In the heart of Brazil, researchers are turning the tables on construction and demolition waste (CDW), transforming what was once considered mere rubbish into a valuable resource for the construction industry. Natália Tavares Gomes, a leading figure from the Advanced Materials Laboratory at the State University of the Northern Rio de Janeiro (UENF), has been spearheading a review of studies that explore the potential of CDW in mortars, both as a partial substitute for cement and sand, and after heat treatment.
The sheer volume of CDW generated globally is staggering, often ending up in landfills and contributing to environmental degradation. However, Gomes and her team are championing a more sustainable approach. “CDW stands out with great potential for recycling and sustainable development,” Gomes asserts, highlighting the urgency of addressing this burgeoning waste stream.
The review, published in the Journal of Materials Research and Technology (translated to English as ‘Journal of Materials Research and Technology’), delves into the intricacies of how different types of CDW and varying degrees of replacement can influence the mechanical resistance of mortars. Fine residual mortar powders, for instance, contribute to the strength of CDW due to their filling effect. Moreover, heat-treated CDWs enhance mechanical strength through the rehydration of products, forming a new C-S-H gel when exposed to water again.
The implications for the energy sector are profound. By recycling CDW, the construction industry can significantly reduce its carbon footprint, a critical factor in the fight against climate change. The energy required to produce cement is substantial, and any reduction in demand for this material can lead to considerable energy savings. “Considering the variety of CDW and its influence on mortar properties, studies are still needed to provide a better understanding for possible applications,” Gomes notes, underscoring the need for continued research in this area.
The commercial impacts are equally compelling. As the construction industry increasingly embraces sustainable practices, the demand for innovative, eco-friendly materials is on the rise. Companies that can harness the potential of CDW stand to gain a competitive edge in this evolving market. The durability of mortars with partial replacements by thermoactivated CDW remains an open question, but the potential is undeniable.
Gomes’s work is a beacon of hope in the quest for sustainable construction practices. By turning waste into a valuable resource, she is not only addressing an environmental problem but also paving the way for a more sustainable future. The journey is far from over, but the path forward is clear. As the industry continues to innovate, the potential for CDW in mortars and beyond is limited only by our imagination.