Start of the Max Planck-Fraunhofer cooperation project RICIMER

A team led by the Max Planck Institute for Solid State Research and the Fraunhofer Institute for Construction Physics has been awarded 1.8 Mio Euro for their project RICIMER – Roman Inspired Cement Innovation by Multi-analytical Enhanced Research. The project will start on March 1, 2022 and run for 4 years.

The goal of this project is the development of Roman-inspired cements with a greatly reduced carbon footprint and improved chemical and mechanical resilience due to their self-healing properties. This will be achieved by using melting products from municipal incineration ashes, which possess a similar chemical composition to volcanic ashes, as a raw material. Until now, only the ancient Romans knew the secret of how to treat such ashes to build concrete structures like the Pantheon in Rome with its astonishing properties. If successful, the project will open new horizons in sustainable construction by closing material cycles and developing future low CO₂ concretes – inspired by the past.

Cement production causes about 20% of the industrial CO₂ emissions world wide. Global efforts to reduce these emissions provide a huge challenge for the cement industry, since the carbon dioxide footprint of the cement production has to be reduced and raw materials for cement production become scarce. Up to now, slags from coal power plants or from iron and steel production form the basis of modern cements. As coal-fired powder plants will be shut down in most parts of the world during the next decades and as steel and iron production gradually shifts from using coke towards hydrogen, the raw material sources for conventional cements are dwindling. Accordingly, there is a high demand for cements with a low carbon footprint and resilience against mechanical stress and chemical corrosion, as the latter properties will reduce the overall cement consumption.

Already 2000 years ago, the ancient Romans already invented such a construction material that exhibits self-healing properties, which led to constructions withstanding sea water aggression and multiple major earthquakes. Roman cements were made from volcanic ashes, called puzzolanes.

For modern, large scale cement production these materials are too expensive. The Fraunhofer Institute for Construction Physics, however, developed a method for the decomposition of municipal waste ashes and showed that the melting products exhibit a mineral composition comparable to volcanic ashes. The goal of the RICIMER project is the utilization of waste as a raw material for sustainable cements, showing beneficial properties such as self-healing and corrosion resistance, like their ancient Roman counterparts. Within this project researcher at the Max Planck Institute for Solid State Research will investigate both ancient Roman cement samples and cement made from municipal waste ashes by state-of-the-art methods including vibrational and solid-state NMR spectroscopy, pair distribution function (PDF) analyses and X-ray powder diffraction. Thereby, a deep understanding of crystalline and amorphous cement phases will be established. This includes possible structural defects such as cation substitution, water interstratification and stacking faults in order to understand the self-healing properties of construction materials based on their microstructure.