Self-healing of asphalt concrete under cyclic loading: Experimental and numerical study

Abstract The present study aims at experimentally and numerically investigating the effect of an encapsulated healing agent on the mechanical characteristics of a stone mastic asphalt (SMA-15) after cyclic loading. As healing agents a thiol-containing urethane AR-polymer (ARP) and a sunflower oil (SfO) are used. The comparison of self-healing results in asphalts show that the use of encapsulated ARP allows to restore strength and stiffness up to 93% of whereas encapsulated SfO restores up to 90%. Without capsules, the self-healing effect is 81%. After self-healing, the structure of asphalt concrete with encapsulated ARP is capable of withstanding 15% and 22% more loads than original SMA-15 and SMA-15 with encapsulated SfO, respectively. To gain numerical insight into the mechanical behavior of the capsules in SMA-15, micromechanical finite element modeling is employed. The model is used to evaluate the effect of damage formation with respect to stresses and strains in the capsules and their propensity to breakage.