Zurich – The Swiss Federal Institute of Technology in Zurich (ETH) has developed an ultra-green, cost-effective concrete that relies on low-CO2 cement and a new formulation of concrete. This enables emissions to be reduced by up to 75 percent. Production of the cement is already underway worldwide.
With its Ultra Green Concrete project, ETH aims to make low-CO2 high-performance concrete generally accessible. The researchers led by Franco Zunino, Senior Scientist at the ETH Institute for Building Materials, are adopting an approach from the Swiss Federal Institute of Technology in Lausanne: There, a cement formulation (LC3) of 50 percent clinker with a combination of fired clay and limestone was found to save around 40 percent CO2 compared to conventional cement. Zunino was involved in this development.
In the ETH project, he is now focusing on a second strategy to save CO2: reducing the amount of cement in the concrete. This dual strategy offers flexibility to adapt low-carbon concrete compositions to individual markets, according to a statement from ETH. “It would be ideal to implement both at the same time,” Zunino is quoted as saying. However, this is difficult in some markets, “as production capacities and infrastructure have to be built up. Nevertheless, it is possible to realize at least one of them and still save CO2.”
According to calculations by Zunino and his team, the CO2 emissions of ultra-green concrete can be reduced from 300 to around 80 to 100 kilograms per cubic meter without compromising the performance of the material. In his opinion, there are therefore no excuses in industrialized countries for not switching to the new, more sustainable building material immediately.
The low-CO2 cement is also more durable and cheaper than conventional cement. Its production is reportedly already running in seven cement plants worldwide. Zunino is convinced that LC3 will be the most widely used type of cement worldwide in ten years’ time. ce/mm