Influence of potassium hydroxide on the physical and mechanical properties of recycled brick waste aggregate

The increasing emphasis on sustainability in construction has driven extensive research into innovative methods for recycling brick waste. Adopting recycled brick products conserves natural resources, reducing landfill disposal and the energy required in new brick production. Recycled brick waste aggregate (RBWA) is one of the recycled brick products that is widely used as a replacement for virgin aggregate in concrete production. However, the high porosity, low density, and susceptibility to elevated water absorption of RBWA, compared to virgin aggregate, restricts its utility in building and infrastructure development. This study proposes a novel modification technique, using potassium hydroxide (KOH), to enhance the properties of RBWA, and investigates the physical and mechanical properties of RBWA modified with KOH. Key parameters for assessing the physical and mechanical properties of aggregate were measured and compared to the untreated RBWA. The analysis results indicated that water absorption in KOH-treated RBWA was reduced by 21.2%, aggregate crushing by 25.1%, and the apparent density increased by 26.4%. Consequently, utilizing KOH-modified RBWA in concrete production could help reduce carbon emissions and lead to more sustainable construction methods.