Recycled or fresh? The source of the ingredients has a big impact on the CO2 balance of concrete

Recycled or fresh? The source of the ingredients has a big impact on the CO2 balance of concrete

A favorable carbon footprint for the construction industry

Readingtime 2 minutes

A Swiss startup is turning concrete rubble into high-quality limestone that also stores carbon dioxide

Concrete largely consists of cement, whose production accounts for around seven percent of global greenhouse gas emissions. The Swiss startup Neustark has now greatly improved the poor CO₂ balance of this ubiquitous construction material. The team headed by Johannes Tiefenthaler and Valentin Gutknecht has developed a technology that extracts carbon dioxide from the atmosphere and locks it up in concrete rubble, which is primarily created by the demolition of buildings. When CO₂ reacts with the calcium hydroxide in concrete, it results in new high-quality limestone that can replace newly produced cement in the production of fresh concrete. This technique enabled the company, which was outsourced from the Swiss Federal Institute of Technology (ETH) in Zürich three years ago, to improve the climate performance of fresh concrete by 10 percent. Neustark’s next plan is to make climate-neutral concrete a reality by 2025.

Photo: Neustark AG


A self-healing construction material

One key to reaching the goal of sustainable concrete is bacteria that fill cracks in materials on their own.


The future of construction

How do we build more sustainably in the future? A discussion between a concrete researcher and an architect.

Construction materials

Cement: Facts and figures

Cement is a basic component of concrete that is in demand all over the world. Billions of tons of it are produced annually.


Crop residues for the fuel tank

Corn, wheat, straw, and millet: Researchers in the USA have found a way to produce ethanol from crop residues.