A FRACTURE TESTING BASED APPROACH TO ASSESS THE SELF HEALING CAPACITY OF CEMENTITIOUS COMPOSITES

The self healing capacity of cementitious composites employed for either building new or repairing existing structures opens challenging perspectives for the use of a material intrinsically able to recover its pristine durability levels, thus guaranteeing a longer service life of the designed applications and a performance less sensitive to environmental induced degradation. One possibility of achieving the aforementioned self-healing capacity stands in the use of additives featuring a “delayed crystalline” activity, which, when in contact with water or atmosphere humidity, form chemical compounds which are able to reseal the cracks thus guaranteeing the recovery of a pristine level of mechanical performance. In order to quantify this self healing ability, either in presence of not of the aforementioned additives, and its effects on the recovery of mechanical properties of concrete a methodology has been developed and will be presented in this paper: it allows the recovery of material properties to be evaluated in terms of stiffness, maximum load and effective crack opening and “self healing” indices to be defined and quantified in a “durability based” design framework.