Zero-thickness interface formulation for fracture analysis of self-healing concrete

A discontinuous-based porosity-based model for concrete subjected to timeevolution self-healing phenomena is presented in this work. The model represents an extension of a fracture energy-based elasto-plastic interface formulation which now includes porosity evolution induced by self-healing mechanisms. The formulation accounts for the characterization of concrete failure behavior in mode I and II fracture types. The post-cracking response is considered by means of specific work softening rules in terms of work spent and porosity evolution. The effects of the aforementioned phenomenon on the recovery of stiffness and load bearing capacities have been evaluated by means of three-point bending (3PB) tests performed up to controlled crack opening and up to failure, respectively, before and after conditioning. Experimental tests are employed as benchmark to validate the proposed model formulation. Particularly, after outlining the mathematical formulation of the constitutive model for interface elements, numerical analysis are compared against test data.