| 11. |
- Chen, Feng, et al.
(författare)
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Towards an understanding of the structural performance of future electrified roads : a finite element simulation study
- 2018
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Ingår i: The international journal of pavement engineering. - : Taylor & Francis. - 1029-8436 .- 1477-268X. ; 20:2, s. 204-215
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Tidskriftsartikel (refereegranskat)abstract
- Nowadays, many novel technologies are under investigations for making our road infrastructure functionbeyond providing mobility and embrace other features that can promote the sustainability developmentof road transport sector. These new roads are often referred to as multifunctional or ‘smart’ roads. Focusin this paper is given to the structural aspects of a particular smart road solution called electrified road or‘eRoad’, which is based on enabling the inductive power transfer technology to charge electric vehiclesdynamically. Specifically, a new mechanistic-based methodology is firstly presented, using a finiteelement simulation and an advanced constitutive model for the asphalt concrete materials. Based onthis, the mechanical responses of a potential eRoad structure under typical traffic loading conditions arepredicted and analysed thoroughly. The main contributions of this paper include thus: (1) introducing anew methodology for analysing a pavement structure purely based on mechanistic principles; (2) utilisingthis methodology for the investigation of a future multifunctional road pavement structure, such as aneRoad; and (3) providing some practical guidance for an eRoad pavement design and the implementationinto practice.
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| 12. |
- Das, Prabir Kumar, et al.
(författare)
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Numerical study on the effect of mixture morphology on long-term asphalt mixture ageing
- 2015
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Ingår i: The international journal of pavement engineering. - : Informa UK Limited. - 1029-8436 .- 1477-268X. ; 16:8, s. 710-720
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Tidskriftsartikel (refereegranskat)abstract
- Asphalt mixtures with similar percentages of air voids can have different morphologies and can age differently. Prediction of ageing behaviour without considering the influence of mixture morphology may thus lead to erroneous conclusions and non-optimal mix design. This article investigates the long-term field ageing of asphalt mixtures by incorporating mixture morphology. For this, a computational analysis on diffusion-reaction process has been conducted by implementing fundamental mechanism of ageing and conducting a parametric sweep of the morphology. To investigate the ageing gradient along the depth of asphalt mixture, diffusion controlled oxidative ageing on one dense and one open-graded field core was investigated. The proposed model based on the mixture morphology information was able to predict the aged viscosity better than the existing model. As mixture morphology is controllable, having insight into how the morphology parameter influences the mixture's ageing susceptibility can be of great value to its design.
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| 13. |
- Edvardsson, Karin, et al.
(författare)
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Dust suppressants efficiency study : in situ measurements of dust generation on gravel roads
- 2012
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Ingår i: The international journal of pavement engineering. - : Informa UK Limited. - 1029-8436 .- 1477-268X. ; 13:1, s. 11-31
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Tidskriftsartikel (refereegranskat)abstract
- Dust suppressants were applied on fifteen 1 km long test sections at four sites in Sweden during three summer seasons with the objective to compare their relative efficiency and determine minimum application rates in Nordic climate. Dust generation from the test sections was measured both visually and by PM10 measurements. All products except lignosulphonate, sugar and bitumen emulsion showed acceptable efficiency. Chloride solutions were the most efficient. Results indicate the possibility to reduce application rates of chlorides by applying them as solutions instead of solids. The minimum application rate for a chloride solution was estimated at 0.8m(3)/km, which is equivalent to a rate reduction of 50% by weight compared with traditionally applied rates of solid chloride. The results are expected to reduce life cycle costs for gravel roads and contribute to environmental gains by reducing the release of dust into the atmosphere and chemicals into the environment.
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| 14. |
- Ekblad, Jonas, et al.
(författare)
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Impact on rutting from introduction of increased axle loads in Finland
- 2020
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Ingår i: The international journal of pavement engineering. - : Taylor and Francis Ltd.. - 1029-8436 .- 1477-268X.
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Tidskriftsartikel (refereegranskat)abstract
- In 2013, Finland introduced legislation increasing gross vehicle weights (GVW) on a number of trucks. Since the actual impact on road damage is nearly impossible to quantify in advance, the present analysis of road surface measurements is intended to provide knowledge regarding the impact on road damage. Rutting is influenced by many conflated phenomena. To indicate and capture the effect on road damage due to the new maximum GVW for certain truck- and trailer combinations, the analysis follows two different but mutually supporting lines of reasoning, empirical and theoretical, respectively. Analysis of measured rut depth is supported by theoretical calculations. Theoretical findings clearly indicate that the relative increase in road damage induced by higher GVW is larger than the increase in relative payload capacity. There was a rapid fleet shift towards heavier trucks after 2013, and statistical (empirical) analysis of road surface measurements shows an increase in rutting after this introduction.
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| 15. |
- Ekblad, Jonas, et al.
(författare)
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Influence of water and mica content on resilient properties of coarse granular materials
- 2008
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Ingår i: The international journal of pavement engineering. - : Informa UK Limited. - 1029-8436 .- 1477-268X. ; 9:3, s. 215-227
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Tidskriftsartikel (refereegranskat)abstract
- Elevated amounts of free mica particles in unbound granular materials used in road construction are believed to detrimentally influence bearing capacity. The objective of presented work was to investigate the influence of mica content on resilient properties of coarse granular material (maximum particle size 63mm) under varying water contents. The test scheme comprised triaxial tests, using constant confining pressures, at incrementally raised water contents up to practically full saturation. Increased mica content was achieved by replacing a part of the base material grading smaller than 4mm, with an equal amount of pure muscovite mica of similar grading, hence keeping the overall particle size distribution unchanged. Generally, resilient modulus decreased with increased mica content and elevated water contents caused reduction in stiffness. In relative terms, the reduction in resilient modulus caused by water decreased with increased mica content.
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| 16. |
- Etikan, M. Kaan, et al.
(författare)
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Experimental and numerical analyses of crushing resistance of unbound road materials
- 2024
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Ingår i: The international journal of pavement engineering. - : Taylor & Francis. - 1029-8436 .- 1477-268X. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- Aggregate breakage in unbound pavement layers can lead to pavement distresses that affect their functionality and service life. Thus understanding the mechanics and clarifying the factors affecting materials breakage resistance are important for ensuring adequate performance of these layers. In this study, aggregate breakage in unbound granular materials (UGM) is investigated experimentally and numerically. Experimentally, aggregate breakage under uniaxial compression is examined for two UGMs prepared with the same aggregate type but different gradations. To capture the experimentally observed influence of gradation and load magnitude on aggregate breakage, a Discrete Element Method (DEM) model was developed, based on granular mechanics particle contact and failure laws. A simple procedure to identify the contact and failure law parameters from experiments is proposed. With those parameters, the model’s capability of capturing the effect of gradation and loading on the aggregate breakage in UGM is evaluated. Based on comparison with experimental findings, it is shown that the model can capture macro-scale properties of UGM, such as its deformation response under uniaxial compression, as well as the amount of aggregate breakage in the material.
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| 17. |
- Guarin, Alvaro, et al.
(författare)
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Disruption Factor of Asphalt Mixtures
- 2013
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Ingår i: The international journal of pavement engineering. - Oxfordshire, UK : Informa UK Limited. - 1029-8436 .- 1477-268X. ; 14:5, s. 472-485
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Tidskriftsartikel (refereegranskat)abstract
- Typically, aggregate gradation is selected to meet Superpave mix design specification; however, many Superpave mixtures have exhibited deficient field performance. The porosity of the dominant aggregate size range (DASR), which is the primary structural network of aggregates, has been extensively validated as a tool to evaluate coarse aggregate structure of laboratory and field asphalt mixtures. Mixtures identified by the system as having poor or marginal gradations resulted in poor rutting resistance. This study focused on how asphalt mixture performance is affected by changes in interstitial component (IC), which is the material between DASR particles. Laboratory testing clearly showed that IC characteristics may have a significant effect on rutting and cracking performance of mixtures. The disruption factor (DF) was developed to evaluate the potential of IC aggregates to disrupt the DASR structure. DF satisfactorily distinguished poor performing mixtures; therefore, it may eventually be used in combination with DASR porosity as a design parameter for rutting and cracking resistant asphalt mixtures.
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| 18. |
- Khavassefat, Parisa, 1984-, et al.
(författare)
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Non-stationary Response of Flexible pavements to Moving Vehicles
- 2016
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Ingår i: The international journal of pavement engineering. - : Taylor & Francis. - 1029-8436 .- 1477-268X. ; 17:5, s. 458-470
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Tidskriftsartikel (refereegranskat)abstract
- In this paper the pavement surface deterioration is investigated based on field measurements of surface roughness profiles obtained in Sweden. A predictive function for surface deterioration, based on average gradient of yearly measurements of the road surface profile in Swedish road network, is proposed. In order to characterise the dynamic loads induced on the pavement by moving traffic a quarter car model is used. Afterwards a non-stationary stochastic approach is used to obtain the yearly response of the pavement to moving loads. The solution is in frequency-wavenumber domain and is given for a non-stationary random case as the pavement surface deteriorates in pavement service life influencing thus the magnitude of the dynamic loads induced by the vehicles. The effect of pavement surface evolution on the stress state induced in the pavement by moving traffic is examined for a specific case of quarter car model and pavement structure. The results showed approximately a 100% increase in the dynamic component of stresses induced in the pavement.
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| 19. |
- Kringos, Nicole, et al.
(författare)
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Modeling of combined physical-mechanical moisture induced damage in asphaltic mixes : Part 1: governing processes and formulations
- 2008
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Ingår i: The international journal of pavement engineering. - : Informa UK Limited. - 1029-8436 .- 1477-268X. ; 9:2, s. 115-128
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Tidskriftsartikel (refereegranskat)abstract
- Moisturehas for a long time been recognised as a serious contributor to premature degradation ofasphalticpavements. Many studies have been performed to collect, describe and measure themoisturesusceptibility ofasphalticmixes. Most of these are aimed at a comparative measure ofmoisturedamage, either via visual observations from field data or laboratory tests or viamechanicaltests, which give a so calledmoisturedamageindex parameter. The research presented in this paper ispartof an ongoing effort at Delft University of Technology, to move away from such comparative or empirical measures ofmoisture-induceddamageand start treatingmoisture-induceddamagein a comprehensive energy based framework. Such a framework would enable realistic predictions and time-assessment of the failure pattern occurring in anasphalticpavement under the given environmental and traffic loading which could be rutting, cracking, ravelling or any combination or manifestation thereof. Themodellingofmoisture-induceddamageis a complex problem, which involves a coupling betweenphysicalandmechanicaldamageprocesses. This paper discusses several modes ofmoistureinfiltration intoasphalticmixesand derives thegoverningequations for their simulations.Moisturediffusion into the mastic film, towards the aggregate-mastic interface and mastic erosion, due to high water pressures caused by the pumping action of traffic loading, are identified as the mainmoisture-induceddamageprocessesand are implemented in a new finite element program, named RoAM. The paper discusses the necessary model parameters and gives detailed verification of themoisturediffusion and advective transport simulations. In the accompanying paper the developed finite element model is demonstrated via an elaborate parametric study and the fundamentalmoisture-induceddamageparameters are discussed.
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| 20. |
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