Changes in glossiness, electrical properties and hardness of red sandstone after thermal treatment

The physical properties (glossiness, hardness, capacitance and electrical impedance) of red sandstone after thermal treatment at different temperature will be performed differently. The experiments show that the entire process can be divided into three stages. (1) 100–400 °C: as the temperature increases, the amount of water that exists as free water inside red sandstone is reduced, and micro-cracks begin to appear at the interior. (2) 400–800...