Skid Resistance Research Articles

Road Surface Texture Evaluation and Relation to Low-Speed Skid Resistance for Different Types of Mixtures

Pavement skid resistance is significant for driving safety. British Pendulum Number (BPN) is commonly used as a low-speed skid resistance indicator, whereas sometimes it is impractical for data collection on roads in service. Since skid resistance is greatly affected by pavement surface texture, this research aims to evaluate pavement surface texture comprehensively and estimate the low-speed friction BPN from road surface texture on macro- and micro- scale. Asphalt Concrete (AC) and Stone Mastic Asphalt (SMA) were included. Road surface texture was evaluated from four aspects, texture depth, amplitude-related Root Means Square (RMS), elevation variances corresponding to different wavebands and texture spectral analysis. Texture depth indicators include Mean Texture Depth (MTD) and Mean Profile Depth (MPD). Elevation variances with three wavebands, from 5 mm to 50 mm, from 0.5 mm to 5 mm and from 0.024 mm to 0.5 mm respectively, were obtained. The results show that MPD is well correlated with MTD. Elevation variances with different wavebands demonstrates that the elevation variance of macro-texture with long wavelengths from 5 mm to 50 mm dominates the total variance. Spectral analysis shows that texture level is larger when the wavelength is beyond 4 mm, which is consistent with elevation variances. A linear regression between BPN and single texture index, as well as multiple linear regression analysis were conducted. The former regression result indicates that it is not feasible to estimate BPN using single index due to low correlation coefficient R2. The latter shows that the BPN can be estimated from texture levels corresponding to 64 mm and 2 mm, and the micro-texture. The R2 can be up to 0.684. This research will contribute to fast acquisition of BPN from pavement surface texture, thus improving skid resistance.

Evaluation Indexes of Skid Resistance of Epoxy Chip Seal Based on Texture Features at Different Scales

Epoxy chip seals are widely used to improve the skid resistance of cement concrete pavements, which is significantly affected by surface texture. However, current methods for characterizing the surface texture structure are not precise, and the standard is not uniform. Therefore, a high-toughness modified epoxy resin chip seal structure was developed to conduct an indoor accelerated abrasion test. The elevation data of the epoxy chip seal under different abrasion times and different abrasion loads were obtained using laser scanning, and the density/sharpness combination parameters were obtained using the Hilbert–Huang transform and spectral analysis. The correlation between the texture parameters and the dynamic friction coefficient was analyzed using a stepwise multivariate quadratic polynomial method. The results showed that the texture structure of the epoxy chip seal surface is positively distributed, and the macroscopic texture occupies 49.45%, while the probability of the microscopic texture is only 4.55%. Meanwhile, the correlation coefficient between the texture parameters and the dynamic friction coefficient is 0.9307, which demonstrates that the selected texture parameters discard the texture components unrelated to skid resistance performance and reflect the distribution of the pavement texture and the skid resistance performance well.

Study on the Characteristics of Steel Slag and its Road Performance in Asphalt Mixture

Based on the characteristics of steel slag, the application progress of steel slag as aggregate in asphalt mixture is summarized. Firstly, the differences in mechanical properties, chemical composition and physical structure of steel slag aggregates treated by different methods are summarized. The surface structure of steel slag is rough and rich in edges and corners, showing good wear resistance and crushing resistance, but there are also problems such as high density, high water absorption and volume instability. Among them, volume instability is the key factor affecting the application of steel slag in asphalt mixture. Then, the effects of steel slag aggregate on the road performance of asphalt mixture, such as water stability, rutting resistance, high temperature stability and low temperature cracking resistance, are summarized in detail. It is found that steel slag instead of coarse aggregate in asphalt mixture can improve the performance of skid resistance, rutting resistance and fatigue resistance. The water damage performance is due to the different sources of steel slag, and the uncertainty of the change results is large. On the whole, steel slag instead of aggregate can improve the road performance to a certain extent, but the volume of steel slag aggregate is unstable, which may bring some variability. In the process of road application, targeted regulation should be carried out to ensure the stability of asphalt mixture performance.

Separation of Macro- and Micro-Texture to Characterize Skid Resistance of Asphalt Pavement.

The skid resistance of asphalt pavement is an important factor affecting road safety. However, few studies have characterized the contribution of the macro- and micro-texture to the skid resistance of asphalt pavement. In this paper, the generalized extreme studentized deviate (GESD) and neighboring-region interpolation algorithm (NRIA) were used to identify and replace outliers, and median filters were used to suppress noise in texture data to reconstruct textures. On this basis, the separation of the macro- and micro-texture and the Monte Carlo algorithm were used to characterize the skid resistance of asphalt pavement. The results show that the GESD method can accurately identify outliers in the texture, and the median filtering can eliminate burrs in texture data while retaining more original detail information. The contribution of the macro-texture on the skid resistance is mainly attributed to the frictional resistance caused by the adhesion and elastic hysteresis, and the main contribution of the micro-texture is a micro-bulge cutting part in the friction mechanism. This investigation can provide inspiration for the interior mechanism and the specific relationship between the pavement textures and the skid resistance of asphalt pavement.

Influence of high cis-1,4-liquid polydienes on properties of carbon-black filled composites

High cis-1,4 liquid polybutadiene (cLBR) and polyisoprene (cLIR) with narrow molecular weight distribution were prepared by the chain-transfer coordination polymerization. The effects of cLBR and cLIR on the physical and dynamic mechanical properties of carbon-black filled composites containing single polybutadiene (PBR) or a blend of PBR/polyisoprene (PIR), were investigated. The results showed that cLBR and cLIR effectively ameliorated filler dispersion compared with the treated distillate aromatic extract (TDAE) oil. The wet skid resistance and rolling resistance of vulcanized PBR/PIR composites plasticized with 5 phr cis-1,4 liquid rubbers were significantly improved. Therefore, a new type of plasticizers cLBR and cLIR that are environmental benign and highly compatible with matrix rubbers, has been discovered to replace the conventional TDAE oil used in fabricating the “green” tyres.

Classification scale for road surface noise based on the CPX method in the Czech Republic

The intention of the research project of the Technology Agency of the Czech Republic is to propose a classification scale for the evaluation of the noise level of pavement layers based on long-term repeated measurements using the Close Proximity Method (CPX). With regard to the other variable parameters (skid resistance, surface unevenness, bearing capacity and defects) that are monitored in the Czech Republic, a five-point scale was also proposed. The scale was tested on the busiest motorway section in the Czech Republic between Prague and Brno, which has been modernized in recent years. The first sections were put into operation in 2014 and the last in 2021. The evaluation of the results of the CPX measurements carried out in regular one-year cycles from 2013 to the present allowed to test the proposed classification scale. This paper will present the results obtained from the modernization of the highway and the proposed classification scale.

Raw rubber network of acid-free natural rubber and its application with solution-polymerized styrene butadiene rubber in green tires

Natural raw rubber was prepared by flash evaporation process (VNR), its raw rubber network was compared with that of acid-coagulated rubber (STR20), and the effects of the ratios of VNR and STR20 to SSBR on the comprehensive performance of green tire composites were investigated. The results showed that compared with 80SSBR composites, the tensile strength and tensile product coefficient of 80VNR composites were improved by 23 % and 94 %, and the Payne effect, compression heat generation, and rolling resistance were reduced by 39 %, 9 %, and 5 %, respectively. Compared with 40STR20/40SSBR composites, the tensile product coefficient, wear resistance, and wet skid resistance of 40VNR/40SSBR composites are increased by 11 %, 5 %, and 5 %, respectively, and the Payne effect, compression heat generation, and rolling resistance were reduced by 46 %, 11 %, and 5 %, respectively. This study increased the amount of natural rubber in the green tire formulations, improving the performance of composites while achieving sustainability.

Adaptive reuse of waste plastic as binders in composites for sustainable construction

Effective and efficient handling of solid waste remains a significant issue, particularly in low- and middle-income countries, and densely populated urban areas. Waste plastic is identified as a major contributor to solid waste streams. This study highlighted the viable reuse of waste Linear low-density polyethylene (LLDPE) plastic as a binder and full replacement for cement in composite blocks. An extrusion technique was adopted to melt the plastic and mix it with the sand fillers to create a homogenous waste plastic binder composite block. Composite block samples were produced at various mixture ratios of 1:1, 1:2, and 1:3 with waste plastic or cement as binder and sand as filler. The composite samples' compressive strength, flexural strength, tensile strength, UPV, thermal conductivity, skid resistance, Cantabro mass loss, and morphology were investigated. In addition, the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis of the composites were carried out. The results showed that composite blocks containing waste LLDPE plastic as binder exhibited lower compressive strength, higher flexural strength, and tensile strength, better thermal insulation, and abrasion resistance compared to composite blocks containing cement as binder. Meanwhile, the cement binder composite gave better skid resistance when the surface was wet than the waste plastic binder composite. However, the waste LLDPE plastic composite mixes considered gave compressive strength above 5 N/mm2, which is the minimum requirement for building bricks according to BS 3921: 1985.

Rapid and environmentally friendly reconstruction of airport runways under combined laser and liquid energy fields: Ushering a new era of low-carbon and efficient rubber removal in the aviation industry

When the aircraft takes off or lands, the tread rubber melts and adheres to the airport runway and its embedded ground lights, forming black pavement rubber marks, affecting the smoothness of the pavement, reducing the lighting degree and friction coefficient of the pavement, and directly affecting the safety of the aircraft take-off and landing. There are many shortcomings in the standard rubber removal methods. The multi-energy field composite laser cleaning technology comprehensively utilizes the laser field and auxiliary hydrodynamic field. It leverages the high-efficiency advantages of laser processing and avoids the shortcomings of its thermal energy surplus, achieving efficient, accurate, and green material removal. Based on this, this article presents for the first time the composite energy-field laser cleaning process mechanism and related performance of rubber mud layer from the surface of cement/asphalt runway and embedded grounding light cover (aluminum alloy)/light window (tempered glass). Pulse laser single energy-field cleaning is suitable for removing rubber marks from cement runways, grounding lamp covers, and light window surfaces. The cleaning mechanism is divided into two types based on the substrate: ablation and thermal stress peeling. Composite energy-field laser cleaning is suitable for removing rubber marks from asphalt runway surfaces, and the phase explosion of the liquid film is the cleaning mechanism. Under appropriate process parameters, laser cleaning can improve the runway's skid resistance, enhance the grounding light cover's corrosion resistance, and increase the grounding light window's transparency. This study can provide a reference for the laser cleaning behavior of different materials and solve the problem of rubber removal on international civil aviation airport pavement, promoting the construction of "safe, green, and smart" airports.

Influence of Aggregate Types on the Long-Term Skid Resistance of Porous Asphalt Mixture Based on the Laboratory MMLS

Influence of Aggregate Types on the Long-Term Skid Resistance of Porous Asphalt Mixture Based on the Laboratory MMLS

Recycling steel slag as aggregate in developing an ultra-thin friction course with high comprehensive road performance

The demand for skid-resistant and wear-resistant alternative aggregates in the preparation of ultra-thin friction course (UTFC) asphalt mixtures is a key direction for achieving high durability and low-carbon development in pavement maintenance. As a typical industrial waste, steel slag with high alkalinity and strong adhesion can facilitate the mechanical property of asphalt mixtures. However, few researches focused on the impact of steel slag on the comprehensive road performance of UTFC mixtures. Hence, the issue merits systematic exploration. In this study, the chemical components, microstructure and morphological characteristics of three steel slags (GXSS, HBSS and IMSS) obtained from different sources were surveyed. Then the stone matrix asphalt (SMA)-5 and open-grade friction courses (OGFC)-5 mixtures with different steel slags were fabricated. And their comprehensive road performances were quantitatively explored via the improved radar chart. The results indicate that steel slag with approximately 40 % Ca content, about 20 % Fe content, irregular shapes and tiny pores endows its wear resistance and strong adhesion. IMSS demonstrates the largest average angularity and form 2D values of 3850 and 7.28, respectively, representing its significant crowding function and interlocking structure. Incorporating steel slag remarkably reinforces the rutting resistance, skid resistance and anti-interlayer shear performance of UTFC. While the effect of water stability and crack resistance of UTFC depend on the category of steel slag. All three steel slags manifest the improvement function on the comprehensive assessment indexes (CAI) of OGFC-UTFC. IMSS-OGFC reveals the optimal comprehensive road performance, achieving the highest CAI of 0.9909. It is inferred that steel slag is more suitable for OGFC-UTFC than SMA-UTFC due to its relatively high CAI and consistent performance regardless of the steel slag type.

Characteristics of Open-Graded Friction Course Macrotexture and Macrostructure and Its Effect on Skid Resistance under Rainfall.

An Open-Graded Friction Course (OGFC) presents a rough surface and a porous structure and provides skid resistance under wet conditions, differing from that of a dense graded mixture. This study explored the distribution of surface macrotexture with depth in OGFC. Using cross-sectional images and semantic image segmentation techniques, the internal structure, porosity, and void size distribution were analyzed to assess the effectiveness of rainfall drainage. Skid resistance was evaluated with a British Pendulum Tester, focusing on the influence of surface macrotexture and internal macrostructure, particularly with regard to contact depth. Results show that finer gradations increase surface roughness peaks, which are concentrated near the top surface. In contrast, coarser mixtures exhibit a greater effective contact depth and more peaks with higher curvature. Finer gradations also result in lower porosity, greater void dispersion, and smaller average void diameters. During heavy rainfall, OGFC-13 exhibits the highest friction coefficient due to its effective contact, surface roughness, and internal voids, which facilitate water expulsion. This research provides insights into the skid resistance mechanism of OGFC in wet conditions and offers practical guidance for selecting the optimal gradation.

Evaluation of Flexible Pavement Friction Coefficients: A Case Study of East-West Highway Near Mahendranagar City, Nepal

Friction is a crucial factor in highway engineering, as it affects the traction between a vehicle's wheels and the road surface. This traction significantly influences the movement, speed, and efficiency of vehicles on highways. The coefficient of friction depends on various factors, such as pavement materials, traffic volume, road age, temperature, and weather conditions. The Skid Resistance Test Method is adopted for the study, which involves using a Portable Skid Resistance Tester to measure the British Pendulum Number (BPN) and then calculating the coefficient of friction by dividing the BPN by 10. An evaluation of a 5 km stretch of the East-West highway near Mahendranagar Bazaar revealed a longitudinal coefficient of friction of 0.354 and a lateral coefficient of friction of 0.184 under both dry and wet conditions. These findings were relevant for design speeds ranging from 60 to 80 km/h and considered an Annual Average Daily Traffic (AADT) of 10,321 Passenger Car Units (PCU) during the year 2023/2024. The assessment also indicated a variance of 0.19% and a poor International Roughness Index (IRI) value of 2.05. These aggregates had specific gravities ranging from 2.6 to 2.67 and were sized at 13.2 mm. The application rate for the aggregates ranged from 12 to 15 kg per square meter. It is important to note that a higher coefficient of friction leads to reduced vehicle efficiency. Thus, it is crucial to carefully consider the coefficient of friction values and detailed specifications to ensure traffic safety and road integrity.

Enhancement of Microwave Heating Technology for Emulsified Asphalt Mixtures Using SiC-Fe3O4 Composite Material.

The application of microwave heating technology can significantly enhance the water evaporation rate of emulsified asphalt mixtures post paving. To improve the microwave absorption and curing performance of these mixtures, SiC-Fe3O4 composite material (SF) was incorporated. This addition aims to enhance the microwave absorption efficiency and accelerate the curing process of emulsified asphalt mixtures under microwave heating. This study begins with an analysis of the microwave absorption principles pertinent to emulsified asphalt mixtures. Subsequently, the microwave heating temperature fields of ordinary emulsified asphalt mixture (EAM), SiC emulsified asphalt mixture (S-EAM), Fe3O4 emulsified asphalt mixture (F-EAM), and SiC-Fe3O4 emulsified asphalt mixture (SF-EAM) were simulated using COMSOL Multiphysics finite element software (COMSOL 6.2). The early strength variations in SF-EAM under different microwave heating durations were then examined through adhesion tests, leading to the proposal of a microwave heat curing process for SF-EAM. Finally, the wear resistance, water damage resistance, rutting resistance, and skid resistance of SF-EAM post-microwave curing were evaluated through wet wheel wear tests, wheel track deformation tests, and road friction coefficient tests. The results indicate that the optimal microwave heating time is 90 s, with the microwave absorption performance of the materials ranked as follows: EAM, S-EAM, F-EAM, and SF-EAM, from lowest to highest. The road performance of SF-EAM complies with specification requirements, and its wear resistance, water damage resistance, and rutting resistance are notably improved after microwave heating.

Components optimization of polyurethane-modified asphalt binder towards compatibility: Insight from molecular dynamics simulations

Polyurethane-modified asphalt demonstrated the enhanced durability and skid resistance, while remaining the drawback in the compatibility between the polyurethane modifier and asphalt binder in practical use. Herein, a molecular-dynamics-simulations based compatibility evaluation method is proposed for the polyurethane modifier and asphalt binder, thereby achieving the cost-effective and efficient components optimization. Twelve components asphalt molecular model was built in Molecular Dynamics to investigate the interaction of asphalt binder to the polypropylene glycol, toluene diisocyanate, and diphenylmethane diisocyanate, respectively. The molecular model of polyurethane modified asphalt binder was verified by the similar loss modulus temperature from the simulation and temperature scanning tests. The simulation outcomes indicate significant variations in the compatibility of different polyurethanes with asphalt, in which diphenylmethane diisocyanate-type polyurethane exhibits the superior compatibility. The compatibility of various polyurethane concentrations in asphalt shows considerable disparity, suggesting that the compatibility index can serve as a criterion for determining the optimal dosage of the modifier. Temperature also exerts an influence on the compatibility of polyurethane modified asphalt binder. Simulation results indicates that 130 °C potentially may be the optimal temperature for its preparation, which is corroborated by the microscopic characterization. This study provides a fundamental framework for the molecular dynamics simulation-based components optimization of polyurethane-modified asphalt, thereby inspiring the targeted design of asphalt materials.

Laboratory and Field Performance Evaluation of NMAS 9.5, 8.0, and 5.6 mm SMA Mixtures for Sustainable Pavement

This study evaluates the laboratory and field performance of stone mastic asphalt (SMA) mixtures with nominal maximum aggregate sizes (NMAS) of 9.5, 8.0, and 5.6 mm. Aggregates and fine aggregates of these sizes were produced using an impact crusher and a polyurethane screen. Mix designs for SMA overlays on aged concrete pavement were developed. Laboratory tests assessed rutting performance using full-scale accelerated pavement testing (APT) equipment and reflective cracking resistance using an asphalt mixture performance tester (AMPT). Field evaluations included noise reduction using CPX equipment, skid resistance using SN equipment, and bond strength using field cores. Results showed that for 8.0 mm SMA mixtures to achieve the same rutting performance as 9.5 mm SMA, PG76-22 grade binder was required, whereas 5.6 mm SMA required PG82-22. The 8.0 and 5.6 mm SMA mixtures showed 22.2% and 25% reduced crack progression, respectively, compared with the 9.5 mm SMA mixtures. Field evaluations indicated that 8.0 mm and 5.6 mm SMA pavements reduced tire–pavement noise by 1.7 and 0.8 dB, increased skid resistance by 8.5% and 2.0%, and enhanced shear bond strength by 150%, compared with 9.5 mm SMA. Overall, the 8.0 mm SMA mixture on aged concrete pavement demonstrated superior durability and functionality toward sustainable pavement systems.

High-quality utilization of reclaimed asphalt pavement (RAP) in asphalt mixture with the enhancement of steel slag and epoxy asphalt

Achieving high-quality utilization of reclaimed asphalt pavement (RAP) is challenging due to the subpar technical performance of aggregates and the aging of asphalt within RAP. This study investigates the use of epoxy asphalt (EA) and steel slag to enhance recycled asphalt mixtures (RAM) for superior performance and increased RAP content. The rheological performance of epoxy asphalt (EA) was evaluated using a dynamic shear rheometer (DSR), and its curing process was analyzed. Steel slag-epoxy recycled asphalt mixtures (SRAM) with 40 %, 80 %, and 100 % RAP were prepared, and their road performance was assessed through Marshall, wheel tracking, and semi-circular bending tests. Additionally, the effects of steel slag’s surface morphology and element distribution on moisture and skid resistance were examined. The volatile organic compound (VOC) emission characteristics were also studied. The results show that EA forms a uniformly dispersed structure, providing excellent high-temperature deformation resistance. EA and steel slag significantly enhanced the road performance of SRAM, with SRAM-80 (80 % RAP, 20 % steel slag) achieving a dynamic stability of 15027 times/mm. Steel slag improved SRAM-80’s skid resistance, with a British pendulum number (BPN) of 68 and a texture depth (TD) of 0.5889 mm. Compared to 60/80 asphalt, EA reduced VOC emissions by over 75 %. Incorporating 80 % RAP and 20 % steel slag into RAM effectively utilizes RAP while enhancing performance.

Influence of Aggregate Properties on Skid Resistance of Pavement Surface Treatments

Influence of Aggregate Properties on Skid Resistance of Pavement Surface Treatments

Evaluating Pavement Skid Resistance: Ensuring Safety and Performance

Skid resistance is a fundamental characteristic of road pavements, directly influencing vehicle control and traffic safety, especially under wet and slippery conditions. Skid resistance is not just about enhancing road surface quality but also about ensuring public safety, economic efficiency, regulatory compliance, and overall user satisfaction within transportation systems. The primary objective of this study is to compare the required and measured skid resistance values of flexible pavement on curved sections of feeder roads originating from Suryabinayak in Bhaktapur district, Nepal. This road is newly developed road with sharp curves which is prone to accidents. This comprehensive study aims with ensuring the safety of drivers and pedestrians by providing necessary recommendations regarding Skid Resistance, Super elevation, Speed of vehicles and Radius of curve. The research encompasses an extensive review of current methodologies for assessing skid resistance, including the British Pendulum Tester. The test results showed that the current pavement design practice of considering skid resistance is unsatisfactory in the case of wet muddy surface.

Thermo-micromechanical finite element modelling of tyre–pavement interaction under UAE environmental conditions

ABSTRACT This work presents a finite element model of the thermo-mechanical behaviour of tyre–pavement interaction, focusing on the effects of temperature variations in the UAE on skid resistance under various tyre operating conditions. The pavement is modelled as multiple layers to account for the stiffness contribution of each layer. The top asphalt layer is modelled at a microscale level to consider its various constituents such as air voids, aggregates and binder. Moreover, the model accounts for the viscoelastic properties of tyre and pavement, considering their dependence on time and temperature. The finite element simulations of a rolling tyre over the pavement have been carried out under different tyre operating conditions and various temperature cases reflecting the winter, spring, and summer seasons in the UAE. The simulation results show that the maximum level of skid resistance occurs during the winter season and thereafter drops by a significant amount during the summer. This research provides good insights about the seasonal variation of skid resistance in the UAE, which enhances road safety.