Effects of Elemental Sulfur on the Aging Trajectory and Adhesion Characteristics of Rubber-Modified Bitumen

Abstract

This study examines the role of sulfur in rubber-modified bitumen and its response to ultraviolet (UV) exposure in terms of its viscoelasticity, creep recovery, healing behavior, surface chemical oxidation, and surface adhesion. Infrared spectroscopy showed a pronounced enrichment of oxidized sulfur and carbon compounds at the surface of sulfur-modified bitumen after mild heating and especially after UV irradiation. 3% added sulfur increased bitumen plasticity by all measures. UV aging marginally decreased bulk metrics of self-healing, but it severely diminished surface adhesion values, indicating that bulk metrics may not be able to accurately reflect crack-healing behavior if bitumen surfaces are prone to oxidative degradation.

Effect of dynamic vulcanization on the performance of high content rubber modified asphalt

“…Carbonyl growth is an evaluation indicator of the oxidative aging of rubber asphalt. 15 However, it was found that sulfur can retard the growth of carbonyl groups of rubber asphalt in another study. 19 Dynamic vulcanization refers to the behavior of vulcanization during dynamic mixing, which has been widely applied in the preparation of thermoplastic elastomers based on rubber/plastic blends.…”

“…Sulfur has almost no effect on carbonyl growth, while it can improve the resistance to hardening and degradation of rubber asphalt. Carbonyl growth is an evaluation indicator of the oxidative aging of rubber asphalt 15 . However, it was found that sulfur can retard the growth of carbonyl groups of rubber asphalt in another study 19 …”

“…The addition of sulfur in rubber asphalt has been reported to ensure uniform dispersion of rubber in asphalt with acceptable high‐temperature properties 15–19 . Morrison et al 17 first used in situ vulcanization grafting in rubber asphalt to improve the high‐temperature properties and low‐temperature fracture toughness of rubber asphalt.…”

“…The addition of sulfur in rubber asphalt has been reported to ensure uniform dispersion of rubber in asphalt with acceptable high-temperature properties. [15][16][17][18][19] Morrison et al 17 first used in situ vulcanization grafting in rubber asphalt to improve the high-temperature properties and low-temperature fracture toughness of rubber asphalt. They suggested that the increase in molecular weight of rubber during vulcanization leads to the improvement of low-temperature toughness.…”

Characterization, Properties and Mixing Mechanism of Rubber Asphalt Colloid for Sustainable Infrastructure

“…Secondly, the release of carbon black from the cross-linked network can bind with asphaltene, preventing the oxidation of asphalt from UV light and oxygen [ 56 ]. In addition, the cross-linking reaction that happened to carbon–carbon double bonds and sulfur-containing bonds brought about a self-healing effect to DRMA, increased fatigue and low-temperature crack resistance [ 58 ].…”