Mineralogical Transformations in Granitoids during Heating at Fire-Related Temperatures

Fire is a major decay agent of rocks and can generate immediate catastrophic effects as well directional anisotropic damage that affect long-term weathering processes. Temperature increase the most relevant factor, among other components in fire, generating mineral transformations bulk mechanical damage. Mineralogical changes at high temperatures are key to understanding overall behaviour. However, studies date were carried out after rock specimens heated target temperature cooled down room temperature. Therefore, these missing observation actual processes during heating. This paper aims compare mineralogical crystalline heating by means XPS different XRD techniques. Samples four granitoids several up 1000 °C evaluate their chemical structural changes. Results show how standardised thermal expansion coefficients not suitable indicator effect on rocks. also estimations from lattice measurements may be an alternative dilatometric tests, they performed with limited sampling, which necessary some studies. Nevertheless, results need interpreted carefully relation rocks, behaviour seemingly contradict macroscopic effect.