Asphalt Pavement Surface Research Articles

Using of Plastic Wastes as Additives in Bituminous Mixes

Plastic wastes are everywhere in today’s lifestyle and are growing rapidly specially in a developing country like Egypt. As these are non-biodegradable, there is a main issue facing the community concerning the handling of this plastic rubbish. On the other hand, different forms of increased distresses in flexible pavements such as cracking and rutting as well as moisture damage ratio should be faced and reduced by modifying the performance of hot asphalt mixtures. The reclaimed plastics that originally made of polymers have been used as an anti-stripping modifier to reduce the appearance of distresses in asphalt pavement surface and increase the resistance against moisture damage. In this research, the recycled plastic wastes have been used according to dry mixing process using contents (0.0, 2.0, 3.0, 4.0 and 5%) from the total weight of hot asphalt mixture. The optimal bitumen content has been derived for each polymer content by using Marshall procedure. The performance of modified bitumen mixtures have been recognized using Marshall quotient (as indicator of the stiffness), static indirect tensile strength and tensile strength ratio (as indicator of moisture damage resistance), dynamic modulus value (as indicator of stiffness of the asphalt mixture when tested in a compressive and repeated load test under different temperatures) and flow number (as indicator of permanent axial deformation resistance). The results obtained that the addendum of plastic rubbish to HMA improves its characteristics such as stability, strength, resistance to moisture damage and permanent deformation. The addition ratio of 3% polymer provides better pavement performance. Moreover, it has an economic importance where it reduces the exhaustion of natural asphalt in paving works by about 14.5%.

High coolingperformances of H‐shape heat sink for thermoelectric energy harvesting system (TEHs) at asphalt pavement

There has been an increased recognition in road thermal energy harvesting for the past decades due to the massive waste heat from the asphalt pavement. This study aims to design a thermoelectric energy harvesting system (TEHs) that converts the waste heat from the surface of asphalt pavement into useful electrical energy. The TEHs utilizes the H-shape element in subterranean cooling in order to achieve a high-temperature difference (ΔT). In this proposed cooling element method, an aluminum plate was welded in between two 1.25 in. of diameters H-shape structures, and two cascaded thermoelectric modules (TEM), APH-127-10-25-S, were placed in between the top plate and bottom plate. The heat transfer analysis for the TEHs is performed using finite element analysis (FEA) simulation and validated with an experimental investigation. Based on simulation results, the H-shape cooling element has a 75% improvement of ΔT from a single rod cooling element design. Furthermore, using a top plate with 100 × 200 mm dimension, also given an extra 8°C of ΔT than the top plate with a 65 × 200 mm dimension, it appears that the conduction shape factor, S, may have influenced the heat distribution in the cooling element. While, in field testing, the results can corroborate with the simulation where the maximum ΔT has reached a similar ΔT of 23°C, with a maximum relative error of 0.057%. Based on the feasibility studies with an application, the TEHs has effectively fully charged 5 F supercapacitors, within 3 hours, for the use of automatic street lights, which substantiated the significance of TEHs design. The present study represents a new perspective for self-sustainable TEHs design integrated with high cooling performances of the H-shape element in subterranean cooling.

Parametric optimization of Ground Penetrating Radar approach for assessing asphalt pavement surface layers compaction

In this study, a parametric analysis was performed and an optimized approach based on Ground Penetrating Radar (GPR) was developed for assessing accurately the compaction of surface layers of hot mix asphalt (HMA) pavements. This approach consists of data acquisition with a 2-Ghz air coupled antenna for determining the dielectric constant of asphalt, and utilization of the capabilities of ALL (Al-Qadi, Lahouar and Leng) and PANK (Päällystealan Neuvottelukunta) models in terms of data analysis supplemented with 3 cores to estimate the relative calibration factors. Field studies were performed to illustrate the validity and effectiveness of the proposed approach, in relation with the typical coring method. The results demonstrated that the estimates of compaction degree (mean values) are statistically identical to that of field cores. Moreover, by using the proposed approach the distributions of estimates are postulated to be more realistic in terms of compaction (non) uniformity of pavement mat appear in the field.

Drainage Capacity and Resistance to Clogging of Porous Asphalt Concrete Based on the Water Penetration Test and Constant Head Permeability Test

Abstract Porous asphalt concrete (PAC) can decrease the risk of hydroplaning, reduce splashing and spraying, improve visibility, reduce traffic noise, and improve driving safety, but the clogging of the void affects its durable function. To investigate this, the fine aggregate was chosen as a plugging agent, and the permeability coefficients and water permeability coefficients were measured by using an asphalt mixture permeability testing device and pavement surface permeameter to simulate a multicycle drainage clogging experiment of PAC. The influence of asphalt mixture design parameters, including voids volume (VV), the nominal maximum aggregate sizes (NMASs), grading types on the drainage capacity, and resistance to clogging, was investigated. The two test results indicated that VV has a manifest influence on both drainage capacity and resistance to clogging. The NMAS has an obvious influence on resistance to clogging but no clear influence on the drainage capacity. PAC with the coarser gradation has better performance on drainage capacity and resistance to clogging. The clogging location is concentrated on the top 40 mm of the PAC-13 specimen. The fine particles with diameters of 0.15 to 2.36 mm are the key particles causing the clogging in the PAC-13 specimen. Water permeability coefficients and permeability coefficients have a very high correlation.

Experimental Investigation on Uniaxial Unconfined Compressive Properties of Ice on Asphalt Pavement Surface

Mechanical deicing is a method to remove the ice on the pavement surface, and the ice strength directly affects the difficulty and effectiveness of the mechanical deicing. This paper aims to investigate the compression strength of ice to facilitate the deicing equipment to crush ice. In this paper, a large-scale freezing laboratory is employed to simulate low temperature environment, and the uniaxial unconfined compressive tests of artificial fresh-water ice under different temperature conditions are carried out through the uniaxial loading system. The compressive strength and modulus of ice are obtained when the substrate is asphalt pavement. The test result shows that the ice compressive strength and modulus respectively distribute from 0.36 MPa to 3.67 MPa and 11.7 MPa to 359.1 MPa when ice temperature varies from -0.7℃ to -7.5℃. The relations between ice temperature and compressive strength are approximately in linear manner, while the relation of compressive modulus and ice temperature shows good power function and exponential relationships respectively when ice temperature ranges from -8℃ to -5℃ and from -5℃ to 0℃. Furthermore, the failure mechanism of ice under relatively lower temperature is due to the development of cut-through cracks inside the ice. The failure mode divides into shear failure and ductile failure and the failure ice is mainly composed of large ice strips and bulks. For the ice with relatively higher temperature especially the ice close to melting point temperature, the ice failure mode is compressive and ductile, and the failure ice is mainly composed of granular ice crystals.

Micro Surfacing Asphalt Pavement as a Mitigation Measure at Accident’s Prone Area along East Coast Expressway Phase 2 (ECE 2)


 
 
 The condition of pavement surface is an essential factor to be considered in mitigation of accidents in highways, as it is in direct contact with users' vehicles, especially in terms of quality of driving, skid resistance and friction. Lack of surface pavement maintenance may lead to accidents, and if taken for granted, it may witness high accident fatalities in the expressways. If the cause of the accidents happening on the roads is due to engineering factors, then adequate mitigation measures should be undertaken to avoid further tragedies from happening. One way of mitigating the accidents on highways is by conducting periodic maintenance of the roads and related highway infrastructure. Micro- surfacing is one of the potential measures, developed from a slurry seal technique. It is the process of applying a mixture of polymer modified bitumen emulsion with 8.0 mm chipping, quarry dust, cement, additives and water on an existing asphalt pavement surface. The current study was carried out to evaluate the performance of micro-surfacing as a mitigation measure, applied on the accident-prone pavement areas along the East Coast Expressway Phase 2 (ECE2). The Portable Pendulum Tester was used to evaluate the skid resistance performance while the texture depth of micro-surfacing was measured using the Sand Patch Test. The results showed tremendous improvement in the skid resistance and texture depth after the application of micro-surfacing. The number of accidents also reduced after the application of micro-surfacing asphalt pavement as a mitigation measure at the identified accident-prone areas along ECE2. Thus, the study confirmed that micro-surfacing asphalt pavement was effective in mitigating the accidents in accident-prone areas along ECE2.
 
 

Evaluation of Anti-icing Emulsified Asphalt Binders

Snow and ice on asphalt pavement surface can significantly affect traffic safety and damage pavements. To reduce its effect, a kind of anti-icing emulsified asphalt binder (AEAB) is developed by adding a certain amount of anti-icing fillers to the modified emulsified asphalt binder. The anti-icing performance and pavement performance of AEAB coating are evaluated. The results show that: the basic properties of AEAB meet the requirement of road maintenance, and the AEAB has excellent anti-icing performance and bonding property. It can facilitate the ice-melting on pavement and reduce the adhesion force between pavements and ice, and the adhesion force can be reduced by about 50%. The AEAB coating can keep an excellent bonding state with the original pavement, which can prolong the service life of the coating. These findings demonstrated the potential of using AEAB coating on asphalt pavement to provide better pavement performance and contribute to traffic safety during snowfall.

A nonlinear spectral element model for the simulation of traffic speed deflectometer tests of asphalt pavements

ABSTRACT A non-destructive testing method suitable for network-level pavement structural evaluation is the traffic speed deflectometer (TSD) test. However, the analysis of TSD measurements still needs a proper parameter back-calculation procedure, which requires an accurate and efficient forward calculation model. As a first step to solving this issue, a nonlinear spectral element model which can simulate TSD tests of asphalt pavements is developed. The model is used to investigate the characteristics and parameter sensitivity of the response of asphalt pavements caused by the TSD loading. The results indicate that the vertical deflection curve along the direction of movement observed on the asphalt pavement surface is slightly asymmetric, and the maximum deflection appears behind the centre of the loading area. In addition, the slope curve of vertical deflection is highly sensitive to the magnitude of the applied force, the moduli of the base layer and subgrade, and the thicknesses of the asphalt layer and base layer. Furthermore, the slope curve is relatively sensitive to the glassy modulus of the asphalt layer. Because of its good predictive capability and high computational efficiency, the proposed model has the desired characteristics to be used as the computational kernel for parameter back-calculation procedures of TSD measurements.

Thermoelectric energy harvesting system (TEHs) at asphalt pavement with a subterranean cooling method

ABSTRACT In this study, a thermoelectric energy harvesting system (TEHs) that utilized the heat from the surface of asphalt pavement is proposed with the aim to investigate the effects of the heat conduction using different shape structures in the subterranean level. The design model consisted of asphalt base holder to hold the asphalt, top plate for heating, and bottom plate for cooling. The top plate is exposed on the asphalt surface to harvest heat from sunlight, and the bottom plate is submerged into the pavement. The bottom plate is then connected to the cooling element, to take advantage of subterranean cooling to achieve a high-temperature difference between the top and bottom plate of the TEHs. In the past studies, subterranean cooling proved to maintain the underground temperature, but there is no assurance of high-temperature difference. Simulation and experimental investigation were conducted on how the shape structure affects the heat conduction in the subterranean level for two types of cooling elements, which is a cylindrical rod and flat bar. Both simulation and experimental results demonstrate that the cylindrical rod has yielded a higher temperature difference compared to the flat bar. Higher output voltage was generated for the case of the cylindrical rod due to more effective cooling, which resulted in larger temperature differences. Contradicted to previous studies, the field-testing has proved the system with asphalt has indeed influenced the temperature distribution into the system with a 24.39% increase of temperature difference in comparison to the system without the asphalt. Hence, the introduction of subterranean cooling and asphalt pavement heating has proved to improve the performance of TEHs, which makes it possible for utilization as an energy harvester.

Thermophysical properties and heating performance of self-healing asphalt mixture with fibres and its application as a solar collector

This paper presents the first analysis on the evaluation of the thermophysical and heating performance of self-healing asphalt mixtures with different contents of steel wool fibres for their potential use as a solar radiation absorbing material in an asphalt solar collector prototype. With this aim, four different dense-graded asphalt mixtures were prepared using the same aggregate gradation and bitumen content, but with different content of steel wool fibres: 0%, 2%, 4%, and 6% by total volume of bitumen. Physical and thermal properties, such as bulk density, air void content, thermal conductivity, specific heat capacity, and thermal diffusivity were evaluated on the asphalt test specimens. Steel wool fibre distribution inside the asphalt mixture samples was also evaluated by X-ray computed microtomography. Moreover, the thermal behaviour of a solar collector prototype, using an asphalt mixture with 4% of steel wool fibres as a solar radiation absorbing material was exposed to solar radiation conditions simulated in laboratory using a novel direct normal irradiance experimental model. This model was developed by the authors to experimentally simulate the maximum and minimum irradiance conditions for the city of Concepcion in Chile. The main results showed that self-healing asphalt mixtures with steel wool fibre addition reduced their thermophysical properties, explained by an increment in their total volume and due to the fibre distribution inside the samples. Additionally, this study proves that asphalt mixtures with 4% of steel wool fibres can be potentially used as a radiation absorbing material, transmitting the infrared radiation from the asphalt pavement surface to the water stored inside it. In short, this study provides the first assessment on the fundamental thermophysical variables of self-healing asphalt mixtures with metallic fibres, with the purpose of exploring their future use for energy harvesting applications.

Mechanical feasibility of using red mud as filler in asphalt mixtures to improve permanent deformation

A lama vermelha é um resíduo sólido resultante do processamento do minério de bauxita para obtenção da alumina (óxido de alumínio – Al2O3), que é o principal composto químico para produzir alumínio. O Brasil possui uma grande reserva de bauxita no estado do Pará e o minério é processado em larga escala. No entanto, no país, a lama vermelha tem sido armazenada inadequadamente no meio ambiente. O Pará está situado no norte do Brasil e apresenta alta temperatura durante todo o ano. O elevado volume de tráfego e as altas temperaturas contribuíram para o surgimento precoce de defeitos nos revestimentos asfálticos dos pavimentos flexíveis. Este estudo laboratorial visa à introdução deste resíduo como fíler em misturas asfálticas densas. Para tanto, foram produzidas misturas de asfalto com 3%, 5% e 7% de lama vermelha (tamanho nominal entre 0,02 a 2.800 micrometros). Como referência, foi produzida uma mistura convencional com 7% de fíler de pó de pedra (tamanho nominal inferior a 0,075 mm). A resistência à deformação permanente das misturas foi avaliada através do simulador de tráfego francês. Como resultado, a mistura com 5% de lama vermelha apresentou o melhor desempenho à deformação permanente e obteve, aos 30.000 ciclos, a porcentagem de afundamento de 3,5%. As misturas asfálticas com lama vermelha apresentaram bom desempenho, com redução da deformação permanente de 12,63 a 42,62% em relação à mistura de referência. A lama vermelha como fíler em misturas asfálticas mostrou ser uma opção viável para reutilizar este resíduo, além de ser uma alternativa ecologicamente adequada.

Penerapan Sistem Pendukung Keputusan (DSS) dalam Manajemen Pemeliharaan Perkerasan

Pavement maintenance for the road network in Surabaya does not yet have a scientific basis such as monitoring and evaluation.This study illustrates the possibility of applying a Decision Support System (DSS) in pavement maintenance management to evaluate the asphalt pavement surface conditions. Common types of Asphalt Concrete pressures include (Asphalt hemorrhage, various pavement cracking modes, pot holes, longitudinal and transverse deformations) with various conditions of severity and intensity included in the system database, mathematical models for calculating severity and levels for each type of distress as well entered. This software was developed in the Microsoft Visual Basic environment using a logic programming process. The pavement condition rating (PCR) of the road section will be determined by the system. The system suggests necessary maintenance actions based on an estimated increase in pavement age and on the cost of alternative treatments. This system is examined in evaluating the asphalt pavement surface conditions of the freeway to Juanda International Airport. Traditional visual inspection and manual calculation procedures have also been carried out. The sidewalk surface is divided into sections, and the sidewalk condition is visually visible Evaluated and assessed using specially designed forms, ranking is in the range (26-93)% representing "very bad to very good" conditions for the road section based on the ranking index provided . Data is entered into the decision support system software developed. The results are very much in accordance with the results of software development. It was concluded that the Decision Support System developed, can help planners, or policy makers to support decision making in the maintenance of pavement.

Vehicle-induced fatigue damage prognosis of orthotropic steel decks of cable-stayed bridges

Orthotropic steel deck (OSD) in a long-span cable-stayed bridge is vulnerable to fatigue damage at the deck-to-rib (DTR) joints due to excessive vehicle-induced dynamic stresses. A framework for fatigue damage prognosis of OSD in long-span cable-stayed bridges is thus presented in this paper. The main features of the framework include hourly traffic loading simulation and prediction, multi-scale finite element bridge model, coupled vehicle-bridge system, mesh-insensitive equivalent stress responses at a DTR joint, response surface models for equivalent stress responses, OSD and pavement interaction, asphalt pavement temperature effect, fatigue test-generated S-N curve, and fatigue damage prognosis. To evaluate the feasibility of the proposed framework and to manifest the effects of pavement roughness, asphalt temperature, and vehicle transverse locations on fatigue damage accumulation, a real long span cable-stayed bridge is investigated as a case study. The results indicate that the developed framework is applicable and that the fatigue damage of a DTR joint is underestimated if the time-variant temperature of asphalt pavement and road surface condition are not considered but the fatigue damage is overestimated without consideration of variable transverse locations of vehicles.

Theory and methodology on safety braking of autonomous vehicles based on the friction characteristic of road surface

<p indent=0mm>Because of the direct contact between the tire and pavement, the skid resistance of asphalt pavement is a basic factor affecting the braking safety of autonomous vehicles. The road skid resistance mainly depends on the texture characteristics of the road surface. Considering the pavement friction characteristics, building a braking model of autonomous vehicles is an effective method to improve the braking safety of autonomous vehicles. In order to develop the safety braking method for autonomous vehicles based on the road surface friction characteristic, an automatic close-range photogrammetry system (ACRP system) was proposed and built based on the circle arranged three cameras close-range photogrammetry (CRP) technology to obtain the asphalt pavement surface texture accurately in real time. Automatic image acquisition and 3D reconstruction were achieved by the ACPR system. Sand patch testing method and laser scanning method (ZGScan) were applied to collect the on-site asphalt pavement texture comparing with the results of ACRP system. It shows the texture data obtained by ACPR system have relatively high accuracy and efficiency with recognition accuracy close to 0.02 mm. Then, the peak adhesion coefficients under different road conditions were calculated by considering the skid resistance contribution of the road surface texture. Based on CarSim/Simulink joint simulation, a braking model for autonomous vehicles was established. The characteristics of the autonomous vehicles during straight normal braking, emergency braking and driving on curved sections were analyzed. Then, the safety braking distance under different conditions was put forward. The research shows that the variation trends of friction coefficient curves under different pavement conditions (dry and wet pavement) are basically the same, which both decrease significantly with the increase of relative slipping ratio. When the speed exceeds <sc>40 km/h,</sc> the curve tends to be gentle, indicating that the actual contact area of the tire-road comes to a stable status when the speed is relatively high. Based on the tire hydroplaning model built by ABAQUS, the peak adhesion coefficient curves for different pavement conditions were obtained. It can be seen that the peak adhesion coefficient of the road surface is convex parabolic distribution at different driving speeds. Moreover, the peak adhesion coefficient gradually decreases as the speed increases. During normal braking, the vehicle should keep relatively low braking deceleration considering passenger comfort. As for emergency braking, autonomous vehicle should be equipped with professional short-range radar, long-range radar and high-definition camera to detect the environment surrounding the vehicle. On rainy days, the braking distance is averagely increased by about 45% compared to sunny days. When the braking distance between vehicles is large enough, it is recommended to brake with a braking force of <sc>4−6 MPa.</sc> Autonomous vehicles should keep a certain safe distance, which requires 1.1−1.2 times of the simulated average value of safety braking distance during the driving process on dry or wet pavement. As the radius of curved sections increases, the acceleration interference values under different road conditions basically reduce. When the radius is greater than or equal to<sc>100 m,</sc> the decrease rate of the acceleration interference value is more significant. In order to improve the braking comfort of the vehicles, the radius of the curved road should be controlled above <sc>100 m.</sc> In this paper, the safety strategies for autonomous vehicles considering pavement surface texture characteristics can provide references for the theoretical design of braking system and braking safety evaluation for autonomous vehicles.

Life cycle cost analysis of Portland cement slurry seal and microsurfacing to correct rutting

ABSTRACTPortland cement slurry seal and microsurfacing can both be used as pavement preservation treatments to fill ruts, which extends service life and decreases road surface life cycle cost. Microsurfacing has a history for being a technically effective and cost-efficient solution for correcting pavement rutting in both asphalt and concrete pavement surfaces. On the other hand, Portland cement slurry seal is a relatively new product that provides an alternative rut filling solution. The potential of both treatments as rut fillers is generally unrecognized and as such, they are both underutilized in that role. This paper compares the life cycle costs of both treatments, using friction data as the primary performance indicator derived from field trial skid data collected over a period of 36 months on the same highway. The paper finds that each alternative performed comparably with regard to surface friction deterioration, and the life cycle cost output was such that either treatment is an economically feasible solution for filling ruts in both asphalt and concrete pavements.

Evaluating the asphalt pavement's surface characteristics by field testing

Pavement management systems are crucial because of monitoring the current pavement condition to supply safe, efficient, comfortable and durable riding surface for vehicles. Driving safety is the most important issue, which is closely related to pavement surface texture. The texture of the pavement surface and its ability to resist the polishing effect of heavy traffic is an important parameter in providing necessary skidding resistance during the service life. In this study, 4 different asphalt pavement sections located in Izmir/TURKEY with having different traffic characteristics were investigated every three months for two years aiming to evaluate the effect of traffic volume on the surface textural and frictional properties of the pavement. The textural properties were evaluated using sand patch test (SPT) and a 3D Laser Scanning System (LSS), while Dynamic Friction Tester (DFT) was employed to assess the frictional properties. As a result, lower Mean Texture Depth (MTD) and Mean Profile Depth (MPD) values were obtained for the increased traffic volumes. High correlation was derived between macro and micro textural properties of the asphalt pavement. Additionally, the textural and frictional properties were found highly related for the investigated asphalt pavement surfaces.

Comparison of pavement surface roughness characteristics of different wearing courses evaluated using 3D scanning and pendulum

Road pavement roughness, in terms of skid resistance, can be described from a geometrical point of view as a texture or from a physical point of view as friction between a tire and a road surface. The paper deals with the comparison of asphalt and concrete pavement surface on selected newly built sections of the D1 motorway near the Ovčiarsko tunnel. Texture measurements were performed with a Static Road Scanner (SRS) capable of recording surface irregularities up to the microtexture level (2.49 µm resolution). A pendulum was used to determine the friction. Subsequently, the texture was evaluated using individual amplitude and wavelength characteristics and the friction was evaluated using the PTV parameter. Finally, correlations were searched between the roughness characteristics of asphalt concrete and cement concrete pavements, but also between texture and friction characteristics.

Research of Deicing and Melting Snow on Airport Asphalt Pavement by Carbon Fiber Heating Wire

In the paper, the method of deicing and melting snow by the carbon fiber heating wire (CFHW) embedded in the airport asphalt pavement is proposed to improve the security of airport operation. The field experiment of deicing and melting snow on the airport asphalt pavement is conducted. Deicing and melting snow, asphalt pavement temperature, ice‐free area ratio, and snow‐free area ratio are analyzed. Electrical power with 350 W/m2 is input to the airport asphalt pavement for deicing and melting snow by the CFHW. In the experiment, 3 mm ice can be melted, and the average infrared ray temperature (IRT) of the airport asphalt pavement surface can achieve an increment of 13.0°C in 2.5 hours when the air temperature is from −7.5°C to −2.2°C. Snow with 3.2 mm precipitation can be melted in 2 hours when the air temperature is from −4.8°C to −3.5°C, and the asphalt pavement temperature can achieve an increment of 5.9°C at the depth of 0.5 cm. The results show that the method of deicing and melting snow on the airport asphalt pavement by the CFHW is practicable in the cold zone.

Asphalt pavement coated by hot-pressed hydrated lime

ABSTRACT Hot-pressed hydrated lime (HL) on the surface of asphalt pavements forms a type of light-coloured cool pavement, which is called hot-pressed HL pavement. In this cool pavement, unmodified HL at the millimetre particle size is commonly used. This study used HL with three particle sizes (1200, 600, and 200 mesh), modified by graft polymerisation and emulsion polymerisation. The cooling effect and laboratory performances (skid resistance, abrasion resistance, anti-glare performance, and erosion resistance) were evaluated. The effects of particle size and surface modification were evaluated, and the cost of this cool pavement type was analysed. Hot-pressed HL reduced the surface temperature of asphalt pavement by about 10°C. The decreased particle size of HL improved both the cooling effect and the erosion resistance. HL modification slightly decreased the cooling effect, but significantly enhanced abrasion resistance, anti-glare performance, and erosion resistance. A particle size of 1200 mesh, spreading dosage of 100 g/m2, and graft polymerisation modification are recommended for HL. Noteworthy, the cooling effect of hot-pressed HL pavements is slightly weaker than that of traditional heat-reflective coating pavements; however, the cost of the former material is only about 0.01 times of the latter.

Finite Element Method-Based Skid Resistance Simulation Using In-Situ 3D Pavement Surface Texture and Friction Data.

Skid resistance is an important surface characteristic that influences roadway safety. Various studies have been performed to understand the interaction between pavement and tires through numerical simulation for skid resistance prediction. However, the friction parameters required for simulation inputs are generally determined by objective assumptions. This paper develops a finite element method (FEM)-based skid resistance simulation framework using in-situ 3D pavement surface texture and skid resistance data. A 3D areal pavement model is reconstructed from high resolution asphalt pavement surface texture data. The exponential decay friction model is implemented in the simulation and the interface friction parameters required for the simulation are determined using the binary search back-calculation approach based on a trial process with the desired level of differences between simulated and observed skid numbers. To understand the influence of texture characteristics on interface friction parameters, the high-resolution 3D texture data is separated into macro- and micro-scales through Butterworth filtering and various areal texture indicators are calculated at both levels. Principal component analysis (PCA) regression analysis is conducted to quantify the relationship between various texture characteristics and the interface friction parameters. The results from this study can be used to better prepare the inputs of friction parameters for FEM simulation.