Pavement Response Analysis Research Articles

Dynamic Response Analysis of Airport Pavement under Impact Loading

The safety of the airport runway, as an infrastructure, is of considerable concern. The existing research has problems of hysteresis and unreasonable load application. In this paper, ANSYS is used to construct a coupled tire–pavement model to study the dynamic characteristics of airport asphalt pavements under impact loading. Taking the Boeing 737–800 as an example, the impact of an aircraft landing on an airport pavement is simulated by applying a dynamic load to the landing gear. The effects of tire pressure, landing pitch angle, and sinking speed on the dynamic response of the airport runway are investigated. The effects of each factor of the airport pavement are analyzed by comparing the maximum effective stress, effective strain, and displacement in the vertical direction at the same position of different structures. The results show that when the tire pressure is 2.0 MPa, the maximum values of effective stress, effective strain, and vertical displacement increase by 29.8%, 19.1%, and 22.2%, respectively, compared with 1.0 MPa. The maximum values of effective stress, effective strain, and vertical displacement at the 3.0 m/s sinking speed increase by 25.2%, 93.1%, and 77.1%, respectively, compared with that at the sinking speed of 1 m/s, which indicates that the effect of sinking speed on the dynamic response of the pavement is more significant. However, the change in the landing pitch angle has little impact on the response parameters of the pavement. Meanwhile, the flexural tensile stress at the bottom of the surface and the equivalent effect at the top of the soil foundation must be considered in the design of the airport pavement structure.

Sensitivity analysis of pavement response to subgrade moisture variations

Moisture has detrimental effects pavement structures. Moisture effects on different structures will vary depending on their dimensions and properties. In this study, sensitivity analysis of pavement response to moisture was conducted using multilayered elastic theory, based on arbitrarily assumed subgrade moduli and the moduli from literature sources, respectively. The selected simulation variables included elastic modulus and thickness of asphalt surface, base and subbase layers as well as axle load. The fatigue and rutting life as well as their sensitivity indexes were obtained for each scenario. The results show that the soil with a relatively higher plasticity generally resulted in a higher sensitivity, whilst this trend was not monotonic with the soil plasticity. Drainage implications were summarized to provide a reference for the pavement drainage design. A drainage design process was proposed by incorporating sensitivity analysis. This study will facilitate the understanding of pavement response under different subgrade moisture conditions and pavement drainage design.

Improved Multi-layer Analysis of Pavement Response Using Neural Networks to Optimize Numerical Integration

This paper presents a new accurate method to compute the mechanical response of pavement structures using an Artificial Neural Network (ANN) model coupled with Multi-Layer Elastic Analysis (MLEA). The ANN model is used to improve the numerical integration of the response function used in the MLEA method. It requires four inputs: total pavement thickness, the diameter of the contact area, radial distance, and depth of the response point; and it was trained on one million hypothetical pavement structures. The developed method has been validated by a comparative analysis against boundary conditions, finite element analysis, and available MLEA solutions using various hypothetical pavement structures. The results demonstrate that the developed solution gives excellent response in the vicinity of the pavement surface together with a significant improvement in computational efficiency.

Numerical simulation of mechanical response analysis of asphalt pavement under dynamic loads with non-uniform tire-pavement contact stresses

The selection of accurate input design parameters is important for understanding the dynamic response of an asphalt pavement structure. The transverse and longitudinal shear stresses that affect the dynamic response of asphalt pavement are not considered in traditional asphalt pavement design. To this end, this study utilizes the finite element method (FEM) to analyze the mechanical response of asphalt pavement under dynamic loads with non-uniform tire-pavement contact stresses. For this purpose, firstly a three-dimensional (3D) finite element (FE) model of a rubber tire is developed. Secondly, the predicted and laboratory measured stresses are compared to develop a 3D FE model of the contact stresses. Finally, a 3D FE model of the tire–pavement contact is analyzed to investigate the influence of shear stresses on the response of the asphalt pavement and the superposition effect of the mechanical response. The results show that the distribution and magnitude of the vertical contact pressure under the free-rolling state are the same as those under the static state, and the traction and braking conditions could change the symmetry of tire-pavement interactions. In addition, the shear stress at the tire-pavement interface affects the peak response of the surface layer, indicating that shear stress plays a considerable role in controlling the development of rutting and longitudinal cracks. Considering the viscoelasticity of the asphalt material, it is observed that the superposition effect of the mechanical response is a comprehensive result of the space–time domains. In conclusion, this study analyzes the influence of tire-pavement contact on the mechanical response of asphalt pavement and proposes input design parameters for improving the design of asphalt pavement.

Permanent Deformation Assessment of Cold Recycled Asphalt Mixtures

The objective of this study was to evaluate the behavior in terms of the permanent deformation of four cold recycled asphalt mixtures stabilized with asphalt emulsion and foamed asphalt. The analysis was conducted considering three flow number test procedures adapted for cold recycled mixtures: (i) ABNT NBR 16505 (method A); (ii) adaptation of the FN test for CRAM according to Kim and Lee’s method (method B); (iii) 3D-Move analysis software simulation of pavement structures to address the stress magnitude for the FN test (method C). The influence of the curing process on the performance of the materials was also verified. The study used an extensive database of computed pavement responses from the four different asphalt pavement structures of the experimental section subjected to axial loading of a tandem axle using the 3D-Move pavement response analysis program. The FN results using the 3D-Move data (method C) demonstrated the good mechanical behaviour with respect to permanent deformation of the cold recycled mixtures subject to axial stress and temperature. The method proposed by Kim and Lee (method B) showed little efficacy for the analysis of the CRAMs tested in this work. The ABNT NBR 16505 method (method A), conventionally used for HMA, highlighted the influence of temperature (60°C) on the CRAM mixtures. For all FN test conditions, the curing was a preponderant factor for the performance of cold recycled asphalt mixtures and should be carefully evaluated to simulate the early stage of the mixtures in the field. It is also important to verify the influence of humidity and temperature on the permanent deformation mechanism of cold recycled asphalt mixtures.

Evaluation of fatigue life of semi-flexible pavement with cement asphalt emulsion pastes

Semi-flexible pavement (SFP) has been receiving more attention in pavement engineering due to its excellent rutting resistance. However, conventional SFP has a lower cracking fatigue resistance than conventional asphalt mixture due to its brittleness. To improve its fatigue resistance, cement-asphalt emulsion paste (CAEP) is employed as a more suitable grouting material to prepare SFP, and the effect of asphalt emulsion content in grout on the fatigue resistance of SFP is investigated. Since the elastic modulus of SFP with different CAEPs differs significantly, the typical tensile stress response of different SFPs in pavement structure varies greatly; thus, the fatigue resistance of SFPs is influenced considerably. To reasonably evaluate the fatigue resistance of SFPs, the fatigue life of SFPs at the typical tensile stress is studied. To this end, firstly, the fatigue models of materials were established for long-term performance evaluation and fatigue life prediction by employing indirect tensile fatigue test. Secondly, the tensile stress at the bottom of surface layer materials under realistic tire-pavement interactions was estimated by a three-dimensional (3D) finite element method (FEM). Finally, obtained tensile stresses from pavement response analysis were used in fatigue models to select an ideal SFP in terms of fatigue performance. The fatigue evaluation results indicated that conventional SFP with cement paste has much lower fatigue resistance than conventional asphalt mixture. The fatigue resistance of SFP can be greatly improved when CAEP is used as grout in SFP. When the asphalt emulsion to cement ratio by mass (AE/C) is 0.4, SFP can have better fatigue resistance than conventional asphalt mixture. Therefore, CAEP with AE/C at 0.4 is recommended as the best grout in SFP to obtain the best fatigue resistance.

Mesoscopic asphalt pavement response analysis using a random aggregate generation-based concurrent multiscale method

Asphalt concrete (AC) layers in asphalt pavements are heterogeneous, but they are generally deemed as homogeneous in engineering practice, which cannot realistically reflect the complex mechanical behavior of asphalt pavement, particularly at finer scales. To resolve this problem, the present study developed a random aggregate generation-based concurrent multiscale method to simulate the mechanical response of asphalt pavement using ABAQUS software. In this method, the mesoscopic structure of AC with a 60 cm length was simulated in the vicinity of tire loading by a random aggregate generation method and embedded into a macroscale pavement model. To account for the effects of pavement structure and environmental factors, three thicknesses of AC layer (10 cm, 15 cm and 20 cm), two types of pavement structures respectively with a cement-treated base (CTB) and a granular base (GB), and two pavement temperatures (5 and 35℃) were adopted in the simulation. The maximum principal stress (MPS) values of fine aggregate matrix (FAM) within the region of interest were sorted and the values at the percentiles of 10%, 20%, …, 90%, 100% were extracted. Besides, the number of the elements with top 1% MPS values were evaluated. Specific statistical analysis was performed on these values to investigate potential damage behavior of the AC layer. The results showed that the MPS at the percentile of 100% is at least three times that at the percentile of 90%, which indicates considerable stress concentrations at the narrow gaps between coarse aggregates. Top-down cracking could be the main cracking pattern for the CTB and GB pavement at low temperatures, and bottom-up cracking may be the main damage mode for the GB pavement at high temperatures. Increasing the thickness of the AC layer may effectively reduce the stress level at top of the AC layer for the CTB pavement at low temperatures.

Mechanical Response Analysis of Asphalt Pavement Based on the Interlayer Contact State between Cement-stabilized Magnesium Slag–Aeolian Sand Base

Mechanical Response Analysis of Asphalt Pavement Based on the Interlayer Contact State between Cement-stabilized Magnesium Slag–Aeolian Sand Base

Dynamic response analysis of vehicle and asphalt pavement coupled system with the excitation of road surface unevenness

This study aims to solve the dynamic responses of the vehicle and asphalt pavement coupled system while considering road surface unevenness and deformation. First, an advanced solving procedure is proposed by decoupling the vehicle-pavement coupled system into two subsystems (i.e., quarter vehicle model with two degrees of freedom, and viscoelastic multilayered asphalt pavement) and solving them independently until the surface deformation has converged through an iterative scheme. During the solving procedure, the finite difference method and integral transform techniques are respectively conducted to compute the dynamic responses of vehicle and pavement. Then, the solutions for the dynamic responses of the pavement are verified through finite element simulation, which highlights the accuracy and efficiency of the proposed solution. The convergence study for the iterative procedure of vehicle-pavement coupled system is conducted, and the coupling effect on pavement and vehicle displacements is investigated. Finally, the effects of the vehicle and pavement parameters (i.e., suspension stiffness and damping, tire stiffness and damping, road surface unevenness, and pavement temperature and vehicle speed related to the viscoelasticity of asphalt material) on the pavement dynamic responses and damages are discussed comprehensively. These numerical investigations could prove that the solutions for the dynamic responses of the vehicle-pavement coupled system has the potential to guide road-friendly vehicle design and pavement service life evaluation.

Response analysis of orthotropic steel deck pavement based on interlayer contact bonding condition

In this research the interlayer contact condition was considered between the adjacent layers of orthotropic steel deck pavement, and an interface contact bonding model was applied to simulate the interlayer bonding condition and evaluate the response of deck pavement under vehicle loads. An advantage of this model is that it can simulate not only the full-bond condition but also the debonding condition at somewhere between adjacent layers. The responses of the orthotropic steel deck pavement were calculated and analyzed by the model, and it found that this model is reasonable and credible to evaluate the responses of the deck pavement comparing with the previous researches. The full-bond condition was an ideal condition between adjacent layers, which was prone to underestimate the responses and deformation of the deck pavement. Moreover, the position and size of the disengaging area have a notable influence on the tensile strain at the top of SMA layer and the bottom of GA layer, and the tensile strain of them also increase with the increase of the disengaging area. Finally, the responses of the steel deck pavement changed obviously when the vehicle speed increase, so the suitable speed limit may reduce the responses and deformation for prolonging the service life of the orthotropic steel deck pavement.

Dynamic pavement response analysis under wide-base tyre considering vehicle-tyre–pavement interaction

The new generation of wide-base tyres shows sustainable benefits in trucking operations and environmental impacts due to less rolling resistance at tyre–pavement interface. It is critical to estimate the influence on pavement response and performance. The objective of this study is to analyse dynamic responses of flexible pavements induced by wide-base tyres using an integrated vehicle-tyre–pavement interaction approach. The impulse response method was used to calculate critical pavement responses under moving loads with random amplitudes estimated using a full-truck model. The impact of wide-base tyre was evaluated through the ratio of critical pavement responses between wide-base tyre and dual-tyre assembly. The analysis results suggest that the prediction of long-term pavement performance under the impact of wide-base tyre needs consider the evolution of pavement surface condition and different failure mechanisms. The study findings emphasise the importance of considering vehicle-tyre–pavement interaction in analysing dynamic pavement responses.

Investigation into fatigue life of interface bond between asphalt concrete layers

ABSTRACT A proper interface bond between adjacent asphalt concrete layers ensures the layers to act monolithically to withstand traffic and thermal loading. The presence of a weak interface results in delamination, slippage and fatigue cracks thereby affects the pavement performance; hence, requires careful evaluation. The objectives of this investigation are three-fold. The first objective is to develop a test protocol to investigate the damage characteristics of the interface bond. The proposed test applies a 5 Hz cyclic shear load on a double-layered asphalt concrete specimen using a Modified Advanced Shear Tester at 23°C. The second objective is to determine the effect of interlayer shear modulus on the pavement response of typical pavement sections using numerical simulations. The interface material model property used in this study is a set of arbitrary values that lies within the typical range of interlayer shear modulus values observed during cyclic shear tests. The third objective is to propose a failure criterion for shear fatigue testing that is based on the critical tensile strain obtained during pavement response analysis. The test outcomes show that specimens with a tack coat at the interface exhibit a significant increase in shear fatigue life resistance compared to specimens with no tack coat.

Mechanical response analysis of asphalt pavement on curved concrete bridge deck using a mesostructure-based multi-scale method

Curved concrete bridges are an important infrastructure form, which meet the needs of modern transportation. Due to their relatively sophisticated geometries, asphalt pavements on the bridge decks are typically subjected to more severe loadings. This study investigated multi-scale mechanical responses of asphalt pavement on a curved bridge deck by using a macro-mesoscale coupling algorithm that can rationally considered the mesostructure of asphalt concrete. The influence of driving speeds, curvature radii, and temperatures on the mechanical responses of different scales was analyzed. The results showed that with the increase of the curvature radius and the decrease of the driving speed, both unevenness of tire loads on the asphalt pavement and stress concentrations in the mesostructure of the asphalt pavement were reduced. Under low temperature, asphalt concrete pavement on the deck encountered stress concentration and mesoscopic damage more easily. Increasing temperature can reduce these effects; however, due to the decrease of its asphalt mortar modulus, plastic deformation may occur in the pavement.

Mechanical response analysis of asphalt pavement on concrete curved slope bridge deck based on complex mechanical system and temperature field

Curved concrete bridges with small radii and large longitudinal slopes are important parts of viaduct ramp, on which the asphalt pavement plays an important role in resisting and dispersing traffic loads. Due to the complexity of curved concrete bridge structures with small radii and large longitudinal slopes, the asphalt pavement is subjected to complex mechanical action under loading. This study investigated the mechanical response of the asphalt pavement on a concrete deck under complex load conditions through a three-dimensional finite element model.The effects of different curvature radii, inside and outside wheel groups, driving speeds and temperature fields on the mechanical response of asphalt pavement were analyzed. The results show that in the process of driving on curved bridge deck, the inside and outside wheels of a vehicle produce different normal forces and longitudinal shear forces due to the influence of centrifugal force and radial force moment. With the decrease of the curvature radius and the increase of the driving speed, nonuniform loads are produced on the bridge deck pavement, which would eventually contribute to nonuniform damages. Under different temperature fields, the bridge deck pavement can undergo different failure modes. Besides, temperature fields have the greatest impact on the damage of bridge deck pavement, followed by driving speeds and curvature radii.

Evaluation of the Response Analysis Approach Used in the Mechanistic-Empirical Pavement Design Guide

Asphalt concrete (AC) is a typical viscoelastic material exhibiting rate-dependent behavior. The rate-dependency of AC should be properly taken into consideration in pavement response analysis to accurately evaluate pavement performance and life. In the Mechanistic-Empirical Pavement Design Guide (MEPDG), the dynamic modulus master curve is used to account for the rate-dependency of the dynamic modulus of AC. However, the rate-dependent phase angle is ignored and a constant phase angle of 0 is assumed. The partial characterization of rate-dependent properties of AC in the MEPDG may lead to inaccurate results. This study compares the pavement responses computed using the MEPDG approach and the layered viscoelastic theory (LVET) which utilizes the complex modulus master curve to fully characterize the rate-dependent properties of AC. Typical three-layer pavement structures were analyzed at three temperatures (−10°C, 20°C and 50°C) and four speeds (10, 40, 80 and 120 km/h). The results show that the horizontal tensile stresses at the bottom of cement-treated base layer obtained from the two approaches are almost the same, and for other responses analyzed, the results obtained from the MEPDG approach are larger than those from the LVET approach, especially for the responses in the AC layer. The normalized difference of the vertical compressive strain at the mid-depth of the AC layer between the two approaches can be up to 100% and that for the horizontal tensile strain at the bottom of the AC layer can be more than 50%.

Effects of Random Non-uniform Load on Asphalt Pavement Dynamic Response

Dynamic response analysis of pavement helps with structure and material optimization. The vehicle loading has a significant effect on the pavement dynamic response, which is usually assumed to be concentrated load, uniform load, or harmonic load without considering the space-time characteristics. In this study, a validated quarter vehicle model and finite element road model were developed to obtain the random non-uniform load. The random non-uniform load integrates the randomness characteristics due to the vehicle-road interaction and spatial characteristics caused by the tire pattern. The impacts of the vehicle weight, speed, and road roughness on the vehicle dynamic load were analyzed. The effect of random non-uniform load on pavement dynamic response was investigated by comparing the pavement responses under constant non-uniform load and constant uniform load. Numerical analyses show that the stress extremum along the transverse and longitudinal sections can reflect the time-space characteristics of the loads. The damage of the surface layer is underestimated when the vehicle load is simplified to be a constant uniform load without considering the random and spatial characteristics.

Impact of freeze-thaw environment on concrete materials in two-lift concrete pavement

The freeze-thaw (FT) damage is a potential severe distress on concrete pavements in seasonal frozen regions. This study focuses on the FT resistance of a two-lift concrete (2LC) pavement, including a polypropylene fiber reinforced concrete (PFRC) top lift and a conventional portland cement concrete (PCC) bottom lift. The rapid FT test was conducted on PCC, PFRC, and 2LC specimens and the relative dynamic modulus and mass loss were measured. The mechanical properties of concrete materials were investigated in laboratory, including compressive, tensile, flexural strengths, and flexural modulus. In the end, the influence of FT damages of concrete materials on pavement responses was evaluated. It is found that with the addition of the PF, the PFRC and the 2LC exhibited better mechanical properties and less mass loss than the PCC after FT cycles. The PFRC and the 2LC behaved better FT resistance than the PCC. The Voigt model can predict mechanical properties of 2LC in freeze-thaw process. Through pavement response analysis, the FT damage was found shortening the service life of 2LCP. In summary, the proposed 2LC pavement was justified a better alternate concrete pavement type on resisting the FT environment in seasonal frozen areas.

Flexible Pavement Response Analysis under Dynamic Loading at Different Vehicle Speeds and Pavement Surface Roughness Conditions

AbstractPavement responses are affected by the magnitude and frequency of dynamic loads generated by vehicles, which are significantly dependent on axle configuration, pavement surface roughness, a...

Dynamic Response Analysis of Airport Asphalt Pavement Subjected to High-Temperature Jet Wake Based on Finite Element Simulation

Abstract With the dramatic increase of air traffic volume and the rapid development of civil aviation airport construction in China, asphalt layers overlaying original concrete pavement in civil aviation airports has become the primary rehabilitation scheme. However, asphalt airport pavement is prone to excessive deformation when subjected to the repeated and heavy aircraft loading, especially when coupled with high-temperature field. However, the impact of high-temperature jet wake is rarely considered in the existing structural design and analysis of airport asphalt pavement. In order to investigate the impact of high-temperature jet wake on the dynamic response of asphalt pavement, the coupling of finite element (FE) simulation of the temperature field and aircraft loading based on sequential decoupling methodology was implemented herein. Firstly, the temperature field distribution induced by the high-temperature jet wake on the asphalt pavement was simulated and analyzed by FE simulation on the ABAQUS CFD platform. Then, the temperature field distribution was integrated within the asphalt pavement structure by combining the temperature field distribution produced by jet wake and thermal conduction between ambient radiation and pavement. Secondly, the viscoelastic parameters of each asphalt layer under the obtained temperature field distribution were calculated to represent more real material properties. Finally, FE simulation of airport asphalt pavement subjected to the coupling of aircraft loading and integrated temperature field was conducted. The results show that the amplitudes of transverse strain, vertical strain, and longitudinal strain of the asphalt pavement considering jet wake together with ambient radiation are basically higher than those without consideration. Consequently, the dynamic responses of airport asphalt pavement produced by jet wake and ambient radiation should be fully considered in the design and analysis of airport asphalt pavement.

Dynamic Pavement Response Analysis under Moving Truck Loads with Random Amplitudes

AbstractThe objective of this paper is to analyze dynamic responses of asphalt pavements induced by random loads under moving truck wheels due to surface roughness. A full-vehicle model was applied...