Anyone who has driven any distance on Europe’s highways will be familiar with the common (and often dangerous) experience of repairs being undertaken on the roads.
Manual repairs to structures lead to endless traffic jams and potential accidents everywhere, but imagine if that could be eliminated by means of concrete that repairs itself! That is exactly what the European HEALCON project aims to achieve: the development of self-healing concrete to improve the durability of structures.
The idea is that structures made of self-healing concrete will have an inherent healing mechanism that becomes active when a crack appears… thus rendering manual crack repair completely obsolete. In order to develop such an innovative technology the European project partners in HEALCON are investigating the use of polyurethane-based polymer resins, super-absorbent polymers and bacteria.
At Technical University in München, the efficiency of those three self-healing mechanisms is being investigated. With the help of non-destructive testing methods a group is assessing how cracks occur, how the healing agents are released and, finally, how efficiently they did their job in healing the cracks.
The first stage of this project has already yielded very promising results on a laboratory scale. All three healing agents have shown great potential. However, in order to scale-up the technique and make it compatible with conventional concrete production and construction methods, further research is necessary.
Before self-healing concrete can be brought onto the market, stakeholders require a proof of efficiency of the healing process. Therefore, non-destructive methods (such as acoustic emission analysis and the time-of-flight ultrasound technique) have been tested on a laboratory scale. Later on in the project, these techniques will be applied to construction elements (e.g. large beams) and finally also to constructions in-situ, like bridges or slabs.