Green recycling of red brick waste into aerogel panels for thermal insulation in buildings

The building sector has faced significant challenges due to its high energy consumption and waste management issues. Huge amounts of construction and demolition waste are abandoned in the streets or accumulated in landfills each year, which can negatively impact the environment if it's not managed correctly. Moreover, the use of heating and cooling systems is the major reason for making the building sector the most energy-harvesting sector and raising its greenhouse gas emissions. To deal with this situation, the demand for heat insulation materials has increased recently. This study suggests a promising solution lies in using waste brick as a precursor for aerogel synthesis instead of expensive and toxic organosiloxane precursors. This is a more cost-effective, feasible, and environmentally friendly approach to producing aerogel in comparison with previous works. Using a sol-gel process and ambient pressure drying technique, we could synthesize aerogel in a short time. Throughout the synthesis of aerogels, physical and chemical characterizations have been done. As a result, XRF analysis confirms that the waste contains 76% silicone and aluminum, which makes it a good precursor. Second, the prepared aerogel has a low density of 0.33 g/cm3 in addition to a highly porous network with a porosity of 84.76%. Finally, in order to characterize its thermal performance, different concentrations of aerogel were incorporated into the HDPE matrix. The composite panels were tested using the heat flow meter method. The results showed a decrease in thermal conductivity of 18%, 34%, and 47% by adding 5, 10, and 15% of aerogel, respectively. So, the as-fabricated WB aerogel panels have good thermal performance and great potential for eco-friendly and energy-efficient design for construction purposes. New method for recycling demolition and construction waste.Red brick waste as a novel aerogel precursor.The developed HDPE-aerogel panels exhibit both excellent thermal conductivity and low moisture content.Thermal conductivity of HDPE-aerogel composite panels achieved 0.066 W/m.K.