Interfacing and compatibility are the most challenging issues that affect the performance of polymer modified asphalt. Mechanisms of interfacial enhancemen

The objective of this study was to explore the interaction mechanism between recycled polyethylene (RPE) and base asphalt to reveal the microscopic mechanism of the two–phase structure formation, separation, and high–temperature stability of RPE–modified asphalt. Density functional theory (DFT) and molecular dynamics (MD) simulations were used to explore the interaction of RPE–modified asphalt at the atomic and molecular scales, and the simulation results were verified by fluorescence microscopy and dynamic shear rheology experiments. The results show that the binding energy of RPE with light components (aromatics and saturates) (730–1030 Ha) was smaller than that of asphaltenes with light components (2750–4330 Ha) in the following order of magnitude: phenol > pyrrole > thiophene > RPE. The charge transfer numbers of RPE with asphalt molecules indicate that RPE interacted weakly with asphaltenes and resins. In addition, MD simulation results show that RPE elevates the diffusion coefficient of asphalt molecules. The two–phase structure of RPE–modified asphalt was observed using fluorescence microscopy, and the RPE phase became larger with increasing development time. The dynamic shear rheology experiment results show that RPE reduced the damping factor while enhancing the complex modulus and rutting factor of asphalt.

Using modified asphalt binder is one of the most effective methods to solve the rutting problem of asphalt pavement, but the traditional G^∗/sin δ parameter is not enough to characterize the rutting resistance of modified asphalt in field use. In order to accurately evaluate the high temperature performance of asphalt and establish the relationship between the rutting resistance of binder and mixture, two kinds of matrix asphalt and three kinds of modified asphalt were selected for DSR and MSCR tests. G^∗/sin δ, nonrecoverable creep compliance J_nr, recovery rate R, and other parameters were used to characterize the permanent deformation resistance of the binder, and the correlation between these parameters and the results of rutting test was analyzed. The results show that J_nr3.2 can accurately characterize the permanent deformation resistance of asphalt, while the stress sensitivity index J_nrdiff is not applicable to all types of modified asphalt. In contrast, J_nrslope can better reflect the stress sensitivity of asphalt, and J_nrslope is significantly correlated with the results of rutting test.

The presence of ice and snow on a road surface in winter will reduce the traffic capacity of the road network, which can easily lead to traffic accidents. In this study, nonchlorine organic snow‐melting salt was added to emulsified asphalt to prepare an anticoagulant ice fog seal. Considering the destructive effect of snow‐melting salt on the stability of emulsified asphalt, polyvinyl alcohol was used as an encapsulation material to form a stable two‐phase system by mixing snow‐melting salt with emulsified asphalt. The zeta potential method was used to test the storage stability of the encapsulated salt solution. The results showed that the material and content of the encapsulation had a significant effect on the stability of the emulsified asphalt and the reduction in the freezing point of the encapsulated salt solution. PVA (1.5%) mixed with 24% sodium acetate was used to prepare an encapsulated salt emulsion, which was mixed with anionic emulsified asphalt and sprayed on the road surface. This significantly reduced the freezing point of road surface water. The recommended spraying dosage of the anticoagulant ice fog seal layer was 0.4 kg/m², which could lower the freezing point by at least −8°C while simultaneously meeting the antislip performance condition. This was shown to be a preventive maintenance technology with both anticoagulant ice and maintenance effects.

To evaluate the effects of the source and admixture of aged asphalt on the rheological properties of reclaimed asphalt binders, the relative viscosity (Δη), relative rutting factor (ΔG*/sinδ), and relative fatigue factor (ΔG*sinδ) were selected as evaluation indicators based on the Strategic Highway Research Program (SHRP) tests to characterize the rheological properties of a reclaimed asphalt binder under medium- and high-temperature conditions. The results of the study showed that the viscosity, rutting factor, and fatigue factor of the reclaimed asphalt binder increased with the addition of aged asphalt; however, the effect of the source and admixture of aged asphalt could not be assessed. The relative viscosity, relative rutting factor, and relative fatigue factor are sensitive to the source, admixture, temperature, and aging conditions, which shows the superiority of these indicators. Moreover, the relative viscosity and relative rutting factor decreased linearly with increasing temperature under high-temperature conditions, while the relative fatigue factor increased linearly with increasing temperature under medium-temperature conditions. In addition, the linear trends of the three indicators were independent of the source and admixture of aged asphalt. These results indicate that the evaluation method used in this study can be used to assess the effects of virgin asphalt and aged asphalt on the rheological properties of reclaimed asphalt binders, and has the potential for application. The viscosity of recycled asphalt increases, and the rutting factor and fatigue factor both increase. The high-temperature stability of reclaimed asphalt is improved, and the fatigue crack resistance is weakened.

This article conducts experimental research on the influencing factors of the anti-skid performance testing system SCRIM for asphalt pavement. Studied the distribution pattern of anti-skid performance test results of the testing system under different testing speeds, test tires, temperature, water film thickness, test wheel position, tire wear degree, and other factors. Revealed the influence law of various influencing factors on the anti-skid performance of asphalt pavement. The test results indicate that the SFC test value decreases with the increase of vehicle speed. The test results of tires made of different materials vary greatly, and tires with wear exceeding 3 mm cannot be used for testing. The influence of water film thickness on the measured values varies depending on the SFC level. The SFC measurement value of the normal trajectory of the vehicle’s driving wheel track is the smallest, and the measurement value of the left trajectory is greater than that of the right trajectory. The SFC measurement decreases as the tire wear increases.