| 1. |
- Abed, Ahmed, et al.
(author)
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Uncertainty analysis of life cycle assessment of asphalt surfacings
- 2024
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In: International Journal on Road Materials and Pavement Design. - : Taylor & Francis. - 1468-0629 .- 2164-7402. ; 25:2, s. 219-238
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Journal article (peer-reviewed)abstract
- The Life Cycle Assessment (LCA) of asphalt pavements are associated with significant uncertainty resulting from variability in the quantity and impact of individual components, the quality of data for each component, and variability of asphalt durability. This study presents a framework to quantify and incorporate the uncertainty of LCA and asphalt durability data into LCA of asphalt surfacings. The suggested framework includes: estimating the uncertainty of asphalt production processes by the pedigree matrix method, conducting a deterministic LCA, applying Monte Carlo Simulation (MCS) to estimate the probability density functions (PDFs) of the considered impacts using the uncertainty data, deterministic solution, and asphalt durability. This framework was applied to six asphalt mixtures; the results show that there is significant uncertainty in the processes that contribute to the environmental impacts. They also showed that considering asphalt durability and its uncertainty is critical and can significantly change the results and interpretation of LCA.
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| 2. |
- Arvidsson, Anna K, 1971-, et al.
(author)
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Friktions- och texturutveckling på nya beläggningar
- 2019
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Reports (other academic/artistic)abstract
- En ny vägyta bör vara och upplevas som säker av trafikanterna oavsett vilket väglag som råder. Det är därför viktigt att vägbanan har en tillfredställande nivå på friktion redan när vägen öppnas. Det finns begränsade dokumenterade kunskaper hur vägen förändras den första tiden efter en beläggningsåtgärd.Syftet med detta projekt är att fastställa hur friktionen förändras under den första tiden efter att vägbeläggningen är lagd och trafikpåsläpp sker. Ambitionen är att kunna avgöra om nylagda vägavsnitt har nedsatt friktion och ge rekommendationer för när en friktionsmätning ska utföras och hur skyltning ska ske i anslutning till beläggningsarbeten. Upplägget har varit att följa olika objekt med täta friktions- och texturmätningar från strax innan trafikpåsläpp tills nivåerna har stabiliserats.Initialt är friktionen hög för att sen avta med mängden trafik. Efter 1–3 veckor nåddes det lägsta värdet och därefter ökade eller stabiliserades friktionen. Gemensamt för alla undersökta sträckor var att det sker stora förändringar i texturnivåerna från att det första fordonet trafikerar vägen och därefter är den starkaste tendensen en sjunkande texturnivå tills en stabil nivå uppnås efter 1–3 veckor.
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| 3. |
- Biligiri, Krishna Prapoorna, et al.
(author)
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Confined E * testing on poroelastic road surface mixtures
- 2012
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In: International Journal on Road Materials and Pavement Design. - : Taylor & Francis. - 1468-0629 .- 2164-7402. ; 13:2, s. 385-395
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Journal article (peer-reviewed)abstract
- In Europe, poroelastic road surface (PERS) material is being tested to a level at which it can be applied on different types of roads as a noise-reducing pavement. Traffic noise reductions of around 10–12 dB have been achieved using PERS in comparison to a conventional dense asphalt concrete. The PERS material is designed as an open-graded mix to have at least 20% air voids by volume.The objective of this research study was to evaluate the effect of six different confinement levels on the E * dynamic modulus testing of PERS mixtures. The major aim of utilising confinement on PERS materials was specifically to simulate and assess field performance characteristics of those mixes in the laboratory. Furthermore, the choice for confinement is essential in order to obtain realistic test results for a porous or open-graded aggregate structure of the PERS mix. AASHTO TP 62-07 was utilised for dynamic modulus E * testing; for confined tests, a lateral air pressure was provided that simulated confining effect on the samples. Confined tests were conducted only on the two variants of the PERS mixtures that had about 50% or greater amount of aggregates by volume of the mix. Moduli (E *) and phase angle (φ) master curves were established using the test results.
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| 4. |
- Biligiri, Krishna Prapoorna, et al.
(author)
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Understanding the fundamental material properties of low-noise poroelastic road surfaces
- 2013
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In: The international journal of pavement engineering. - : Taylor & Francis. - 1029-8436 .- 1477-268X. ; 14:1, s. 12-23
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Journal article (peer-reviewed)abstract
- The main purpose of this study was to characterise the fundamental material (stiffness) properties of the poroelastic road surfaces (PERS) relevant to the pavement design. The research encompassed preparation of five variants of PERS mixtures in the laboratory based on the combinations of rubber, aggregate and binder components. Two standard test procedures were utilised: stress–strain sweep test and dynamic modulus E* test. First, stress–strain sweep test was performed at 1 mm/min strain rate to investigate the PERS mixtures' elastic characteristics. Hysteresis loops were plotted between force and strain change, which indicated that in all the mixes, the samples were stable to resist against higher hysteresis losses during successive cycles of testing. Also, lower losses were observed with increasing rubber contents; the results can be used in optimising the rubber content in the PERS to further assess rolling resistance and friction. Next, dynamic modulus E* test was performed on the PERS. The dynamic moduli varied based on the blending of rubber and aggregates proportion; the PERS mixes with higher amount of aggregates and lower amount of rubber had higher moduli. A comparison of moduli between the PERS mixtures and a typical asphalt concrete (AC) mix indicated that the PERS were softer than the AC mix by about 20–1500 times; the softness characteristics of the PERS would plausibly provide higher noise-dampening response. The methods employed so far covered stress–strain, and stiffness characteristics, which could be used in pavement design and the evaluation of rolling resistance and noise-reducing properties. Although this study is just a portion of a much more comprehensive laboratory test programme, these tests along with the upcoming laboratory tests are envisaged to aid in selecting the most promising PERS materials for the application on trafficked roads
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| 5. |
- del Barco Carrión, A. Jiménez, et al.
(author)
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Pavement, Roadway, and Bridge Life Cycle Assessment 2020 : Towards a sustainability assessment framework in Europe
- 2020
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In: Pavement, Roadway, and Bridge Life Cycle Assessment 2020. - London : CRC Press. - 9781003092278
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Conference paper (other academic/artistic)abstract
- Pavement Life Cycle Management is a 2-year international project aiming at supporting European National Road Authorities (NRAs) to introduce sustainability in their practices by providing training on Life Cycle techniques and a user-friendly package to support their widespread implementation. The first task in Pavement Life Cycle Management (PavementLCM) project is the creation of a Sustainability Assessment (SA) framework that complies with EN15643-5 and consequently include the three pillars of sustainability, use a life cycle approach and use quantifiable sustainability performance indicators. This paper presents the first steps towards the creation of the framework which includes the following steps: 1) review of the available Product Category Rules (PCRs) related to asphalt mixtures and pavement activities; 2) definition of the object of the assessment; 3) review and survey of NRAs practices of the main research efforts in Europe towards the definition of sustainability performance indicators.
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| 6. |
- Kalman, Björn, 1961-, et al.
(author)
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Beständighet hos asfaltbeläggningar : utmattning av asfaltlager som utsätts för upprepade belastningar i närvaro av vatten
- 2005
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Reports (other academic/artistic)abstract
- Brister i asfaltlagers beständighet kan antas orsaka stora kostnader för samhället. För att förbättra beständigheten på asfaltbeläggningar har vattenkänsligheten undersökts på bitumenbundet bärlager. Av speciell betydelse för bärlager är dess förmåga att motstå utmattning. Samband mellan töjningsnivån i underkant av bärlagret och förmågan att motstå utmattning är av vikt vid dimensionering av bitumenbundna lager. Hur vatten påverkar dessa samband är därför av stor betydelse för att kunna göra en lägesspecifik dimensionering eftersom olika vägkonstruktioner i olika klimat utsätts för mer eller mindre vatten.Två bärlagerbeläggningar, AG16, undersöktes med en speciell försöksuppställning i VTI:s wheeltracking-utrustning, med syftet att studera sprickinitiering och sprickpropagering i konstruktionerna under torra respektive våta förhållanden. De två beläggningarnas styvhetsmoduler och hur dessa påverkades av s.k. vinterkonditionering studerades parallellt med utmattningsprovningen.Sambandet mellan töjningsnivån i utmattningsförsöken och antalet belastningar till sprickinitiering var likvärdigt för de två bärlagren samt relativt oberoende av om bärlagren testades under torra eller våta förhållanden. Likaså var sprickpropageringen, dvs. antalet belastningar mellan det att en spricka bildats i underkanten i beläggningen och till dess sprickan är genomgående, likvärdiga för de två beläggningarna under torra förhållanden. Undersökningarna visar däremot att sprickpropageringen gick markant snabbare för ett av materialen vid närvaro av vatten. Detta material uppvisade också större sänkning av styvhetsmodulen vid vinterkonditionering.
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| 7. |
- Kalman, Björn, 1961-
(author)
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Erfarenheter av cirkulär återanvändning av slitlagerbeläggningar
- 2024
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In: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 421-421
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Conference paper (other academic/artistic)abstract
- Att asfalt går att återvinna till 100% har varit känt sedan lång tid. Slitlagerbeläggningar är mer utsatta än de övriga de strukturella lagren i vägen. Direktkontakt med däck och dubbdäck samt exponering mot syre och UV-strålning samt vatten gör att materialkraven på råmaterialen och färdig produkt är mer omfattande för slitlagerbeläggningar. Vid återvinning av asfalt är det lätt att material från olika lager i konstruktionen blandas. Det var därför inte tillåtet att använda återvunnen asfalt i nya slitlagerbeläggningar i Sverige innan 2017 då denna begränsning lyftes. Vi har gjort en uppföljning av hur slitlagerbeläggningar tillverkade med respektive utan återvunnen asfalt presterat på ett antal högtrafikerade vägar i Mellansverige under fem år samt även undersökt beläggningarnas slitstyrka gentemot dubbdäck i en provvägsmaskin. Slitlagerbeläggningarna som ingår i studien är tillverkade vid olika typer av asfaltverk. Spår- och texturutvecklingen under fem år var likartad för provsträckorna med återvunnen asfalt och referenssträckorna på de 6 testplatserna. Dubbdäckslitaget för provmaterialen och motsvarande referensmaterial i försök med provvägsmaskinen. Resultaten visar att med en noggrann separering och hantering av de olika återvunna asfaltsmaterialen går det att tillverka slitlagerbeläggningar baserade på återvunnen asfalt med samma kvalitet som dito baserade på 100 % nya råvaror.
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| 8. |
- Kalman, Björn, 1961-, et al.
(author)
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Estimation of durability of new surface courses using accelerated load test and expert's opinions
- 2022
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In: Proceedings of the 11th International Conference on the Bearing Capacity of Roads, Railways and Airfields. - London : CRC Press. - 9781003222910 ; , s. 502-510
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Conference paper (peer-reviewed)abstract
- There is an increasing interest among road authorities in studying sustain ability assessment of road infrastructure. The durability of the surface course is a critical factor in these calculations and must be carefully considered in the analysis. New types of asphalt mixes with the potential to improve the results in the sustainability assessment have no proven track record and are thus more likely not to be used until solid perform ance data is available. To bridge the gap and diminish the uncertainty about the durability of Green asphalt mixes for surface courses, a combination of laboratory tests and tests in a circular road simulator were performed. Eight mixes were tested in total, four stone mastic asphalt mixes and four porous asphalt mixes. Each group contained a reference mix with well-established performance. The mixes were characterized with dynamic IDT, com plex shear modulus and water sensitivity using MiST (moisture induced stress test). Part of the loose mixes was oven aged at 85 °C simulate long term ageing. Plates of aged and virgin mixes were then tested in a circular road simulator in a program set up to check their sensitivity towards rutting, raveling, freeze-thaw cycles, polishing and fatigue. A combination of expert’s opinion from academia and national road administrations together with the data from the tests were used to estimate the performance of the new Green mixes.
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| 9. |
- Mantalovas, Konstantinos, et al.
(author)
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European National Road Authorities and Circular Economy : An Insight into Their Approaches
- 2020
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In: Sustainability. - : MDPI. - 2071-1050. ; 12:17
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Research review (peer-reviewed)abstract
- The pavement engineering industry, having realized the significance of the impacts that it imposes on the environment through the production, construction and management of its products and assets, has been driven towards a more sustainable and circular way of operating. This has partly been through asphalt recycling, which is an area that many road authorities have prioritized. However, not all the National Road Authorities (NRAs) and/or sector stakeholders seem to be adequately familiar with the Circular Economy (CE) concept. This paper attempts to assist the transition of NRAs to a more circular way of doing business, by analyzing the current situation of CE within national/regional authorities and NRAs. To do so, a questionnaire was sent to different NRAs and an online search was conducted to identify the ways that NRAs communicate their CE practices. Findings indicate that, although the majority of the NRAs are familiar with CE as a concept, not many actions have been taken so far towards its holistic implementation. Finally, there is a significant lack of CE expertise and communication within these bodies.
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| 10. |
- Sandberg, Ulf, 1946-, et al.
(author)
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Design Guidelines for Construction and Maintenance of Poroelastic Road Surfaces
- 2005
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Reports (other academic/artistic)abstract
- A poroelastic road surface is a wearing course made essentially of rubber granules bound together with a binder and with a selection of particle sizes resulting in a porous structure. This report describes attempts to construct and test in laboratory and field experiments three poroelastic surfaces intended for road traffic noise reduction in urban areas. The studied surfaces were made up of rubber particles bound with polyurethane to create a 30 mm thick porous structure with 30-35 % interconnecting air voids. Laboratory experiments indicated very low wear of the test specimens due to exposure to studded tyres as well as very low emissions of particles in the air. They also indicated rolling resistance to be comparable to that of a conventional asphalt surface. Adhesion to the base course and skid resistance received particular attention and the laboratory experiments indicated satisfactory performance. Three types of poroelastic road surfaces were laid in 2004 on one lane of a street in Stockholm City carrying a mix of light and heavy traffic (5400 AADT, 50 km/h posted speed). Wet skid resistance measurements and dry braking tests indicated satisfactory performance. Noise measurements with the CPX method indicated tyre/road noise reductions relative to the adjacent asphalt surface of 10-15 dB(A).After a few months, the experiment was interrupted due to the underlying asphalt surface separating from the asphalt layer beneath it. This was very unfortunate since the rubber surfaces and the adhesion of them onto the first asphalt layer still seemed to perform well. The report includes comprehensive descriptions of the testing, production and maintenance of the tested poroelastic surfaces. An exception is the results in terms of wet friction and noise measured in the Stockholm street experiment, since this is the subject of another report and therefore not treated here. Furthermore, this report includes comprehensive conclusions and recommendations for further work.
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| 11. |
- Sandberg, Ulf, 1946-, et al.
(author)
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Possibilities to reduce tyre/road noise emission on paving stones and other block surfaces
- 2007
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Reports (other academic/artistic)abstract
- Block surfaces, made of stones or cement concrete, have a widespread use in today's cities and towns. However, there are many examples where the use of block surfaces has led to complaints from people living or working close to streets with such pavements; complaints that mostly focus on the extra noise generated by the traffic on such surfaces. The EU-project SILENCE has recognized this sensitive balance and therefore included a subtask with the title “Noise reduction for paving stone surfaces for streets of high cultural or historic importance”. The objectives are stated as:To produce a ranking in relation to noise of commonly used types of paving stonesTo develop and test quieter types of paving stones
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| 12. |
- Sandberg, Ulf, 1946-, et al.
(author)
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The Poroelastic Road Surface : Results of an Experiment in Stockholm
- 2005
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Reports (other academic/artistic)abstract
- A poroelastic road surface is a wearing course made essentially of rubber granules bound together with a binder and with a selection of particle sizes, resulting in a porous structure. This paper reports attempts to construct and test in laboratory and field experiments three poroelastic surfaces intended for road traffic noise reduction in urban areas. The studied surfaces were made up of rubber particles bound with polyurethane to create a 30 mm thick porous structure with 30-35 % interconnecting air voids. Laboratory experiments indicated very low wear of the test specimens due to exposure to studded tyres as well as very low emissions of particles in the air. They also indicated rolling resistance to be comparable to that of a conventional asphalt surface. Adhesion to the base course and skid resistance received particular attention and the laboratory experiments indicated satisfactory performance.Three types of poroelastic road surfaces were laid in 2004 on one lane of a street in Stockholm City carrying a mix of light and heavy traffic (5400 AADT, 50 km/h posted speed). Wet skid resistance measurements and dry braking tests indicated satisfactory performance. Noise measurements with the CPX method indicated tyre/road noise reductions relative to the adjacent asphalt surface of 10-15 dB(A). After a few months, the experiment was interrupted due to the underlying asphalt surface separating from the asphalt layer beneath. This was very unfortunate since the rubber surfaces and the adhesion of them onto the first asphalt layer still seemed to perform well.
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| 13. |
- Tušar, M., et al.
(author)
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Investigation of the performance of conventional and polymer modified bitumen
- 2011
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Conference paper (other academic/artistic)abstract
- Work in SPENS (Sustainable Pavements for European New member States) project was divided into six working groups within each of them surveys were carried out in two or three tasks. In the frame of Task 4.1, we established the advantages and disadvantages of different types of paving grade and modified bitumen. Seven binders were included in the study. The binders were used to make asphalt concrete (AC) with either limestone aggregate or siliceous aggregate, stone mastic asphalt (SMA) and porous asphalt (PA) with siliceous aggregate. The binder test methods included in the study have been the standard test methods, the moduli obtained from the dynamic shear rheometer and the stiffness determined with a bending beam rheometer. Asphalt samples were tested on the wheel tracking, stiffness at different temperatures, water sensitivity and the Marshall stability at different temperatures.The relations between asphalt mechanical properties and the mechanical and visco-elastic properties of the binder have been studied. The multivariate data analysis has been done with modern orthogonal projection methods, i.e. with the partial least squares (PLS) algorithm.
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| 14. |
- Winter, Marius, et al.
(author)
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Design of flexible pavements with cold recycled asphalt bases : comparison of five national approaches
- 2020
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In: Proceedings of 8th Transport Research Arena TRA 2020.
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Conference paper (peer-reviewed)abstract
- The Application of reclaimed asphalt is becoming increasingly important in the European Road Network. Beside the conventional recycling options (i. e. hot asphalt mixtures), cold recycling has been successfully applied in numerous road structures within the secondary and the main road network. However, the standard design procedures for common pavement materials as well as the approaches for cold recycling differ from one country to another. The comparison of five national pavement design procedures shows, that different design approaches may result in similar pavement structures for standard road materials (here: hot asphalt mixtures). The available specifications for pavement design with cold recycled materials indicate generally a surplus of thickness compared to standard structures. This varying surplus in thickness indicates different safety conditions applied in the analysed countries. In order to validate the existing pavement design procedures for cold recycling materials, two options will be followed. On the one hand mechanistic pavement design is applied which allows the calculation of required layer thicknesses. On the other hand, pavement design based on empirical values can be used.
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| 15. |
- Winter, M., et al.
(author)
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Validation of national empirical pavement design approaches for cold recycled asphalt bases
- 2021
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In: Eleventh International Conference on the Bearing Capacity of Roads, Railways and Airfields. - London : CRC Press. - 9781003222880 ; , s. 87-95
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Book chapter (other academic/artistic)abstract
- The applied pavement design procedures differ from country to country within Europe. Especially the use of cold recycling materials which is handled similar to hot-mix asphalt (HMA) in the most available guidelines isn’t sufficient researched. To verify developed procedures, practical trial sections are indispensable. Within this study cold recycled asphalt base layers (CRAB) were assessed according to the German procedure for monitoring and evaluation of road surface conditions. It can be concluded, that the general applied empirical design approach, in which the CRAB layer thickness is increased by 50 % compared to a HMA base will result in a feasible pavement structure. In general, the re-designing of the sections according to various national empirical pavement design approaches partly results in high differences for same layer types.
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