Self-healing capability of fibre reinforced cementitious composites

In order to investigate the self-healing capability of fibre reinforced cementitious composites (FRCC), mechanical properties and surface morphology of crack in FRCC were studied. Three types of FRCC specimens containing (1) polyethylene (PE) fibre, (2) steel cord (SC) fibre, and (3) hybrid fibres composite (both of PE and SC) were prepared. These specimens, in which cracks were introduced by tension test, were retained in water for 28 days. The self-healing capability of the specimens was investigated by means of microscope observation, water permeability test, tension test and backscattered electron image analysis. It was found that many very fine fibres of PE were bridging over the crack and crystallization products became easy to be attached to a large number of PE fibres. As a result, water permeability coefficient decreased and tensile strength was improved significantly. Therefore amount of the PE fibre per volume was indicated to have a great influence on self-healing. Furthermore, by means of backscattered electron image analysis, it was also shown that the difference of hydration degree in each FRCC has only little influence on the self-healing capability in case of the employed test series.