Review on dynamic analysis of road pavements under moving vehicles and plane strain conditions

This paper reviews works on the dynamic analysis of flexible and rigid pavements under moving vehicles on the basis of continuum-based plane strain models and linear theories.The purpose of this review is to provide in-formation about the existing works on the subject,critically discuss them and make suggestions for further research.The reviewed papers are presented on the basis of the various models for pavement-vehicle systems and the various methods for dynamically analyzing these systems.Flexible pavements are modeled by a homogeneous or layered half-plane with isotropic or anisotropic and linear elastic,viscoelastic or poroelastic material behavior.Rigid pavements are modeled by a beam or plate on a homogeneous or layered half-plane with material properties like the ones for flexible pavements.The vehicles are modeled as concentrated or distributed over a finite area loads moving with constant or time dependent speed.The above pavement-vehicle models are dynamically analyzed by analytical,analytical/numerical or purely numerical methods working in the time or frequency domain.Representative examples are presented to illustrate the models and methods of analysis,demonstrate their merits and assess the effects of the various parameters on pavement response.The paper closes with con-clusions and suggestions for further research in the area.The significance of this research effort has to do with the presentation of the existing literature on the subject in a critical and easy to understand way with the aid of representative examples and the identification of new research areas.

Effect of Seasonal Variations on the Behavior of Flexible Pavements in Burkina Faso: Towards Alternating and Periodic Loading of Multi-Axle Heavy Goods Vehicles for Road Durability

Bituminous materials are heat-sensitive, and their mechanical properties vary with temperature. This variation in properties is not without consequences on the performance of flexible road structures under the repeated passage of multi-axles. This study determines the influence of seasonal variations on the rate of permanent deformation, the rut depth of flexible pavements and the effect of alternating loading of heavy goods vehicles following the temperature variations on the durability of roads. Thus, an ambient and pavement surface temperature measurement was carried out in 2022. The temperature profile at different layers of the modelled pavement, the evaluation of deformation rates and rutting depth were determined using several models. The results show that the permanent deformation and rutting rates are higher at the level of the bituminous concrete layer than at the level of the asphalt gravel layer because the stresses decrease from the surface to the depth of the pavement. On the other hand, the variations in these rates, permanent deformations and ruts between the hot and so-called cold periods are more pronounced in the bitumen gravel than in bituminous concrete, showing that gravel bitumen is more sensitive to temperature variations than bituminous concrete despite its higher rigidity. Of these results, we suggested a periodic and alternating loading of the different types of heavy goods vehicles. These loads consist of fully applying the WAEMU standards with a tolerance of 15% during periods of high and low temperatures. This regulation has increased 2 to 3 times in the durability of roadways depending on the type of heavy goods vehicle.

Do aeolian deposits and sand encroachment intensity shape patterns of vegetation diversity and plant functional traits in desert pavements?

The effects of sand encroachment on composition,diversity,and functional patterns of vegetation in drylands are rarely studied,and yet addressing these aspects is important to deepen our understanding of the biodiversity conservation.This study aimed to investigate the effect of sand encroachment on plant functional biodiversity of desert pavements(gravel deserts)in the Sahara Desert of Algeria.Plants were sampled and analyzed in three desert pavements with different levels of sand encroachment(LSE)and quantity of aeolian deposits(low,LLSE;medium,MLSE;and high,HLSE).Within the sample-plot area(100 m^(2)),density of every plant species was identified and total vegetation cover was determined.Plant taxonomic and functional diversity were analyzed and compared between LSE.Result showed that 19 plant species in desert pavements were classified into 18 genera and 13 families.Asteraceae and Poaceae were the most important families.The species Anabasis articulata(Forssk)Moq.characterized LLSE desert pavements with 11 species,whereas Thymelaea microphylla Coss.&Durieu ex Meisn.and Calobota saharae(C&D)Boatwr.&van Wyk were dominant species of desert pavements with MLSE(14 species)and HLSE(10 species),respectively.The highest values of species richness and biodiversity were recorded in desert pavements with MLSE,while low values of these ecological parameters were obtained in desert pavements with HLSE.Desert pavements with LLSE were characterized with the highest values of species abundances.Plant communities were dominated by chamaephytes,anemochorous,arido-active,and competitive stress-tolerant plants.The increase in LSE along the gradient from LLSE to HLSE induced significant changes in plant community variables including decreases in plant density,plant rarity,lifeform composition,morphological type,and aridity adaptation.Desert pavements with HLSE favor the degradation of vegetation and trigger biodiversity erosion.

Thermal Properties Reconstruction and Temperature Fields in Asphalt Pavements: Inverse Problem and Optimisation Algorithms

A two-layer implicit difference scheme is employed in the present study to determine the temperature distribution in an asphalt pavement.The calculation of each layer only needs four iterations to achieve convergence.Furthermore,in order to improve the calculation accuracy a swarm intelligence optimization algorithm is also exploited to inversely analyze the laws by which the thermal physical parameters of the asphalt pavement materials change with temperature.Using the basic cuckoo and the gray wolf algorithms,an adaptive hybrid optimization algorithm is obtained and used to determine the relationship between the thermal diffusivity of two types of asphalt pavement materials and the temperature.As shown by the results,the prediction accuracy achievable with this approach is higher than that of the linear model.

In-site health monitoring of cement concrete pavements based on optical fiber sensing technology

Premature stress of cement concrete pavements i the coupled action of construction technique,structural ma-terial and environmental action.It is quite diffiault to accurately get the actual stress distribution merely based on the theoretical or simulation analysis.Ther efore,in-situ health monitoring is particularly si gnificant to obtain the stress or strain information for the assessment on structural perfor mance of cement concrete pavements.To contribute this topic,different kinds of FBG based sensors have been specially designed to measure the tem-perature,pressure and deformation in cement concrete pavements.A relatively long-term monitoring has been aonducted to collect the effective data after the solidification of the pavement lasts for about 15 d.Data analysis indicates that the temperature variation inside the pavement was very stable,with maximum ampltude smaller than 2.25°C in Sep.2020.The longitudinal,transverse and ver tical deformations of the pavement behaved in non-umniform distribution,and partial me asuring points suffered from large tensile force.The concrete course had better deformation resi stance than that of the soil base,and local interfacial micro void defects existed in the soil base.The preliminary results can help to understand the actual structural performance of cement concrete pavements based on the optical fiber sensing sys tem.

Elements of automated survey of pavements and a 3D methodology

Sound transportation infrastructure is critical for economic development and sustainability. Pavement condition is a primary concern among agencies of the roadway infrastructure. Automation has become possible in recent years on collecting data and producing results for certain aspects of pavement performance, while challenges remain in several other categories, such as automated cracking survey. This paper reviews the technological advances on automated survey of pavements, and discusses the most recent breakthroughs by the team led by the author in using 3D laser imaging for capturing 1 mm surface images of pavements.

Advances and development trends in eco-friendly pavements

The major contemporary in road pavement engineering is related to the creation of green and sustainable infrastructures,e.g.,reduction of environmental impacts,increase in traffic safety,and transportation efficiency,etc.This review presents the recent trends in research and the technical solutions developed so far to address these challenges.After the analysis of research status in the past decades,a novel technology system of eco-friendly pavements is proposed considering two solutions,materials modification and structure improvement.The construction of an eco-friendly pavement can be achieved thanks to several different technologies ensuring permeable,noise-reducing,self-luminous,and exhaust-decomposing properties as well as apporting lower heat absorbing and enhanced anti-/de-icing characteristics.A systematic review of these technologies is presented pivoting on four main aspects:technical principle,material and structural composition,performance evaluation,and engineering application.The current trend in road engineering is combining the pavement infrastructure with various eco-friendly functions,e.g.,water permeability,noise reduction,low heat absorption,exhaust gas decomposition,and anti-/de-icing.Finally,the review lists the drawbacks of the existing technologies,including high cost,single function,etc.,and depicts the future developing direction and architecture of the next generation of eco-friendly pavements in which the road infrastructure should have more environmentally friendly functions than the existing technology.

Control Points of the Compaction Technology for Subgrades and Pavements in Municipal Road Engineering

With the rapid development of current social economy,China’s infrastructure construction is constantly increasing.The development of transportation industry and road structure which serve as infrastructure facility for the vehicles are fundamental aspect in economy growth.It’s not only convenience to people for travel,but also as a good foundation for the development of economy.Therefore,the quality of road construction is of great significance importance in the process of development.As technology advances,engineering construction is continuously expanding,especially in the road engineering sector.In this point,it’s necessary to impose strict quality control over related matters and ensure the quality and safety of municipal road construction.In the construction of municipal road engineering,one of the most important components is the compaction of subgrades and pavements,which requires more supervision.The compaction should match the requirements of road design and implement relevant work.

Analytical prediction and field validation of transient temperature field in asphalt pavements

This work presented the development and validation of an analytical method to predict the transient temperature field in the asphalt pavement.The governing equation for heat transfer was based on heat conduction radiation and convection.An innovative time-dependent function was proposed to predict the pavement surface temperature with solar radiation and air temperature using dimensional analysis in order to simplify the complex heat exchange on the pavement surface.The parameters for the time-dependent pavement surface temperature function were obtained through the regression analysis of field measurement data.Assuming that the initial pavement temperature distribution was linear and the influence of the base course materials on the temperature of the upper asphalt layers was negligible,a close-form analytical solution of the temperature in asphalt layers was derived using Green's function.Finally,two numerical examples were presented to validate the model solutions with field temperature measurements.Analysis results show that the solution accuracy is in agreement with field data and the relative errors at a shallower depth are greater than those at a deeper one.Although the model is not sensitive to dramatic changes in climatic factors near the pavement surface,it is applicable for predicting pavement temperature field in cloudless days.

Numerical analysis of applying special pavements to solve the frost heave diseases of high-speed railway roadbeds in seasonally frozen ground regions

The Haerbin-Dalian Passenger Dedicated Line is the first high-speed railway constructed in the seasonally frozen ground regions of northeastern China. Frost heave diseases occurred in the first winter of its operation （between October 2012 and January 2013）, and frost heave was observed mainly in the roadbed fills that were considered not susceptible to frost heave. This paper proposes applying two special pavements -- black pavement and insulation-black pavement -- to improve the thermal regime of the roadbed. Three numerical models of the roadbed temperature field were built based on the field con- ditions of the Changchun section （D3K692＋840 to D3K692＋860）. The results show that： （1） Compared with cement pave- ment, black pavement and insulation-black pavement could reduce the freezing index at the roadbed surface by 37% and 64%, respectively, which could influence the maximum frozen depth; （2） the maximum frozen depths under the black pavement and insulation-black pavement were respectively 1.3-1.4 m and 1 m. Compared with cement pavement, they could reduce the maximum frozen depth by 0.4 m and 0.7-0.8 m, respectively, which would reduce the permitted amount of frost heave by 4 mm and 7-8 ram, which would meet the deformation limit established by the Code for Design on Special Subgrade of Railway; （3） the freezing periods of the black pavement and the insulation-black pavement were, respectively, approximately four months and two months. Compared with cement pavement, they could reduce the freezing period by approximately 19 days and 40 days, respectively, and delay the initial freezing time by 9 days and 18 days; and （4） compared with cement pavement, black pavement and black-insulation pavement could reduce the frozen areas of roadbeds in the cold season, which suggests that these two special pavements could provide better thermal stability for roadbeds.

Evaluation and Selection of Sealants and Fillers Using Principal Component Analysis for Cracks in Asphalt Concrete Pavements

The objective of this paper was to develop a comprehensive evaluation method and index to evaluate the performance of sealants and fillers for cracks in asphalt concrete pavements using the method of principal component analysis. The performance experiments including cone penetration, softening point, flow, resilience and tension at low temperature respectively were conducted by reference of ASTM D5329 for eight sealants and fillers often used in China. There by a principal component model was developed and weight of every index was calculated. The experimental results show that there are significantly different performances for sealants and fillers often used in China. Principal component analysis is an objective method that evaluates and selects the performance of sealants and fillers for cracks in asphalt concrete pavements.

Theoretical Development and Engineering Practice of Pavements in China

This paper presents a comprehensive review of historical theory development and current construction practice of pavement engineering in China. Mechanical models, design guides, construction techniques, evaluation methods and maintenance standards are elaborated for Portland cement concrete （PCC） pavements methodology among pavements of rural highways, urban roads and asphalt concrete （AC） pavements. Differences in design and airport fields are discussed based on service requirements. Lessons and experiences based on the past 20 years＇ construction practice and pavement performance are summarized. Current research areas in pavement engineering associated with unconventional geological and/or landscaping in China＇s highway construction and national strategic plan for pavement engineering are also covered.

Causes of Cracks on Recently Constructed Flexible Pavements: A Case Study on Kabati to Mareira Road in Kenya

Increased surface roughness of road due to emergence of cracks makes travelling on the road uncomfortable to road users;reduces road safety;increases wear and tear of vehicles, which push up the operating costs of vehicles, and increases travel time leading to the loss of useful man-hours to the local economy. The main objective of the study was to establish the causes of cracks on recently constructed flexible pavements with focus to Kabati to Mareira Road. To realize the study objectives, a case study was done on Kabati to Mareira road. Primary data comprising traffic count surveys;field and laboratory data for coring for compressive strength tests, tests on bearing capacity of pavement structure, and pavement deflection measurements analysis tests on improved pavement materials were undertaken on the road under study. The Secondary data on traffic axle load survey along the road under study were obtained from Kenya Rural Roads Authority, Ministry of Roads. The traffic loading was found to be 1.1 million equivalent standard axles over a design period of 15 years at a growth rate of 5%, which is on the lower limit of T4 assumed during the design stage. The material characteristics recommended in design are sufficient for the designed traffic loading. The range of UCS values was 1.12 to 5.83 MPa for soaked cores and 4.76 to 6.94 MPa for un-soaked cores. The DCP results showed that subgrade has a mean CBR of 15% and a median of 14% (subgrade class S4);the sub-base has a mean CBR of 53%, a range of 16% to 93% and thickness of 186 mm and;the base has a mean CBR of 145% a range of 20% to 433% and thickness of 137 mm. The ratio of modulus achieved after construction for base to sub-base is 2.7:1 and 10.7:1 for the sub-base and subgrade. It is concluded that design has no aspect in development and propagation of cracks. Cracks were caused by combination of factors, namely: sub-grade does not provide sufficient support to the pavement due to high base and sub-base strengths;and the variation of strength for pavement layers and the collapse of some cores during soaking process point to cases of inadequate/non-uniform mixing and insufficient curing of the pavement layers. Recommendation is made that the stabilizer content for base and sub-base to be varied in accordance with the properties of natural material being used based on frequency set out in standard specifications;and use of fully flexible pavements where the fill material adopted is alluvial or expansive clays. Emphasis should be placed on adequate pavement support. In improved pavement construction, the stabilizer should be uniformly distributed, thoroughly mixed and pavement layers sufficiently cured.

Use of Waste Plastic in Flexible Pavements-Green Roads

Wrappers of betel nuts, chocolates, chips, hand bags, cold drink bottles and all other forms of plastic create significant environmental and economic problem. They consume massive energy and other natural resources, depleting the environment in various ways. In manufacturing firms, construction industries and products delivery services, use of plastic is a priority to handle and pack things comfortably due to its light weight, cost effectiveness and strength. Plastics cannot be banned as it will result in usage of natural resources like paper, wood at a great extent. It is made up of various chemical elements and is regarded as a highly pestilent material which does not easily degrade in the natural environment after its usage. Waste plastics are made up of Polyethylene, Polystyrene and Polypropylene. Temperature varying between 120℃ - 160℃ gives the softening point of these plastics [5]. They do not produce any toxic gases during heating but the softened plastics have tendency to form a lamination or coating over the aggregate, when it is sprayed over the hot aggregate at 160℃. The main objective of this paper is to discuss the significance of plastic in terms of cost reduction, increase in strength and durability when these plastics are heated and coated upon the aggregates (160℃) to compensate the air voids with plastic and binds with aggregate to provide stability.

Developing a Maintenance Model for Pavements Vulnerable to Climate Change in South Eastern Nigeria

The South East region of Nigeria faces widespread flood during rainy seasons as a result of inadequate drainage channels, poor drainage management and most often the absence of drainage. The increase in rainfall can be attributed to climate change. Climate change has become one of the most common sources of road pavement failure in the region which leads to rapid need of maintenance as a result of flooding and this problem is becoming worse yearly. Most roads in the region suffer submergence because of flooding. In this research work, a predictive model will be developed to control maintenance of road infrastructural systems in the South-East in terms of fatigue. This work is limited to pavement behavior with respect only to fatigue life using the mechanical/elastic properties as the input parameter using additives in the established failure conditions considering Federal roads in the South East as case studies. It is also important to note that the research has a well-defined assumption within the scope to expectancy is 20 years. The loads causing pavement failure are ≥80 KN single axle. Passenger cars will not be included in the passenger. The performance of flexible pavement in real life is synonymous with performance of hot mix asphalt concrete (HMA) in the laboratory. The fatigue life of a pavement is the number of load repetitions ≥80 KN single axle load and finally, traffic loads and moisture are the only contributors to pavement damage.

Multi-gene genetic programming extension of AASHTO M-E for design oflow-volume concrete pavements

The American Association of State Highway and Transportation Officials Mechanistic-Empirical Pavement DesignGuide (AASHTO M-E) offers an opportunity to design more economical and sustainable high-volume rigid pavementscompared to conventional design guidelines. It is achieved through optimizing pavement structural andthickness design under specified climate and traffic conditions using advanced M-E principles, thereby minimizingeconomic costs and environmental impact. However, the implementation of AASHTO M-E design for low-volumeconcrete pavements using AASHTOWare Pavement ME Design (Pavement ME) software is often overly conservative.This is because Pavement ME specifies the minimum design thickness of concrete slab as 152.4 mm (6 in.). Thispaper introduces a novel extension of the AASHTO M-E framework for the design of low-volume joint plain concretepavements (JPCPs) without modification of Pavement ME. It utilizes multi-gene genetic programming (MGGP)-based computational models to obtain rapid solutions for JPCP damage accumulation and long-term performanceanalyses. The developed MGGP models simulate the fatigue damage and differential energy accumulations. Thispermits the prediction of transverse cracking and joint faulting for a wide range of design input parameters and axlespectrum. The developed MGGP-based models match Pavement ME-predicted cracking and faulting for rigidpavements with conventional concrete slab thicknesses and enable rational extrapolation of performance predictionfor thinner JPCPs. This paper demonstrates how the developed computational model enables sustainable lowvolumepavement design using optimized ME solutions for Pittsburgh, PA, conditions.

Effect of dual and new generation wide-base tire assembly on inverted pavements

The conventional flexible pavements have been constructed such that the stiffness of the layer reduces with depth.The crust thickness becomes significantly high for heavy traffic corridors resulting in the consumption of large quantities of construction materials and also increasing environmental pollution.Inverted pavements with the aggregate interlayer(AIL)or stress absorbing membrane interlayer(SAMI)are considered to be one of the alternatives for thick conventional flexible pavements for heavy traffic corridors.The AIL or SAMI is placed between a stiff cement-treated base and asphalt concrete layer to function as crack relief layers.This change in the composition alters the behaviour of inverted pavements compared to the conventional flexible pavements.On the other hand,wide-base tires are being increasingly preferred by trucking industries due to increased fuel economy and cargo capacity.However,the effect of wide-base tires on the performance of inverted pavements is yet to be investigated.In this study,the 3D finite element(FE)models of inverted pavements considering different crack relief layers were developed,and load from dual-wheel and wide-base tires were applied.The stress-strain evolution in the various layers of inverted pavements was investigated and discussed in this study.The results indicated the higher stress and strains due to wide base tires compared to the dual-wheel assembly.Further,pavement with SAMI was found to result in lower stress and strains in the asphalt concrete layer compared to AIL pavements.

Semi-flowable self-consolidating concrete using industrial wastes for construction of rigid pavements in India:An overview

The construction of rigid pavements using conventionally vibrated concrete consumes a significant amount of energy as it requires rigorous vibrations.This also requires a high number of laborers and creates noise during construction.Thus,a new kind of concrete called semi-flowable self-consolidating concrete(SFSCC)for pavement construction using slip-form paving technology is reviewed in this article.The SFSCC requires no energy for compaction as it gets compacted under its self weight.It also renders shape stability in the fresh state which is critical to expedite the construction in slip form concreting.The review focuses on the need,evolution,and requirement of the ingredient materials,mix design,and methods for testing the properties of SFSCC.Further,the utilization of industrial wastes in the construction industry and the production of self-consolidating concrete are discussed.The literature on the effect of different materials on the properties of such concrete and field studies in this context are discussed.Lastly,its suitability as pavement construction material either in normal rural roads or in low-volume village roads is discussed in the Indian context.The review reveals that relatively less amount of study on SFSCC in general and as a pavement material in particular is available in the literature and pursuant to this,creates a wide scope of research.

Mitigating Urban Heat Island Effects: A Review of Innovative Pavement Technologies and Integrated Solutions

In this review paper,we present a thorough investigation into the role of pavement technologies in advancing urban sustainability.Our analysis traverses the historical evolution of these technologies,meticulously evaluating their socio-economic and environmental impacts,with a particular emphasis on their role in mitigating the urban heat island effect.The evaluation of pavement types and variables influencing pavement performance to be used in the multi-criteria decision-making(MCDM)framework to choose the optimal pavement application are at the heart of our research.Which serves to assess a spectrum of pavement options,revealing insights into the most effective and sustainable practices.By highlighting both the existing challenges and potential innovative solutions within thefield,this paper aims to offer a directional compass for future urban planning and infrastructural advancements.This review not only synthesizes the current state of knowledge but also aims to chart a course for future exploration,emphasizing the critical need for innovative and environmentally sensitive pavement tech-nologies in the creation of resilient and sustainable urban environments.

A review of top-down cracking in asphalt pavements:Causes, models, experimental tools and future challenges

In the last decades,a new type of distress has been observed more and more frequently on asphalt pavements.This distress,ascribable to fatigue failure,has been named top-down cracking(TDC) because it consists in longitudinal cracks that initiate on the pavement surface and then propagate downwards.A series of surveys recently carried out on Italian motorways highlighted that TDC can affect up to 20%-30% of the slow traffic lane.Therefore,in order to achieve a better understanding of such distress,this paper reviews causes,models and experimental tools and highlights future challenges for TDC.The literature review indicates that TDC can evolve on the pavement surface in three stages(i.e.,single crack,sister cracks,alligator cracking) and,below a certain depth,the cracks can form angles of 20°-40° with respect to the vertical plane.Even though multiple factors contribute to TDC development,thick pavements are more likely to fail due to TDC induced by tire-pavement contact stresses,especially in the presence of open-graded friction courses(OGFCs).Moreover,in literature there are several TDC models based on mechanics(e.g.,fracture mechanics or continuum damage mechanics) which allow a rigorous study of crack initiation and propagation.Future challenges include the identification of a reliable and feasible test method,among those proposed in literature,to study the TDC performance of asphalt mixtures and the implementation of TDC in pavement management systems(PMSs) through the definition of criteria for TDC recognition in the field as well as for the rehabilitation depth evaluation.Finally,more research is needed for open-graded asphalt mixtures,which present critical drawbacks in terms of TDC.