CO2 binding concrete aims to turn construction into carbon sink

by Robert Schreiber
Berlin, Germany (SPX) Mar 29, 2026
Concrete is one of the most widely used construction materials, but its cement content makes it a major source of greenhouse gas emissions.

Researchers at Karlsruhe Institute of Technology are working with partners in the EU-funded C-SINC project to turn concrete into a carbon sink by partially replacing conventional cement clinker with a new CO2 binding material.

The team is focusing on magnesium silicates that can react with carbon dioxide in a targeted and accelerated mineralization process to form magnesium carbonate.

Used as a secondary cement additive, this mineralized material can replace part of the Portland cement clinker that typically serves as the main binding agent in concrete.

Project members extract CO2 from industrial exhaust gases and feed it into the mineralization process, which allows the gas to be chemically bound in solid mineral form instead of being released to the atmosphere.

According to the researchers, the resulting concrete not only generates significantly fewer emissions during production but can also function as a long term storage medium for carbon dioxide because the CO2 remains locked in the mineral structure for very long periods.

Existing cement substitutes such as fly ash from coal combustion and ground blast furnace slag are expected to become scarce as coal fired power plants are phased out and the steel industry transforms its processes, increasing the need for alternative binders.

Within C-SINC, KIT scientists led by Professor Frank Dehn test how concretes made with the new secondary binder behave in terms of load bearing capacity, durability, and safety.

The research combines machine learning methods, structural mechanical modeling, and experimental work to understand how the new binding agent affects fresh and hardened concrete and to optimize mix designs for practical use.

The teams investigate material performance on small laboratory specimens and on large scale structural elements, aiming to generate reliable parameters and design rules that will allow engineers to use the new concretes in real construction projects.

A key goal of the project is to move quickly from laboratory development to application, so the research plan closely links simulations, physical testing, and full scale trials at KIT's materials testing facility in Karlsruhe.