Experimental Investigation of Gypsum’s Mechanical Properties Using Triaxial Compression Tests

Abstract

Gypsum is a widely used sulfate mineral, and it is an important construction material used to make plaster and drywall due to its rapid hardening and low thermal conductivity. However, its mechanical performance under varying stress conditions, particularly the influence of water content on strength and deformation behavior remains underexplored. This study investigates the mechanical properties of gypsum through triaxial testing, focusing on stress-strain response, failure modes, and the Mohr-Coulomb failure criterion. Wet gypsum specimens with pore saturations of 10%, 20%, and 40%, were subjected to controlled loading conditions (0.414 MPa) to evaluate the impact of moisture on mechanical strength. Experimental results demonstrate that increased water content reduces peak strength. X-ray micro-computed tomography (Micro-CT) was used to analyze internal microstructural changes, revealing variations in particle distribution, and observing cementations formed inside of the gypsum samples. This study offers better insights into the mechanical response of gypsum, supporting its effective application in geomechanics and engineering practices.