Microscopical characterization of the self healing mechanisms in high performance cementitious composites reinforced with steel and natural fibres

In this paper a thorough microscopical and chemical (by means of TGA) characterization of the cracked/healed surfaces in HPFRCCs, reinforced with different types of fibres, has been performed in order to understand the nature of the reactions governing the crack healing phenomenon. Effects of self healing on fibre matrix interface have been also investigated in order to have a deeper understanding of the mechanisms governing the phenomenon. The role of natural fibres as vehicles of the environmental moisture inside the bulk material has also been confirmed. Additional healing reaction products forming at the fibre matrix interface, in the case of natural fibres, have been clearly identified, further contributing to the enhancement of the healing capacity of cementitious composites and improved recovery of pristine levels of mechanical performance.