Resurfacing Research Articles

КЕРАМИКАЛЫҚ ЖОЛ ТӨСЕНІШТЕРДІ ӨНДІРУДЕГІ КЕРАМИКАЛЫҚ МАССА КОМПОЗИЦИЯСЫН ЖЕТІЛДІРУ

The article presents the results of a study of the chemical and mineralogical composition of the raw material components in the ceramic mass and provides techniques for the technology of laying ceramic material by vibropressing using talc rock in the mass and methods for determining the composition of clay raw materials. Formulations for the production of ceramic road surfaces, taking into account the factors of preference for mixtures to improve the properties of the finished product as a molding, drying and ceramic material, have been studied in two different components. It was found that the introduction of talc into the ceramic composition has an effect on the formation of high-temperature augite and amphibole phases and the intensification of the formation of minerals in clay, on the formation of high-temperature phases - sanidine, ackermanite elements. This process leads to an increase in the physical and mechanical properties of the resulting samples.The main patterns of formation of the structure and phase of ceramic compositions by firing in the temperature range 1000оC-1100оC were studied by isothermal control.In this pattern, sintering processes with solid and solid liquid-phase syntheses were carried out to ensure the phase - mineral composition, the study clarified the production of high-strength and frost-resistant ceramic pavement. In order to be used in the improvement of the city territory (sidewalks, alleys, park areas, playgrounds, etc.), the possibility of obtaining ceramic road surfaces that meet environmental and operational requirements has been proven. It has been established that one of the priority properties of ceramic road surfaces is a significant abundance of their porosity (25-30%), which allows you to quickly absorb moisture from precipitation (rain, sleet, etc.) and filter water through the body into the ground.Such properties of ceramic paving stones prevent the accumulation of moisture on the surface of the roadway and create comfortable conditions during pedestrian movement, reducing the likelihood of ice formation on the surface of the paving stones in the cold season.

Automated road surface diagnostic system with image complexing

Automated road surface diagnostic system with image complexing

Analysis of the mechanical behavior of asphalt pavement under multiple coupling effects

To reveal the damage mechanism of asphalt pavement caused by the spatial rotation of the stress principal axis, and the influence range of excess pore water pressure on the pavement under the coupling action of multiple fields, the finite element software was used to build the three-dimensional highway asphalt pavement models. Under the consideration of gravity's impact on dynamic computation results, the study investigated the variation patterns of the direction cosines of the principal stress axes of asphalt structural pavement elements under the action of moving loads, as well as the distribution laws of excess pore water pressure. The results indicate that the influence of gravity on dynamic computation results increases gradually with the depth of the pavement, reaching an error of first principal stress of 40.1 % at the bottom of the lower layer. During the movement of loads, the pavement elements directly under the load undergo rotation of the principal stress axes in the xy, xz, and yz planes under different physical fields. With increasing pavement depth, the angle between the first principal stress and the z-axis primarily fluctuates between −90° to 0° and 90° to 180°. The cosine of the angle between the first principal stress and the x-axis and z-axis undergoes instantaneous positive and negative conversion, which can easily lead to transverse and longitudinal cracks on the road surface. The influence widths of excess pore water pressure along the longitudinal and transverse directions of the pavement increase with the pavement depth, with maximum widths of 5.426 m and 2.075 m, respectively. These findings offer new insights into the mechanisms behind the formation of transverse and longitudinal cracks on asphalt pavement and hold significant implications for the improvement of asphalt design methods.

Expanding the Accessible Forest Areas by Improving Forest Road Standards and Utilizing Mobile Fire-fighting Teams

In Turkey, most of the roads (66%) in forests consist of Type-B secondary forest roads with limited technical standards. The lack of technical standards used on these roads and the lack of road structures and surface material limit the fire truck’s speed and increase the travel time of the firefighting team. Improving forest road standards will contribute to driving safety and increasing the design speed, thereby expanding the forest areas that can be reached within the critical response period, reducing possible wood raw material losses. There is no study in the national and international literature investigating the contribution of forest road standards improvement to firefighting activities and the effects on possible wood raw material losses due to forest fires. In this study, it was aimed to investigate the effects of improving forest road standards on expanding accessible forest areas within the critical response time, especially in forests with high fire risk, and thus reducing potential wood raw material losses. Antalya Forestry Regional Directorate, where forest fires are seen most frequently and the amount of burned area is the highest in Turkey, was selected as the study area as one of the forest regional directorates where forest fires are seen most frequently and the amount of burned area is the highest in Turkey. In the solution process, primarily the forest areas that can be reached by the firefighting team (including mobile teams used in emergencies) within the critical response time were determined by considering the existing road network in the study area. Then, the possible increase in the accessible forest areas was investigated when the road standards are improved. Within the scope of the study, the impact of mobile teams used in emergency situations on forest areas reached during the critical response period was also evaluated. According to the results, in the scenario where current road standards and stationary teams were evaluated, it was determined that only 59.54% of the forest areas could be reached by initial response teams during the critical response time, and if road standards were improved, this rate increased to 71.69%. On the other hand, in the scenario where current road standards and stationary and mobile teams were evaluated together, it was determined that 70.40% of the forest areas could be reached by initial response teams during the critical response time, and if road standards were improved, this rate increased to 78.17%. The results obtained have shown that improvements in road standards and the presence of mobile teams have a very effective role in combating forest fires.

Fracture properties of asphalt mixtures containing high content of reclaimed asphalt pavement (RAP) and eco-friendly PET additive at low temperature

Low-temperature cracking is one of the main types of distress that affects asphalt pavement performance over its service life. At the same time, the accumulation of plastics, especially polyethylene terephthalate (PET), and the potentially harmful effects of these plastics requires special attention in order to find ways to reduce them. Previous studies have paid less attention to the impact of PET on low-temperature cracking in asphalt mixtures and the simultaneous interaction between PET and reclaimed asphalt pavement materials (RAP) on fracture behavior of asphalt mixture. In this study, a value-added substance called PET Additive (PA), which is extracted from chemical processing of PET was blended with asphalt binder at different dosages (1–3 %) to use in the mixture of hot mix asphalt (HMA). Reclaimed Asphalt Pavement (RAP) was also added to the HMA mixtures at rates of 25 and 50 % by aggregate mass and the resulting asphalt mixtures were tested to characterize the load carrying ability and cracking resistance indexes of the modified HMA mixtures. Circular shaped test specimens with different mixture types and different geometries were manufactured. Results showed that the asphalt mixture containing PA has better performance than the control mixture; among all mixture types, a mixture containing 2 % PA and 25 % RAP had the better fracture resistance at low temperatures. Finally, the results demonstrate that the fracture behavior in Edge Notch Disc Bend (ENDB) and Semi-Circular Bend (SCB) specimens had similar trends.

Road surface semantic segmentation for autonomous driving

Although semantic segmentation is widely employed in autonomous driving, its performance in segmenting road surfaces falls short in complex traffic environments. This study proposes a frequency-based semantic segmentation with a transformer (FSSFormer) based on the sensitivity of semantic segmentation to frequency information. Specifically, we propose a weight-sharing factorized attention to select important frequency features that can improve the segmentation performance of overlapping targets. Moreover, to address boundary information loss, we used a cross-attention method combining spatial and frequency features to obtain further detailed pixel information. To improve the segmentation accuracy in complex road scenarios, we adopted a parallel-gated feedforward network segmentation method to encode the position information. Extensive experiments demonstrate that the mIoU of FSSFormer increased by 2% compared with existing segmentation methods on the Cityscapes dataset.

An Investigation of Globe Temperature in Street Canyons: A Scaled Model Study Implementing Cool Materials

The measurement of globe temperature (GT) is essential for investigating pedestrian thermal comfort in street canyons. The globe thermometer is the most common instrument used to measure GT; however, its application in scale models has not been thoroughly investigated to date. Therefore, this study explicitly investigates globe thermometer measurements in scale models and analyzes the need for customization of the globe thermometer for more reliable measurements. Scaling down with respect to the size of the globe thermometer and the effect of solar orientation/envelope materials are investigated in this study. The initial experiments were carried out in an outdoor setting using a typical street canyon model (scale 1:100) with an east-west street orientation. The results of the experiment are presented to compare a low solar reflectance street canyon (albedo of 0.4) and a high solar reflectance canyon (albedo of 0.6) in terms of surface temperatures, heat flux, and globe temperature. It is observed that although the wall and road surface temperatures are lower for the high solar reflectance canyon compared to those for the low solar reflectance canyon, the GT (measured at pedestrian height) is higher in a high reflectance canyon during the daytime, which could be due to the combined effect of direct radiation and short-wave reflection. However, for the hours after sunset, a reverse effect is observed, i.e., the GT becomes lower (up to 0.8 °C) in the case of a high reflectance canyon compared to that for the low reflectance canyon. Furthermore, the study emphasizes the impact of solar reflectance of canyon surfaces on GT values, due to the view factors that the globe thermometer on those surfaces.

Smart Rumble Strip System to Prevent Over-Height Vehicle Collisions.

Collisions of over-height vehicles with low clearance bridges is commonly encountered worldwide. They have caused damage to bridge structures, interruption to traffic, injuries or even fatalities to road users. To mitigate such risks, passive systems that involve warning gantries, flashing lights and illuminated signage are commonly installed. Semi-active systems using laser- or infrared-based detection systems in conjunction with visual warnings have been implemented. Nevertheless, some drivers ignore these visual warnings and collisions continue to occur. This paper presents a novel concept for a collision prevention system, which makes use of a series of sensor-activated, motorized rumble strips. These rumble strips span across a certain distance ahead of a low clearance bridge. When an over-height vehicle is detected, a mechanism is triggered which elevates the rumble strips. The noise and vibrations produce a vigorous alert to the offending driver. They also increase effective friction of the road surface, thus assisting to slow down the vehicle and shorten the stopping distance. The strips will be lowered after a certain time has elapsed, thus minimizing their effects on other vehicles. This article presents a conceptual framework and quantifies the vibration and noise caused by rumble strips in road tests. Road tests indicated that the vibration level typically exceeded 1 g and noise level reached approximately 90 dB in the cabin of a 3.5-ton truck. Fabrication of a proof-of-concept mechanized rumble strip model was presented and verified in an outdoor environment. The circuitry and mechanical design, and requirements in actual implementation, are discussed. The proposed event-triggered rumble strip system could significantly mitigate over-height vehicle collisions that cause major disruptions and injuries worldwide. Further works, including a comprehensive road test involving various types of vehicles, are envisaged.

Feasibility Assessment of Mudstone Aggregate as an Alternative Material for Colored Asphalt Pavement in South Korea

Colored asphalt pavements have been implemented in South Korea to enhance visibility and lane distinction; however, color fading, accelerated deterioration, and increased pothole occurrence have been noticed. As a solution, alternative materials that can be used for the construction of colored asphalt pavements are being explored. This study evaluates the feasibility of using mudstone aggregate in constructing colored asphalt pavement in South Korea. Initially, aggregate quality tests were conducted on mudstone samples to assess their suitability compared to standard criteria. To enhance the visibility and color retention of colored asphalt, addition of pigment in the colored asphalt pavement mixture was considered and evaluated. The asphalt mixtures were evaluated for deformation, crack and viscoelastic properties using the Kim test, indirect tensile (IDT) strength test, and dynamic modulus test, respectively. Results showed that mudstone aggregate exceeded quality standards and the colored asphalt mixtures demonstrated superior deformation strength and crack resistance compared to typical SMA. However, the addition of pigment slightly reduced these properties. Overall, the findings suggest mudstone aggregate as a viable alternative for constructing colored asphalt pavements, offering potential improvements in durability and color retention.

Innovations in recycled construction materials: paving the way towards sustainable road infrastructure

The expansive development of infrastructure has led to increased consumption of virgin aggregates in road construction, resulting in significant environmental impacts. To address this issue, there is a pressing need for sustainable alternatives that utilize recycled materials in pavement applications. This paper presents a comprehensive review of a decade-long research program focused on the development and evaluation of sustainable pavement materials, such as recycled and waste aggregates, industrial by-products, and natural fibers. The research encompassed a wide range of innovative materials and technologies, such as geopolymer-stabilized recycled aggregates, cement-stabilized waste materials, natural additive-modified cement stabilization, and recycled aggregate-geogrid reinforcement systems. The experimental framework employed a combination of mechanical testing, durability assessment, microstructural analysis, and environmental safety evaluation to assess the performance and sustainability of these materials. The key findings demonstrated the superior mechanical properties, improved durability, and environmental suitability of the recycled materials compared to conventional virgin aggregates. The successful implementation of these sustainable solutions in real-world projects highlights their potential to reduce the environmental footprint of road infrastructure development. Furthermore, the paper discussed the practical implications of the research outcomes for pavement design and construction, as well as future research directions to further advance the field of sustainable pavement engineering. The findings of this research report can be used as guidance for researchers, practitioners, and policymakers seeking to upcycle the widespread adoption of recycled materials in road application and contribute to the development of a more sustainable and resilient transportation infrastructure.

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.

Improved micromechanics model for piezoresistive polymethyl methacrylate modified with carbon nanotubes: considering the effect of mineral fillers

ABSTRACT Polymethyl methacrylate (PMMA) modified with carbon nanotubes (CNTs) shows promise as a piezoresistive material for road pavements. The micromechanics model holds significance in designing and optimising the piezoresistive performance of CNTs-modified PMMA. In this paper, the excluded volume is introduced to characterise the effect of mineral fillers, as the main components in PMMA mastic, within the micromechanics model. The investigation integrates Scanning Electron Microscopy (SEM), Monte Carlo numerical simulation, and electrical conductivity tests. Subsequently, a parameter analysis is conducted to optimise the piezoresistive sensitivity. SEM results reveal two representative interphase morphologies and identify the excluded volume of mineral fillers. It is estimated as 19.4% of the solid volume of mineral fillers through the numerical simulation. Moreover, the modelled electrical conductivity of PMMA mastic using the improved model precisely aligns with experimental results. These could validate and quantify the excluded volume of mineral fillers and then improve the micromechanics model for piezoresistivity. The parameter analysis demonstrates that mineral fillers markedly enhance the piezoresistive sensitivity of PMMA mastic. It is suggested to prepare PMMA mastic with a lower Poisson’s ratio and volume fraction of CNTs. This improved micromechanics model could guide the design and optimisation of piezoresistive polymers in intelligent road systems.

Application of the Semi-Supervised Learning Approach for Pavement Defect Detection.

Road surface quality is essential for driver comfort and safety, making it crucial to monitor pavement conditions and detect defects in real time. However, the diversity of defects and the complexity of ambient conditions make it challenging to develop an effective and robust classification and detection algorithm. In this study, we adopted a semi-supervised learning approach to train ResNet-18 for image feature retrieval and then classification and detection of pavement defects. The resulting feature embedding vectors from image patches were retrieved, concatenated, and randomly sampled to model a multivariate normal distribution based on the only one-class training pavement image dataset. The calibration pavement image dataset was used to determine the defect score threshold based on the receiver operating characteristic curve, with the Mahalanobis distance employed as a metric to evaluate differences between normal and defect pavement images. Finally, a heatmap derived from the defect score map for the testing dataset was overlaid on the original pavement images to provide insight into the network's decisions and guide measures to improve its performance. The results demonstrate that the model's classification accuracy improved from 0.868 to 0.887 using the expanded and augmented pavement image data based on the analysis of heatmaps.

Assessment of Semi-Flexible Pavement Using Styrene-Butadiene Emulsion Modified Cement Grout

Semi-flexible pavement (SFP) is a type of road surface that combines open-graded asphalt concrete with cement grout for wearing courses containing 18 to 28% air voids. This study investigates the effectiveness of two types of cement grouts using modified styrene-butadiene emulsions, Sika Latex and Sika Latex TH, with varying amounts ranging from 4.5% to 7.5% and 7.5% to 9%, respectively. The goal of the paper is to determine the appropriated type of styrene-butadiene emulsion type for SFP. To create the SFP, the selected grout and Vinkems Asphalsol grout with a water-cement ratio of 0.45 were poured into the asphalt structure, resulting in an SFP with 22.8% air voids. Additionally, several experiments were conducted to evaluate the effectiveness of SFP. These experiments included the Marshall stability test, indirect tensile strength test, and resilient modulus test. The study results showed that Sika Latex 6.5% and Sika Latex TH 9% had good properties for use in SFP.

Mechanism-based shift factors to predict the fatigue performance of cemented pavement materials

AbstractCemented pavement materials (CPMs) are essential components in pavement structures, yet accurately predicting their service life due to fatigue damage remains challenging. Laboratory fatigue test results are commonly employed to predict the service life of CPMs by applying a lab-to-field shift factor (SF). However, traditional approaches rely heavily on experimental data, posing challenges in ensuring the certainty of lab-to-field results. Additionally, inconsistencies in lab-to-field fatigue failure criteria further complicate SF development. To address these challenges, this study proposes a mechanism-based methodology for developing SF. This methodology comprises a rigorous two-scale fatigue model developed by the authors to characterise the fatigue performance of CPMs at the lab scale and predict their performance at the field scale, thereby facilitating the development of SFs. These SFs are established based on a consistent lab-to-field fatigue failure criterion (i.e. the modulus reduction of CPMs). By accounting for strain differences between laboratory and field scales, SFs are derived in the strain-fatigue life space. Application of this approach to typical Australian CPMs, namely siltstone and hornfels, yields mechanism-based SFs of 1.19 and 1.21, respectively.

Wheel Slip Equilibrium Point Model Reference Adaptive Control Based PID Controller for Antilock Braking System: A New Approach

This paper presents a new approach to wheel slip control in Antilock Braking System (ABS) using an Approximated First Order Wheel Slip (AFOWS) Model Reference Adaptive Control (MRAC) based PID (AFOWS-MRAC-PID) controller. An ABS was modeled in a MATLAB/Simulink environment using a quarter car model with the proposed controller. Simulations were conducted with a wide range of adaptation gains (50, 100, 150, 200, and 250) to study the effectiveness of the proposed control system. The results revealed that the proposed system could track and maintain 10% wheel slip and eliminate oscillation (instability) in terms of overshoot associated with conventional PID controllers, particularly on wet and snowy road surfaces, using adaptation gains of 150, 200, and 250. Overall, the proposed system provided the best performance in terms of stopping distance, vehicle braking velocity, and braking torque on all road surfaces with an adaptation gain of 250, although braking on dry road surfaces was the most effective.

Urban trees left high and dry – Modelling urban trees´ water supply and evapotranspiration under drought

Abstract Long-lasting extreme weather conditions are expected to occur more frequently in the future owing to climate change, as demonstrated by the recent heat waves. In particular, the decrease in precipitation during the summer months had a significant impact on urban tree water availability. Therefore, it is imperative to develop methodologies for determining the available water supply and evaporation rates for urban trees. We mapped data from 49 urban small-leaved linden trees with varying characteristics including groundwater levels, shading situations, tree pit sizes, pavement materials, and sealing ratios. By combining these data with an adapted Penman-Monteith method to calculate evapotranspiration, we simulated the soil water storage and evapotranspiration rates of these trees during the very dry year of 2018 as an example. Model validations were performed using lysimeter and sap-flow studies on Tilia cordata trees in 2022.
During the growing season, most trees experienced water stress on > 85% of the days because of weak precipitation events that failed to refill soil water storage. In contrast, trees with additional water supply through capillary rise reached water stress approximately 45 d later. The model results suggest that many trees will require additional water supply during predicted droughts in the future, which could have significant implications for urban forestry management. This model approach can be used to test and refine future water supply management strategies, making it a useful planning tool for improving the water efficiency of trees in urban areas and blue-green infrastructure.

Effect of adding dune sand to bituminous concrete intended for wearing courses

The 20th century was marked by the development of road infrastructure around the world, which necessitated a great need for pavement materials which in turn had to meet certain geotechnical criteria such as hardness, grain size and cleanliness. A traditional pavement body generally includes gravel, but unfortunately these materials are not available in some areas. From there was born the need to use local materials, such as tuff and dune sand, which exist in abundance and which are inexpensive and which have proven their effectiveness in road construction. The semi grained bituminous concrete SGBC intended for wearing layers, known by the name BC 0/14, generally is prepared by mixing two components: aggregates and bitumen. The design of this material considers several criteria related to one hand to the aggregates, namely mechanical characteristics, shape, and cleanliness of stones, the blue value of the fine, the particle size of the mixture (% passing through), the choice of the bitumen grade and mechanical performance as well the water resistance of asphalt concrete 0/14. The present work aims to study the influence of the substitution of the fraction 0/3 mm of the crushed sand (usually used in this type of materials) by fine dune sand, on the mechanical performance including Duriez and Marshall Stability and water resistance.

A state-of-the-art assessment in developing advanced concrete materials for airport pavements with improved performance and durability

Concrete materials, as the main component of airport pavement, provide essential attributes such as strength and toughness required by airport pavement. With the rapid development of air transportation, the compression and cracking resistance performances required by airport pavement are dramatically boosted with the ever-growing weight and the frequency of aircraft. In recent years, high-performance concrete materials with excellent properties have shown great potential in improving durability and extending the service life of pavement. This review presents a-state-of-the-art assessment guided by the pavement performance requirement, material design mechanism, application cases and future application guidance of advanced cementing materials in airport pavement improvement. Firstly, the functions of each structural layer of airport pavement and their effects on the surface layer are summarized. Then, the design mechanism and application cases of advanced concrete materials were summarized with the future application guidance to be given. Finally, the application scenarios, testing mechanism and testing effect of nondestructive testing methods for airport pavement performance evaluation are summarized. This review provides a comprehensive assessment of the development and applications of advanced concrete materials for airport pavement, paving avenue to achieve high performance and long service life of airport pavement.

Introducing the rubber plate impact method: a versatile alternative to close proximity test for tire-pavement noise characterization on asphalt highways

Despite its widespread use, the close proximity (CPX) test for tire-pavement noise is limited to existing pavements, posing challenges for timely and effective corrections of noisy pavements. Additionally, the CPX test entails significant procurement and operation costs. Addressing these issues, this study introduces the rubber plate impact (RPI) method as a simple experimental technique for assessing tire-pavement noise in both laboratory and field settings. The RPI test utilizes the folding motion of the treaded rubber plate on the road surface to simulate air pumping and tread impact noise as two main contributors to tire-pavement noise. Indoor RPI tests on asphalt concrete samples of dense graded asphalt and porous asphalt mixes revealed dominant effects of air void content and associated surface texture on the level of noise. The RPI testing procedure was verified at 17 highway test sections, where both CPX and RPI tests were conducted for comparison. Multiple linear regressions between RPI and CPX data were analyzed to propose CPX prediction models at different speeds (80, 100, 120 km/h), and the performance of these prediction models was validated with independent noise datasets collected from four different highway routes. The findings suggest promising prospects for the RPI test as a cost-effective and versatile alternative to CPX for tire-pavement noise characterization on asphalt-surfaced roads, with implications for road materials design and noise mitigation strategies.