Concrete is everywhere we look in our modern world. Thomas Edison even innovated the concrete making process, improving the output of rotary kilns by a factor of four; and then going on to develop poured concrete houses and other large structures. He also worked in biology to discover a new natural resource for rubber when there were fears that it would run out.
He once said, “Great forces, material forces, undoubtedly exist, under our very noses, of which we know at present absolutely nothing about.”
Bioconcrete technology is the exact kind of bioengineering that Edison took an interest in later in his career. It is concrete that heals itself using bacteria.
Henk Jonkers, of Delft University of Technology, in the Netherlands, has designed a new type of concrete that can fix its own cracks. His secret sauce involves calcium lactate, setting the bacteria and calcium lactate into capsules made from biodegradable plastic and adding the capsules to the wet concrete mix.
When cracks eventually begin to form in the concrete, water enters and opens the capsules. The bacteria then germinate, multiply and feed on the lactate, and in doing so they combine the calcium with carbonate ions to form calcite (limestone) which closes up the cracks. The concrete mending process may take a few weeks to complete.
We have all seen those rust-brown streaks that stain things like bridge abutments, pillars, and many other concrete objects. The real problem with concrete cracks is water in-leakage and the rusting of reinforcing bars that can weaken the structural integrity of the concrete structure.
Bioconcrete is a good way to address the problem of water leakage and rusting of reinforcing bars. It is a prime example of how nature and engineering can work well together.
Work continues with this technology to develop a spray-on healing liquid for large surface areas. Who knows? Maybe they would have used this technology on the old Yankee stadium, if it was still around, which was built with Edison Portland Cement.