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.

This paper presents a study on the effects of two laboratory compaction methods, namely, vibrating compaction and modified Proctor compaction on the stress-strain characteristics and shear strength of graded crushed stone. The results of the triaxial shear test show that samples made by vibrating compaction possess higher peak strength, higher initial modulus of elasticity, and lower failure strain than samples made by the modified proctor compaction. Specifically, the cohesion, friction angle, and shear strength of the samples made by the vibrating compaction increase by 38%, 2 degrees, and 10%, respectively, over the samples made by the modified Proctor compaction. In summary, the vibrating compaction method generally performs better than the modified Proctor compaction method, owing to a better distribution of particle orientation. Therefore, it is recommended that, in practice, the vibrating roller should be applied for the construction of graded crushed stone.

The evolution of the skid resistance of asphalt road surfaces was simulated in a laboratory. Asphalt plates were taken from a test track. They were polished using the self-developed Aachen Polishing Machine with real tires under various conditions followed by the measurement of their skid resistances using the Wehner/Schulze machine. The differences between summer and winter with regard to water and the dust composition were simulated and their influence on the skid resistance was analyzed. The process of removing the binder, polishing the aggregate and a periodical fluctuation of the skid resistance can be accurately described by a skid resistance prediction model. One could conclude that for the asphalt samples the change of the polishing conditions entailed a fluctuation of the skid resistance coefficient between two final states.

The impact of ice and snow in seasonally frozen regions has led to a significant decline in the flatness and skid resistance of highway pavements, creating severe traffic safety hazards. With economic development driving the transition from road construction to maintenance, this study proposes enhancing Ultra-Thin Wearing Course (UTWC) maintenance materials with anti-icing performance and snow-melting properties. The study first employed the Marshall mix design method to develop gradations for two common types of UTWC asphalt mixtures: the dense-graded GT-8 and the open-graded NovaChip^® Type-B. Using the volume substitution method, aggregates were replaced with equivalent volumes of ceramic grains. The optimal asphalt–aggregate ratios for the mixtures with varying ceramic grain contents were determined, and the influence of ceramic grains content on the asphalt–aggregate ratio was analyzed. The results indicate that the optimal asphalt–aggregate ratio increases with higher ceramic grains content. Subsequently, the high-temperature performance, low-temperature performance, and water stability of UTWC with varying ceramic grain contents were evaluated. Overall, NovaChip^® gradation mixtures demonstrated superior road performance compared to GT-8 gradation mixtures. Moreover, an increase in ceramic grains content enhanced the high-temperature performance of UTWC but moderately reduced its low-temperature performance and water stability. Finally, the effects of different ceramic grain contents and snowmelt agent types on the anti-icing and snowmelt properties of UTWC were examined. The results revealed that higher ceramic grains content improved snowmelt effectiveness. Considering the road performance of the specimens, a ceramic grains content of 40% was recommended. Furthermore, calcium chloride (CaCl₂) exhibited superior anti-icing performance compared to other snowmelt agents.

Asphalt permeable pavement (APP) is a passive structural low impact development material and component of green infrastructure for rainfall-runoff control. Multifunctional engineered APP can fulfill requirements as a load-transmitting surface while serving as a more environmentally conscious infrastructure material that functions to restore the in situ hydrology, reduce runoff, filter, and treat infiltrating runoff, reduce thermal pollution and temperature, also provide the load-carrying capacity of conventional pavement. Based on the determination of main value indices for runoff pollutants, the efficiency of controlling runoff pollutants has been studied from materials and structures of permeable pavement in this paper, then put forward to the keys of material and structure design for permeable pavement, which will provide techniques for designing ecotypic permeable pavement. All the results indicate high particle separation and the removal rate of chemistry oxygen demand can be achieved with APP. The effectiveness of APP for particle and COD removal also requires that these particle deposits are managed on a periodic basis through practices such as pavement cleaning.

Based on analysis of the influence degrees of structure types at early damages of cement pavements in large-grade highways, combined structure type of cement stabilized crushed stone drainage base and semi-rigid base is proposed. Base on function analysis of drainage base, design principles and indices of the cement stabilized crashed stone mixture are determined. And then, the type of coarse framework, distributing of cement slurry, and the component of grading are determined according to new characters of material design method which including the optimum vibrating compaction techniques and the dynamic stress press-in test having confined pressure and the volume design method in grading components. Finally, the method for determining the reasonable consistency of cement stabilized crushed stone mixture is presented, which adopts porosity diversity and strength as evaluation criterion. The void-framework cement stabilized crushed stone mixture demanding drainage base function will be consequently designed.