The Japanese company, TIS & Partners, has developed a construction material called CO2 Structure, which is claims hardens quickly, delivers 2.5 times the tensile strength of concrete, is made from cheap materials and sequesters carbon dioxide.
High silicon content sand is put into an air tight mould that can be virtually any shape. CO2 is pumped into the mould and bonds with the silica to make a solid material, as hard as a brick, in less than a minute. However, while this material is very strong under lateral loads it crumbles under tensile pressure.
The company then bathes the bricks with a binder such as epoxy or urethane. This creates a hardened block which can be used as a strong building component.
Whereas concrete takes 28 days to harden to its full strength, the CO2 Structure bricks become 2.5 times as strong as concrete in less than 24 hours, making them ideal for emergency building.
Because of their their tensile strength, the bricks can be used to build walls that require little or no steel reinforcement.
Since the brick’s main component is common sand, they can be manufactured almost anywhere and the finished bricks can be more easily transported than concrete.
As well as all that, the product promises to be a valuable way to sequester carbon.