Self healing concrete, or also known as bioconcrete, was developed because as you know concrete tended to crack no matter how you mixed it. Jonhkers, a microbiologist was asked whether or not it would be possible to produce a self healing concrete that would literally fill up cracks formed over time, by a concrete technologist. After 3 years of development and research, Jonhkers was able to produce the material bioconcret by adding in a bacteria that lives in little air pockets within the concrete mixture, which once is exposed to water, it would being to produce a limestone secretion that would automatically seal up the crack in the concrete.