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✍️ By: Team BC1.NL
Concrete that repairs itself
Concrete cracks, sometimes shortly after a new structure is completed. A structure with cracks has reduced water resistance, even if the cracks are small hairlines. This increases the risk that oxygen and moisture can reach the reinforcement, potentially causing it to corrode, which can lead to serious damage.
Why does concrete crack?
Concrete cracks, sometimes shortly after a new structure is completed. A structure with cracks has reduced water resistance, even if the cracks are small hairlines. This increases the risk that oxygen and moisture can reach the reinforcement, potentially causing it to corrode, which can lead to serious damage. Those cracks often run from the surface all the way through the structure, so you can end up with real leakage problems. Making structures waterproof is therefore the main application of self-healing concrete.
What is self-healing concrete?
There is now technology that allows concrete to repair itself when cracks form. This technology was developed at TU Delft in the Netherlands and uses microorganisms that produce limestone when they come into contact with oxygen and water.
What is it made of, and how long does it last?
It is made by mixing bacteria, together with nutrients for those bacteria, into the concrete mixture. Very specific bacteria are used, selected for two properties: they mix easily into concrete and they survive there for at least 50 to 100 years. Once water reaches a crack, they become active and seal it.
How does a crack close?
In the film the difference is shown with two test pieces. In the first, the crack runs visibly through the concrete. In the second, which contains the self-healing agent, that same crack is completely filled with limestone and you have to look closely to see where it ran. The crack closes over its full depth, inside the structure as well as at the surface, so the concrete is watertight again.
Where does it make the biggest difference?
The product can be used for basically all types of concrete, but the difference is greatest where future repairs are difficult or cause disruption. With infrastructure, a motorway has to be closed for a repair, and that costs money and inconvenience for everyone. With self-healing concrete you do not have to come back for years.
Why does less maintenance matter?
Because the safety of a concrete structure depends on how much maintenance it gets. This product extends the phase before maintenance is needed. And precisely where little maintenance is carried out, it contributes to the safety of the structure.
Basilisk Contracting BV makes the concrete
Basilisk Contracting BV is responsible for the market introduction of this self-healing concrete, which can be applied to both existing concrete structures and new construction projects.
