Pavement Systems Engineering

Reclaimed asphalt pavement (RAP) has become a viable and sustainable pavement recycling option. Pavement engineers are investigating a variety of technologies, including warm mix asphalt (WMA) technology and alternative materials, like reclaimed asphalt pavement (RAP), in the construction of pavements due to worries about global warming and environmental pollution, rising energy costs, and limited financial resources. Repurposing old asphalt materials, RAP presents a tempting proposition as the infrastructure sector grapples with cost-effective alternatives and environmental issues. It is possible to reduce the need for virgin materials and minimize waste disposal by careful processing and mixing RAP into fresh asphalt mixtures. The paper covers the material characterization of RAP materials, virgin aggregates, and VG-30 bitumen. Samples are made for many tests, such as Marshall stability, indirect tensile strength (ITS), and tensile strength ratio (TSR), and mix designs are created for the Marshall mix design process. Results suggest that the mechanical properties and durability characteristics of asphalt mixes are greatly impacted by the addition of a high RAP concentration. The study balances stability, air voids, voids in mineral aggregate (VMA), and voids filled with asphalt (VFA) to determine the ideal binder amount for each RAP percentage. All things considered, this study advances knowledge about sustainable pavement building techniques and lays the groundwork for the successful integration of RAP into asphalt mixes, opening the door to a more economical and ecologically conscious road construction industry.

This study investigates the influence of incinerated biomedical waste ash (IBMWA) on the properties of cement-treated road base materials (CTRB). IBMWA, a by-product of high-temperature (850–1100 °C) incineration of biomedical waste, contains inorganic components that could potentially enhance or modify the characteristics of road construction materials when used as a partial replacement for cement. CTRB was prepared by replacing OPC with 0%, 20%, 40%, 60%, 80%, and 100% IBMWA in order to determine the recommended maximum dosage of IBMWA, without compromising its effectiveness. The laboratory performance of CTRB with IBMWA was assessed, which includes unconfined compressive strength (UCS), indirect tensile strength (IDTS), resilient modulus (MR), and wetting and drying (W-D) resistance. The research results demonstrated that the incorporation of IBMWA had a positive influence on the characterization of CTRB. The strength characteristics of CTRB containing IBMWA increased with an increase in curing time. However, the strength of CTRB decreased with the increase of IBMWA content. The 7 days UCS of CTRB containing 20% IBMWA met the specification of base course as set by IRC: 37–2018. Additionally, after 12 cycles of wetting and drying, considered mixtures exhibited weight loss below the thresholds established by IRC: 89–2018. The concentrations of heavy metals in these mixtures remained below the limit set by the United States Environmental Protection Agency (US EPA) standards. Thus, partially replacing OPC with IBMWA in CTRB can mitigate heavy metal leaching issues, with 20% IBMWA identified as the suggested maximum dosage for effective performance.

In the pavement industry, the use of reclaimed asphalt pavement (RAP) material is increasing due to its cost-effectiveness. However, substituting RAP for virgin aggregates and binder can lead to poor workability and degraded overall performance of the pavement. To address these issues, rejuvenators are being employed. This study explores the effect of waste engine oil (WEO) as a rejuvenator on the volumetric properties of recycled mixtures (RMs) with different RAP contents in the direction of sustainable pavements. The study investigates the optimum dosages of WEO through Marshall stability criteria for different RAP contents. Additionally, a comprehensive cost analysis is performed to evaluate the cost of different mixtures and hot mix asphalt (HMA). Results indicate that the inclusion of RAP significantly affects the volumetric properties of bituminous mixtures, which can be restored using WEO. The optimal dosages of WEO exhibit the volumetric properties of different RMs similar to the properties of HMA or within the limits suggested by specifications. Furthermore, 12 to 29% of cost savings can be achieved associated with virgin and waste materials, their transportation, and production of bituminous mixture with using 20 to 50% RAP. This study highlights the role of WEO as a sustainable rejuvenator, enabling increased utilization of RAP.

This study investigates the impact of fractionating Reclaimed Asphalt Pavement (RAP) on the stiffness properties of cold asphalt mix (CAM). The RAP material was divided into fine (passing through 2.36 mm) and coarse (ranging from 19 mm to 2.36 mm) fractions, along with an unfractionated type. For each type of fractionation, four RAP dosage levels (25, 50, 75, 100%) were evaluated. CAM was prepared with the optimal emulsion content at an air void of 10 ± 1% for all 13 mix combinations. The Indirect Tensile Stiffness Modulus (ITSM) was conducted at three temperatures (15 ℃, 25 ℃, and 35 ℃) for all 13 mix combinations. The Indirect Tensile Strength (ITS) and Resilient Modulus (RM) tests were also conducted at 25℃. Based on the findings, ITSM of CAM dropped with temperature for all fractionations. Regardless of temperature, the ITSM increased with the dosage of RAP for all fractionations. Compared to coarse and unfractionated mixes, fine fractionated mixes showed a 31% and 30% reduction in stiffness, respectively. Tensile strength improved by 53% for the coarse fraction (at 100% RAP) and by 38% for the unfractionated mix (at 50% RAP), but there was no appreciable change when fine RAP was added up to 50%. The RM values improved by 24, 83, and 92% for fine, coarse, and unfractionated mixes at increasing RAP doses. This study recommends using coarse fractionation over unfractionated and fine-fractionation of RAP in CAM for better tensile strength and stiffness characteristics.

With features including improved drainage, soil stabilization, and erosion management, natural geotextiles have become essential components in the construction of roads. The incorporation of coir geotextile reinforcement has the potential to enhance the structural performance of pavements, extend their lifespan, and mitigate settlement issues caused by subgrade soil instability. One of the objectives of this study is to evaluate both fresh coir sample and already laid coir geotextile sample from 2 different study areas chosen at Thiruvananthapuram, Kerala, through laboratory testing using Scanning Electron Microscopy (SEM). The second objective is to investigate the potential for enhancing geotextile performance through the application of different coatings: used cooking oil, paint, and bitumen, each offering unique properties and benefits. Even though the coir geotextile is said to have a life span of five years, from the study it was seen that the coir geotextile which was laid in the road for almost 12 and 18 months, was severely degraded. SEM analysis showed large cracks and pores in coir geotextile, which promoted the water absorption and thus degradation. Thus, to improve the lifespan, the coir geotextile was coated with three materials. The findings revealed that used cooking oil and paint showed inconsistent performance and limited effectiveness as a coating material. Bitumen emerged as more reliable option for improving the performance of coir geotextiles. Improved understanding of how coatings influence geotextile performance can lead to more sustainable construction practices, resulting in cost savings, enhanced structural integrity, and prolonged service life for transportation infrastructure.

This study explores the potential of stabilized granular lateritic soil as a viable alternative to high-quality aggregates in pavement layers. Laboratory studies were carried out to thoroughly evaluate the strength and long-term durability qualities of stabilized lateritic soil with various cement contents. Notably, increasing the cement content to 3% resulted in a remarkable threefold increase in unconfined compression strength compared to untreated samples. Moreover, significant improvements were experimentally observed in soaked California Bearing Ratio and indirect tensile strength, highlighting the effectiveness of stabilization. Long-term durability was rigorously evaluated through wetting–drying (W-D) cycles, revealing that the stabilized soil met established performance criteria. This confirms its suitability for use in both low and high-volume road construction projects. These findings underscore the improved material performance achievable through proper stabilization techniques. In conjunction with existing literature, this study supports the ongoing research and development of cost-effective and durable road construction materials utilizing locally available resources. By leveraging stabilized lateritic soil, infrastructure projects can potentially reduce dependency on scarce high-quality aggregates, mitigate environmental impacts associated with aggregate mining and transport, and promote sustainable construction practices.

Using sustainable materials in pavement construction has become essential nowadays to conserve material resources. This paper discusses the effect of Waste Transformer Oil (WTO) and Waste Engine Oil (WEO) on the performance of 100% RAP mixes produced at reduced mixing temperatures and compaction efforts. The mixing temperatures selected in the study are 125, 135, 145, 155, and 165 °C. Compaction efforts selected are 75 and 50 blows. The rejuvenator dosages used are 0.5 and 1% by weight of RAP content. Marshall samples were cast and tested for Marshall stability and flow. Volumetric properties (air voids, VMA, and VFA) are also determined for all the samples. 0% oil dosage could satisfy all the Marshall properties at 125 °C at 75 blows. 0% oil dosage at 155 and 165 °C and 0.5% WEO dosage at 135 °C could satisfy all the Marshall properties at 50 blows. It is concluded from the results that adding WEO at 0.5% dosage improves the workability of the mix, leading to better compaction, and helps in producing mixes at reduced temperatures and compaction effort. 100% RAP mixes can be produced at reduced mixing temperatures and compaction efforts with WEO as the rejuvenator. Testing of RAP mixes by adding fresh aggregates with or without a fresh binder may be tried to check the effectiveness of WTO as a rejuvenator for the future scope of the work. Performance-based testing of 100% RAP mixes may also be tried as the future scope of work.

Master curve, a tool for predicting and characterizing asphalt’s rheology, utilizes master curve models. The accuracy of a master curve model varies when neat asphalt is modified, attributed to the changes in the rheology, which necessitate the selection of an appropriate master curve fitting model for modified asphalts. In this direction, an effort was carried out in this research work to analyse the reliability and accuracy of two popular rheological models, the Christensen Anderson (CA) model and the sigmoidal model for Rice Husk Ash Modified Asphalt (RMA), through statistical goodness of fit indicators. In order to arrive at this objective, rheological characterization of RMA was carried out by performing temperature and frequency sweep tests. Shift factors were determined using the Williams–Landel–Ferry equation, and master curves for the complex modulus of the binders were developed. Further, a detailed goodness-of-fit analysis was carried out on the CA and sigmoidal model fitting techniques. The research results showcased that both models exhibit lower accuracy at high temperatures compared to intermediate and low temperatures. When comparing the precision of the models, the sigmoidal model exhibits greater accuracy than the CA model. However, the rate of error accumulation with the increase in RHA dosage is higher in the sigmoidal model in comparison with the CA model. Overall, it can be concluded that RHA modification significantly influenced the performance of the CA and sigmoidal models.

This study investigates the effects of multi-walled carbon nanotubes (MWCNTs) on the engineering properties of soil-fly ash mixes, with a focus on enhancing California Bearing Ratio (CBR) for potential use as subgrade material in pavement construction. Soil-fly ash mixes were treated with various concentrations of MWCNT, SHMP (Sodium Hexametaphosphate), and cement. An optimal model and an alternative model were developed using CART regression analysis, with R2 values of 0.95 and 0.84 for training and testing of the optimal model, respectively. A 13-node CART model was selected over a 26-node model to balance predictive accuracy and interpretability. The maximum CBR value observed was 50.78% for a mix of 0.01% MWCNT, 2% SHMP, and 3% cement (20% soil replacement with fly ash), compared to a minimum CBR of 4.39% for untreated natural soil. The findings suggest that adding MWCNT and cement to soil-fly ash mixes significantly enhances CBR, supporting the use of these stabilized materials for developing resilient subgrade layers.

The study aims to evaluate the structural adequacy of Low-Volume Roads (LVRs) in Kerala using the Falling Weight Deflectometer (FWD). The analysis of pavement deflection data involves a back-calculation process, where pavement layer moduli are derived from deflection values obtained via FWD. This process utilizes specialized software and customized programming. Specifically, the KGPBACK software package is adopted for back-calculation, and a Python program is employed to perform back-calculation using the BISAR (Bitumen Stress Analysis in Roads) method in MATLAB. For this study, LVRs with a surface type of Open Graded Premix Carpet (OGPC) and Bituminous Concrete of thickness 40 mm (BC-40) are selected. These roads are constructed directly above a granular layer and have a thin bituminous surface layer. Estimating the remaining life of LVRs involves evaluating their current condition and predicting future performance under anticipated traffic loads and environmental conditions. The remaining life in the base year has been estimated in accordance with IRC: 115-2014 and IRC: 37-2018, based on the rebound deflection obtained using FWD. The selected LVRs for the study are found to be safe against fatigue and rutting criteria. The back-calculated moduli using KGPBACK and the BISAR method reveal that pavement layer moduli can be accurately simulated by both methods. Furthermore, the BISAR method can be adopted as an alternative to KGPBACK software. The validated moduli values also provide a good model fit when comparing the deflection values.

The use of hot mix asphalt (HMA) and conventional aggregate in road construction has the unintended consequence of accelerating resource depletion, environmental impact, and the consumption of fossil fuels. Building pavement sustainably is essential to prevent this. One kind of Cold Mix Asphalt (CMA) that provides a sustainable route ahead is Cold Bitumen Emulsion Mixtures (CBEMs). Waste issues are addressed and flexible pavement development is promoted by using waste materials as fine aggregates in cold-mix asphalt. This study examines the mechanical performance of replacing virgin fine aggregate with Waste Glass (WG) at different percentages (0% to 100%, in 20% increments), with a focus on fatigue life and resistance to moisture damage. Up to 60% WG content in CBEM-WG mixes showed mechanical performance that was on par with that of conventional HMA and normal CBEM (NCBEM), increased continuously beyond 60% addition, and showed maximum performance at 100% dosage. Moisture damage resistance declines as WG concentration rises, but is at par with HMAA statistical analysis was done to show the feasibility and accuracy of using waste glass in place of virgin materials in terms of mechanical properties. The coefficient of determination R2 > 0.9 for all criteria indicates a significant effect of waste glass addition on fatigue performance.

Utilising electric vehicles (EVs) appears to be a viable way to create a road transportation system that is sustainable. Electrified road systems or eRoad systems are one of the many intriguing ideas under consideration at the moment. This engineering review article aims to offer key insights into the potential impacts of wireless EV charging systems on pavement performance and its broader implications for transportation infrastructure. The idea of inductive power transfer (IPT) technology is covered in detail in this review, highlighting the fundamental ideas behind it. While IPT-based eRoads for wireless charging of EVs offer significant technological advances, they also pose engineering challenges in terms of heat management, material compatibility, and structural performance. This study highlights the potential advantages and challenges of wireless EV charging along with its implications for pavement infrastructure. It also provides insights into both the promising efficiencies of IPT-based eRoads and the engineering risks associated with integrating these systems into roadway structures, such as thermal strain, fatigue, and load-induced deterioration. Understanding these impacts is essential for developing resilient eRoad designs that maintain structural integrity while accommodating emerging charging technologies. Also, recommendations have been made to focus more on prospective solutions for overall improvement in pavement performance.

Modifying asphalt profoundly impacts the oxidation of asphalt, considering the performance characteristics for high and intermediate temperature conditions. Aging significantly impacts the inherent properties of asphalt concerning intermolecular properties, which are responsible for the service life of the asphalt mix. Thus, it is important to have a constructive understanding of the role of modifiers in asphalt aging behavior before consideration. Therefore, this present study utilizes a comprehensive laboratory approach to the aging behavior of asphalt and to understand the impact of chitin as a modifier. The aging behavior of chitin-modified asphalt was investigated using different aging indices concerning different physical, rheological, and chemical parameters, tested at high and intermediate temperatures. The investigated parameters inferred that the inclusion of chitin can enhance the resistance of base asphalt and can be more effective at high dosages of chitin.

Due to scarcity of virgin aggregates, the use of reclaimed asphalt pavement (RAP) as a substitute for natural aggregates has gained popularity. Despite the fact that RAP is recycled in asphalt pavement, there is still excess RAP, and its use in concrete pavements has expanded in recent years. According to a survey, 95 percent of India’s pavement is bituminous pavement. As a result, the maintenance and reconstruction of such pavements generate RAP, which can be reused in concrete pavements as well as surface course, base course, and subbase of flexible pavements. Various studies on the properties of reclaimed asphalt pavement and its optimal requirements for usage in concrete have been conducted throughout the years. In this study, a total of eight concrete mixes with various proportions of processed coarse RAP (20%, 40%, and 60%) and a fixed percentage (40%) of GGBFS with different proportions of processed coarse RAP were prepared to enhance the interfacial transition zone in PQC. A study of fresh properties like slump value; hardened properties like density; mechanical properties like compressive strength, split tensile strength, and flexural strength; durability properties such as abrasion resistance; and time-dependent properties such as shrinkage of PQC mixes was carried out in the present study. The new processing technique enhanced the properties of RAP inclusive PQC mixes and the strength of all the concrete mixes was above the design target strength. It was observed that there was a reduction of more than 60% in the binder content of RAP aggregates as a result of the processing of RAP. The partial replacement of cement by GGBFS also enhanced the properties of concrete mixes. However, with the increase in the percentage of replacement levels of RAP, the properties of concrete mixes were slightly reduced, but the reduction was much less. Based on the strength and durability properties of PQC, it was concluded that GGBFS with processed coarse RAP aggregate up to 40% can be used in pavement quality concrete (PQC). Hence, this study proves to be effective in the utilization of process RAP aggregates with GGBFS in PQC.

The conventional approach to designing flexible pavements relies heavily on practical experience and simplified two-dimensional computer analysis. However, there is a growing trend in the transition towards more advanced mechanistic design methods, which aim to overcome the limitations associated with stress, strain, and displacement predictions in pavement analysis. This study examines the critical implications of departing from a circular contact area assumption in pavement design, as the Layered Elastic Theory proposed. Accurate tire-pavement interaction is essential to evaluate the pavement damage caused by various tire configurations. Actual tire measurements in this study revealed substantial deviations between the assumed circular contact area and actual contact areas for dual axle with reductions of 3.4% and three-axle trucks with reductions of 5.6%, leading to concentrated loads on smaller surface areas. This concentration results in elevated stress levels on the pavement surface, increasing the risk of damage and fatigue failure. The study revealed that. The study also identifies increased strain values, indicating a greater likelihood of rutting. Finite Element Analysis (FEA) using Abaqus FEA software was used to analyze the pavement responses. The study recommends considering actual contact areas, highlighting the importance of precision in engineering calculations and paving the way for more resilient and sustainable transportation infrastructure.

Pavement construction sector is exploring the possibilities of using bitumen-stabilized material (BSM) due to its environmental benefits, cost-effectiveness, and convenience of application. Based on laboratory investigations, this study analyzes the effect of aggregate temperature (AT) and bitumen emulsion content (BEC) on the performance of BSM. The mix design parameters, including BEC and AT, were optimized using a central composite design (CCD) using the response surface methodology (RSM). Furthermore, additional experiments were performed to validate the optimum solution given by the model. The results indicate that the effect of AT on the mechanical and volumetric properties of BSM is more significant at lower BEC. Validation of the optimum design method showed that RSM optimization is a successful method for BSM mix design.

Asphalt surface treatments using asphalt emulsions are widely used in the road industry for pavement preservation, with chip seal being particularly popular due to its low initial cost and ease of construction. High float asphalt emulsions (HFAE) have been developed as an alternative to traditional asphalt emulsions to mitigate common issues such as bleeding, draining, and aggregate chip loss associated with chip seals. Unlike traditional asphalt, residue from HFAE exhibits unique characteristics, traditionally assessed through float tests. This study investigates the behavior of HF emulsified asphalt residues using alternative physical and rheological tests. Visual flow and drain down experiments were conducted to evaluate asphalt's resistance to flow and draining, while a stress sweep test measured the viscosity of HF emulsified asphalt residue. The results showed that HFAE residue demonstrated significant resistance to flow and drain down. Rheological evaluation via the stress sweep test revealed that HFAE residue exhibits a yield stress nature not present in the original asphalt, contributing to its high float characteristics. Understanding how yield stress varies with the type or percentage of emulsifier used can provide valuable insights, enabling researchers to select appropriate HF emulsifiers based on specific field requirements.

This study investigated the sensitivity of design inputs, namely, resilient modulus of asphalt layer and base layer, and thickness of base layer, on the performance of flexible pavement. A total of 15 pavement sections were considered in this study, and the sensitivity analysis was conducted based on the horizontal tensile strain at the bottom of asphalt layer and fatigue life. Study findings revealed that when the modulus of asphalt mixture was lower than the target or design level, it resulted in higher horizontal tensile strain at the bottom of the asphalt layer. In addition, if the thickness of base layer is lower than the design thickness due to construction variability, the fatigue performance of the pavement system would be significantly reduced. Thus, any divergence in material properties and thickness of layer from the target or designed level would potentially alter the overall performance of flexible pavement system. Overall, it was envisioned that the findings from this study would help researchers, engineers, practitioners, and other stakeholders to quantify the change in design variables and determine their associated impacts on pavement performance.

The goal of the current study is to evaluate chitin's impact on asphalt binder's resistance to intermediate temperature cracking. To produce modified asphalt binder specimens for the investigation, a conventional grade asphalt binder (VG-30) and chitin (Ch) are used as modifiers. By the mass of VG-30, the Ch doses were chosen as 0, 0.5, 1, 1.5, 2, 2.5, and 3%. Temperature sweep and linear amplitude sweep (LAS) tests were used to assess the intermediate temperature cracking performance of conventional and modified bitumen. The results of the investigation on cracking performance parameters showed that the Ch contributes favourably to the bitumen binder's resistance to fatigue cracking. According to the Superpave fatigue factor, adding Ch can enhance the ductile property of modified bitumen, which results in increased resistance to fatigue cracking. Similarly, the fatigue cycle parameter showed that the Ch-modified bitumen can withstand strain better, hence postponing the bitumen binder's fatigue damage for a longer period.

Being one of the most expansive soils, black cotton soil is not considered as a foundation material for any civil engineering infrastructure. However, due to the unavailability of good soil, the researchers and practitioners are motivated to identify methodologies to improve the engineering properties of black cotton soil for its use in civil engineering construction. Among the various possible methods of ground improvement, soil stabilization is chosen by a majority of engineers due to its multitude of advantages. In this direction, the research study investigates the effect of mineral-stabilized black cotton soil on flexible pavement analysis and design. To achieve the objective, black cotton soil was stabilized at various percentages of mineral stabilizers at 0, 2, 4, and 6%, and the engineering properties of the stabilized soil were determined from the laboratory studies, including, standard proctor, unconfined compressive strength, and California bearing ratio. At the optimum stabilizer dosage derived from laboratory studies, pavement analysis using the Plaxis 3D software was carried out to understand the improvement in the mechanistic behavior of mineral-stabilized soil. Further, pavement design in accordance with IRC 37:2018 was performed to quantify the reduction in overall pavement thickness with subgrade stabilization. The results showcased that the stabilization of black cotton soil with mineral stabilizer significantly enhanced the engineering properties of the soil and thus resulted in a better-performing pavement structure with reduced construction cost. Overall, it can be concluded that the mineral stabilization of black cotton soil is a promising solution for pavement subgrade improvement.

This study investigates the inherent variability in the viscoelastic properties, specifically the complex modulus and phase angle of unmodified asphalt binder. Understanding these properties is essential for highlighting the performance-based behavior of asphalt binders. Despite the very controlled environment in which tests for these properties are done, variability persists due to its complex nature. This might contribute to uncertainties in the pavement response. In this research, fifteen samples of unmodified VG10 asphalt binder were subjected to frequency sweep tests across various temperatures and loading frequencies. The experimental data enabled the construction of a frequency and temperature master curve using the WLF equation and a sigmoidal model. The temperature master curve was also drawn using a modified version of the WLF equation. Variability in the complex modulus and phase angle values was quantitatively evaluated using statistical indicators, which include coefficient of variation, interquartile range, interdecile range, and interpercentile range. The results indicated a significant variability in the lower reduced frequency for complex modulus and the reverse trend for phase angle. While in temperature master curves, the variability was relatively higher in lower temperatures for both complex modulus and phase angle. These findings underscore the necessity for enhanced understanding and control of binder properties to mitigate the impact on pavement performance.

This study investigates the dispersion and physical performance of VG30 asphalt binders modified with reduced graphene oxide (rGO) and graphene nanoplatelets (GNP). These nanoparticles were blended with the asphalt binder in varying proportions (0, 0.5, 1, and 1.5%) using a high-shear mixer. The softening point tests were performed on both unaged and samples aged for two and six hours using the Rolling Thin Film Oven (RTFO). Storage stability was assessed over a 48-h period at 163 °C, and fluorescence microscopy was used to examine the uniformity of the nanomaterials within the raw binder. The test results demonstrated that rGO and GNP significantly influenced the physical characteristics of the neat binder. It was observed that all modified asphalt samples showed increased softening point value with respect to aging. However, the addition of rGO or GNP reduced the SPI, which increased again when the content exceeded 1%. Storage stability tests revealed that incorporating up to 1.5% of rGO and GNP into the base binder-maintained uniformity during high-temperature storage, indicating compatibility between the nanomaterials and the asphalt binders. Fluorescence microscopy revealed that rGO and GNP were uniformly dispersed in the asphalt binder up to a concentration of 1%.

Integrating wireless charging into road networks represents a major leap in transportation engineering, enhancing sustainability and supporting the widespread use of electric vehicles (EVs). This innovation can mitigate range anxiety and simplify the charging process, reducing reliance on dedicated charging stations. This study examines the design of basic inductive primary and secondary coils, evaluating their performance when connected to individual or shared power sources. The study further explores the efficacy of magnetic flux generation with varying vertical and horizontal distances between the coils. This investigation aids in identifying the best coil positioning and configuration for efficient wireless power transfer. From the perspective of wireless power transfer, a charging infrastructure prototype is also made to investigate the influence of concrete plates on magnetic flux transmission. Comparative analyses between different conditions (no barrier, porous concrete plate, and PCC plate) highlight the distinct advantages of using porous plates, both vertically and horizontally. These insights are crucial for coil designing in wireless energy transfer technology, advancing sustainable transportation systems, and shaping the future of electric mobility.

Conserving natural resources and addressing environmental concerns are significant motivations for repurposing waste materials in pavement construction. Aggregates, fillers, and asphalt binders are conventionally amalgamated to formulate the asphalt mixture for constructing the pavement's surface layer. In the Northeastern region of India, the availability of conventional aggregates is scanty. Therefore, it creates a platform to work on using different building demolition wastes to replace traditional fillers in asphalt mixtures. This research looks at using three types of building demolition waste, such as brick dust, plaster dust, and concrete block dust, along with conventional fillers, i.e., stone dust and lime dust. To determine the physical and chemical properties of employed fillers, tests such as uncompacted bulk mass, particle size distribution, methylene blue, X-ray diffraction, and specific gravity are performed. Fillers and asphalt binder are combined in three distinct filler/binder (F/B) ratios (0.6, 0.8, and 1) to create asphalt mastic. On these mastics, rheological characteristics (complex modulus, storage modulus, loss modulus, phase angle, and complex shear modulus) are examined. To further examine the performance of the asphalt mix, moisture susceptibility, creep tests, and cantabro abrasion tests are performed. The results of the entire study indicate that, aside from traditional filler, or stone dust, plaster dust performs better, with an F/B ratio of 0.8 due to its cementitious properties.

For modern researchers, waste materials such as plastic and oil have become a serious issue for environmental pollution and health risks. This work aims to analyze various engineering properties of asphalt mix and investigate the impact of pyrolytic char on the partial replacement of asphalt binder. In different proportions of 6, 8, 10, and 12% by weight of asphalt binder, pyrolytic char takes the place of asphalt binder. The outcome of the experiment demonstrates that the binder stiffens and gets stronger. The asphalt binder has demonstrated the best results in terms of strength, hardness, and stiffness at 8% replacement. Certain properties of the binder are negatively impacted by increased stiffness. Hence, waste engine oil is used as a modifier for reducing the stiffness properties, and the outcome is favorable. By weight of the partially replaced binder, 3, 5, and 7% of the waste engine is added. According to test results, 5% of the binder's initial characteristics have been recovered. Indirect tensile strength has increased, and creep deformation has decreased along with improvements in Marshall Stability values. Additionally, the tensile strength ratio is below the allowable threshold. Multiple test results indicated that a combination of 8% pyrolytic char and 5% waste engine oil, i.e., COMB 8–5 meets every requirement as VG30.

The utilization of reclaimed asphalt pavement material (RAP) is restricted due to the rigidity and maneuverability challenges linked to RAP. This problem is resolved by employing warm mix asphalt (WMA), which enhances the amount of RAP utilized by creating mixtures with equivalent or superior characteristics, such as improved workability and reduced viscosity compared to hot mix asphalt (HMA) at lower temperatures. The aim of this work is to analyze the rheological properties and impact on aging mechanism of asphalt binders mixed with large amounts of Artificial Reclaimed Asphalt Pavement (RAP) produced using Warm Mix Asphalt (WMA) additive and Waste Industrial Oil (IWO) using Fourier transform infrared spectroscopy (FTIR). The VG30 asphalt underwent partial replacement with Rejuvenated RAP, with a weight proportion of 50%. The rheological properties were assessed by the use of a Dynamic Shear Rheometer (DSR), which allowed for the measurement of complex viscosity and PG grading. Additionally, aging simulation was performed utilizing the rolling thin film oven (RTFO) and Oven aging methods. The RTFO test was used to measure the loss of volatiles, while the FTIR test was conducted to analyze the oxidation characteristics. The FTIR spectra investigation revealed the formation of extra C═C, C─O, C═O, and OH bonds as a result of the aging process.

The Open Graded Friction Course (OGFC) asphalt mix is known for its uniform grading, predominantly containing single-sized coarse aggregates with minimal fines. It is typically applied in thin layers (around 20 mm) over impermeable road surfaces. OGFC offers notable advantages in regions with heavy rainfall, enhancing pavement surface infiltration capacity and lateral water drainage due to the underlying surface’s impermeability. However, challenges such as raveling and rutting have impacted the consistency of pavements using OGFC mixes. This study aims to mitigate raveling concerns by incorporating Polymer Modified Binder into OGFC mixes. Crumb Rubber (10, 15, 20 and 25% by weight of bitumen) and Reclaimed Polyethylene (2, 4, 6, 8 and 10% by weight of bitumen) were utilized to modify conventional bitumen. The optimal polymer quantity was determined by comparing draindown and abrasive resistance among OGFC mixes at different binder levels. Rutting susceptibility of both conventional and modified mixes was assessed at the optimum binder content. The findings revealed that OGFC mixes prepared with modified binders exhibited enhanced abrasive resistance compared to those using conventional binder. Specifically, the OGFC mix incorporating 6% reclaimed polyethylene modified binder demonstrated a remarkable 7.5% decrease in abrasion loss compared to the conventional mix. Additionally, it exhibited a 35.2% improvement in rutting susceptibility, surpassing the performance of the 20% crumb rubber modified mix. Consequently, reclaimed polyethylene modified mixes proved more effective in enhancing the rutting resistance of the OGFC layer.

Flexible pavement comprises of multiple layers designed to adapt to traffic loads and environmental conditions. Bitumen, a key binder in flexible pavements, provides cohesion and waterproofing, ensuring durability and load distribution. The depletion of petroleum sources has resulted in increased bitumen expenses and limiting availability, hence reinforcing the necessity for an alternative binder. Bitumen undergoes degradation as it ages. With increasing rigidity and brittleness, it compromises with the performance of the pavement. Henceforth, there is a growing interest in recycling and rejuvenating the ageing bitumen pavements due to the increased emphasis on sustainable construction. Rejuvenators, including motor oil, waste vegetable oil, high-density polyethylene, thermoplastics, used tires, coal fly ash, diatomite powder, etc. have been found to be efficient in restoring the qualities of aged bitumen. This paper reviews the effectiveness of using waste oils to rejuvenate bitumen, focusing on the chemical interactions between the two and the subsequent enhancements in flexibility and durability. The studies indicate that waste oils can greatly enhance the bitumen's capability to withstand cracking at low temperatures and increase its durability under repeated stress. However, the effectiveness of this improvement depends on the type and dosage of the oil utilized. Issues such as the possibility of excessive softness, variations in the content of oil, and the requirement to optimize the amount of rejuvenator used are also discussed.

The present study aims to investigate the effect of low-density polyethylene (LDPE) waste plastic coupled with warm mix asphalt additive (WMA) on moisture susceptibility of bituminous mixes. Bituminous concrete-II gradation (i.e., BC-II) was selected for preparing the mix. Viscosity grade binder (VG-30) and basalt aggregate were used for the study. Initially, a wet process was adopted, i.e., waste plastic collected domestically was shredded and added to bitumen with 7.5, 10.0, and 12.5% dosage of plastic by weight of bitumen to prepare a set of plastic modified bitumen. Secondly, bitumen was modified with 6% WMA additive, i.e., zeolite which was further treated with 7.5, 10.0, and 12.5% dosage of waste plastic by weight of bitumen to prepare another set of waste plastic-WMA modified bitumen. Using the prepared binder sample, bituminous mixes were designed following Marshall method of mix design. The moisture susceptibility of the prepared mixes, namely control mix, waste plastic modified mix, and plastic-WMA modified mixes were tested using Indirect Tensile Strength (ITS) and Boiling water tests. Results revealed that plastic modified mixes were found to have higher resistance to moisture damage compared with control mix. It was found that tensile strength ratio (TSR) based on ITS test has highest value of 90.42% for 10% plastic modified bituminous mixes compared with control mix (TSR = 84.99%) indicating improved resistance to moisture damage. In addition, 10% plastic modified bituminous mixes showed 99% coating of bitumen retained after boiling water test. It was also interesting to note that incorporation of zeolite did not improve the performance of the mix against moisture damage. Hence, based on the findings of the present study, it may be concluded that the addition of 10% plastic may be used to improve the moisture susceptibility of bituminous mixes.

Indian roads experience heterogenous traffic conditions with variations in static and dynamic features of vehicles. The major problem that the roads face is that the vehicles do not adhere to the strict lane discipline and readily occupy the lateral spaces on the road. Overtaking process involves lane changing maneuvers, acceleration and deceleration actions and also estimation of speed and distance of the oncoming vehicles. The analysis of vertaking maneuvers revealed distinct trends among vehicle pairs. Predominantly, the highest frequency of overtaking instances occurred between cars and two-wheelers, accounting for 26.49% of occurrences with cars being the prevailing overtaking vehicles. Following this, car-car pairing exhibited 20.51% of overtaking occurrences. Moreover, the study underscored that overtaking times is influenced not only by the type of vehicles overtaken but also by the road gradient. Generally, overtaking durations correlated positively with increased road gradient, except notably at site 4, where a 1.343% gradient showcased an unexpected trend. Furthermore, the outcomes derived from the Multiple Linear Regression (MLR) model underscored the significant impact of road gradient, type of overtaking vehicles, speed of overtaking vehicles and acceleration on overtaking duration, reflected in their respective coefficient values of 1.122, −0.25, −0.16 and 0.13 respectively. This highlights their substantial role in shaping overtaking dynamics on roadways. Overall, this research underscores the substantial impact of road gradient on the calculation of overtaking sight distance, emphasizing the crucial need for Transportation Engineering to prioritize the inclusion and analysis of road gradients in their assessments.

The integration of red mud (RM), an alkaline by-product of alumina production, into pavement construction has both promising opportunities as a potential bulk utilization route (in million-ton scale) and substantial challenges as well. RM’s high alkalinity poses environmental hazards if not managed correctly, yet its potential as a raw material in construction could mitigate these risks. Recent research has explored the transformation of RM into advanced construction materials such as geopolymer concrete and grouting materials for pouring into semi-flexible pavements. Sensitivity analyses and microstructural evaluations indicate that RM-based materials, when optimized with additives like ground granulated blast furnace slag and alkali activators, demonstrate improved fluidity, early strength, and heavy metal encapsulation, thereby minimizing environmental threats. Laboratory studies have demonstrated that RM, when incorporated into pavement materials, results in the improvement of mechanical properties and durability. RM-blended asphalt mixtures exhibit improved stiffness, rutting resistance, and moisture resistance. RM has also been found to augment the mechanical properties and sustainability of geopolymer concrete by improving its strength, durability, and environmental benefits when combined with materials like blast furnace slag, metakaolin, fly ash etc. Before the incorporation of RM into pavement layers becomes a widely accepted practice, its compatibility with normally applied pavement materials, long-term durability and leaching characteristics for environmental safety must be discussed and addressed scientifically. Potentially, its pre-neutralization of alkaline components with waste acidic gases (e.g., CO2 and SOX) is emerging as a promising approach in circular economy framework for utilization in pavements. In this paper, we focus on these aspects in detail and systematically present the material properties of RM affecting the performance of pavement layers via coupled hydro-mechanical and chemical interactions.

The reduction of aggregate-bitumen bond caused by moisture damage is a major cause of premature failure of asphalt pavement. This failure is mainly caused due to adhesive failure, which involves weakening of bond at aggregate-bitumen interface. This becomes more dominant if bitumen film is thin or improper coating of bitumen over aggregate surface occurs. In conventional mixing of aggregate and bitumen, coarse aggregates receive thin bitumen film as compared to fine aggregates. The large difference among the specific surface area of different sizes of aggregates leads to non-uniform distribution of the binder. To avoid this, a new mixing technique known as “two-phase mixing” was adopted in the study. In this technique, coarse aggregates were initially mixed with the partial binder. After its pre-coating, fines were mixed with it followed by adding remaining binder. A comparison between asphalt mixes prepared using one-phase and two-phase mixing have been done in terms of tensile strength ratio (TSR) and dynamic modulus. These tests were performed at various freeze–thaw (0, 1, 3 and 6) cycles. Also, the effect of moisture conditioning on rheological properties of two-phase mixes were studied and compared with that of conventional one-phase mixes. The moisture resistance of the mixes was compared using a damage factor introduced in sigmoid function adopted for dynamic modulus mastercurve fitting. Using this, the extent of shifting of mastercurve in downward direction was estimated. Both elastic and viscous properties of asphalt mixes were decreased by moisture conditioning. The adopted two-phase was found to produce more moisture resistant asphalt mixes. Lastly, a correlation between TSR and damage factor introduced in sigmoid equation for moisture damage was done, which showed a good correlation.