One of the candidates for the European Inventor Award is a new formulation of concrete that is self-healing and repairs any cracks itself.
Over time many concrete structures develop cracks which threaten their stability. To counter this a microbiologist Hendrik Jonkers at Delft University has improved long-term stability by adding a limestone-producing bacteria to the mix.The result is a self-healing bioconcrete which could provide a cheap and sustainable solution, markedly improving the lifespan of buildings, bridges and roads.
Jonkers got his inspiration for the project from the way the bones in the human body are healed naturally through mineralisation from osteoblast cells. He developed a similar self-regeneration technique for our most widely used construction material.
His solution employs a limestone-producing bacteria to close up gaps in concrete. The robust, naturally occurring bacteria ̶ either Bacillus pseudofirmus or Sporosarcina pasteurii, already exist in highly alkaline lakes near volcanoes and seemed tailor-made for the job. They are able to lie dormant for up to 200 years and only begin important repair work only after cracks appear and it comes into contact with water.
The potential for the patented technology is impressive. Because around 70% of Europe’s infrastructure is comprised of concrete, maintenance is an extremely costly affair. HealCON, an EU FP-7 funded project, estimates the annual maintenance cost for bridges, tunnels and earth-retaining walls in the EU member countries at up to € 6 billion.
Jonkers’ self-healing bioconcrete is expected to hit the market in 2015.