On the relationship between the mechanical strength and mineral microstructure of biotite granite under temperature influence

Many studies are currently focusing on the mechanical properties of granite from macroscopic and microscopic perspectives, but only several influence rock mineral composition using a combined macro-micro assessment. The biotite in Gaoligong Mountains was selected as research object, variation strength characteristics at 20–130°C were obtained through uniaxial compression experiments. rock’s compressive elastic modulus reached peak values 40°C. main components determined by X-ray powder diffraction quartz, biotite, albite, potash feldspar. With Material Studio software, molecular dynamics simulations carried out crystal models feldspar 20–130°C, relevant parameters calculated. experimental data compared analyzed. results show that: 1) due to thermal expansion minerals rock, original cracks between particles partially closed, sample is largest 40°C; 2) temperature mostly affects quartz phases, increases first then decreases with increase. albite less affected temperature; 3) that reaches value certain range. critical different because also contains small amount argillaceous siliceous phyllite, some calcareous cement beside composition; 4) structural changes temperature. bond length while mechanism increase for these two it requires further exploration.