Experimental study of real-time temperature-dependent nonlinear deformation of sandstone

•The real-time heat treatment test of sandstone was performed at a moderate temperature range.•The two-part Hooke’s model is valid for the nonlinear deformation subject to real-time temperature of sandstone.‘•Thermal weakening is due to an increase in the soft part range 25℃-125℃.•Thermal strengthening is attributed to the thermal expansion of the hard part range 125℃-200℃.•The real-time temperature dependent nonlinear deformation relationships are proposed.