In the heart of Europe, a mountain of construction and demolition waste (C&DW) grows each year, with concrete making up a substantial third of the pile. While recycling efforts have primarily focused on repurposing coarse aggregates, a significant portion—20-30%—of the recycled output consists of fine particles and hydrated cement powder (HCP). This often-overlooked byproduct could be a game-changer for the construction industry, according to a recent study published in the journal *Developments in the Built Environment* (translated as *Advances in the Built Environment*).
Lead author Pablo Muñoz, affiliated with the Universidad Internacional de La Rioja in Spain and the Universidad Autónoma de Chile, has been exploring innovative ways to breathe new life into this often-discarded material. His research investigates the potential of substituting clay with up to 30% HCP in the production of fired clay bricks, a process that could leverage the high-temperature firing already involved in brick manufacturing.
The study reveals that incorporating HCP into bricks enhances their properties, particularly at higher firing temperatures. “We found that the bricks’ mechanical strength and durability improved with the addition of HCP,” Muñoz explains. “This is a significant finding, as it opens up new possibilities for utilizing recycled materials in construction.”
However, the environmental implications present a complex trade-off. While the use of HCP reduces thermal conductivity, making bricks more energy-efficient in use, the global warming potential and water consumption impacts are higher. “This poses a challenge,” Muñoz acknowledges. “We need to balance the improved material performance with the environmental cost.”
The commercial impacts for the energy sector could be substantial. As the demand for sustainable building materials grows, the ability to repurpose HCP could drive innovation in brick manufacturing. “This research could shape future developments in the field,” Muñoz suggests. “By finding ways to mitigate the environmental impacts, we can make the process more viable and attractive to manufacturers.”
The study’s findings highlight the need for further research and development to optimize the use of HCP in brick production. As the construction industry continues to seek sustainable solutions, the insights from this research could pave the way for more eco-friendly and efficient building practices. The study is published in the journal *Developments in the Built Environment*, offering a glimpse into the future of recycled materials in construction.