Self-healing capacity of asphalt mortars with encapsulated rejuvenators using fatigue tests under strain- and stress-controlled conditions

Abstract

A promising technique to promote self-healing in asphalt mixtures involves adding biopolymer capsules with rejuvenation agents during the fabrication of the mix. Several laboratory tests have been proposed to assess the effectiveness of this technique. Among these, fatigue-healing-fatigue tests are of particular interest, as fatigue damage is a primary source of crack initiation and propagation. There are two experimental approaches for performing fatigue testing: strain- or stress-controlled mode. The selection of the mode is crucial when as-sessing mixtures with encapsulated rejuvenators, as it impacts the potential activation of the capsules (i.e., the release of the internal healing agent). This study evaluates the self-healing capacity of long-term aged asphalt mortars with capsules using fatigue-healing-fatigue tests under strain- and stress-controlled conditions with a resting period of 3 hours at 22°C and 45°C. The results show that the capsules enhance the healing capacity of asphalt mortars when tested under a stress-controlled mode and high temperatures, while no significant differ-ences were observed compared to the control mortar at the intermediate temperature. This information provides valuable information about the field conditions under which the use of these mixtures can extend the service life of the material.