Pavement Design Research Articles

Impact of cement content in cement bound materials on the reflection cracking performance of asphalt pavements

This study investigates the impact of cement contents in cement bound material (CBM) on asphalt pavement reflection cracking, considering two levels: 4.5 % (CBM1) and 5.4 % (CBM2). Mechanical properties of CBMs, including elastic modulus, rupture modulus, and thermal expansion, were evaluated. Simultaneously, properties of asphalt pavement layers (wearing course and base course) underwent assessment through dynamic modulus, flow number, and overlay tests. Resilient modulus tests were conducted for subbase and subgrade layers. Laboratory test outcomes served as inputs for a AASHTOWare Pavement ME Design program. The results indicated that despite CBM2's higher elastic modulus and rupture modulus, CBM1 outperformed in pavement design. Based on the outcomes from pavement design program CBM1 exhibited lower total transverse cracking (400.19 m/km) compared to CBM2 (403.38 m/km) after 6 years of service. The higher cement content in CBM2 was identified as a potential contributor to increased cracking, attributed to shrinkage during cement hydration process. Moreover, the higher cement content showed a higher coefficient of thermal expansion (CTE), where CBM1 displayed a CTE of 70 µm/°C, while CBM2 material had a CTE of 40 µm/°C. These findings emphasize the intricate relationship between cement content in CBM and pavement performance, crucial for effective design considerations.

Bibliometric Analysis of Road Damage Due to High Rainfall Intensity in Mountainous Areas Using VOSviewer

Road damage is one of the many things encountered in the world of construction. Road damage must require prompt handling, so as not to interfere with every activity and safety of road users. Therefore, road damage must require rapid handling. This research uses bibliometric analysis related to road damage in mountainous areas, capturing research data for the period 2000 to 2023. Research on road damage aims to determine the development of research from year to year. This research uses keywords to get the closest indicators related to the research topic. The relationship between keywords and research topics is significant to get accurate data on previous to current research topics. This bibliometric research was sourced from the Crossref database on November 23, 2023. This research uses the Research Information System (RIS) format to capture data using Publish or Perish software. The format is filtered again using VOSviewer software. VOSviewer aims to visualize the results of data processing that has been netted. The netting results were obtained from several dominant keywords, namely Asphalt, Pavement Material, Pavement Design, and Road Material. This research nets 993 documents out of 1000 research documents netted from 2000 to 2023. The documents netted include 1 grant, 31 standards, 10 components, 2 datasets, 3 reports, 859 journal-article, 2 journals, 49 book chapters, 30 proceedings articles, 1 posted content, 1 book, 1 other, 3 proceedings. This research was carried out to analyze the development of previous research up to the present.

An appraisal of statistical and probabilistic models in highway pavements

Accurate performance prediction is crucial for safe and efficient travel on highway pavements. Within pavement engineering, statistical models play a pivotal role in understanding pavement behavior and durability. This comprehensive study critically evaluates a spectrum of statistical models utilized in pavement engineering, encompassing mechanistic-empirical, Weibull distribution, Markov chain, regression, Bayesian networks, Monte Carlo simulation, artificial neural networks, support vector machines, random forest, decision tree, fuzzy logic, time series analysis, stochastic differential equations, copula, hidden semi-Markov, generalized linear, survival analysis, response surface methodology and extreme value theory models. The assessment meticulously examines equations, parameters, data prerequisites, advantages, limitations, and applicability of each model. Detailed discussions delve into the significance of equations and parameters, evaluating model performance in predicting pavement distress, performance assessment, design optimization, and life-cycle cost analysis. Key findings emphasize the critical aspects of accurate input parameters, calibration, validation, data availability, and model complexity. Strengths, limitations, and applicability across various pavement types, materials, and climate conditions are meticulously highlighted for each model. Recommendations are outlined to enhance the effectiveness of statistical models in pavement engineering. These suggestions encompass further research and development, standardized data collection, calibration and validation protocols, model integration, decision-making frameworks, collaborative efforts, and ongoing model evaluation. Implementing these recommendations is anticipated to enhance prediction accuracy and enable informed decision-making throughout highway pavement design, construction, maintenance, and management. This study is anticipated to serve as a valuable resource, providing guidance and insights for researchers, practitioners, and stakeholders engaged in asphalt engineering, facilitating the effective utilization of statistical models in real-world pavement projects.

Using mechanistic-empirical simulations and nonparametric testing to explore variability in the expected performance of reference asphalt pavement designs

This study explored the variability in expected performance of eight reference asphalt pavement designs using AASHTOWare pavement ME software. Nonparametric tests showed that structures with a high-modulus asphalt base on an unbound base significantly delayed maintenance. Varying pavement layer materials significantly affected the simulations, except the asphalt surface and asphalt base (when used on an unbound base). Moreover, recycling rates in AC asphalt bases over 60% significantly improved performance over no recycling; however, air void content and effective binder percentage seemed to be key in these findings. Finally, this study showed that meeting material specifications does not guarantee equal performance.

An efficient analysis method for system reliability of semi-rigid base asphalt pavement structure based on direct probability integral method

The structural design parameters of asphalt pavement inherently possess randomness. Reliability theory aids in considering the stochastic nature of these parameters in asphalt pavement design. However, as the number of considered random factors increases, the complexity of reliability calculation models and the consumption of computational resources also significantly escalate. To analyze the structural reliability of semi-rigid base asphalt pavements more efficiently and accurately, a method combining Weighted Kernel Density Estimation (Weighted-KDE) with Direct Probability Integration Method (DPIM) using sampling strategies was employed. Furthermore, integrating the equivalent extreme value principle, an asphalt pavement structural system reliability analysis method was proposed, considering multiple failure mode correlations. The numerical solution steps of this method are also outlined. Based on the typical semi-rigid asphalt pavement structure in China, this study utilized the elastic layer system method (the program Apbi) and a computational program developed in MATLAB to compare the efficiency and accuracy of calculating reliability between DPIM and the Monte Carlo Simulations (MCS). The computational outcomes indicate that, under the premise of selecting 18 random parameters, DPIM can achieve the required accuracy in assessing the reliability of asphalt pavement structure and system reliability. Analyzing how the number of samples affects the computational results reveals that using weighted-KDE and DPIM only needs a few hundred sample points to limit the relative error within 4 %, compared to the results obtained from 105 samples in MCS. The research findings demonstrate that DPIM incorporating the principle of equivalent extreme value events can serve as an efficient analytical approach for assessing the system reliability of asphalt pavement structures characterized by more complex failure modes.

A view on the state of practice in transportation geotechnics in Australia

A transport project typically involves design and construction of pavements, track, earthworks, ground improvement and structures. In addition, there are a host of other factors that practitioners need to consider such as ground modelling, sustainability and management of uncertainties. This paper attempts to provide an insight into the many factors that practitioners need to address in order to present a snapshot of the state of practice at this point in time. Some data is obtained via a survey distributed mainly to Australian practitioners. The author provides some interpretation of the survey data and commentary based on his experience in the Australian context.Fundamental attributes of a practitioner are considered to be understanding ground behaviour, applied mechanics including various forms of analysis and experience. It is argued that our ability to develop ground models has regressed in recent decades during which time our analytical capability has increased. However, although significant advancements in analysis have been made, often design uses simple methods for a range of reasons. Our knowledge of the ground is always imperfect and hence experience is required to understand the implications of what we know and do not know.The host of other factors include sustainability, resilience, digital methods, standards and legislation, litigation and claims, and education. These are discussed partly as emerging areas of practice and partly because there are non-technical aspects of practice that are as important as the technical aspects.Geotechnical practice will evolve into the future. Transport infrastructure will get bigger, heavier, faster and longer and practice will need to evolve to match these changes. While practitioners currently often use simple methods these may not be applicable in the future and hence practitioners will need to have a deep understanding of their subjects to succeed including ground modelling, applied mechanics, sustainability, resilience, artificial intelligence and human skills.

Influence of Thermoplastic Polyurethane on the Properties of Asphalt Cement and the Elastic Behavior of Asphalt Mixtures

The useful life of pavements determines the design of asphalt mixtures. However, premature structural failures and low durability are one of the main problems in pavement engineering today. The action of loads produced by traffic, exposure to environmental factors and the inadequacy of conventional designs of asphalt pavements are some of the main problems associated with the durability of the pavement. The modification of asphalt binders is an alternative that has been used for some years to improve the properties of bituminous material. Among the modifying materials are elastomers, a class of polymers with elastic properties that can be heat-treated. In this study, the asphalt was modified by wet means by adding 5, 10 and 15% of Thermoplastic Polyurethane (TPU) by weight of the binder. Subsequently, standard samples were prepared with the characterized constituents and mixtures with the modified asphalt cement. Consequently, tests were carried out to obtain the optimal mixture that improves the properties of conventional pavement. The results show that the optimal TPU addition content is 5%. With this percentage, the modified binder presented a greater elastic recovery of up to 5.60% and a reduction of up to 42.6% in penetration compared to conventional asphalt. In addition, using the Marshall method, it was determined that the stability of the modified mixtures was much higher than that of standard mixtures for light, medium and heavy traffic; so, they will have a higher resistance to deformation and better fatigue behavior.

Mechanistic-empirical pavement design to include mechanical performance of rubberized asphalt pavements in the use stage of life cycle assessment

The use phase of road pavements includes fuel consumption, urban heat island, and leaching. Life cycle assessment (LCA) often omits the use phase for its complexity. The use phase should also consider the durability of the asphalt mixtures. This study used the Mechanistic-Empirical Pavement Design to include the durability of five asphalt mixtures (control, styrene-butadiene-styrene - SBS, polymer coated rubber - PCR dry and wet, and devulcanized rubber - DVR) in the LCA of 1-mile road pavement over 50 years. Considering only the impact of the mixture production, the control mix had a carbon footprint 12.9 % lower than the other mixtures. When including the durability, the control mixture's carbon footprint was 69 % and 84 % higher than SBS and PCR dry mix, respectively. This study showed the importance of including the mechanical performance of the asphalt mixtures to better evaluate the environmental impact of road pavements over the service life.

Impacts of climate change on environmental and economic sustainability of flexible pavements across China

Pavements are susceptible to accelerated deterioration due to changing climate conditions, leading to increased maintenance and excess fuel consumption through pavement-vehicle interaction. China's diverse climates raise concerns about the environmental and economic sustainability of flexible pavements amid climate change and the effectiveness of preventative maintenance strategies. This study examines climate change's potential impacts on long-term pavement performance, greenhouse gas (GHG) emissions, and costs, employing the Mechanistic-Empirical Pavement Design Guide method. The calibrated World Bank's Highway Development and Management Model 4 assesses the impacts of surface characteristics on vehicle fuel consumption. Life cycle assessment and life cycle cost analysis quantify GHG emissions and costs. Results reveal significant pavement deterioration in Southeast and Central China. Preventative maintenance strategies reduce fuel consumption, with GHG emissions and cost savings from smoother driving conditions outweighing those from maintenance. These insights stress the importance of proactive maintenance strategies for mitigating climate-induced deterioration and enhancing sustainability.

Mechanistic-empirical assessment of axle load legal limits on Brazilian roadways

This paper presents a comprehensive mechanistic-empirical assessment of axle load legal limits policy on Brazilian roadways, considering the intricate balance between enhanced freight transportation and potential pavement deterioration. Focusing on the prevailing flexible pavements, the study explores factors such as asphalt concrete stiffness, thickness, and axle-load increments, accounting for variations in tire-load and pressure. The analysis reveals complex relationships between these factors and their impact on pavement distress mechanisms, particularly fatigue cracking and rutting. The investigation highlights the substantial influence of axle load legal limits adjustments, even seemingly minor ones, on pavement damage, ride quality, safety, and operational efficiency. A calibrated model for assessing mechanistic-empirical load equivalency factors (LEFs) was developed, offering insights into the disparities between the model and existing empirical equations used in the Brazilian Pavement Design Guide (BPDG). This comparison underscores the potential underestimation of axle load legal limits adjustments in the current approach, emphasizing the importance of informed decision-making in transportation policy. In conclusion, this study provides critical insights for policymakers and engineers while considering axle load policy adjustments. The findings emphasize the significance of accurate engineering considerations to sustainably balance economic growth, road safety, and efficient freight transportation within Brazil’s evolving road network.

Effect of stabilizing subgrade layer using various additives on the flexible pavement design

Soil stabilization involves enhancing the physical properties of soil to increase its stability, durability, and ability to support heavy loads, making it a crucial technique in civil engineering and construction. The process is used to reduce soil permeability and compressibility and increase its shear strength. To achieve this, various additives are used. This paper evaluates RoadCem (nanomaterial) and traditional additives such as cement, lime, and ashes materials such as rice husk ash (RHA) and fly ash (FA) as by-product materials in clayey soil stabilization. The used percentages of Lime were (2, 4, 6, and 8%), cement and RoadCem (3, 6, 9, and 12%), FA (3, 6, 9, 12, and 15%), and RHA (5, 10, 15, 20, and 25%) by dry weight of the tested soil. Various tests were used to examine and evaluate the physical and engineering characteristics of the treated soil, modified proctor, atterberg limits, free swelling (FS%), unconfined compressive strength (UCS), California bearing ratio (CBR), and resilient modulus (Mr) as well as microstructure tests [scanning electron microscopic (SEM)]. All admixtures were tested and subjected to two curing periods, 7 and 28 days. The results indicated that the optimum additives percentages were selected as 6% FA and 15% RHA activated by 6% lime and 6% for both RoadCem and cement. At these percentages, plasticity, FS%, and optimum moisture content (OMC) values were decreased. In contrast, maximum dry density (MDD), UCS, CBR%, and Mr values were increased. In addition, the correlation between Mr and both CBR and UCS was drawn. SEM results showed that major changes were observed in the microstructure of treated samples due to the forming of cementitious materials. The study evaluated the effect of subgrade stabilization on reducing base layer thickness under light, medium, and heavy expected traffic loads with an economic analysis to examine the benefits of subgrade stabilization. The cost analysis showed that the optimal economic additives were RoadCem and cement.

Integrated design optimization method for pavement structure and materials based on further development of finite element and particle swarm optimization algorithm

The maintenance design for existing asphalt pavements, characterized by their typical structure and material composition, falls short of meeting the diverse requirements of pavements. There is an urgent need for a more rational design approach that can achieve accurate pavement design while also reducing construction costs. This paper focuses on selected conventional road surface structures and conducts an analysis of how pavement structure and materials impact fatigue life and construction expenses. It employs Python to perform three-dimensional finite element road modeling, analysis, and data extraction at specific locations, using normalized fatigue equation to calculate pavement fatigue life. The optimization variables selected are the modulus E and thickness h, with pavement maintenance cost serving as the optimization target function. The particle swarm optimization algorithm is employed for optimizing these variables. A comparative analysis is carried out for five improved optimization algorithms, optimizing combinations of inertia weight, learning factors, particle speed, number of particles, and iteration times. The results reveal that the enhanced optimization algorithms significantly improve iteration trends, featuring velocity limitations and natural selection mechanisms. Between 0 and 20 iterations, all algorithms search for the optimal solution over a wider interval with greater fluctuations. Between 20 and 30 iterations, each algorithm gradually converges towards its solution, stabilizing in the later stages. Based on optimization speed and actual engineering cost benchmarks, the NDPSO algorithm is selected, resulting in a 52.8% reduction in actual engineering costs. Adjustments to the particle count and iteration number of the NDPSO algorithm are made based on computational cost and optimization accuracy, thus choosing 20 particles and 50 iterations as the recommended parameter combination. By combining automated finite element modeling, analysis, and particle swarm optimization, this paper offers a novel and effective automated design reference for extending the lifespan of asphalt pavement structures.

Prediction of effective equivalent linear temperature gradients in bonded concrete overlays of asphalt pavements

PurposeThe time-varying equivalent linear temperature gradient (ELTG) significantly affects the development of faulting and must therefore be accounted for in pavement design. The same is true for faulting of bonded concrete overlays of asphalt (BCOA) with slabs larger than 3 x 3 m. However, the evaluation of ELTG in Mechanistic-Empirical (ME) BCOA design is highly time-consuming. The use of an effective ELTG (EELTG) is an efficient alternative to calculating ELTG. In this study, a model to quickly evaluate EELTG was developed for faulting in BCOA for panels 3 m or longer in size, whose faulting is sensitive to ELTG.Design/methodology/approachA database of EELTG responses was generated for 144 BCOAs at 169 locations throughout the continental United States, which was used to develop a series of prediction models. Three methods were evaluated: multiple linear regression (MLR), artificial neural networks (ANNs), and multi-gene genetic programming (MGGP). The performance of each method was compared, considering both accuracy and model complexity.FindingsIt was shown that ANNs display the highest accuracy, with an R2 of 0.90 on the validation dataset. MLR and MGGP models achieved R2 of 0.73 and 0.71, respectively. However, these models consisted of far fewer free parameters as compared to the ANNs. The model comparison performed in this study highlights the need for researchers to consider the complexity of models so that their direct implementation is feasible.Originality/valueThis research produced a rapid EELTG prediction model for BCOAs that can be incorporated into the existing faulting model framework.

Predictive Model for Determining Saturation Profiles under Pavements during Flood Events

Pavements are highly susceptible to water infiltration during floods, resulting in reduced serviceability, shortened life span, and poor durability. To enhance pavement resilience and mitigate the rising risks associated with flooding events, this study aims to propose a method to predict the short-term temporal evolution of saturation levels within pavement structures resulting from inundation events. The methodology involves conducting a series of finite-element-based hydraulic simulations considering various influential factors such as pavement structure, subgrade type, groundwater table level, and flooding scenario. Time-descriptive indicators, including peak saturation time and restoration time, are calculated from the simulated volumetric water content data. To capture the complex relationships between the input parameters and output indicators, machine learning (ML) methods are employed to construct a predictive model for saturation profiles during flooding events. The results demonstrate that the 2nd-degree polynomial provides the best fit for the saturation changes within the vadose zone, and the random forest algorithm outperforms other ML methods, achieving the highest accuracy in projecting saturation changes during flooding events. The predictive model offers valuable insights for decision-making processes, including determining the optimal timing to reopen submerged roadways to traffic, and evaluating the moisture damage caused by the inundation. Overall, this research contributes to enhancing pavement resilience and enables the design and management of resilient pavements under changing climate conditions and extreme weather events.

Evaluation of the Fatigue Performance of Full-Depth Reclamation with Portland Cement Material Based on the Weibull Distribution Model

The full-depth reclamation with Portland cement (FDR-PC) technology embodies an environmentally friendly approach to solving the damage to old asphalt pavement. Fatigue failure emerges as the predominant mode of degradation for FDR-PC pavement. The fatigue characteristics of the full-depth reclamation with Portland cement cold recycled mixtures were evaluated through four-point bending tests. Three contents (4%, 5%, 6%) of cement and three base-to-surface ratios (10:0, 8:2, 6:4) were utilized. The fatigue equations were derived for the mixtures using a two-parameter Weibull distribution. The results indicate that all correlation coefficients of the Weibull distribution model surpass 0.88, effectively projecting the lifespan of FDR-PC. With increases in cement contents and base-to-surface ratios, the fatigue life of the mixture extends, though with an augmentation of stress sensitivity. Comparative analysis with the fatigue equation model parameters of the current Chinese specifications for the design of highway asphalt pavement reveals that mixtures with a 4% cement content and combinations of a 5% cement content with a low base-to-surface ratio meet the requirements for inorganic-binder-stabilized soil. Additionally, mixtures with a 5% cement content and a high base-to-surface ratio, along with those with a 6% cement content, fulfill the specifications for inorganic-binder-stabilized granular materials.

Revolutionising Egyptian pavement design: a comprehensive E* database and advanced modeling approach for contextually informed performance predictions

ABSTRACT This research assesses the dynamic modulus (E*) as a pivotal rheological attribute for characterizing viscoelastic behaviour in various indigenous asphalt mixtures across diverse scenarios. An exhaustive investigation involving 32 laboratory-designed asphalt mixes and two field mixes explores the influence of traffic loading patterns, air voids, binder sources, and climatic conditions on E*. Utilizing Superpave gyratory compaction, 68 E*-specimens are compacted and subjected to E*-testing, leading to master curve development. Evaluation of NCHRP 1-37A and NCHRP 1-40D Witczak models demonstrates their fair to excellent accuracy in predicting E* for Egyptian mixes. The NCHRP 1-40D model stands out with an R² of 0.94, showcasing superior accuracy and minimal bias. This study integrates AASHTOW are Pavement ME Design (PMED) to analyse pavement sections, revealing the impact of design factors, characterized by measured E*, on predicted pavement performance, encompassing asphalt concrete rutting, alligator cracking, longitudinal cracking, and terminal international roughness index. The investigation highlights the marginal impact of substituting predicted E* for measured E* on AASHTOWare pavement performance indicators for Egyptian mixes under default binder characteristic values. This research contributes valuable insights into the interplay of E* and pavement performance, facilitating wellinformed decisions in pavement design and analysis across diverse conditions in the Egyptian context.

ANALISIS PENINGKATAN PERKERASAN LENTUR KE PERKERASAN KAKU PADA RUAS JALAN BUARAN - BENDANPETE STA 0+00 - 1+700 JEPARA JAWA TENGAH .

Afif Junaidhi, Nim 191230000357, Analysis of the improvement of flexible pavement to rigid pavement on the buaran - bendanpete sta 0+00 - 1+700 jepara central java road 2023., Yayan Adi Saputro, S.T., M.T., Nor Hidayati, S.T., M.T., Civil Engineering, Faculty of Science and Technology1, Nahdlatul Ulama University1 Jepara1. With roads, everyone can increase their mobility while fulfilling important activities. As time goes by and the length of service lasts, road conditions eventually decline, both in terms of service level and structural condition. The method used for analysis of rigid pavement on roads is the 2017 Pavement Design Manual1 Method and the method used for planning road surface drainage dimensions refers to SNI 03-3424-1994 concerning Procedures for Road Surface Drainage Planning. The results of rigid pavement planning research calculations using the 2017 Pavement Design Manual method resulted in a concrete plate thickness of 275 mm, a thin concrete layer1 (LMC) of 100 mm, a class A aggregate drainage layer of 150 mm. Connections in rigid pavement are divided into two, namely longitudinal connections with tie bars using Ø 161- 6001 threads, and transverse connections with dowels using plain reinforcement D 32 - 300. The material used is planned to use concrete. The calculation results obtained are that the channel base width is 65 cm, the wet channel height is 35 cm, and the guard height is 40 cm

Carbon footprint assessment of maintenance and rehabilitation techniques for sewer systems

ABSTRACT The research study presented in this paper sets out to improve our understanding of the environmental impacts associated with the maintenance and rehabilitation of conventional gravity sewer systems and, through this, support decision-making processes in sewer system management. The objects assessed are open trench replacement, trenchless renovation, open trench and trenchless spot repair, inspection, and hydraulic cleaning of sewer pipes. Carbon footprint assessment was carried out according to the ISO14067:2018 standard. The life cycle stages considered included raw material extraction, manufacturing processes, maintenance/rehabilitation, and the transportation of materials. The functional unit was defined as: ‘A gravity sewer section with a length of 45 metres and a diameter of 200 to 1500 mm operating in normal conditions over a period of 100 years in the Netherlands’. A sensitivity analysis was included to assess how the results vary as a consequence of changes in the input dimensions. The findings of this study suggest that the main opportunities for reducing the environmental impacts of conventional, open trench pipe replacement lie in the choice of the pipe material and the design of the asphalt pavement that requires reinstatement. Adopting trenchless sewer rehabilitation technologies can significantly reduce the environmental burdens of sewer system rehabilitation.

Poisson's ratio testing method and multi-factor influence quantification model of asphalt pavement materials

The current standard in China does not specify the standard test method for determining Poisson's ratio, and the Poisson's ratio used in pavement design is often roughly fixed, which can result in large errors in the calculations and analysis of road structure. In this paper, the research on different test methods for Poisson's ratio is carried out and the non-linear characteristics of tensile and compressive Poisson's ratio on pavement materials under different influencing factors are analyzed. The results indicate that the absolute value of the ratio between transverse rebound strain and longitudinal rebound strain under 50% of the maximum destructive load can objectively characterize the mechanical properties of Poisson's ratio, and it is the optimal measurement method for Poisson's ratio in asphalt pavement materials. The Poisson's ratio of two pavement materials both decreases with the increase of loading rate and gradually tends to a constant value. Cement dosage and temperature are the most significant factors affecting the tensile and compressive Poisson's ratio of cement stabilized crushed stone and asphalt mixture, respectively. Specifically, when cement dosage increases by 1%, the Poisson's ratio of cement stabilized crushed stone decreases by approximately 10%, and the temperature has a significant influence on the difference in tension and compression for Poisson's ratio of asphalt mixture (up to 40%). The asphalt content corresponding to the minimum Poisson's ratio is basically consistent with the optimal asphalt content obtained by the Marshall volume method. Based on these, a quantification value-taking model is established of the tensile and compressive Poisson's ratios of typical asphalt pavement materials varying with multiple factors. The research results can serve as a reference for the scientific value-taking of pavement structural design parameters considering the different mechanical characteristics of materials in tension and compression.

Optimizing roads for sustainability: Inverted pavement design with life cycle cost analysis and carbon footprint estimation

Inverted pavements have proven performance across the world and there is a need to optimize the layer thickness and material properties of the pavement addressing the critical failures in the Mechanistic-Empirical Pavement Design. The present study is made on bituminous concrete pavement with traffic up to 50 MSA and studying the critical factors affecting the pavement performance. The Minitab’s Response Surface Methodology − Box Behnken method was used for the Design of Experiments which includes critical factors and responses obtained from ANSYS finite element modeling of the inverted pavement. The critical factors and responses are normally distributed and indicate a linear relationship with the least error. The composite desirability for minimum stress and strains in the pavement layers was found to be 0.89. The optimized pavement thickness and layer material properties were validated with two pavement field cross sections of different Indian National Highways and it is observed that the optimized cross-section is safe. Further, this research paper carried out Life Cycle Cost Analysis and Life Cycle Assessment of inverted pavement with optimized pavement cross-section obtained including the carbon footprint during the vehicle operation phase. The study demonstrated the benefits of inverted pavement with reduced costs and carbon emissions. Thus, this approach paves the way towards sustainable and long-lasting pavements.