Styrene-butadiene-styrene block copolymer (SBS) is the most commonly used asphalt modifier. Studying the aging process of SBS-modified asphalt and clarifying the role of SBS and asphalt in the aging process can provide a basis for the targeted regeneration of SBS-modified asphalt. In this research, the physical and chemical changes of SBS and asphalt in the aging process were studied by FTIR (Fourier Transform Infrared Spectroscopy) analysis and SARA (Saturate, Aromatic, Resin, and Asphaltene) analysis. The effects of the thermal oxidation of asphalt and SBS on the viscosity and tensile properties of the SBS-modified asphalt were investigated by Brookfield Rotational Viscosity Test, force ductility test, and molecular dynamics simulation. Furthermore, the influence of asphalt and SBS aging on the adhesion property of the asphalt-aggregate interface was analyzed. The results show that the impact of SBS aging on the increase of viscosity and tensile yield stress was far less than that of asphalt aging. The adhesion energy of the modified asphalt-silica interface increases with both aging of SBS and asphalt. SBS and asphalt jointly influence the performance of modified asphalt in the aging process, but asphalt aging is the dominant factor.

Intelligent compaction (IC) has been successfully used for soil and base compaction of highways. However, the application of IC technology to monitor the construction quality of asphalt pavement faces complications with compaction processing. This study monitored the compaction process of asphalt layers using an IC-based method. The compaction data were first collected during the construction of a local road in Mardan, Pakistan, including IC data, in-place density, and temperature at the asphalt layer surface. The collected IC data were then used to compute the intelligent compaction measurement values (ICMVs). The support vector regression analysis was performed to predict the roller amplitude and in-place density using the ICMVs. To explore the correlations in compaction measuring/monitoring indicators, this study also explored the correlations between the ICMVs with core density, temperature, and amplitude. Experiment results indicated that the predicted roller amplitude values from the support vector regression model were close to the measured ones. There were high correlations between the roller amplitudes and temperatures with the compaction measurement values (CMVs). In contrast, the correlation between the in-place core densities and CMV values was low. Additionally, the CMVs of the backward pass were higher than the forward one in each compaction cycle because the pavement density increased and the air void decreased after each forward pass.