Spraying surface treatment asphalt emulsion to old porous asphalt (PA) pavement is a feasible preventive maintenance technique to alleviate the ravelling distress of PA. However, the insufficient penetration depth and non-uniform distribution of conventional asphalt emulsion in PA pavement restrict its maintenance effectiveness. Inspired by the good wettability and diffusion capacity of the rejuvenator, it was innovatively used to optimize asphalt emulsion. The maintenance mechanism of rejuvenator-optimized asphalt emulsion in damaged PA was comprehensively investigated from morphological, physicochemical, and rheological perspectives, respectively. One petrol-based rejuvenator named aromatic oil, and one bio-based rejuvenator named tall oil were selected to optimize conventional asphalt emulsion. Computed tomography (CT) scanning results showed that the penetration depth of the two rejuvenator-optimized asphalt emulsions in PA was about 40 mm, which is twice the depth of conventional asphalt emulsion. Rejuvenator-optimized asphalt emulsion was uniformly distributed in PA with a better coating efficiency, which improves the ravelling resistance of damaged PA. Gel permeation chromatography (GPC) analysis revealed that adding rejuvenator emulsion to asphalt emulsion significantly softened aged asphalt and reduced its molecular weight. Rheological analysis indicated that rejuvenator-optimized asphalt emulsion enhanced stress relaxation property and cracking resistance of aged asphalt binders in PA. The findings of this study are hoped to postpone the road rehabilitation work and prolong the service life of old PA pavement.

Paper details:

Construction and Building Materials 464 (2025): 140185

https://doi.org/10.1016/j.conbuildmat.2025.140185