Researchers at Ghent University have unveiled Belgium's first paving stones made entirely from household waste ash. The pilot is part of AshCycle, a Horizon Europe initiative that converts combustion ash into raw materials for low-carbon construction.
The Belgian consortium includes waste management giant Veolia, Ghent University and the companies ResourceFull, Orbix and SECO. The ash collected from incinerators is processed in Grimbergen before being tested in Ghent, where Professor Stijn Matthys' team studies its strength, durability and environmental impact.
“This is a CO2-negative stone,” said Professor Matthys. “We use CO2 together with ash and metal slag to form solid concrete. At a European level, the technology could save up to 20 megatons of CO2 annually. This is not a miracle solution, but it is a significant step towards a greener construction industry.”
“It is a significant step towards a more environmentally friendly construction industry”
Two 50 square meter test areas were created on the university campus: one with alkali-activated materials and another with carbstone technology, which captures CO2 during production.
Peter De Vylder, technical director of Veolia, highlighted the potential of the project: “For every 100 kilograms of residual waste, about 20 kilograms of ash remains. We can convert these residues into fully compliant building materials. This is a real opportunity for commercialization.”
Veolia says the initiative aligns with its GreenUp strategy and focuses on reuse and carbon-neutral innovation. The consortium's goal is to increase production within five years.
#FlandersNewsService | Samples of recycled household waste during a presentation of the first results of the AshCycle recycling project by a waste processing company in Ghent © BELGA PHOTO JONAS D'HOLLANDER