With Self-Healing Concrete, Micro-cracks in Buildings May Soon be Forgotten


Published Date : Jun 10, 2015

Micro-cracks in buildings may soon be a thing of the past, thanks to a novel invention by a team of researchers from Netherlands’ Delft University of Technology. 

Concrete has been one of the most significant contributors to the expansion of civilization. Right from the Pantheon that the Romans built nearly 2,000 years ago to condos and apartments that we live in today, structures have withstood the harsh impact of nature over the years owing to the concoction made from aggregate, water, and cement. However, this material, which may seem indestructible, does face a recurrent challenge: micro-cracks which form as the concrete dries.

The tiny fissures are subjected to external forces and pressure and become bigger, allowing water and other chemicals to flow in and destroy the steel reinforcement of the structure. Apart from looking ugly, this also reduces the stability of the building. Even though the cracks can be replaced, it is a pricey affair and most often a difficult one. This is especially true for structures that are constantly exposed to moisture or are underground. 

Architects, therefore, seek to avoid designing sharp corners that are more susceptible to break and crack with time. Engineers, on the other hand, reinforce structures with extra steel to make sure that the openings do not become too big. 

Henk Jonkers, a researcher from the Delft University of Technology, began working on the construction project back in 2006. He says that his inspiration was the human body, which has to ability to repair broken bones. The biggest hurdle that Jonkers and his team faced was looking for bacteria that have the capacity to survive in severe alkaline concrete conditions and stay dormant until they eventually come in contact with moisture.