Developing an eco-friendly cement-free binder solution for the construction industry

“The project started back in 2010 when the Eyjafjallajökull volcano erupted. The company, Gerosion, has been doing research on various materials for use in the construction industry, including volcanic ash. Last summer, Sigrún Nanna Karlsdóttir, one of my teachers at the University of Iceland, offered me a position with Gerosion funded by the Icelandic Student Innovation Fund. It involved researching the possibilities of binding carbon dioxide, CO2, using geopolymer technology with the intention of creating a concrete binder called AlSiment. While working there I realised what a huge potential the project has and that’s what motivated me the most,” says Gonzalo Patricio Eldredge Arenas, who is studying for his master’s degree in geothermal engineering at UI, when asked about how and why he got to work on the project. Gonzalo worked on the project alongside fellow student Heiðar Snær Ásgeirsson to huge success; they were awarded the annual President’s Student Innovation Award in January.

Their project is called “Environmentally friendly cement-free Alsiment binder” and Heiðar Snær also chanced upon it through his studies at UI. “I got to know Gerosion through a project I did with them during the last semester of my undergraduate degree that involved the use of plastic waste as a raw material in the ferrosilicon industry. Following on from there I worked on a summer project with the company in 2022 and so it made sense to work on another project for the summer of 2023, this time focusing on AlSiment,” says Heiðar Snær who graduated with a bachelor's degree in chemical engineering in 2022 and is now studying for his master’s in the same subject at the Technical University of Denmark, DTU.

Many future possibilities using the AlSiment concrete binder technology

Heiðar and Gonzalo worked on the project for three months last summer under the guidance of Sunna Ólafsdóttir Wallevik, CEO and co-founder of Gerosion, Dr. Kristján Friðrik Alexandersson, partner and board member, Dr. Jan Přikryl, a specialist at Gerosion and Sigrún Nanna Karlsdóttir, co-founder and professor in the Faculty of Industrial Engineering, Mechanical Engineering and Computer Science at the University of Iceland. Gerosion has developed environmentally friendly solutions for both the construction and the energy intensive industries, by transforming waste of the metallurgical industry into a valuable raw material. AlSiment is one of those projects and it involves using a cement-free concrete binder. This concrete binder can be made using waste from energy intensive industries such as steel- and aluminium production but can also be made with natural resources like geothermal silica and volcanic ash, both of which are easily accessible in Iceland.

Cement production releases an enormous amount of carbon dioxide into the atmosphere, in fact 7-8% of all greenhouse gases released by human activity come from cement production. Reducing cement production is therefore hugely important and essential that whatever replaces it functions in the same way without the environmental impact.

Gonzalo and Heiðar believe that by using the AlSiment technology it will be possible to reduce carbon emissions significantly. “The AlSiment technology can help the construction industry to reduce carbon emissions. It releases 70% less carbon than cement and it is possible to reduce carbon emissions even more by binding carbon dioxide. Our current aim is to make AlSiment carbon neutral,” Gonzalo says.

What are the future possibilities with AlSiment? “The technology has been used in the production of eco-friendly stone slabs and using it to produce other green building materials is in the works. With more research it might be possible to use the technology on load-bearing construction,” say Gonzalo and Heiðar and it is clear that AlSiment has great potential to reduce carbon emissions within the construction industry.

More opportunities with Gerosion

When asked if they are going to continue their work on developing the AlSiment technology or work on something else with Gerosion, Gonzalo replies in the affirmative: “Yes, I’m working on my master’s project with Gerosion, it’s a continuation of the AlSiment project. For this project I’m testing the use of waste from geothermal power plants for the AlSiment binder. Gerosion is also working on producing cement-free stone slabs using the AlSiment technology.”

Heiðar, who is currently finishing his master’s degree in Denmark and plans to work there after he graduates says: “You never know, I might get another opportunity in the future to work with Gerosion on exciting technological developments like AlSiment.”