In the heart of Ostrava, Czech Republic, researchers at the VSB—Technical University of Ostrava are making strides in sustainable construction, with implications that could ripple through the energy sector. Radoslav Gandel, leading a team from the Department of Building Materials and Diagnostics of Structures, has been investigating how recycled construction waste can be repurposed as aggregate in high-performance concrete. The findings, published in the journal ‘Buildings’ (which translates to ‘Stavby’ in Czech), offer a promising glimpse into a more sustainable future for construction materials.
The study compared the mechanical properties of high-performance concrete mixtures, some of which included recycled concrete aggregate (RCA) as a substitute for natural aggregate. “We wanted to understand how much recycled material could be used without compromising the concrete’s performance,” Gandel explains. The team tested mixtures with 15% and 30% RCA, alongside a reference mixture containing only natural aggregate.
The results were encouraging. While the compressive strength of the concrete decreased slightly with higher proportions of RCA, the flexural strength remained stable across all mixtures. “This suggests that recycled aggregate can be used in structural applications without significant loss of performance,” Gandel notes. Moreover, the concrete demonstrated adequate resistance to de-icing agents and sulfuric acid, crucial for structures exposed to harsh environments.
One of the most intriguing findings was the improved flexural strength of specimens subjected to frost-resistance tests. This unexpected boost in strength could be due to ongoing hydration or microcrack healing, offering a new avenue for research.
The study also assessed the structural performance of reinforced concrete beams made from these mixtures. Remarkably, the beams with partial aggregate replacement achieved a higher load-bearing capacity than the reference beams. This finding could have significant implications for the energy sector, where robust, sustainable materials are in high demand for infrastructure projects.
The research also introduced an innovative optical surface evaluation method, which proved to be a valuable complement to conventional strength testing. This approach could streamline quality control processes in the construction industry, reducing costs and improving efficiency.
Gandel’s work is part of a growing trend towards sustainability in the construction industry. As the demand for eco-friendly materials increases, recycled aggregate concrete could become a mainstream choice for builders and developers. “Our findings support the potential of recycled aggregate concrete for structural applications,” Gandel states. “This could significantly reduce the environmental impact of construction projects, particularly in the energy sector.”
The implications of this research extend beyond the construction industry. As the world grapples with climate change, the need for sustainable materials has never been greater. Gandel’s work offers a promising solution, one that could help reduce waste and lower carbon emissions.
In the coming years, we may see recycled aggregate concrete becoming a standard choice for construction projects, from buildings to energy infrastructure. As Gandel and his team continue to explore the potential of this innovative material, the future of sustainable construction looks brighter than ever.