Evaluation of the thermal performance of eco-friendly bricks fabricated with incorporation of mullite residues

The aim of this research was the produc-tion of clay-brick, from red clay, waste from a disused electric furnace, reinforced with ceramic fibers, to obtain a ceramic mate-rial with refractory characteristics. The clay/waste particle proportion was 50:50 by weight, and the incorporation of fiber was 10% and 20% by volume, to obtain a ce-ramic by sintering at 1000°C, for 2 hours. The designed materials were characterized by X-ray diffraction, the flexural and com-pressive strength, density, porosity, and absorption were determined. The thermal performance was also verified by direct ex-posure to 1000°C flame. The results showed that as ceramic fiber was incorporated, the compressive strength decreased by 17.3% for AF10 and 17.0% for AF20. The flexural strength values were at 3.4 MPa. The coe-fficient of thermal conductivity was 0.5322 W/m.K, and, during direct flame exposure, the samples achieved a thermal gradient of ~ 700 °C for samples 2 cm thick. The mi-neralogical phases obtained for the bricks were mullite, corundum, and cordierite, which are considered refractory.