Variation of Wave Velocity and Porosity of Sandstone after High Temperature Heating

This paper reports the variations of mass, porosity, and wave velocity of sandstone after high temperature heating. The range of temperature to which the sandstone specimens have been exposed is 25-850 degrees C, in a heating furnace. It has been shown that below 300 degrees C, porosity and wave velocity change very little. Above 300 degrees C, there is a rapid increase in porosity, but the wave velocity decreases significantly. The results of thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC) and mercury intrusion porosimetry (MIP) suggest that a series of changes occurred between 400 and 600 degrees C in sandstone could be responsible for the different patterns of variation in porosity and wave velocity.