Reinforced concrete under fire: Thermal path reconstruction

This paper presents the results of a post-fire investigation on a Reinforced Concrete industrial warehouse located in Cagliari (Italy). The authors applied several methods in order to identify the maximum temperature distribution and to assess the materials degradation. Optical and Scanning Electron Microscopy, X-ray diffraction, Thermogravimetric and Differential Thermo-Analysis and calibrated Colorimetry provided useful indications to carefully determine the changes in the mineralogical composition and microstructure of concrete. The absence or presence of some specific phases (like Portlandite) or the variations of colours (reddening of original pinkish-beige aggregates) are benchmark signs capable of assessing the maximum temperature with high accuracy. The approach and the data showcased in this work can be useful for other post-fire investigations and for the tuning of the relevant theoretical and numerical models.