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A rubber composite was prepared by using methyltriethoxysilane (MTES) to modify silica (SiO2) and epoxidized eucommia ulmoides gum (EEUG) as rubber additives to endow silica with excellent dispersion and interfacial compatibility under the action of processing shear. The results showed that compared with the unmodified silica-reinforced rubber composite (SiO2/EUG/SBR), the bound rubber content of MTES-SiO2/EEUG/EUG/SBR was increased by 184%, and its tensile strength, modulus at 100% strain, modulus at 300% strain, and tear strength increased by 42.1%, 88.5%, 130.8%, and 39.9%, respectively. The Akron abrasion volume of the MTES-SiO2/EEUG/EUG/SBR composite decreased by 50.9%, and the wet friction coefficient increased by 43.2%. The wear resistance and wet skid resistance of the rubber composite were significantly improved.

Waste rubber tires are an area of global concern in relation to reducing the consumption of petrochemical products and environmental pollution. Herein, eco-friendly high-performance thermoplastic polyurethane (PU) elastomers were successfully in-situ synthesized through the incorporation of ground tire rubber (GTR). The excellent wet-skid resistance of PU/GTR elastomer was achieved by using mixed polycaprolactone polyols with Mn = 1000 g/mol (PCL-1K) and PCL-2K as soft segments. More importantly, an efficient solution to balance the contradiction between dynamic heat build-up and wet-skid resistance in PU/GTR elastomers was that low heat build-up was realized through the limited friction between PU molecular chains, which was achieved with the help of the network structure formed from GTR particles uniformly distributed in the PU matrix. Impressively, the tanδ at 60 °C and the DIN abrasion volume (Δrel) of the optimal PU/GTR elastomer with 59.5% of PCL-1K and 5.0% of GTR were 0.03 and 38.5 mm3, respectively, which are significantly lower than the 0.12 and 158.32 mm3 for pure PU elastomer, indicating that the PU/GTR elastomer possesses extremely low rolling resistance and excellent wear resistance. Meanwhile, the tanδ at 0 °C of the above-mentioned PU/GTR elastomer was 0.92, which is higher than the 0.80 of pure PU elastomer, evidencing the high wet-skid resistance. To some extent, the as-prepared PU/GTR elastomer has effectively solved the “magic triangle” problem in the tire industry. Moreover, this novel research will be expected to make contributions in the upcycling of waste tires.

Stone matrix asphalt (SMA) mixture has been widely used in pavement engineering for its preferable in-service performance. However, deterioration of SMA pavement in skid resistance is apparent under traffic loading. There remains lacking attention on skid resistance attenuation of SMA pavement, which in turn is important for skid durability design in practice. Hence, this study aims to perform a thorough investigation to reveal the skid resistance attenuation law of SMA pavement. Multiple types of SMA-13 mixtures prepared by different material designs were selected to conduct a kneading test that simulates real surface states of in-service SMA pavement. Pressure-sensitive film and a 3D laser scanner were utilized for evaluating anti-skid performance and skid durability. The finite element (FE) method is introduced to simulate vehicle braking distance for skid-resistance evaluation. The results show that skid resistance attenuation of SMA pavement consists of two stages: In the first stage, the skid resistance of SMA pavement experiences a short enhancement, followed by a long-term weakening stage. Abundant surface texture of SMA helps to mitigate the impact of traffic load on skid resistance. The FE analysis and pressure-sensitive film results demonstrate the potential of skid durability design of SMA pavement based on the skid resistance attenuation law.

Asphalt pavement skid resistance, governed by surface texture, is critical for traffic safety. Most research has focused on full-depth textural characteristics, often overlooking the depth of tire–pavement contact under real traffic conditions. This study introduces the concept of the Effective Depth of Skid Resistance (EDSR) to describe the effective depth of tire–asphalt contact, improving skid resistance assessment accuracy. Using blue linear laser scanning, surface textures of three common asphalt pavements with wearing courses—AC-13, AC-16, and SMA-13—were analyzed, and friction coefficients were measured using a British pendulum. After pre-processing three-dimensional texture data, fractal dimensions at various depths were calculated using the box-counting method and correlated with the friction coefficients. Previous studies show an insignificant correlation between full-depth asphalt pavement textures and skid resistance. However, this study found a significant positive correlation between skid resistance and pavement textures at specific depths or the EDSR. A depth with a correlation exceeding 0.9 was defined as the EDSR. Linear formulas were established for each pavement type within these EDSR ranges. A theoretical model was developed for predicting skid resistance, showing an over 80% accuracy against real-world data, indicating its potential for improving road surface performance detection.

Many rubber friction theories or some method combined theories and field-experiments are employed to evaluate the pavement skid-resistance deterioration due to the evolution of surface textures. However, these methods are difficult to be implemented in the analysis of situations with multi-factor coupling and some extreme conditions. This study developed a framework to evaluate the skid-resistance deterioration of asphalt pavements. In this framework, the portable laser scanning was used to create the digital worn pavement model, and a hydroplaning finite element (FE) model for these digital worn pavements was constructed to evaluate coupling effects of the texture evolution and factors of slip ratio, slip angle, velocity and water film on braking-cornering characteristics of tire. In this study, the deterioration of skid-resistance of five typical asphalt pavements due the surface texture wear was systematically investigated by this framework. Compared with previous works, this study established the rubber friction models for each digital worn pavement considering the energy hysteresis of rubber and the power spectrum density of surface texture. And the rubber friction model was used to define the interaction behaviors between the tire and corresponding wore pavements in the FE hydroplaning model, rather than using an empirical friction model or a fixed friction coefficient.

To explore the research status on mechanism of the skid-resistance for asphalt pavement, the related achievements of the rubber friction, the tire–road contact, and the influence factors were reviewed. The rubber friction was reviewed from the mechanism and rubber friction model. The tire-road contact was studied from the modeling methods, the evaluation methods, and the skid-resistance mechanisms at different conditions. The influence factors of skid-resistance were summarized from different designing processes. This review showed that the appropriate contact or evaluation model should be selected according to the required parameters. Although the finite element method is widely used, the accuracy of the model, the boundary conditions, and the load cases need to be further improved. The optimized aggregates and asphalt binders, reasonable gradation, reasonable geometric design, and strict construction quality control are necessary for good initial skid-resistance. Pavement texture as an important factor affecting skid-resistance should be considered in pavement gradation design, especially for wearing layer technology.

This study intends to predict the long-term skid resistance of steel slag asphalt mixture (SSAM) from the mineral composition of the aggregates. The polished stone value (PSV) and mineral composition of the aggregates were assessed using the accelerated polishing test and X-ray diffraction, respectively. The hardness (H) and surface texture richness (STR) of the aggregates were calculated from the mineral composition of the aggregates, and then a multivariate linear model was established between PSV and H and STR. The British pendulum number (BPN) and three-dimensional morphology of the SSAM were then evaluated using a British pendulum and a pavement laser scanner, respectively. Finally, an exponential relationship was established between BPN, aggregate PSV, and various aggregate amounts of SSAM. The results show that steel slag with H, STR, and PSV was better than natural aggregates and can significantly improve the skid resistance of pavement, but the relationship between steel slag content and long-term skid resistance of SSAM was not linear, and SSAM with 50% steel slag content had the best skid resistance. The mathematical model developed can predict the long-term skid resistance of SSAM from the mineral composition of the aggregates. The model can be used by designers to predict the long-term skid resistance of steel slag asphalt pavements at the design stage and thus better determine the proportion of steel slag to other aggregates.

Slip risk on surfaces used by humans or active in mechanisms is studied to mitigate its effects or harness its beneficial outcomes. This article presents pioneering research on the risk of surfaces created using 3D printing technology. The study examines three materials (Polylactic Acid, PLA; Polyethylene Terephthalate Glycol, PET-G; and Thermoplastic Polyurethane, TPU), considering three print head movement directions relative to the British Portable Skid Resistance Tester (BSRT) measurement direction. In addition, surface roughness tests were performed. Dry tests showed that the structure created by the printing direction perpendicular to the movement direction is the safest in terms of slip risk. The SRVs of the measured samples on a qualitative scale were classified on this scale as materials with low or extremely low slip risk (ranging from 55 to 90 SRV dry and 35 to 60 SRV wet). Referring to the influence of the type of material on the SRV, it was found that the safest material in terms of reducing the risk of slipping in dry conditions is TPU and, in wet conditions, PLA. During wet tests, the best properties that reduce the risk of slippage in most cases are shown by the printing direction on a horizontal plane at an angle of 45° to the direction of movement. Statistical analysis showed that the printing direction and roughness do not have a statistically significant effect on the SRV, but the type of material and the type of method (dry and wet) and their interaction have a significant effect.

This study investigates the skid resistance performance of asphalt mixtures containing composite aggregates of basalt and limestone. The research aimed to predict the service life of the asphalt mixtures and identify the optimal basalt content for enhanced performance. Using an accelerated friction tester, friction indices such as the British pendulum number (BPN), mean texture depth (MTD), and dynamic friction coefficient (Dµ) were measured. The study conducted accelerated wear tests on mixtures with varying basalt contents under different water flow rates and loads. Results indicate that anti-skid performance decreased with increasing water flow, load, and wear cycles, initially showing a sharp decline followed by a gradual stabilization. Orthogonal experiments determined that basalt content had the most significant impact on skid resistance, followed by load and water flow rate. By converting skid resistance and MTD values into IFI values, a four-area diagram was created to illustrate skid resistance deterioration. The four-area IFI diagram also demonstrated that higher basalt content significantly enhances the skid resistance and service life of asphalt mixtures. Cost analysis based on life prediction showed that a 40% basalt content mixture is cost effective while maintaining excellent skid resistance. A test section study further validated that a 40% basalt content ensures good skid resistance, with indoor test predictions aligning closely with field data. Although the test section has been operational for only two years, ongoing monitoring will provide further insights into long-term skid resistance performance.

Curved texturing is an effective technique to improve the skid-resistance performance of concrete pavements, which relies on the suitable combination of the groove parameters. This study aims to optimize these parameters with the consideration of skid-resistance performance and driving stability. A pressure film was adopted to obtain the contact stress distribution at the tire–pavement interface. The evaluated indicator of the stress concentration coefficient was established, and the calculation method for the stationary steering resistance torque was optimized based on actual tire–pavement contact characteristics. Test samples with various groove parameters were prepared use self-design molds to evaluate the influence degree of each groove parameter at different levels on the skid-resistance performance through orthogonal and abrasion resistance tests. The results showed that the groove depth and groove spacing had the most significant influence on the stress concentration coefficient and stationary steering resistance torque, respectively, with the groove depth having the most significant influence on the texture depth. Moreover, the driving stability and durability of the skid-resistance performance could be balanced by optimizing the width of the groove group. After analyzing and comprehensively comparing the influences of various parameters, it was found the parameter combination with width, depth, spacing, and the groove group width, respectively, in 8 mm, 3 mm, 15 mm, and 50 mm can balance the skid-resistance performance and driving stability. The actual engineering results showed that the R2 of the fitting between the stress concentration coefficient and SFC (measured at 60 km/h) was 0.871, which proved the effectiveness of the evaluation index proposed in this paper.