Effect of Water on Mechanical Properties of Coal Measures Mudstone Using Nanoindentation

Mudstone rich in clay minerals exhibits an obvious water-induced weakening effect, and the mechanical properties of mudstone are significantly affected by groundwater. To investigate effect water on characteristics at microscale, a series uniaxial compression nanoindentation tests were conducted specimens different moisture contents. Microscale measurements upscaled to estimate corresponding magnitudes macroscale using Mori-Tanaka method. The results showed that indentation modulus varied significantly, from as low 0.2 GPa quite high value 125 GPa, indicating strongly heterogeneous distribution mudstone. illustrated significant microscale water-sensitivity like minerals. occupied highest proportion believed play important role For water-bearing specimens, comparison with elastic data obtained common method indicated similar values those predicted homogenization this study technique is feasible experimental assess rock materials.