Deformation Of Pavement Research Articles

Establishment of control standard for plastic deformation performance of graded crushed stone

Abstract Plastic deformation of graded crushed stone (GCS) exceeding a certain threshold is prone to cause the failure of GCS base and the excessive deformation of asphalt pavement. However, few studies have been conducted regarding a control standard of the plastic deformation performance of GCS. This study attempted to establish the control standard by setting a threshold of an evaluation indicator. The plastic deformation index (PDI) was proposed as the evaluation indicator. The plastic deformation of GCS base at failure was obtained on the basis of the typical asphalt pavements with GCS base and a failure criterion with 4% plastic strain. The plastic deformation of GCS base at a given time (i.e., corresponding to the number of load repetitions) was further calculated based on the stress condition of GCS base and a prediction model for the plastic deformation of GCS base. The requirement for PDI values of different highway grades were determined by the calculation equation of PDI, and the control standard was ultimately established. The results showed that: the PDI value should be less than or equal to 1900 mm· number for expressway and first-grade highway; the PDI value should be less than or equal to 2200 mm· number for secondary road.

EFFECTS OF PAVEMENT SURFACE DEFORMATIONS ON TRAFFIC FLOW

Pavement surface deformations have a significant effect on speed profile of vehicles and traffic flow conditions. These deformations limit driving properties and increase vehicle operation and maintenance costs. Additionally, they cause many problems such as accidents, slower movement speeds, capacity loss and severe discomfort states. There are many factors having an effect on road capacities and they vary according to different road and traffic flow conditions. In this study, it is aimed to investigate and develop models to estimate shockwave and bottleneck forming, capacity loss and speed reduction, which occurred on examined road links caused by pavement deformations. For the prediction of road capacity, flow–density (q–k) relationship, bottleneck and shockwave analysis methods were used. In the scope this study, deformed road links were divided into three sections; Section A – before deformation zone, Section B – deformation zone, and Section C – after deformation zone. All three sections were investigated and empirical results were obtained. According to analysis results, it was found that pavement surface deformations have a negative effect on the level of road service capability. Obtained results also showed that there are significant reductions in capacity relatively by up to 44 and 26% would result from surface deformations on deformed lanes and non-deformed adjacent lanes.

An implicit finite element framework considering damage and healing effects with application to cyclic moving load on asphalt pavement

• A thermodynamically consistent constitutive model of self-healing materials is discretized implicitly. • The Newton–Raphson iterative procedure is employed to update the internal variables. • Corresponding material consistent tangent matrix is presented a program is developed with application to asphalt pavements . • A 3D finite element model of asphalt pavement is presented under high cycle vehicles movement loadings. • The effects of damage and healing process on rutting performance of asphalt pavement are studied. In this work, the effect of healing process on the damage recovery and delaying the permanent deformation in smart asphalt pavements is numerically studied. In order to analyze the effect of healing, a 3D finite element model of asphalt pavement is presented under high cycle vehicles movement loadings. To study the mechanical behavior of the pavements, a thermodynamically consistent constitutive model has been discretized implicitly and implemented into the commercial FE software ABAQUS. In this regard, the implicit time integration scheme of the constitutive equations and corresponding material consistent tangent matrix are presented. Also, the Newton–Raphson iteration procedure is employed to calculate the internal variables such as permanent deformation, damage and healing parameters at each time increment. The results show that the healing affects the lifetime and load capacity of the pavements and leads to such a reduction in damage growth rate. Furthermore, damage recovery capability is degraded with the growth of permanent deformation and damage. It is demonstrated that without considering the healing effects, the model prediction underestimates the pavement lifetime with higher damage growth rate which is not a valid observation.

Evaluation of rigid pavement on apron of terminal 3 Soekarno-Hatta International Airport using finite element method

The development of transportation technology is indicated by the appearance of a new aircraft gear configuration, dual trim. The load repetitions of the movement of aircraft with dual-tridem gears, such as B-777-300ER aircraft with MTOW 28 tons, on Terminal 3 Soekarno-Hatta International Airport (SHIA) apron may cause pavement deformation, resulting in long-term fatigue and structural failures. Therefore, the performance of the existing rigid pavements to hold the loads for the next 20 years should be evaluated. Firstly, the equivalent annual departure and coverage of the aircraft in the airport up to 2037 is calculated. Next, the existing rigid pavement structure of the apron in the airport is modeled using a finite element method to calculate thermal stress and fatigue analysis for either the dowel or the slab. Our study result shows that the coverage value for the next 20 years is 86,534 with the maximum deflection of 0.055 mm and the maximum stress of 0.496834 MPa. The calculated thermal stress is 1.55 MPa, resulting in load repetition for the slab 1,241,484 and an infinite load repetition for the dowel.

Investigation of shear strength of interface between roadbase and geosynthetics using large-scale single-stage and multi-stage direct shear test

The application of geosynthetics in the road pavement industry as a reinforcement has increased dramatically in recent years. Geosynthetic inclusions can significantly: (i) increase the bearing capacity of the pavement, (ii) prolong the road service life, (iii) reduce maintenance costs, iv) diminish unfavourable large vertical and lateral pavement deformations; and (v) prevent reflective cracking and reduce crack propagation. Although considerable research has been carried out on the interfaces between soils and geosynthetics through large-scale direct shear testing, there is a lack of research in the interfaces between roadbase materials and geosynthetics in pavement engineering. The main innovation of this paper is to investigate the shear strength behaviour of the interfaces existing in a geosynthetic-reinforced pavement. One interface is existing between roadbase and geosynthetic reinforcement for base reinforcement; another one is existing between roadbase and subgrade with geosynthetic reinforcement for subgrade stabilisation. Therefore, a series of laboratory, large-scale direct shear tests was carried out on roadbase materials with and without the inclusion of geosynthetics, under applied normal stresses of 25, 50, 75 or 100 kPa, representing the magnitude of the overburden pressure in the pavement. In addition, theoretical interpretations are developed to back up the experimental results, and to quantify the contribution of different shear strength components mobilised along the interface between roadbase materials and geogrids. Finally, the applicability of multi-stage, large-scale direct shear box testing is assessed by comparing the results obtained with those from conventional single-stage tests obtained in the present experimental study.

Dynamic Response Analysis of Rutting Resistance Performance of High Modulus Asphalt Concrete Pavement

In order to systematically study the rutting resistance performance of High-Modulus Asphalt Concrete (HMAC) pavements, a finite element method model of HMAC pavement was established using ABAQUS software. Based on the viscoelasticity theory of asphalt, the stress and deformation distribution characteristics of HMAC pavement were studied and compared to conventional asphalt pavement under moving loads. Then, the pavement temperature field model was established to study the temperature variation and the thermal stress in HMAC pavement. Finally, under the condition of continuous temperature variation, the creep behavior and permanent deformation of HMAC pavement were investigated. The results showed that under the action of moving loads, the strain and displacement generated in HMAC pavement were lower than those in conventional asphalt pavement. The upper surface layer was most obviously affected by outside air temperature, resulting in maximum thermal stress. Lastly, under the condition of continuous temperature change, HMAC pavement could greatly reduce the deformation of asphalt material in each surface layer compared to conventional asphalt pavement.

Performance Evaluation of Conventional and High Modulus Asphalt Concrete with Novolac Polymer Modifier Using Aashtoware Software

In order to changes the original asphalt characteristics, there are many additives have been used to produce or modify the High Modulus Asphalt Binder (HMAB). Even though the hard grade asphalt binder has some disadvantages, such as the aging process due to high mixing and compacting temperature, which can negatively affect the pavement performance, some other advantages include increasing stiffness modulus of asphalt binder and high resistance to permanent deformation. Also, using the hard grade asphalt binder will save construction costs by reducing the asphalt pavement thickness due to its high stiffness modulus. In Iraq, the Novolac modifier and its Cross-linking Agent (Hexamine) was used for the first time as a modifier for asphalt which can significantly improve the rheological properties of asphalt and its role in HMA. This study focuses on estimating the thickness reduction of flexible pavement due to using High Modulus Asphalt Concrete (HMAC). The reduction in permanent deformation and thickness of pavement were estimated for suggested pavement structure sections implemented HMAC mixture compared with the pavement section implemented conventional mixtures using AASHTOWare software version 2.3. The analytical results indicate that adding 4% of Novolac modifier and 15 % of Hexamine (form weigth of Novolac) is reduced the permanent deformation and bottom up cracking by 30% and 46 % compared to conventional mix, respectively. However, it can be concluded that adding Novolac polymer modifier enhanced the pavement performance.

Laboratory and in-situ tests for estimating improvements in asphalt concrete with the addition of an LDPE and EVA polymeric compound

Pavement deformation is a critical issue in the design of pavement structures and the related mixture. Asphalt concretes may be very sensitive to this problem, in compliance with the viscoelastic behaviour of the adopted bitumen. To improve the material performance, many attempts have been made to introduce in the mixture other materials as “modifiers” or “additives” for increasing the permanent deformation resistance and the elastic modulus of the material. Among the different possible materials, polymers determined significant improvements in the road pavement performance.In this paper, the authors tested the adoption of a specifically engineered polymeric compound, in order to evaluate its effects on a generic asphalt mixture. Several tests were used to prove the effectiveness of the modification. Tests were performed not only in the laboratory, but also in an actual pavement section of the International Airport of Palermo in Sicily. Tests results prove that a proper mix-design can assure a decrease in the permanent deformations, remarkable growth of the material modulus with a reduced bitumen percentage, with economical savings. Finally, regarding fatigue resistance, the modified mixture with low bitumen content assures performance comparable to the control mix containing higher bitumen percentage. Then, the proposed application can be very useful to improve pavement performance even when using softer binder, easier to find in the Italian context.

Principal component analysis-based predictive modeling and optimization of permanent deformation in asphalt pavement: elimination of correlated inputs and extrapolation in modeling

Permanent deformation in asphalt pavement is a function of material properties, loading, environmental conditions, and structural design (e.g., thickness of pavement layers). Because of the large number of effective variables and their nonlinear interrelationships, it is not easy to develop a predictive model for permanent deformation. In this study, a laboratory database containing accumulated strain values (output) and material properties (inputs) from several asphalt pavements has been used to develop a predictive model for permanent deformation. We first show that the inputs are highly correlated, then principal component analysis (PCA) is used to compute a set of orthogonal pseudo-inputs. Two predictive models based on the pseudo-inputs were developed using linear regression analysis and artificial neural networks (ANN) and are compared using statistical analysis. Extrapolation using empirical predictive models is highly risky and discouraged by experienced practitioners, so to guard against extrapolation, a method is developed to determine an input hyper-space. The above-developed model, along with an n-dimensional hyper-space, provides sufficient information for supporting an optimization algorithm for finding the minimum accumulated strain. An asphalt pavement design with accumulated strain value of 1772 micro-strain (0.02 in. in a 10-in.-thick asphalt pavement layer) is obtained by solving the optimization problem and the design parameters meet flexible pavement design specifications. The proposed framework is able to generate accurate predictive models when the original inputs are highly correlated and able to map to an optimal point in the fitted input space.

Automatic pavement defect detection using 3D laser profiling technology

Abstract Asphalt pavement defects e.g. cracks, potholes, rutting, often cause significant safety and economic problems, thus, to automatic detect these defects is vital for pavement maintaining and management. The fact that 3D defect detection methods is superior to traditional 2D methods and manual survey methods in terms of accuracy and comprehensiveness has been widely recognized. Based on 3D laser scanning pavement data, an automatic defect detection method is proposed to detect pavement cracks and pavement deformation defects information simultaneously in this paper. Specifically, a sparse processing algorithm for 3D pavement profiles is first designed to extract crack candidate points and deformations support points, these processing is based on the assumption that the cracks are microscopic local defects while deformations are macroscopic defects in profiles. Then, the crack information can be detected by combining the extracted candidate points and an improved minimum cost spanning tree algorithm. On the other hand, the deformation depth information is acquired based on the profile standard contours which are constructed by profile envelopes and deformation support points, the accurate location and classification information of deformation defects can be obtained by the regional depth property. Experimental tests were conducted using real measured 3D pavement data containing two categories of defects. The experimental results showed that, based on the 3D laser scanning data, the proposed method can effectively detect typical cracks under different road conditions and environments, with the detection accuracy above 98%. Furthermore, different types of deformation defects including potholes, rutting, shoving, subsidence, can also be accurately detected with location error less than 8.7%.

IMPROVING RUTTING RESISTANCE OF HOT MIX ASPHALT BY DATES KERNEL POWDER

In Iraq, the significant increase in the number of passenger cars and trucks (increased inaxle loads) in addition to the unprecedented rise of temperature in the summer hasincreased the risk of permanent deformation of flexible pavement (Rutting) in recenttimes. Lower costs maintenance and extending serves life of flexible pavements are themain objectives of this study by improving rut resisting of it using the waste locallyavailable materials (Dates Kernel Powder).The Superpave design criteria is used to determine optimum asphalt content at 4% airvoids for hot mix with Lime Stone Dust and Dates Kernel Powder as a filler materials tothree types of aggregate blend. Preparing 54 samples with dimension (400*300*50) mmat 110˚C compacted temperature to test it by Wheel-Tracking device at 40˚C, 50˚C and60˚C. Based on wheel-tracking device results, it can be show that there was a significantdecrease in the value of the Rut Depth when using the Dates Kernel Powder as analternative to Lime Stone Dust as a filler materials in Hot Mix Asphalt and it can be usedto improve the rut resisting; the maximum percent of reduction is 67.71 after 3000 cycleof passing at 60ºC and 49.35 as a minimum percent of reduction after 5000 cycle at 40ºCtested temperature, then it can be seen that the impact of Hot Mix Asphalt with DatesKernel Powder is less at high temperatures than mixes with Lime Stone Dust on RutDepth value.

A mechanistic approach to predict built-in temperature in concrete pavements

The built-in temperature difference (BITD), defined as the temperature difference between the top and bottom of a slab at the final setting time, is an important parameter for analysing curling stress and slab deformation in concrete pavements. However, the available methods for estimating this parameter are very limited. A method to predict the BITD in a concrete pavement was therefore developed. To do this, a numerical model was developed to predict the temperature distribution in a concrete slab at early age using a transient one-dimensional finite-difference method. A mathematical equation for predicting concrete final setting time presented in the literature was used and incorporated in the numerical model to predict the BITD. The results of the numerical model showed good agreement with field data. Using the proposed model, the effects of climatic conditions, placement time, pavement thickness and concrete mix proportion on the BITD were also evaluated. The results showed that climatic conditions, placement time and concrete mix proportion have substantial effects on the BITD, whereas pavement thickness has only a slight effect. The proposed model can be used to predict the BITD in concrete slabs for given concrete mix design, placement time, pavement thickness and environmental conditions.

Wheel Force Sensor-Based Techniques for Wear Detection and Analysis of a Special Road.

Automobile proving ground is important for the research of vehicles which are used for vehicle dynamics, durability testing, braking testing, etc. However, the road in automobile proving grounds will inevitably be damaged with the extension of the service life. In most previous research, equipment similar to a laser profilometer was used to detect the quality of the road, the principle of which is to reflect the quality of the road by measuring the roughness of the pavement. This method ignores the elastic deformation of the road itself when the vehicle is traveling and it is difficult to compensate for the error. Therefore, this paper presents a new method based on a force sensor to reduce the impact of elastic deformation, such as tire deformation, pavement deformation, and wheel rim deformation. In this study, force sensors mounted on the wheels collect the three-dimensional dynamic force of the wheel. The presented method has been tested with two sets of cobblestone road loads, and the result shows that the load intensities imposed by the test vehicle on the target road are 88.3%, 91.0%, and 92.05% of the intensity of the load imposed by the test vehicle on a standard road in three respective dimensions. It is clear that the proposed method has strong potential effectiveness to be applied for wear detection and analysis of a special road.

A Component Decomposition Model for 3D Laser Scanning Pavement Data Based on High-Pass Filtering and Sparse Analysis.

High-precision 3D laser scanning pavement data contains rich pavement scene information and certain components associations. Moreover, for pavement maintenance and management, there is an urgent need to develop automatic methods that can extract comprehensive information about different pavement indicators simultaneously. By analyzing the frequency and sparse characteristics of pavement distresses and performance indicators—including the cracks, road markings, rutting, potholes, textures—this paper proposes 3D pavement components decomposition model (3D-PCDM) which decomposes the 3D pavement profiles into sparse components x, low-frequency components f, and vibration components t. Designed high-pass filter was first employed to separate f, then, x and t are separated by total variation de-noising which based on sparse characteristics. Decomposed x can be used to characterize the location and depth information of sparse and sparse derived signals such as cracks, road marks, grooves, and potholes in profiles. Decomposed f can be used to determine the slow deformation of pavement. While decomposed t reflects the fluctuation of the pavement material particles. Experiments were conducted using actual pavement 3D data, the decomposed components can obtain by 3D-PCDM. The effectiveness and accuracy of the x are verified by actual cracks and road markings, the accuracy of extracted sparse components is over 92.75%.

Rutting Evaluation of Alaskan Asphalt Pavement Containing Sustainable Materials

Abstract Permanent pavement deformation, or rutting, is one of the most noticeable distresses in hot mix asphalt. In Alaska, pavement rutting concerns exist at different levels because of seasonal climate change and traffic variation across the entire state. A number of sustainable materials in recent years have been used in Alaska’s pavement construction for their durability and economic and environmental benefits. These materials include modified or highly modified asphalt, warm mix asphalt (WMA), and recycled asphalt pavement (RAP). Using these materials in asphalt pavements may overturn the current understanding of rutting performance in Alaska. Therefore, this study aimed at conducting comprehensive rutting evaluations of these sustainable materials and their applications in Alaska. Based on data collected from 29 Alaskan mixtures, Spearman’s rank correlation coefficient (ρ) was used to discover the link between asphalt pavement analyzer (APA) rut depth and asphalt mixture performance tester parameters for rutting evaluation in order to identify good rutting indicators. The correlation of APA rut depth and flow number (FN) was found to be the strongest, and FN was recommended for rutting evaluation if the APA test was not available. APA results confirmed the good rutting resistance of asphalt mixtures containing high-end modified binders, such as WMA that is produced by adding Sasobit and RAP. Preliminary field evaluation showed no significant rutting concerns in Alaska regarding the application of mixtures containing modified binders, WMA, and RAP.

Evaluation of the impact of pavement degradation on driving comfort and safety using a dynamic simulation model

The dynamic effects exerted by the vehicles on the road pavement have been thoroughly investigated over years. The main reason for this investigation is the major influence on the propagation and worsening of the pavement damages exerted by the dynamic loads rather than the static ones. To date, the modelling theories of systems have evolved, along with the computational capability of the modern calculators. To this effect, three-dimensional simulations of the tire-surface interaction are commonly used. These simulations take into account the dynamics of the load and the consequent deformation of the pavement. However, previous studies aimed at analyzing the above interaction for the optimisation strategies of the maintenance activities within the context of effective road asset management. On the contrary, this work focuses on the safety-related issues linked with the dynamic effects suffered by the vehicle, when passing on different road defects. The goal of this study is to analyse numerically the kinematic and the dynamic effects of the pavement degradations (and in particular rutting) on the driving safety. The simulation of the main characteristics and the evolution of the pavement damages over the time (e.g., the simulation of the tire-pavement contacts and the dynamic response on the vehicles) is a useful method for the development of safe and comprehensive rehabilitation programs. These are of paramount importance to limit the accident rates. The effects on the driving safety was analysed using a simulation model for the vehicles behaviour in the case of damaged pavements. Different road geometries and vehicle types were considered to evaluate the rutting effects on safety, as a function of the evolution stage of this type of pavement damage. In more detail, the performance characteristics of the vehicles, the dynamic and kinematic parameters (e.g., the vehicle trajectory and the vertical acceleration), were collected for pavement conditions with progressively high levels of rutting. The study proposes a theoretical model of qualitative relationships between differing stages and location of rutting, and the consequent effects on driving safety for different types of vehicles (passenger cars and powered two wheelers). It is worth to emphasize the relevance of this research for maintenance prioritization purposes at the road network level. Priority is based on the level of risk associated with the pavement degradations and with different types of vehicle.

Finite element modelling of the rolling resistance due to pavement deformation

ABSTRACTRolling resistance is defined as the energy lost when the vehicle tyre rolls over a pavement surface. The pavement surface texture, roughness and deformation are shown to influence rolling resistance to varying degrees. Several recent studies have focused on determining the vehicle rolling resistance primarily based on pavement surface characteristics without quantifying the effect of pavement elastic deformations on this parameter. This paper focuses on isolating the pavement structure-induced component of the rolling resistance by performing finite element (FE) modelling on flexible and rigid pavement structures using the ABAQUS software under a moving wheel load. The structure-induced rolling resistance (SRR) was shown to be significant for flexible pavements with thin structures and weak support, and relatively insignificant for rigid pavements and thick flexible pavements at low temperature. Due to the complexity of the FE analyses, a reliable procedure was developed for predicting the SRR for in-service pavements using falling weight deflectometer data. Quantifying the effect of SRR can lead to the construction of pavement structures with lower rolling resistance, which in turn will reduce the fuel consumption and the carbon footprint of the roadway network.

Stress dependent and redistribution behaviour of unbound granular material

ABSTRACTThe paper is presented to investigate the tensile stress modification effect on unbound granular materials. The theory of tensile stress modification was proposed and discussed. Seven granular constitutive models were applied in finite element analysis and the calculated strains were compared and verified by results measured in the field. It is shown that the stress modification is essential to accurately predict pavement deformation. The distribution of stress attenuation factor in granular layer is plotted and discussed when Uzan model is applied in theory analysis. It is found that the convergent modulus of granular reduces significantly and the tensile stress or strain at the bottom of asphalt layer increases as a result of the stress modification effect.

The application of non-destructive methods in the diagnostics of the approach pavement at the bridges

The article presents the possibility of using non-destructive methods of road pavement diagnostics as an alternative to traditional means to assess the reasons for premature cracks adjacent to bridge objects. Two scanning methods were used: laser scanning to measure geometric surface deformation and ground penetrating radar (GPR) inspection to assess the road pavement condition. With the use of a laser scanner, an effective tool for road deformation assessment several approach pavement surfaces next to the bridges were scanned. As the result, a point cloud was obtained including spatial information about the pavement deformation. The data accuracy was about 3 mm, the deformations were presented in the form of deviation maps between the reference surface and the actual surface. Moreover characteristic pavement surface cross-sections were presented. The in situ measurements of the GPR method were performed and analysed in order to detect non-homogeneity in the density of structural layers of the pavement. Due to the analysis of the permittivity of individual layers, it was possible to detect non-homogeneity areas. The performed GPR measurements were verified by standard invasive tests carried out by drilling boreholes and taking cores from the pavement and testing the compaction and air voids content in asphalt layers. As a result of the measurements made by both methods significant differences in layer compacting factor values were diagnosed. The factor was much smaller in the area directly next to the bridgehead and much larger in the zone located a few meters away. The research showed the occurrence of both design and erection errors as well as those related to the maintenance of engineering structures.

Usage of digital image correlation in assessment of behavior of block element pavement structure

In diagnostics of existing road pavement structures deflection measurements have fundamental meaning, because of ability to assess present stiffness (bearing capacity) of whole layered construction. During test loading the reaction of pavement structure to applied load is measured in central point or in a few points located along a straight on a 1.5 ÷ 1.8 m distance (i.e. Falling Weight Deflectometer) in similar spacing equal to 20 ÷ 30 cm. Typical measuring techniques are productive and precise enough for most common pavement structures such as flexible, semi-rigid and rigid. It should be noted that in experimental research as well as in pavements in complex stress state, measurement techniques allowing observation of pavement deformation in 3D would have been very helpful. A great example of that type of pavements is a block element pavement structure consisting of i.e. paving blocks or stone slabs. Due to high stiffness and confined ability of cooperation of surrounding block elements, in that type of pavements fatigue life is strongly connected with displacement distribution. Unfortunately, typical deflection measurement methods forefend displacement observations and rotation of single block elements like paving blocks or slabs. Another difficult problem is to carry out unmistakable analysis of cooperation between neighboring elements. For more precise observations of displacements state of block element pavements under a wheel load a Digital Image Correlation (DIC) was used. Application of this method for assessment of behavior of stone slabs pavement under a traffic load enabled the monitoring of deformations distribution and encouraged to formulate conclusions about the initiation mechanism and development of damages in this type of pavement structures. Results shown in this article were obtained in field tests executed on an exploited pavement structure with a surface course made of granite slabs with dimensions 0.5x1.0x0.14 m.