Strategies for mineralogical analysis of concrete after exposure to fire

Abstract

Understanding the chemical and mineralogical changes that occur in concrete after exposure to high temperatures, such as during fires, is essential to define the necessary measures to ensure the stability of structures built with this material. Aiming to contribute to this field of study, this work investigates the modifications in the mineralogy of concrete exposed to high temperatures, proposing a simple and consistent methodology for its analysis. The research covers three types of concrete, produced with different aggregates (granite, carbonate, and pebbles). The analyses were carried out using X-ray diffraction (XRD) and thermogravimetry (TG/DTG) techniques, as well as the determination of insoluble residue (IR) by gravimetry. Variables such as the depth of the concrete in relation to the fire-exposed surface and the type of aggregate impacted the results obtained. The combination of XRD and TG/DTG techniques provided a more precise mineralogical analysis for the concretes in this study.