How does it work?
Concrete will crack!
One of the properties of concrete is that it will always crack. With a good design and good application this cracking can be reduced, but even the little (hair) cracks can cause big problems. Cracked concrete has pore water resistance and the freeze-thaw resistance of the concrete will be limited. Also, the durability of cracked concrete will be greatly reduced. Through the cracks moisture and oxygen is able to reach the steel reinforcement which can cause the steel to corrode. This could cause serious damage to the concrete structure.
Repair of damaged structures is expensive and often causes discomfort. Especially for the infrastructure the maximum availability of our tunnels, bridges and viaducts is an important precondition. Structural safety is an important aspect for marine structures. Corroding concrete due to seawater (salt) can be disastrous for our water retaining structures and could lead to high maintenance costs. Wouldn’t it be nice if these structures could repair themselves?
How does it work?
Self-healing concrete is developed at the Delft University of Technology and is based on a autonomous repair system which is made possible by limestone-producing micro-organisms (bacteria). When the bacteria come in contact with oxygen and water they are capable of converting certain nutrients to calcium carbonate (limestone).
Autonomous repair system
When cracks appear in the concrete specially selected bacteria and nutrients will facilitate an autonomous repair system. The technique and time of adding the bacteria depends on the chosen product. The bacteria are triggered when they get in contact with water and oxygen, which will be present due to prier crack formation. The bacteria need a certain alkalinity which is either provided by the concrete itself or by the Basilisk product.
When in presents of water, oxygen and nutrients the bacteria will start to multiply. This will insure a wide dispersion of bacteria inside the entire crack. The widely dispersed bacteria will start to convert the present nutrients into calcium carbonate (limestone), which will eventually seal the crack.
Due to the formation of limestone the crack is autonomously repaired, increasing the durability of the concrete structure.
The autonomous repair system is accommodated in several products which are suitable for both new and existing concrete structures. An overview of these products can be found in this page.
Exclusively in the Kingdom of Saudi Arabia and also for the first time in the Middle East the award winning European innovation, bio concrete also called as self-healing concrete.