poisson's ratio. the result show that Porosity has the greatest effect on the tensile strength parameter, which can change the tensile strength by ۲۷۰% with a ۲۰% change.

کلیدواژه ها:

Porosity ، Uniaxial Compressive Strength ، Tensile Strength ، Mechanical properties ، Rock-like materials