The Effect of UV Irradiation on the Chemical Structure, Mechanical and Self-Healing Properties of Asphalt Mixture

Abstract

Although huge numbers of investigations have been conducted for the ultraviolet (UV) aging of asphalt binder, research rarely focuses on the asphalt mixture. In order to evaluate the aging effect of UV radiation on the asphalt mixture, a dense grade of asphalt mixture was designated and aged by UV radiation for 7, 14 and 28 days respectively. After that, the chemical functional groups of asphalt binder were tested by Fourier transform infrared spectrometer (FTIR). The semi-circular bending strength and fatigue resistance of asphalt concrete were tested to characterize the mechanical properties of the asphalt concrete. To evaluate the self-healing effect of the macro-structure continuity of asphalt concrete intuitively, the computed tomography (CT) scanning machine was used to characterize the crack size of asphalt concrete samples both before and after self-healing. The results show that, with the increase of UV irradiation time, the relative ratios of the C=O and S=O bands’ areas of recovered asphalt binder increase significantly. UV radiation can significantly weaken the mechanical and self-healing properties of asphalt mixture, making the asphalt mixture to have worse macro-structure continuity, lower failure strength and worse fatigue resistance. Moreover, the longer the UV irradiation time is, the degradation effect of UV radiation on asphalt mixture becomes more obvious.

Effects of Microwave Heating and Long-Term Aging on the Rheological and Chemical Properties of Recovered Bitumen

“…Fresh bitumen had no peaks of the carbonyl group. Likewise, in Figure 9b, the sulfoxide group can be observed in the FTIR spectra, occurring due to thermo-oxidative aging during the production and storage of bitumen [44]. Figure 9b demonstrates that bitumen 1 and the PAV bitumen had a similar tendency in the sulfoxide zone.…”

“…The changes caused by aging can be found between 2000 and 600 cm −1 . These wavenumbers correspond to functional groups related to the oxidation process [44]. The peaks of the carbonyl and sulfoxide groups can be found at wavenumbers 1700 and 1030 cm −1 , respectively [44].…”

Effects of two-organic-acid-dissolved chitosan on antibacterial properties of bamboo pulp-based fabrics

“…These observations showed that a layer of chitosan film was coated on the fibers' surface of chitosan treated BPFs, indicating that chitosan was chemically cross-linked on the fibers' surface. 21,22 This is mainly because the smaller molecular weight of the chitosan molecules not only deposited on the grooves and gaps on fibers' surfaces, but also entered the loose area of BPFs and reacted with carboxyl group to cross-linking.…”

Sustainable Designed Pavement Materials

“…They concluded that rejuvenators can soften aged pavement materials and consequently recover the road performance. Furthermore, self-healing characteristics of pavement materials were reported by Wu et al [13], Li et al [14], and Cai et al [15]. Wu et al [13] found that UV irradiation will weaken the macro-structure and lower the failure strength and healing index.…”

“…Furthermore, self-healing characteristics of pavement materials were reported by Wu et al [13], Li et al [14], and Cai et al [15]. Wu et al [13] found that UV irradiation will weaken the macro-structure and lower the failure strength and healing index. Li et al [14] designed steel fiber modified asphalt concrete to promote the induction heating technology, while Cai et al [15] used engineered cementitious composites mortar to prepare flexible pavement materials with certain healing property.…”