If we told you there was a sustainable substitute for concrete you’d probably say rubbish!… and you would be right. The dream of a resource-saving, emissions-reducing replacement for concrete is becoming a reality in the form of BituBlock – made from post-consumer waste. Dr. John Forth of the University of Leeds is behind the revolutionary process that turns rubbish into a strong, less-energy intensive structural material that is poised to make concrete obsolete.
BituBlock is a high-performance product that is about six times stronger than traditional concrete block. It’s made by mixing waste products like recycled glass, metal slag, sewage sludge and incinerator ash with a sticky binder called bitumen, also used in road paving. The mixture is compacted in a mold and heat-cured, which oxidizes and hardens the bitumen.
While high recycled content is a vital part of sustainable construction, BituBlock’s landfill diverted ingredients are just part of what makes it so groundbreaking. Concrete is the most widely-used construction material with over ten billion tons produced annually. About 7% of global CO2 emissions come from concrete production. The primary source of CO2 emissions generated by concrete manufacturing is Portland cement, responsible for 74% to 81% of total CO2 emissions. In BituBlock, the bitumen binder replaces the Portland cement.
Structurally superior, BituBlock is gaining commercial interest and the project team, which also includes Dr. Salah Zoorob from the University of Nottingham, expects BituBlock to be market ready in just 3-5 years. Plans are also underway to develop ‘Vegeblock’ using waste vegetable oil.