Sustainable Aggregates for Low-Carbon Construction
1 October 2026
Affiliation
NTU
Focus topic
CO2-to-Aggregates
Low-Carbon Aggregates for Concrete Applications
Summary
Aggregate is the largest ingredient in concrete by volume and the single biggest carbon sink available in construction materials, yet existing CO₂-mineralised aggregates are still carbon-positive and too weak, typically 5-15 MPa against the 30 MPa structural concrete needs. This invention produces construction aggregate from waste-derived materials while permanently incorporating carbon dioxide (CO₂) into the aggregate.
Achievements: The result reached 31 plus or minus 4 MPa compressive strength with 26.8% CO₂ uptake by weight, giving a net footprint of minus 0.186 kg CO₂ per kg of aggregate. Replacing half the natural sand in 50 MPa structural concrete cut embodied carbon about 10% with no strength penalty; in mortar, full replacement produced carbon-negative mortar with mechanical performance intact. At half the density of sand it is also a lightweight aggregate.
Carbon abatement potential is net negative, combining permanent mineral storage of CO₂ inside the concrete with displacement of mined aggregate.
What makes this novel compared to best-in-class technology?
The raw materials are derived from waste streams and captured CO₂, creating a sustainable pathway to produce construction aggregates. The resulting aggregates can replace mined gravel in concrete while permanently storing carbon within the built environment.
TRL Level
1-3
Relevant for
Ready-mix concrete and precast producers, aggregate suppliers, desalination plants supplying reject brine
About
Inventors: Yang En-Hua, Chen Xi
Affiliation: Nanyang Technological University, Singapore (NTU), School of Civil and Environmental Engineering (CEE)
Contact NTU for licensing opportunities and more information.
Please quote ID ref [2025-319] in your email.