Pavement Systems Engineering

Table of Contents

1. Impacts of Design Variables on Pavement Design: Sensitivity Analysis for Flexible Pavement

   Priyaranjan Tiadi, Durgesh Kumar Verma, Malaya Kumar Sahu, Gourab Saha

   Abstract

   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.

2. Assessing Intermediate Temperature Cracking Performance of Chitin-Treated Asphalt

   Aditya Kumar Das, Mahabir Panda, Ayyanna Habal

   Abstract

   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.

3. Effect of Mineral-Stabilized Black Cotton Soil Subgrade on Flexible Pavement Analysis and Design

   Sudeshna Purkayastha, Veena Venudharan

   Abstract

   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.

4. A Study on the Variability of Viscoelastic Response of Unmodified Asphalt Binder

   T. M. Aparna, L. Anjali Balan, Aravind Krishna Swamy

   Abstract

   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.

5. Assessment of Dispersion and Physical Characteristics of Asphalt Binders Enhanced with Graphene

   Kajol Kankane, Priyansh Singh

   Abstract

   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%.

6. Evaluating the Impact of Plain and Porous Concrete Coverings on Electromagnetic Induction Generated by a Basic Coil Setup

   Bimala Noatia, Amlan Jyoti Mahanta, Uddipta Borah, Hrishikesh Choudhury, Amlandeep Dutta, Ambika Kuity

   Abstract

   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.

7. Effects of Building Demolition Waste Materials as Filler on Performance of Mastic and Asphalt Mix

   Sayantan Sasmal, Ambika Kuity

   Abstract

   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.

8. Performance Assessment of Asphalt Binder Enhanced with Plastic Pyrolytic Char and Waste Engine Oil

   Sayantan Sasmal, Ambika Kuity, Azaz Alam

   Abstract

   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.

9. Influence of RAP Binder and Waste Oil on the Performance of Conventional Binder Containing Warm Mix Additives

   Mayank Mehrotra, Abhishek Mittal, Karanjeet Kaur Sandhu

   Abstract

   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.

10. Enhancing OGFC Performance with Sustainable Modified Binders: Rutting Resistance and Durability Evaluation

    Sakshi Sharma, Chirag Bhasin, Ankur Sharma, Pardeep Kumar Gupta

    Abstract

    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.

11. Performance Evaluation of Bitumen with Waste Oils as Rejuvenator: State of the Art Review

    Vishal Sharma, Kshitij Jassal, Umesh Sharma

    Abstract

    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.

12. Effect of Waste Plastic on Moisture Damage Resistance of Warm Mix Asphalt Mixtures

    Ankita Singh, Ayyanna Habal, Vinamra Mishra

    Abstract

    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.

13. Analysis of Overtaking Behaviour on Undivided Two-Lane Roads in Hilly Region

    Rizwan Khan, Manasvi Katiyar, Abhinav Kumar

    Abstract

    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.

14. Hydro-Mechanical and Chemical Interactions of Red Mud in Pavements: Challenges and Opportunities for Circular Economy

    Kamran Ilahi, Solomon Debbarma, B. R. Anupam, Divyadeep Harbola, George Mathew

    Abstract

    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 SO_X) 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.

15. Effect of Moisture Conditioning on Rheological Properties of Two-Phase Hot Mix Asphalt

    Ajit Kumar, Sudhir Varma

    Abstract

    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.