Innovation: high-performance ultrasound premixing plant

This year‘s winner of the Innovation Award of the Supplier Industry for Concrete Components goes to Cottbus: Sonocrete presents an innovation that takes on the challenges posed by CO₂ emissions in the concrete industry. This technology, developed by Dr. Christiane Rössler of Bauhaus University and by Dr. Ricardo Remus, Managing Director of Sonocrete, promises a sustainable future for the construction industry.

Conventional concrete production encounters obstacles in dealing with the reduction of CO₂ emissions. Because the most important – and, until now indispensable, constituent in concrete: cement – also carries the heaviest emission rucksack. Climate-friendly cement such as CEM II and CEM III already exist. They contain a lower clinker content than previously used cement types. However, they have the disadvantage that they, as a rule, allow the concrete to harden more slowly, which negatively affects cost efficiency.

Acceleration of hydration

And this is precisely where Sonocrete begins. The Sonocrete premixing plant accelerates the reaction of the cement, and thus the reaction of the concrete, with the aid of high-performance ultrasound technology. All of this is without the use of heat or chemical activators. In this way, the use of the Sonocrete system results in significant reduction of the cement and/or clinker content in the concrete formulation, without compromising early strength and quality. By this method, CO₂ emissions can be reduced by up to 30 %.

And this is how it functions: one part of cement and one part of water in the concrete formulation is premixed in the plant and treated with ultrasound. The ultrasound in the cement slurry generates cavitation, which creates extreme local conditions. This results, first, in an improved dispersion of the cement and, second, in faster formation of strength-building C-S-H phases. Following curing time, this activated suspension is placed, at the begin of mixing, into the mixer together with the remaining constituents and the mixing process is started as usual. The remaining production of the concrete and of the construction components is not changed.

The Sonocrete technology was not only thoroughly tested in the laboratory: it has also been used in real operations – beginning with a prototype on industrial scale. With this prototype, the Sonocrete team toured concrete plants in Germany and Austria for one year, in 2022. They supported concrete production in these plants and demonstrated that their technology not only functions in theory, but can also be successfully used in practice. The tour ended with the production of climate-friendly concrete for the Maintenance Center of German Railways in Cottbus. Savings of 30 % in CO₂ emissions were realized in production of beams and columns.

One of the greatest advantages of the Sonocrete plant is that it can be integrated and used in nearly every precast plant. The technology functions as a bypass system and can be seamlessly integrated in the existing production processes without significantly changing usual concrete production. The first plant has already been installed in a precast plant in North Rhine-Westphalia, and two other plants are in the completion phase.