Exploring flexural performance and abrasion resistance in recycled brick powder-based engineered geopolymer composites

Background

Due to growing global concerns regarding the management of construction waste, this study investigates the feasibility of creating engineered geopolymer composites by replacing traditional industrial by-products (slag) with construction waste, specifically recycled brick waste powder.

Results

Polyvinyl alcohol fibers were incorporated into the engineered geopolymer composite mixtures. The substitution of slag with recycled brick waste powder was carried out at varying percentages: 0, 20, 40, 60, 80, and 100%, resulting in six different engineered geopolymer composite mixtures. The study evaluated the flexural strength, sorptivity, water absorption, and abrasion resistance of the engineered geopolymer composites, and also, microstructural characterization was conducted using scanning electron microscopy. The findings demonstrated that incorporating recycled brick waste powder into the engineered geopolymer composite mixes resulted in a decrease in flexural strength by 35.59% and a notable increase in midspan deflection by 339% when slag was replaced. Concurrently, there was a significant rise in water absorption and sorptivity by approximately 304 and 214%, respectively, when slag was entirely substituted with recycled brick waste powder. Conversely, abrasion resistance decreased, with the inclusion of recycled brick waste powder resulting in an 84% increase in volume change. The scanning electron microscopy (SEM) analysis showed active geopolymerization of recycled brick waste powder within the engineered geopolymer composite mixtures.

Conclusions

The results of this investigation demonstrate that it is feasible to produce engineered geopolymer composites using recycled brick waste powder instead of slag. The greater ductility and increased midspan deflection point to areas that require further optimization, even in spite of the observed decreases in flexural strength and abrasion resistance. The SEM examination reveals an active geopolymerization, highlighting the potential of recycled brick waste powder to produce environmentally friendly and sustainable construction materials. These results offer a good starting point for further studies that try to maximize the durability and performance of these composites.