Waste-derived Phosphate-based Eco-binders for Net-zero and Circular Infrastructure

The construction sector is responsible for nearly 37% of global CO2 emissions, with Portland cement alone contributing around 7%. At the same time, Europe faces resource challenges, including phosphorus scarcity, excess sewage sludge, and the annual management of over 830 million tonnes of construction and demolition waste. Addressing these challenges requires a paradigm shift toward circular, waste-based construction solutions. The PHOENIX project pioneers the first fully circular phosphate-based geopolymer binder produced entirely from municipal and industrial wastes. Unlike existing EU projects that focus separately on alkali activation or aggregate recycling, PHOENIX uniquely valorises sewage sludge incineration ash, phosphogypsum leachates, and recycled concrete aggregates (RCA), creating 100% waste-derived composites without synthetic activators. This dual innovation directly supports the EU’s Green Deal, Circular Economy Action Plan, Raw Materials Strategy, and upcoming EN 206 / CEN/TC 350 standards. The project is structured into five objectives: (RO1) source and characterise EU-relevant waste streams; (RO2) optimise phosphate-binder formulations; (RO3) integrate RCA and assess binder–aggregate interactions; (RO4) evaluate durability, microstructural evolution, and environmental safety; and (RO5) validate pilot-scale performance (50–100 kg) with life cycle and techno-economic assessment. For 30 months, PHOENIX will advance from TRL 2–3 to TRL 5–6, reinforced by secondments at UniMAP in Malaysia and IIT Indore in India and a six-month industrial placement at Recycle it Global Ltd. in the UK for prototype development and market validation. By demonstrating scalable, low-carbon alternatives to cement, PHOENIX will cut emissions, valorise EU waste streams, and equip SMEs with affordable technologies, delivering scientific excellence, industrial impact, and EU-specific added value in the transition to net-zero, resource-efficient infrastructure.