Self-healing capacity of fiber reinforced cementitious composites. State of the art and perspectives

Design of building structures and infrastructures is mainly based on four concepts: safety, serviceability, durability and sustainability. The latter is becoming increasingly relevant in the field of civil engineering. Reinforced concrete structures are subjected to damages that produce cracks which, if not repaired, can lead to a rapid deterioration and would result into increasing maintenance costs to guarantee the anticipated level of performance. Therefore, self-healing concrete can be very useful in any type of structures, as it allows to control and repairing cracks as soon as they are likely to occur. The effectiveness of self-healing can be improved with the use of fibers due to their capacity to control crack width and enhance multiple crack formation. In that way, researchers should use advanced cement based materials (FRCC, HPFRCC, etc.) and techniques (autogenous and engineering healing) to satisfy all demands in which sustainability and durability are key factors. Compared to the large number of investigations on selfhealing of plain concrete, self-healing studies on Fiber Reinforced Cementitious Composites (FRCC) are still limited. Therefore, the main objective of this paper is to provide a deep literature review on this subject in order to clarify what is known (What now?) and finally to identify those gaps which still require further studies (What next?) such as: healing capacity under sustained stress, repeatability healing/cracking cycles as well as healing capacity for cracks and damages occurring at later concrete ages.