In the quest for sustainable construction materials, researchers are turning to an unlikely ally: construction and demolition waste (CDW). A recent review published in the journal *Buildings* (translated as “Buildings”) explores how alkali-activated materials (AAMs), also known as geopolymers, can be enhanced using CDW, potentially revolutionizing the building industry and offering significant benefits for the energy sector.
Luca Baldazzi, a lead author from the Department of Civil, Chemical, Environmental and Materials Engineering at the University of Bologna, explains, “Alkali-activated materials have long been considered a sustainable alternative to traditional ordinary Portland cement (OPC). However, their production still consumes energy and emits carbon. By incorporating CDW, we can address both the disposal issue and enhance the sustainability of AAMs.”
The review highlights the dual benefits of using CDW: as a precursor for manufacturing AAMs and as a replacement for natural aggregates. This approach not only reduces the environmental impact of construction but also mitigates the exploitation of natural resources like river sand and gravel. Baldazzi emphasizes, “A new circular economy could be created based on CDW recycling, fostering a more eco-friendly building practice.”
However, the path to widespread adoption is fraught with challenges. The variability in CDW composition, the cost of mechanical and thermal treatment, and the complexity of alkali-activated mix-designs pose significant hurdles. Public skepticism about recycled materials in construction further complicates the scenario.
Despite these challenges, advancements in technology are making large-scale reuse of CDW more feasible. Baldazzi notes, “Thanks to comprehensive protocols, building information modeling (BIM) software, and machine learning models, we are better equipped to overcome these obstacles.”
The commercial implications for the energy sector are substantial. By reducing the energy consumption and carbon emissions associated with traditional cement production, the use of AAMs and CDW can contribute to a more sustainable energy future. This research could shape future developments in the field, paving the way for innovative, eco-friendly construction practices that align with global sustainability goals.
As the construction industry continues to evolve, the integration of CDW into AAMs offers a promising avenue for reducing environmental impact and fostering a more sustainable built environment. The review published in *Buildings* serves as a crucial step in this direction, providing valuable insights and paving the way for future advancements.