The compression strength of this eco-concrete, measured 28 days after setting, is a record-breaking 107 megapascals (MPa), while normal high-strength concrete is specified to withstand at least 55 MPa.
The raw materials for this record-breaking dry concrete are blast furnace slag, which is a byproduct of iron production, and solid sodium silicate, which is also known as water glass. The production process itself is simple and works well at room temperature.
The use cases for this new dry concrete could include applications that require particularly high strength, but tests have also been made of its suitability as a floor material, for wall tiling and for different kinds of interior design components.
The research was carried out as part of the GEOBIZ project, for which Postdoctoral Researcher Tero Luukkonen is acting as project manager and researcher in charge. The goal of the project is to commercialise a cement-free eco-concrete that uses side flows from the metal industry. The project is funded by Business Finland, and also involves participation from six Finnish companies.
The University of Oulu has seen the development in this area of the largest cluster of expertise in the Nordic region. At the moment, there are 19 researchers working in this field as part of the Fibre and Particle Engineering Research Unit led by Professor Mirja Illikainen.
The discovery was published in the distinguished Journal of Cleaner Production.
Last updated: 25.1.2019