Pothole repair for porous pavements requires the patching mixture to have sufficient connected air voids, high strength, low moisture susceptibility, and high abrasion resistance. In this study, a cold patch asphalt mixture for porous pavements was designed. Turpentine was used as the solvent for the cutback asphalt, replacing diesel. The bentonite-cement was used as a mineral filler to improve adhesiveness between the aggregates and asphalt. Laboratory tests were conducted to investigate the initial strength, fully cured strength, moisture susceptibility under soaking and freeze-thaw cycling, and abrasion resistance of the designed cutback asphalt mixture. Test results showed that turpentine had a similar solubility parameter with asphalt but a higher evaporation rate than that of diesel. The cold mixtures had sufficiently high air voids of 20%. The cold mixtures produced with turpentine showed higher initial and cured strength, lower moisture susceptibility, and higher abrasion resistance, as indicated by a lower Cantabro loss value. Due to the relatively good solvability with asphalt and the higher evaporation rate of turpentine, the cold mixtures were thoroughly mixed, the aggregates were more evenly coated, and the performance of the designed mixtures was greatly improved.

As a closed space, the functional requirements of the tunnel pavement are very different from ordinary pavements. In recent years, with the increase of requirements for tunnel pavement safety, comfort and environmental friendliness, asphalt pavement has become more and more widely used in long tunnels, due to its low noise, low dust, easy maintenance, and good comfort. However, conventional tunnel asphalt pavements cause significant safety and environmental concerns. The innovative polyurethane thin overlay (PTO) has been developed for the maintenance of existing roads and constructing new roads. Based on the previous study, the concept of PTO may be a feasible and effective way to enrich the innovative functions of tunnel pavement. In this paper, the research aims to evaluate the functional properties of PTO, such as noise reduction, solar reflection and especially combustion properties. Conventional asphalt (Open-graded Friction Course (OGFC) and Stone Mastic Asphalt (SMA)) and concrete pavement materials were used as control materials. Compared with conventional tunnel pavement materials, significant improvements were observed in functional properties and environmental performance. Therefore, this innovative wearing layer can potentially provide pavements with new eco-friendly functions. This study provides a comprehensive analysis of these environmentally friendly materials, paving the way for the possible application in tunnels, as well as some other fields, such as race tracks in stadiums.