Self-healing capacity of fiber reinforced concretes with different additions

The improvement of service life of concrete structures has become essential for both economical and environmental reasons: nowadays cement industry produces about 8% of global CO2 emissions and 50% of the annual construction budget is spent for rehabilitation and maintenance of existing structures. Self-healing materials opens the way to a new structure concept, characterized by an enhanced longevity, thanks to the provided capacity of self-repairing and recovering the original performances after being damaged. Concrete is suitable to be employed with this aim, thanks to its reactivity under suitable environmental conditions. Its self-healing capacity depends on many factors, such as the presence of additions, width of crack, type and duration of exposure to several external conditions. In this work, the problem of self-healing of concrete will be investigated with reference to a normal strength fiber reinforced concrete. The effect of different widths of crack, exposure times to wet/dry cycles, application of a through-crack compressive stress and the ability of different additions to trigger the self-healing capacity of material will be considered. A methodology for the assessment and quantification of mechanical recovery will also be proposed.