Recent advances on self healing of concrete

In this paper an overview is given of new developments obtained in research on self healing of cracks in cement based materials and asphalt concrete. At Delft University various projects are running to study self healing mechanisms. The first project that is discussed is Bacterial Concrete, in which bacteria are mixed in concrete, that can precipitate calcite in a crack and with that make concrete structures water tight and enhance durability. In a second project hybrid fiber reinforced cementitious materials are studied that can mechanically repair cracks when they occur. The last project described in this paper is on the raveling of porous asphalt concrete and how to heal this damage by incorporating embedded microcapsules or steel fibers. The state of the art results in all projects show that self healing is not just a miracle, but materials can be designed for it