Experimental Investigation of the Performance of a Hybrid Self-Healing System in Porous Asphalt under Fatigue Loadings

Abstract

Self-healing asphalt, which is designed to achieve autonomic damage repair in asphalt pavement, offers a great life-extension prospect and therefore not only reduces pavement maintenance costs but also saves energy and reduces CO2 emissions. The combined asphalt self-healing system, incorporating both encapsulated rejuvenator and induction heating, can heal cracks with melted binder and aged binder rejuvenation, and the synergistic effect of the two technologies shows significant advantages in healing efficiency over the single self-healing method. This study explores the fatigue life extension prospect of the combined healing system in porous asphalt. To this aim, porous asphalt (PA) test specimens with various healing systems were prepared, including: (i) the capsule healing system, (ii) the induction healing system, (iii) the combined healing system and (iv) a reference system (without extrinsic healing). The fatigue properties of the PA samples were characterized by an indirect tensile fatigue test and a four-point bending fatigue test. Additionally, a 24-h rest period was designed to activate the built-in self-healing system(s) in the PA. Finally, a damaging and healing programme was employed to evaluate the fatigue damage healing efficiency of these systems. The results indicate that all these self-healing systems can extend the fatigue life of porous asphalt, while in the combined healing system, the gradual healing effect of the released rejuvenator from the capsules may contribute to a better induction healing effect in the damaging and healing cycles.

Experimental Testing and Constitutive Modelling of Pavement Materials

“…Six papers used laboratory tests and numerical simulations to assess the performance of different road materials and structures, including emulsified cold recycling asphalt mixtures, self-healing asphalt binder, reactive powder concrete and bridge deck pavement. The findings provide in-depth understandings in terms of various road materials key performance [14][15][16][17][18][19].…”

Healing Evaluation of Asphalt Mixtures with Polymer Capsules Containing Rejuvenator under Different Water Solutions

“…The presence of water prevents the proximity of asphalt molecules around the crack and slows down the rate of crack closure. Under the action of sodium salt solution, the colloidal equilibrium of asphalt at the crack is destroyed, the stable structure of the asphalt colloid is lost, the interaction force between the components is weakened, and the oil with lighter density undergoes dissolution and diffusion in the erosion process of sodium salt solution [49]. The reason may be that the water intrusion and sodium salt erosion degree gradually aggravated and thus decreased the natural healing ability of the asphalt binder.…”

Impact of Rejuvenator-Modified Mastic on Asphalt Mixture Stiffness: Meso-Scale Discrete Element Method Approach

“…Consequently, the damage rate surpasses the healing rate, allowing microcracks to propagate and increase in size. Over the past decade, researchers have explored several methods to overcome these limitations, including induction heating [9], 2 of 22 microwave heating [10], encapsulated rejuvenators [11], and combined methodologies [12]. These methods aim to improve the healing rate, extend the pavement service life, and reduce the frequency and costs of maintenance operations.…”