Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 26) Show all publications
Lövqvist, L., Balieu, R. & Kringos, N. (2019). A micromechanical model of freeze-thaw damage in asphalt mixtures. The international journal of pavement engineering
Open this publication in new window or tab >>A micromechanical model of freeze-thaw damage in asphalt mixtures
2019 (English)In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268XArticle in journal (Refereed) Published
Abstract [en]

Freeze-thaw damage in asphalt pavements is a complex phenomenon dependent on many parameters such as moisture infiltration, temperature and mechanical properties of the asphalt constituents as well as the interface between them. As a first step in creating a comprehensive multiscale model including all of these parameters, a micromechanical model has been developed. This model couples the infiltration of moisture and the associated damage, the expansion caused by the water inside the air voids freezing, and the mechanical damage. The expansion of the air voids is implemented by applying a volumetric expansion in the air voids dependent on the temperature. The cohesive damage in the mastic and adhesive damage in the mastic-aggregate interface are included by implementing an energy-based damage model and the cohesive zone model, respectively. To show the capabilities of the model, the effect of different parameters (the number of freeze-thaw cycles, the gradation of the microstructure, and the freezing time) was investigated through simulations. From the analyses it was concluded that the model was capable of capturing the deteriorating effect of an increasing number of freeze-thaw cycles, and was sensitive to the freezing time in the freeze-thaw cycles.

Place, publisher, year, edition, pages
TAYLOR & FRANCIS LTD, 2019
Keywords
Frost damage, moisture damage, modelling, asphalt mixture, microstructure, FEM
National Category
Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-259446 (URN)10.1080/10298436.2019.1656808 (DOI)000482542700001 ()2-s2.0-85071029790 (Scopus ID)
Note

QC 20190920

Available from: 2019-09-20 Created: 2019-09-20 Last updated: 2019-10-15Bibliographically approved
Balieu, R., Chen, F. & Kringos, N. (2019). Life Cycle Sustainability Assessment of Electrified Road Systems. International Journal on Road Materials and Pavement Design
Open this publication in new window or tab >>Life Cycle Sustainability Assessment of Electrified Road Systems
2019 (English)In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402Article in journal (Refereed) Epub ahead of print
Abstract [en]

The widespread use of Electric Vehicles (EVs) has been one of the main directionsfor pursuing a sustainable future of road transport in which, the deployment ofthe associated charging infrastructures, static or dynamic, has been included as oneof the main cornerstones for its success. Different electrified road (eRoad) systemswhich allow for dynamic charging of EVs by transferring electrical power from theroad to the vehicle in-motion, either in a conductive or contactless way, are underactive investigation. One of the important tasks in feasibility analysis of suchinfrastructure is to quantitatively assess its environmental performance and, thus,the consequential influences to the sustainability of road electrification as a whole.Having this concern in mind, in this study, a systematic LCA study is carried out in which the environmental impacts from the different life cycle stages have beencalculated and compared among several promising eRoad systems. In a next step,suitable strategies can be accordingly made to minimize these impacts in a most effectiveway; and more importantly, the LCA results of this study can serve as one ofthe important bases for conducting a more comprehensive and objective evaluationof the potential environmental benefits EVs could bring.

Place, publisher, year, edition, pages
Abingdon, UK: Taylor & Francis, 2019
Keywords
Electrified Road System, Dynamic charging, Life Cycle Assessment
National Category
Infrastructure Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-246053 (URN)10.1080/14680629.2019.1588771 (DOI)000461976800001 ()2-s2.0-85063072590 (Scopus ID)
Funder
Swedish Energy Agency, 41405-1
Note

QCR 20190318

Available from: 2019-03-12 Created: 2019-03-12 Last updated: 2019-08-27Bibliographically approved
Lövqvist, L., Balieu, R. & Kringos, N. (2019). Modeling the evolution of winter damage in an asphalt concrete microstructure. In: : . Paper presented at The Transportation Research Board (TRB) 98th Annual Meeting, Washington DC, January 13–17, 2019.
Open this publication in new window or tab >>Modeling the evolution of winter damage in an asphalt concrete microstructure
2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Winter damage in asphalt pavements is a complex phenomenon which may cause pothole formation, dislodging of stones and structural layer separation. In order to reduce the winter damage, knowledge about the process in both the pavement and on a microstructural level is required. This paper focuses on modeling the process of damage evolution on a microstructural level in order to identify and understand the different phenomena influencing the degradation process. In this paper the evolution of winter damage in an asphalt concrete microstructure was modeled throughout the course of two winter seasons. The simulations include freezing and thawing cycles as well as additional damage originating from snow plows, both based on real weather data from Luleå in the north of Sweden. The results show a large increase of damage in both the mastic and the aggregate-mastic interface, and thereby also vertical displacement of the top surface, after the first freeze-thaw cycle. During the following freeze-thaw cycles the mastic damage continuous to increase but with a decreasing rate while the damage in the aggregate-mastic interface is only affected by the manually added damage from the snow plow. These results indicate a need to include the growth of -and emergence of new air voids in the model as well as an investigation of the actual behavior and influence of the damage evolution in the interface regions.

Keywords
Asphalt, pavement engineering, damage, FEM, Micromechanics
National Category
Infrastructure Engineering
Identifiers
urn:nbn:se:kth:diva-247715 (URN)
Conference
The Transportation Research Board (TRB) 98th Annual Meeting, Washington DC, January 13–17, 2019
Note

QC 20190513

Available from: 2019-03-26 Created: 2019-03-26 Last updated: 2019-05-15Bibliographically approved
Lövqvist, L., Balieu, R. & Kringos, N. (2018). A Coupled Micromechanical Model of Frost Damage in Asphalt. In: Transportation Research Board 97th Annual Meeting, Washington DC, January 7-11, 2018: . Paper presented at Transportation Research Board 97th Annual Meeting.
Open this publication in new window or tab >>A Coupled Micromechanical Model of Frost Damage in Asphalt
2018 (English)In: Transportation Research Board 97th Annual Meeting, Washington DC, January 7-11, 2018, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Frost damage in asphalt pavements is an important factor influencing the performance of the pavement. This type of damage occurs during freeze-thaw cycles when ice forms in the air voids, causing microstructural changes and degradation of material properties, thus affecting the performance of the pavement. It is therefore necessary to understand the process of frost damage in order to prevent it. However, experimental testing is often expensive and time consuming and only a limited number of numerical models dealing with the topic exist. In this work, a numerical micromechanical model has been developed that couple the diffusion of moisture in the asphalt to the damage occurring in a freezing and thawing environment. In this paper, the model is presented and applied on an asphalt microstructure obtained by x-ray scanning of a real asphalt sample. The effect of including frost damage is shown by comparing the behavior of a damaged microstructure to the behavior of an undamaged microstructure. It is revealed that the strength of the damaged microstructure reduces to about 50% of the strength of the undamaged microstructure. Furthermore, the coupling of the moisture content in the air voids to the expansion of the air voids is proved to be important since the assumption that all air voids are fully saturated overestimates the decrease in strength. The next step in this research will be to validate the model with laboratory data. A validated model can assist in improving the predictions of frost damage and help in developing better laboratory tests.

National Category
Infrastructure Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-224877 (URN)
Conference
Transportation Research Board 97th Annual Meeting
Note

QC 20180404

Available from: 2018-03-27 Created: 2018-03-27 Last updated: 2018-04-04Bibliographically approved
Lövqvist, L., Balieu, R. & Kringos, N. (2018). Freeze-thaw damage in asphalt: a set of simplified simulations. In: Stephen Goodman (Ed.), Proceedings of Canadian Technical Asphalt Association 63rd Annual Conference: . Paper presented at Canadian Technical Asphalt Association 63rd Annual Conference.
Open this publication in new window or tab >>Freeze-thaw damage in asphalt: a set of simplified simulations
2018 (English)In: Proceedings of Canadian Technical Asphalt Association 63rd Annual Conference / [ed] Stephen Goodman, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Winter damage in pavements, such as potholes, dislodging of stones and structural layer separation, occurs during and after winter seasons. This damage is caused by several processes, such as freezing and thawing action, moisture accumulation, traffic loads and winter maintenance actions, which combined makes winter damage a highly complex phenomenon. To better understand this process and, in the future, being able to predict the damage propagation by modeling, this paper discusses the possibility to separate these actions and phenomena into different cases. The focus in this paper is on the freezing -and thawing damage and how it is affected by different environmental conditions, inspired by real weather data from the City of Luleå in the north of Sweden. To investigate this, a microscale model is utilized. The results from the simulations show an increasing adhesive damage with the number of freeze-thaw cycles while the cohesive damage in the viscoelastic mastic increases is the most severe for a period with several days of freezing temperatures. A discussion of how the separation of winter damage into different cases will contribute to the ultimate goal of a multiscale model is also included.

Keywords
Asphalt, Micromechanics, FEM
National Category
Infrastructure Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-247712 (URN)
Conference
Canadian Technical Asphalt Association 63rd Annual Conference
Note

QC 20190513

Available from: 2019-03-26 Created: 2019-03-26 Last updated: 2019-05-15Bibliographically approved
Zhu, J., Balieu, R., Lu, X. & Kringos, N. (2018). Microstructure evaluation of polymer-modified bitumen by image analysis using two-dimensional fast Fourier transform. Materials & design, 137, 164-175
Open this publication in new window or tab >>Microstructure evaluation of polymer-modified bitumen by image analysis using two-dimensional fast Fourier transform
2018 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 137, p. 164-175Article in journal (Refereed) Published
Abstract [en]

Aiming to quantitatively evaluate the microstructure of polymer-modified bitumen (PMB) for roads, this paper employs the two-dimensional fast Fourier transform(2D-FFT) to process the microscopic and numerical images of four PMBs. The related derivative parameters, including the characteristic frequency and wavelength, are computed from the 2D-FFT power spectrum. The results show that the absence/presence of a characteristic frequency (range) on the power spectrum can indicate the lack/existence of the corresponding periodical structural pattern(s) in the original PMB image. A lower characteristic frequency usually represents a coarser PMB microstructure while a higher one implies a finer PMB microstructure. The 2D-FFT method is thus valid for differentiating various PMB microstructures. The proposed method is also capable of quantitatively evaluating the effects of temperature and the temporal evolution of PMB microstructure during phase separation. As the separation continues, the decrease of characteristic frequency indicates the coarsening process of a PMB microstructure. Additionally, the numerical reproduction of the observed phase separation is evaluated with the same method. The quantitative comparison with the experimental results reveals that the simulations fairly reproduced the microscopy observation results despite some deviation. The proposed method provides a foundation for the microstructure-based modelling of PMB performance in the future.

National Category
Civil Engineering
Identifiers
urn:nbn:se:kth:diva-218190 (URN)10.1016/j.matdes.2017.10.023 (DOI)000414669500016 ()2-s2.0-85032973707 (Scopus ID)
Note

QC 20171204

Available from: 2017-12-04 Created: 2017-12-04 Last updated: 2017-12-04Bibliographically approved
Chen, F., Coronado, C. F., Balieu, R. & Kringos, N. (2018). Structural performance of electrified roads: A computational analysis. Journal of Cleaner Production, 195, 1338-1349
Open this publication in new window or tab >>Structural performance of electrified roads: A computational analysis
2018 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 195, p. 1338-1349Article in journal (Refereed) Published
Abstract [en]

Given its promise for enhanced sustainability, electrified road (eRoad) has become a realistic option to support the clean and energy efficient Electrical Vehicles (EVs). To investigate the structural implications, this study focuses on a promising eRoad system which is a dynamic application of the Inductive Power Transfer (IPT) to provide electrical power wirelessly to EVs in-motion. A computational study is made in which, via a series of Finite Element Modeling (FEM) analyses on the eRoad structural response under various rolling conditions, is found that eRoads could have quite different pavement performances comparing to the traditional road (tRoad). Importantly, harsh loading due to vehicle braking or accelerating could incur higher potential of premature damage to the structure, whereas sufficient bonding at the contact interfaces would improve the structural integrity and delay the damage risks. In addition, localized mechanical discontinuities could also be a critical threat to the performance of the overall structure. To ensure that eRoads fulfill their sustainability promise, it is thus recommended that more focus should be placed on the possible measures, such as new structures and materials, to improve the structural integrity and thus the overall pavement performance of the integrated system.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Electrified Road, Inductive Power Transfer, Pavement Structure, Finite Element Modeling
National Category
Infrastructure Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-229718 (URN)10.1016/j.jclepro.2018.05.273 (DOI)000440390900114 ()2-s2.0-85048130589 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, 605405
Note

QC 20180611

Available from: 2018-06-06 Created: 2018-06-06 Last updated: 2018-08-16Bibliographically approved
Chen, F., Balieu, R., Cordoba, E. & Kringos, N. (2018). Towards an understanding of the structural performance of future electrified roads: a finite element simulation study. The international journal of pavement engineering, 20(2), 204-215
Open this publication in new window or tab >>Towards an understanding of the structural performance of future electrified roads: a finite element simulation study
2018 (English)In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268X, Vol. 20, no 2, p. 204-215Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
Taylor & Francis, 2018
Keywords
electrified roads, asphalt materials, constitutive modelling, Finite Element simulation, pavement damage
National Category
Infrastructure Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-195591 (URN)10.1080/10298436.2017.1279487 (DOI)000449283000008 ()2-s2.0-85009992434 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, 605405
Note

QC 20170123

Available from: 2016-11-03 Created: 2016-11-03 Last updated: 2018-11-28Bibliographically approved
Chen, F., Taylor, N., Balieu, R. & Kringos, N. (2017). Dynamic application of the Inductive Power Transfer (IPT) systems in an electrified road: Dielectric power loss due to pavement materials. Construction and Building Materials, 147, 9-16
Open this publication in new window or tab >>Dynamic application of the Inductive Power Transfer (IPT) systems in an electrified road: Dielectric power loss due to pavement materials
2017 (English)In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 147, p. 9-16Article in journal (Refereed) Published
Abstract [en]

Inductive Power Transfer (IPT) technology is seen as a promising solution to be applied in an electrified road (eRoad) to charge Electric Vehicles (EVs) dynamically, i.e. while they are in motion. Focus in this study was placed on the dielectric loss effect of pavement surfacing materials on the inductive power transfer efficiency, induced after the integration of the technology into the physical road structure. A combined experimental and model prediction analysis was carried out to calculate this dielectric loss magnitude, based on which some preliminary conclusions as well as a prioritization of future focus needs were summarized in detail.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Pavement materials, Dielectric loss, Inductive Power Transfer, Electric Vehicle
National Category
Civil Engineering
Identifiers
urn:nbn:se:kth:diva-210988 (URN)10.1016/j.conbuildmat.2017.04.149 (DOI)000403854100002 ()2-s2.0-85018641699 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, 605405
Note

QC 20170808

Available from: 2017-08-08 Created: 2017-08-08 Last updated: 2017-08-08Bibliographically approved
Zhu, J., Balieu, R., Lu, X. & Kringos, N. (2017). Numerical investigation on phase separation in polymer modified bitumen: Effect of thermal condition. Journal of Materials Science
Open this publication in new window or tab >>Numerical investigation on phase separation in polymer modified bitumen: Effect of thermal condition
2017 (English)In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803Article in journal (Refereed) Published
Abstract [en]

With the aim to understand the effect of thermal condition on phase separation in polymer-modified bitumen (PMB), this paper numerically investigates four PMB binders under five thermal conditions between 140 and 180 °C. Based on a phase-field model previously developed by the authors for PMB phase separation, the updated model presented in this paper uses temperature-dependent parameters in order to approach the concerned temperature range, including mobility coefficients, interaction and dilution parameters. The model is implemented in a finite element software package and calibrated with the experimental observations of the four PMBs. The experimental results are well reproduced by the model, and it is thus believed that the calibrated parameters can represent the four PMBs. The simulation results indicate that the model proposed in this paper is capable of capturing the stability differences among the four PMBs and their distinct microstructures at different temperatures. Due to the transition of some PMBs from the thermodynamically stable state at 180 °C to the unstable state at 140 °C, a homogenization process may occur during the cooling applied numerically. After the transition, the PMBs start to separate into two phases and gradually form the binary structures controlled by the temperature. It is indicated that the cooling rate slightly affects the final pattern of the PMB binary microstructure, although the process can be more complicated in reality due to the potential dynamic reasons.

Place, publisher, year, edition, pages
Springer, 2017
National Category
Infrastructure Engineering
Research subject
Civil and Architectural Engineering
Identifiers
urn:nbn:se:kth:diva-195087 (URN)10.1007/s10853-017-0887-y (DOI)000397817100033 ()
Note

QC 20161103

Available from: 2016-11-01 Created: 2016-11-01 Last updated: 2017-05-29Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-7333-1140

Search in DiVA

Show all publications