Self-healing of cracks in concrete via bacterial aerobic metabolic conversion of organic compounds

Abstract

Self-healing of cracks in concrete can be achieved by application of bacteria which metabolically convert organic compounds under aerobic conditions yielding limestone. Added to the concrete mix as part of a healing agent, bacteria can, via metabolic activity resulting in limestone formation, seal cracks of up to 0.8mm width resulting in waterproofing and increased frost damage resistance of the concrete. Besides increasing the autogenous crack healing capacity of concrete, these bacteria can also be applied to improve bond strength of repair mortar and act as limestone producing agent in liquid concrete repair systems. This paper will review current state-of-the art bacteria-based self-healing concrete technologies investigated and applied by the Delft University research group specifically using bacteria which yield limestone after aerobic metabolic conversion of organic compounds under alkaline conditions.