Self healing capacity of high performance fibre reinforced cementitious composites: state of art and vision for the future

Cracked state is the normal service condition of reinforced concrete structures: cracks, if not properly controlled, can lead to a rapid deterioration and would result into increasing maintenance costs to guarantee the anticipated level of performance. Self-healing concrete can be a valuable asset allowing to control and repair cracks as soon as they are likely to occur. The effectiveness of self-healing can be improved with the use of fibres due to their capacity to control crack width and enhance multiple crack formation. The use advanced cement based materials (as e.g. HPFRCC) and techniques (stimulated autogenous and engineered healing) becomes hence crucial to face the challenges of durability and sustainability of new and existing structures. The paper provides a state of art on the current knowledge on the topic and identifies those gaps which still require further studies, such as healing capacity under sustained stress and repeatability healing/cracking cycles. Finally, the issue of consistently incorporating self-healing outcomes into durability-based design approaches for structures made of or retrofitted with HPFRCCs is addressed.