Papers
Info
Dynamic Behavior in Transition Zones and Long-Term Railway Track Performance
Transition zones between embankments and bridges or tunnels are examples of critical assets of the railway infrastructure. These locations often exhibit higher degradations rates, mostly due to the development of differential settlements, which amplify the dynamic train-track interaction, thus further accelerating the development of settlements and deteriorating track components and vehicles. Despite the technical and scientific interest in predicting the long-term behavior of transition zones, few studies have been able to develop a robust approach that could accurately simulate this complex structural response. To address this topic, this work presents a three-dimensional finite element (3D FEM) approach to simulate the long-term behavior of railway tracks at transition zones. The approach considers both plastic deformation of the ballast layer using a high-cycle strain accumulation model and the non-linearity of the dynamic vehicle-track interaction that results from the evolution of the deformed states of the track itself. The results shed some light into the behavior of transition zones and evidence the complex long-term response of this structures and its interdependency with the transient response of the train-track interaction. Aspects that are critical when assessing the performance of these systems are analyzed in detail, which might be of relevance for researchers and practitioners in the design, construction, and maintenance processes.
Year: 2021
Number Pages:
658909.
Author(s): Paixão, A.; Varandas, J.; Fortunato, E.
: Frontiers in Built Environment - Transportation and Transit Systems
Editor: Frontiers Media S.A.
Volume:
7.
Keywords: railway tracks; transition zones; non-linear resilient behavior; three-dimensional numerical modeling; high-cycle strain accumulation model; permanent deformation; train-track interaction
Info
Geomechanical assessment of an inert steel slag aggregate as an alternative ballast material for heavy haul rail tracks
The geomechanical behaviour of railway ballast is a key aspect in the performance of ballasted tracks, mainly under increased axle loads and/or train speeds. Recently, and driven by the circular economy paradigm, some researchers have evaluated the use of alternative ballast materials as replacement for traditional natural crushed rocks. This work presents a comparison between the geomechanical behaviour of a granite aggregate and the one of an electrical arc furnace steel slag aggregate, with the trade designation of
Year: 2021
Author(s): Delgado, B.; Fonseca, A.; Fortunato, E.; Paixão, A.
: Construction and Building Materials
Editor: Elsevier
Volume:
279.
Keywords: Heavy haul railway track; Cyclic loading triaxial tests; Ballast behaviour; Steel slag ballast
Info
Performance Assessment of Reclaimed Asphalt Pavement (RAP) in Road Surface Mixtures
Considerable amounts of Reclaimed Asphalt Pavement (RAP) are produced every year,as the road network requires maintenance to ensure the safety and comfort of its users. RAP is a 100%recyclable material and a useful fit to be re-introduced into another cycle without downgrading itsfunctionality. Despite the current knowledge about the benefits associated with RAP use, it is not yetlargely applied in several countries. This paper aims to validate, on the basis of both short- and longtermmechanical behaviours, the application of a bituminous mixture with a high RAP incorporationrate (75%) in road pavement wearing courses. A crude tall oil rejuvenator was used. Both short- andlong-term oven ageing procedures were employed to simulate the ageing that occurs during mixtureproduction and in-service life, respectively. The tests for validating the RAP mixture as an alternativesolution comprised stiffness, resistance to fatigue, permanent deformation, and determination ofthe water sensitivity. Furthermore, the RAP bitumen mobilisation degree was evaluated and amixing protocol was established. In comparison with virgin bituminous mixtures, it was found that,in general, the high RAP mixtures presented similar or better behaviour. The ageing process hada hardening effect namely in terms of stiffness and resistance to permanent deformation, withoutsignificant effects on the resistance to fatigue and water damage.
Year: 2021
Author(s): Antunes, Vítor; Neves, J.; Freire, A. C.
: Recycling
Editor: MDPI
Volume:
6, 32.
Keywords: rejuvenator; RAP; mechanical behaviour; bituminous mixture; ageing
Info
Subgrade reinforcement of old railway tracks using short soil
The subgrade of old railway tracks often exhibits poor geotechnical behaviour, particularly regarding the soils on which the ballast layer rests. Such poor behaviour implies significant maintenance costs and possession times. The reinforcement of subgrade soils by injection of binders may mitigate these malfunctions, but previous applications showed some limitations, and the quality of the results depends on many factors. Herein, the authors present some studies on the development of a subgrade reinforcement method, which minimises the impact on train operation, by using short soil
Year: 2021
Number Pages:
15p.
Author(s): Fortunato, E.; Paixão, A.; Morais, P.; Santos, C.; Morais, J.; Cruz, J.; Cruz, N.
: Transportation Geotechnics
Editor: Elsevier
Volume:
29.
Keywords: Track measurements; Physical modelling; Soil
Info
Abrasion evolution of steel furnace slag aggregate for railway ballast: 3D morphology analysis of scanned particles by close-range photogrammetry
Electric Arc Furnace steel slag aggregate has potential for wider application in railway infrastructures. Nonetheless, its use in ballast layers, as an alternative to natural crushed rock, is often restricted, which is not consistent with the sustainable construction paradigm. To characterise the morphology and performance of this material, quantitative analyses were conducted on the abrasion and 3D morphology evolution of particles by micro-Deval testing. Slag particles showed higher angularity and surface texture indices than natural granite; retained these characteristics longer; and yielded comparable or lower surface wear. These findings support the potential use of slag aggregate as an alternative ballast material.
Year: 2020
Author(s): Paixão, A.; Fortunato, E.
: Construction and Building Materials
Editor: Elsevier
Keywords: Spherical harmonics; Photogrammetry; Abrasion; Particle morphology; Electric Arc Furnace steel slag aggregate; Railway ballast
Info
An assessment of contact and laser-based scanning of rock particles for railway ballast
Performance of traditional railway structure depends significantly on the behaviour of its support layers, particularly the ballast. This layer
Year: 2020
Number Pages:
100302.
Author(s): Jerónimo, P.; Resende, R.; Fortunato, E.
: Transportation Geotechnics
Editor: Elsevier
Volume:
22.
Keywords: Rock breakage; Contact scanning; Laser; 3D scanning; Particle shape; Railway ballast
Info
Long-term deformation of railway tracks considering train-track interaction and non-linear resilient behaviour of aggregates
Railway track designers and maintenance entities have long been pursuing for a robust and reliable method topredict the track
Year: 2020
Author(s): Varandas, J.; Paixão, A.; Fortunato, E.; Zuada Coelho, B.; Hölscher, P.
: Computers and Geotechnics
Editor: Elsevier
Volume:
126.
Keywords: Non-linear resilient behaviour; Three-dimensional numerical modelling; Railway tracks; Permanent deformation; Train-track interaction
Info
Transfer Learning for Pavement Performance Prediction
Accurate pavement performance prediction models are essential to ensure optimal allocation of resources in maintenance management. These models are developed using inventory and monitoring data regarding pavement structure, climate, traffic, and condition. However, numerous road agencies have limited pavement data. Due to the inexistence of historical data, data collection frequency, and/or quality issues, the amount of data available for the development of performance models is reduced. As a result, the resource allocation process is significantly undermined. This paper proposes a transfer learning approach to develop pavement performance prediction models in limited data contexts. The proposed transfer learning approach is based on a boosting algorithm. In particular, a modified version of the popular TrAdaBoost learning algorithm was used.To test the proposed transfer learning approach, a case study was developed using data from the Long-Term Pavement Performance (LTPP) database and from the Portuguese road administration database. The results of this work show that it is possible to develop accurate performance prediction models in limited data contexts when a transfer learning approach is applied. All the models resulting from this approach outperformed baseline models, especially in what regards long-term forecasts. The results also showed that the transfer learning models perform consistently over different time frames, with minor performance losses from one-step to multi-step forecasts. The findings of this study should be of interest to road agencies facing limited data contexts and aiming to develop accurate prediction models that can improve their pavement management practice.
Year: 2020
Number Pages:
154
Author(s): Marcelino, P.; Antunes, M. L.; Fortunato, E.; Gomes, M.
: International Journal of Pavement Research and Technology
Editor: Springer
Volume:
13.
Keywords: Predictive maintenance; Pavement Management Systems (PMS); Machine learning; International Roughness Index (IRI); Pavement performance models; Transfer learning
Info
Development of a Multi Criteria Decision Analysis Model for Pavement Maintenance at the Network Level: Application of the MACBETH Approach
This paper proposes the application of the MACBETH approach for the development ofa multi criteria value model to enable the prioritization of maintenance and rehabilitationinterventions in the pavements of road networks according to technical, economic,and social aspects. A case-study design considering the Portuguese network wasundertaken to illustrate the proposed approach. Using an interactive structuring processdeveloped with the decision-maker, a set of five evaluation criteria related to maintenancecosts, traffic, pavement condition, safety, and social equity were defined. The MACBETHapproach was then used to build value functions and establish relative weightsfor the criteria. An application of the resulting model was made to a portfolio ofpossible intervention projects, prioritizing them according to the principle of benefit/costmaximization. The case-study demonstrated the application of the MACBETH approachand its suitability to solve the decision-making problem, thus proving the usefulness ofthis approach for road agencies with pavement management responsibilities.
Year: 2019
Number Pages:
1-10pp.
Author(s): Marcelino, P.; Antunes, M. L.; Fortunato, E.
: Frontiers in Built Environment
Editor: Frontiers
Volume:
5.
Keywords: Pavement management system (PMS); Decision-making; Maintenance & rehabilitation; Road & highways; Prioritization algorithm; MACBETH; Multi criteria decision analysis
Info
ESTADO DA ARTE IBERO-BRASILEIRA SOBRE A APLICAÇÃO DE AGREGADOS DE ESCÓRIAS DE ACIARIA EM MISTURAS BETUMINOSAS
Na Europa, e de uma forma geral por todo o mundo, existe uma grande procura de agregados para a construção civil, principalmente para a construção de estradas. Existe também uma preocupação crescente com a conservação dos recursos naturais e com o ambiente, que tem levado à procura e utilização de agregados secundários, nomeadamente resíduos/subprodutos industriais cujas propriedades químicas, físicas, mecânicas e ambientais viabilizam a substituição dos agregados naturais, como é o caso desde há longa data dos agregados de escórias de aciaria. As escórias de aciaria são resíduos/subprodutos inevitáveis do fabrico do aço, os quais após um processamento adequado constituem agregados artificiais de excelente qualidade, segundo váriosautores, para o fabrico de misturas betuminosas a aplicar em camadas de pavimentos rodoviários.A par do crescimento da indústria do aço a nível mundial, encontra-se assim a produção de escórias de aciaria e a necessidade de se identificarem soluções para o seu aproveitamento. A sua utilização na construção de estradas, como material alternativo aos agregados naturais é já há algumas décadas a sua principal aplicaçãoem vários países, constituindo uma alternativa relativamente abundante e promissora.Este artigo caracteriza o estado do conhecimento na Península Ibérica e no Brasil, relativamente ao uso de escórias de aciaria (em particular, de forno de arco elétrico) em misturas betuminosas para pavimentos rodoviários.
Year: 2019
Number Pages:
19-50.
Author(s): Freire, A. C.; Maia, A.
: Revista Geotecnia
Editor: Revista Geotecnia
Volume:
146.
Keywords: Escórias de aciaria, misturas betuminosas, conservação de recursos.
|
Comunicação
Info
Analysis of the Properties of Recycled Aggregates for Unbound Granular Asphalt Pavement Layers
The main purpose of this paper is to analyse the most important properties of recycled aggregates from construction and demolition waste (CDW) used in road construction and maintenance, especially in unbound base and sub-base pavement layers. The National Laboratory of Civil Engineering (LNEC), in cooperation with the Technical University of Lisbon (IST), is carrying out a research project concerning the study of crushed concrete, which represents the majority of CDW generated by building and bridge construction in Portugal. Two origins of crushed concrete were analysed: material from laboratory crushing of cubic concrete specimens, used previously in compression strength tests and material from in situ crushing of CDW, obtained from a concrete building demolition site near Lisbon. The geometrical, physical and mechanical characterisation of materials in the laboratory was based on standard European tests established for natural aggregates: particle size distribution, shape index, flakiness index, Los Angeles fragmentation, micro-Deval wear, crushed and broken surfaces, sand equivalent, methylene blue and the compaction test. A chemical characterisation of all materials was also undertaken. The paper presents the laboratory test results and also discusses the main critical aspects related to the test procedures in light of the non-traditional nature of the CDW material. In 2006, LNEC published a guide, LNEC E 473, for the use of recycled aggregates in unbound base and sub-base pavement layers. Test results were compared with the requirements covered by this guide. Some main conclusions and recommendations derived from this analysis are presented in the paper.
Year: 2010
Author(s): Freire, A. C.
Keywords: Recycled aggregate; Cdw; Road pavement
Info
Assessment of Fatigue Resistance and Aging of Asphalt Mixtures in Portugal
In Portugal, the stiffness modulus and the fatigue resistance of asphalt mixtures are generally assessed through four-point bending tests on prismatic shaped specimens (4PB) based on European standard EN 12697-24-Annex D. Traditionally, these tests are performed at a load frequency of 10 Hz. However, in the present context of European material specifications standards, namely EN 13108-20 concerning type testing, it also became necessary to evaluate the fatigue behavior in 4PB tests performed at a load frequency of 30 Hz. In addition, surface fatigue failure cracks which initiate from the top are becoming a more common pavement distress, mainly in thick pavements. In order to assess the influence of asphalt aging on fatigue resistance of asphalt mixtures for wearing courses, an experimental study was carried out, in which a typical Portuguese surface course asphalt mixture, produced with dense graded granite aggregates and with different penetration grade bitumen (35/50×10-1 mm and 50/70×10-1 mm), was used. The assessment of the effect of aging was performed after submitting test specimens to laboratory simulated aging, and comparing the fatigue life of the aged and the un-aged prismatic specimens. This paper presents the main results achieved so far concerning the fatigue resistance assessed in 4PB tests performed at a load frequency of 30 Hz, and it may be concluded that the asphalt mixtures involved in this study have exhibited a satisfactory behavior, and have showed low sensitivity to aging.
Year: 2010
Number Pages:
355-361pp.
Author(s): Dias, J. P.; Batista, F. A.; Lopes, M. G.
Keywords: Asphalt mixtures; Four-point bending tests; Aging; Fatigue resistance
Info
Assessment of the traffic
Traffic noise is an important branch of the environment pollution which deeply affects the populationand for that reason it has been included in the set of pavement performance indicators.Nevertheless, the knowledge on the environmental impact of the existing surface pavement layers isvery limited, particularly for what respects to tyre/road noise of thin layers. These layers are at thepresent time widely used in a great extent with rubberized asphalt both in urban and rural roadsespecially in the north of Portugal due to environmental concerns. In this paper the comparison ofthe tyre/road noise (Lmax) generated in roads with thin surface layers is made. The noise levelsgenerated by light and heavy vehicles are set according to the Statistical Pass-By Method (SPB) ofwhich test methods is described in the standard ISO 11819-1:1997. At management level theinformation provided by tyre/road noise tests is essential to support environmentally sustainableconstruction and maintenance alternatives. Furthermore, at project level, the results give someinsight about the relation surface layers/traffic composition.
Year: 2010
Number Pages:
6 p.
Author(s): Freitas, E.; Antunes, M. L.
Editor: 16th World Road Meeting
Keywords: Test methods; Noise limits; Maintenance; Thin layers; Traffic noise
Info
Characterization and Design Criteria for Recycled Warm Mix in Plant -Case Study
Half warm mix asphalt recycling (HWMR) is a promising new technique for reclaimed asphalt pavement (RAP) recycling under development inPortugal. The technique is based in mix recycling RAP at low temperatures, between 70ºC and 100ºC. An attempt to apply this technique wasmade for the first time at EN 244 road, in the stretch between Ponte de Sôr and close to Gavião. The project was initially conceived by
Year: 2010
Number Pages:
5 p.
Author(s): Almeida, M. D.; Castro Gomes, J. P.; Antunes, M. L.
Editor: 16th World Road Meeting
Keywords: Deformation and fatigue; Recycling; Warm-mix; Pavements; Bituminous
Info
I&D para a valorização das escórias de aciaria de forno de arco eléctrico em obras geotécnicas
A prevenção da produção de escórias de aciaria (EA) de forno de arco eléctrico (FAE) afigurase não praticável de forma significativa, pelo que, a estratégia de gestão destes resíduos deverá privilegiar as soluções de valorização. A valorização será possível se forem encontrados benefícios económicos, o material satisfizer os valores previstos nas especificações de natureza ambiental e de engenharia, e o seu desempenho em obra for equivalente aos dos materiais naturais. Este trabalho sistematiza a informação técnica-científica, internacional e nacional, na vertente da valorização de EA em obras geotécnicas. Finalmente estabelece o processo de investigação e desenvolvimento (I&D) que deve suportar um estudo de avaliação do desempenho técnico, de engenharia, ambiental e sócio-económico de um novo produto (agregado reciclado) para o mercado.
Year: 2010
Number Pages:
1973-1982.
Author(s): Roque, A. J.; Fortunato, E.
Info
Improvements of Neural Networks Application for Backcalculation
Road pavements require maintenance in order to provide good service levels during their life period. Because of the significant costs of this operation, the timing of eachmaintenance intervention should be carefully planned, to avoid unnecessary interventions, but also to prevent irreparable damages to the pavement and avoid safety faults of the pavement.Nowadays, there is a wide array of tools available on the market to do surveys on roadpavements. Equipments like the Falling Weight Deflectometer complemented with theGround Penetrating Radar provide huge amounts of data, allowing performing analysis along the pavement, in a continuous way, instead of analyzing just target points of the pavement.The analysis of this data, however, can be complex and time consuming, becoming a troublesome task.To solve this problem, the use of Artificial Neural Networks (ann) toperform the backcalculation of the data acquired was tested. With these tools it is possible to perform the structural characterization almost instantaneously, saving time and resources and, at the same time, providing results within the expected range. Taking into account that theperformance of the ANN can be improved if the number of outputs is reduced, a study wasperformed aiming at developing dedicated ANNs for structural characterization of thepavement. The sensitivity of the ANNs response to changes in inputs is addressed, aiming at quantifying the influence of an erroneous measurement. In this study, a computer program was developed, using MATLAB, in order to create, train and tests the Artificial Neural Networks. Using this program, the pavement layer moduli can be evaluated using ANNs. This paper presents the methodology adopted for the study, the main results obtained and final considerations regarding ANN application to pavement structural evaluation.
Year: 2010
Number Pages:
511-519p.
Author(s): Martins da Cunha, D.; Fontul, S.; Lopes, M. G.
Editor: © Universidade do Minho
Keywords: Artificial neural networks; Pavements; Characterisation; Evaluation
Info
Rail track structural analysis using three-dimensional numerical models
The current competitive growth of transport systems and the rising demands placed on rail transportation, especially regarding safety, operation quality and increase of efficiency, inevitably have promoted the optimization of systems that comprise the railway infrastructure. From this perspective and taking into account the present paradigm of sustainable development, the optimization of rail track design and the reduction of its life cycle costs assume greater relevance. Attaining a better knowledge of the role of the elements that comprise structure, namely the influence of thickness and mechanical characteristics of the substructure layers, is essential to achieve such objectives. Within this context, the analysis of numerical models is a useful tool to a better understanding of the track behaviour and thus to optimize the design of structural solutions. The present study focuses on the analysis of different track structures using three-dimensional numerical modelling, in order to reach a closer reproduction of the spatial distribution of the loads applied on the structure. For some supporting layers, linear and nonlinear constitutive laws are used to reproduce the behaviour of the granular material. Stress and deformation results, obtained on different layers, are presented and the suitability of different solutions of track structures is discussed.
Year: 2010
Author(s): Paixão, A.; Fortunato, E.
Editor: CRC Press
Keywords: Design; Nonlinear analysis; Numerical modelling; Rail track
Info
Sharing knowledge and field pratice for recycling road and road related materials: the Direct-Mat project
In order to facilitate the share of national experiences on dismantling and recycling of road and road related materials, a three-year European project was initiated in January 2009, within the UE 7thFramework Programme Transport. This project involves partners from 15 participating countries for a budget of 1,2 million Euros and itsmain outcome will be the construction of a European Web database and the preparation of bestpractice guides on DIsmantling and RECycling Techniques for road MATerials (
Year: 2010
Number Pages:
6 p.
Author(s): Antunes, M. L.; Descantes, Y.; Arm, M.; Pihl, K.; André, J.; Mollenhauer, K.; de Bock, L.; Gobert, J.
Editor: 16th World Road Meeting
Keywords: Best practice; Recycling; Demolition; Road materials
Info
Study of the behaviour of bituminous mixtures resistant to fuel
Fuel spillage on the wearing courses of road and airport pavements can significantly affect fuel resistant bitumen performance. The use of modified bitumen specifically manufactured to give the asphalt mixture a better resistance to the action of the fuel is an interesting solution for use in areas with specific requirements of that point of view.In order to assess the performance of asphalt resistant fuel a study, sponsored by PETROGAL, was developed in LNEC, in which asphalt mixtures were produced with three types of bitumen - a 35/50 pen grade bitumen penetration, and two modified bitumen
Year: 2010
Number Pages:
6.
Author(s): Freire, A. C.; Antunes, M. L.
Editor: 16th World Meeting
Keywords: Water sensitivity; Permanent deformation; Resistance to fuel; Fuel spillage
Info
Utilização de materiais reciclados em obras geotécnicas: aspectos sócio-económicos
Nos últimos anos tem-se assistido, por todo o mundo, a uma tentativa de proceder ao aproveitamento de materiais reciclados em obras de Engenharia Civil. De facto, em particular no que se refere às obras geotécnicas, existe uma vincada convicção de que a aplicação destes materiais na sua construção, incentivará a valorização dos resíduos e permitirá adaptar a construção aos princípios do desenvolvimento sustentável, nomeadamente pela redução das quantidades de resíduos a depositar em aterro e pela preservação dos materiais naturais não renováveis. No entanto, a decisão de utilizar um material reciclado, assumindo que o material é adequado ao fim em vista, dependerá, muitas vezes, de uma análise sócio-económica. Neste trabalho, apresentam-se e discutem-se alguns aspectos de carácter sócio-económico que devem ser contemplados no âmbito da utilização de materiais reciclados em obras geotécnicas.
Year: 2010
Number Pages:
1941-1950.
Author(s): Fortunato, E.; Roque, A. J.
|
Books
Info
Application of a gap-graded asphalt rubber wearing course in the rehabilitation of the pavement of two national road stretches (EN104 and EN105) located in the north of Portugal - Field and laboratory
This case study refers to the first significant experience with asphalt rubber, manufactured by the wetprocess, applied on a full scale rehabilitation project in Portugal. It concerns the application of a gapgradedasphalt rubber wearing course in the rehabilitation of the pavement of National road stretchesEN 104 between Azurara and Trofa and EN 105 between Travagem and Santo Tirso. / O presente caso de estudo refere-se à primeira experiência relevante, em Portugal, na qual seutilizaram misturas com betume modificado com borracha reciclada de pneus na reabilitação deestradas nacionais. Diz respeito, em particular, à aplicação de misturas betuminosas rugosas combetume modificado com borracha em camadas de desgaste, no âmbito da reabilitação do pavimento deum troço da estrada nacional EN 104, entre Azurara e Trofa, e da estrada nacional EN 105, entreTravagem e Santo Tirso.
Year: 2010
Number Pages:
23pp.
Author(s): Batista, F. A.; Antunes, M. L.; Santos, C.
Editor: LNEC
Volume:
NS 122
Keywords: Pt; Laboratory test; National road; Rubber; Recycled materials; Road pavement rehabilitation; Asphalt; In situ test; Asphaltic road pavement
Info
Application of an open-graded asphalt rubber wearing course in the rehabilitation of the pavement of a stretch of the National Road EN 14 located in the North of Portugal - Field and laboratory case s
This case study refers to a successful application of an asphalt rubber wearing course in the frame ofthe rehabilitation of the pavement of the National Road EN 14 between
Year: 2010
Number Pages:
20pp.
Author(s): Batista, F. A.; Antunes, M. L.
Editor: LNEC
Volume:
NS 123
Keywords: Pt; Laboratory test; In situ test; National road; Rubber; Recycled materials; Road pavement rehabilitation; Asphaltic road pavement; Asphalt
Info
Application of hot mix asphalt with 20% - 25% reclaimed asphalt in the rehabilitation of the pavement of the motorway A1 between Pombal and Condeixa (Portugal) - Field and laboratory case study
This case study refers to plant hot mix recycling works in the frame of the rehabilitation of a stretch ofthe motorway A1, located in the centre of Portugal.It concerns the use of 20% - 25% of Reclaimed Asphalt in the production of two different asphaltconcrete mixtures for application in binder courses. / O presente caso de estudo refere-se ao fabrico e aplicação de misturas betuminosas recicladas a quenteem central, num troço da auto-estrada A1 localizado no centro do País. Neste caso, foram utilizadas nofabrico de duas misturas diferentes, uma Mistura Betuminosa Densa e um Betão BetuminosoSubjacente à Camada Drenante, respectivamente, cerca de 20 % e 25 % de misturas betuminosasrecuperadas.
Year: 2010
Number Pages:
20pp.
Author(s): Batista, F. A.; Antunes, M. L.
Editor: LNEC
Volume:
NS 119
Keywords: In situ test; Laboratory test; Asphaltic cement road pavement; Recycled materials; Motorway; Road pavement rehabilitation; Hot mix asphalt
Info
Application of hot mix asphalt with 35% - 40% reclaimed asphalt in the rehabilitation of the pavement of the National road EN 105 between Travagem and Santo Tirso (Portugal) - Field and laboratory cas
This case study refers to the first known application of RAP in the production of hot mix asphaltconcrete in Portugal. It concerns the application of a plant hot mix recycled asphalt concrete as abinder course in a national road stretch located in the North of Portugal. / O presente caso de estudo refere-se à primeira obra realizada em Portugal, na qual se procedeu àreutilização de materiais betuminosos fresados na reabilitação de um pavimento flexível de um trechode uma estrada nacional (EN105), situada no Norte do País. Os materiais fresados foram reciclados emcentral mediante a incorporação de novos materiais, e posteriormente utilizados em camadas deregularização.
Year: 2010
Number Pages:
20pp.
Author(s): Batista, F. A.; Antunes, M. L.
Editor: LNEC
Volume:
NS 118
Keywords: In situ test; Laboratory test; Asphaltic cement road pavement; Recycled materials; National road; Road pavement rehabilitation; Hot mix asphalt
Info
Cold insitu recycling of the pavement of EN 260 between Serpa and Vila Verde de Ficalho (Portugal) - Field and laboratory case study
This case study refers to an application of cold in situ recycling of an old asphalt pavement usingbitumen emulsion.The rehabilitation works were performed in 2 phases: The first phase consisted in recycling theexisting asphalt and granular layers up to 120 mm deep and application of a slurry surfacing. Thesecond phase consisted in placing an asphalt cold mix binder course and a new slurry surfacing. / O presente caso de estudo refere-se à aplicação de misturas betuminosas recicladas a frio
Year: 2010
Number Pages:
20pp.
Author(s): Antunes, M. L.; Batista, F. A.
Editor: LNEC
Volume:
NS 120
Keywords: Pt; National road; Laboratory test; In situ test; Asphalt binder; Cold mix asphalt; Recycled materials; Road pavement rehabilitation; Asphaltic road pavement; Bitumen emulsion
Info
Rehabilitation of the IP2 pavement between Barragem do Fratel and EN 118 (Portugal) using cold insitu recycling of existing asphalt layers - Field and laboratory case study
This case study refers to a successful application of cold in situ recycling of asphalt layers from aheavily cracked pavement using bitumen emulsion.A new hot mix asphalt binder course and a new wearing course were placed on the recycled layer. / O presente caso de estudo refere-se a uma aplicação bem sucedida de reciclagem a frio
Year: 2010
Number Pages:
20pp.
Author(s): Antunes, M. L.; Batista, F.A.
Editor: LNEC
Volume:
NS 121
Keywords: Pt; Laboratory test; In situ test; Asphalt binder; Cracked road pavement; Cold mix asphalt; Recycled materials; Road pavement rehabilitation; Asphaltic road pavement; Bitumen emulsion
|
Capítulo de Livro
Info
Case Study of an Inert Steel Aggregate in Road Construction: Characterization and Monitoring of the Structural Behaviour
The use of alternative materials, in particular industrial by-products and waste materials, in the construction oftransport infrastructures and geotechnical works, has been promoted across the world. Nonetheless, considering that, in most situations, the application of some of these materials is fairly recent, little information is available on the long-term performance of the infrastructures in which they were used. This work mentions some characteristics of the Inert Steel Aggregate for Construction (ISAC). It presents some results related to the evolution in the surface characteristics and the structural behaviour of a field trial built on a road section in Portugal. ISAC was used in the embankments and pavement layers. The visual inspection, the results of the mechanical tests performed, and the values of the settlements measured on the surface markings about ten years after the section is open to traffic led to conclude that the pavement in the zone where ISAC was used as a construction material is, in general, in a better condition and presents better structural performance than the adjacent areas built with natural materials. The embankment's maximum settlements in the areas with ISAC were similar to the ones observed in the adjacent areas.
Year: 2023
Number Pages:
5p.
Author(s): Fortunato, E.; Roque, A. J.; Gomes Correia, A.
: Advances in Geoengineering, Geotechnologies, and Geoenvironment for Earth Systems and Sustainable Georesources Management
Editor: Springer
Keywords: Long-term performance; Structural behaviour; Mechanical properties; Inert Steel Aggregate for Construction (ISAC)
Info
Testing and monitoring in railway tracks
Railway tracks may be perceived as simple physical structures, but in fact they entail a significant level of complexity as refers to the assessment and prediction of their transient and long-term behaviors. These mostly result from the intrinsic characteristics of their components and of the dynamic interaction with the suc-cessive passing trains at different speeds and with different loading characteris-tics. The railway industry
Year: 2022
Number Pages:
229-255.
Author(s): Fortunato, E.; Paixão, A.
: Advances on Testing and Experimentation in Civil Engineering
Editor: Springer
Keywords: Monitoring; Testing, Instrumentation; Railway Tracks
Info
Modelação numérica avançada do comportamento estrutural de vias-férreas
A via férrea balastrada é uma estrutura relativamente simples, mas exibe um comportamento complexo, nomeadamente devido às distintas solicitações dinâmicas a que está sujeita, e à forma como se comportam e interagem os seus diversos elementos. O método dos elementos finitos é particularmente adequado à análise do funcionamento destas estruturas, possibilitando a modelação das ações e a utilização de modelos constitutivos avançados para os diversos materiais que constituem o sistema, permitindo considerar a variação das características físicas e geométricas no espaço. Neste capítulo descreve-se e demonstra-se a aplicação de uma ferramenta de modelação numérica tridimensional, concebida especificamente para o cálculo da resposta dinâmica da via-férrea, cujo desenvolvimento, ao longo dos últimos anos, tem tido a contribuição dos autores. Para além da apresentação e validação da ferramenta de modelação, são apresentados estudos relativos à análise do comportamento da via em situações particulares.
Year: 2021
Number Pages:
1-32.
Author(s): Fortunato, E.; Paixão, A.; Varandas, J.
: Modelação Matemática em Engenharia de Transportes. A experiência do Departamento de Transportes do LNEC.
Editor: LNEC
Info
Técnicas de machine learning em sistemas de gestão de pavimentos
A utilização de machine learning tem despertado a curiosidade e o interesse do meio académico e empresarial. Com efeito, a aplicação de machine learning, baseada em técnicas capazes de aprender com os dados, tem sido efetuada com sucesso em diversos contextos. Este sucesso é particularmente evidente nas áreas que utilizam grandes volumes de dados e que procuram obter informação que permita alimentar modelos de previsão.Na área dos Transportes, para além da resolução de questões relacionadas com a mobilidade, é expectável que a aplicação de técnicas de machine learning venha a ser cada vez mais frequente em questões relacionadas com a gestão de infraestruturas, em particular no estabelecimento de modelos de previsão do comportamento.Neste capítulo procura-se evidenciar o potencial da aplicação de machine learning em sistemas de gestão de pavimentos, através da descrição de alguns dos trabalhos desenvolvidos pelos autores neste domínio, essencialmente relacionados com a aplicação de machine learning no desenvolvimento de modelos de previsão do desempenho dos pavimentos, uma das temáticas essenciais dos sistemas de gestão de pavimentos.
Year: 2021
Number Pages:
47-70.
Author(s): Fortunato, E.; Antunes, M. L.; Marcelino, P.
: Modelação Matemática em Engenharia de Transportes. A experiência do Departamento de Transportes do LNEC.
Editor: LNEC
Info
Análise comparada de um agregado de escória de aciaria como material alternativo para lastro de vias férreas do tipo heavy haul por meio de ensaios triaxiais
Este artigo apresenta uma etapa de uma pesquisa mais abrangente que está em andamento na Universidade do Porto, no âmbito do grupo de pesquisa Construct-Geo, que visa avaliar os aspectos geomecânicos de materiais alternativos para uso como camada de lastro em vias férreas do tipo heavy haul. São apresentados resultados de ensaios triaxiais monotônicos e cíclicos conduzidos em corpos de prova de 150 mm de diâmetro por 300 mm de altura, em escala reduzida numa proporção de 1:2,5 em relação à granulometriade lastro padrão AREMA N. 24. Analisou-se um agregado de escória de aciaria, quimicamente e ambientalmente, inerte comparativamente a um agregado de granito, relativamente à resistência e à deformabilidade. Os ensaios cíclicos foram conduzidos em dois escalões de carga de 500.000 ciclos, sendo cada escalão compatível com o carregamento imposto por vias do tipo heavy haul com, respectivamente,32,5 toneladas/eixo e 40 toneladas/eixo. Os resultados mostraram que o lastro de escória de aciaria apresentou parâmetros de resistência superiores comparativamente ao lastro de granito e um melhor comportamento quanto à deformabilidade, expresso por maiores valores de módulo de resiliência, menoresíndices de quebra e degradação de partículas e uma maior tendência de estabilização das deformações plásticas, fenômeno conhecido como shakedown e que também foi investigado.
Year: 2019
Number Pages:
55-70pp..
Author(s): Delgado, B.; Fonseca, A.; Fortunato, E.; Coelho, D.
: As Engenharias frente a Sociedade, a Economia e o Meio Ambiente 3
Editor: Atena
Volume:
3.
Keywords: Ensaios Triaxiais; Escória de Aciaria; Lastro Ferroviário
Info
Current state of the use of recycled materials in geotechnical works in Portugal
The reuse of recycled materials in geotechnical works has awakened a growing interest in the last few years in Portugal. A committee (GT-VROG) within the Portuguese Geotechnical Society (SPG) was created recently for analysing the current state of this kind of use and for promoting it nationwide. As part of the activities of the group, a national survey within producers of waste materials and potential users in geotechnical works was carried out, and a national seminar was organised within the framework of the activities of the TC-3 of the ISSMGE, in order to discuss the present situation in the country and the best ways to develop the reuse of this kind of materials in geotechnical applications. The seminar had the participation of representatives of the different entities interested on the subject (producers, users, administration and research centres), as well as of invited foreign specialists from other European countries. Taking advantage of the results of these activities, the current state of the use of recycled materials in geotechnical works in Portugal is briefly presented and analysed next.
Year: 2007
Author(s): Fortunato, E.; Santayana, F.
Editor: Taylor & Francis
Keywords: Geotechnical works; Recycled materials
|
Tese de Doutoramento
Info
A New Approach for the Maintenance Management of Transportation Infrastructures using Machine Learning
Transportation infrastructures are vital to our society. These infrastructures naturally tend to deteriorate over time. A set of activities is then required to manage existing assets in accordance with sound management principles. These activities are usually integrated into systems that manage infrastructures according to technical, social and economic aspects. This research aims to examine the potential of applying machine learning techniques to current transportation infrastructure management systems. Machine learning is an application of artificial intelligence enabling systems to automatically learn and improve from experience (data), arriving at solutions not explicitly programmed. Powered by algorithms that can learn from data, machine learning leads to efficient and effective systems that improve over time. Over the last few years, the application of machine learning has transformed several industries and could do so for transportation infrastructure as well.To achieve the research objectives, a set of studies was performed. Each of these studies had a specific objective, the set of which can be expressed as follows: to define combined performance indicators for pavement condition assessment using machine learning; to develop machine learning models for pavement performance prediction; to formulate machine learning solutions to overcome pavement data issues, such as missing data; to integrate machine learning techniques into decision support systems for pavement maintenance management. Together these studies explored the development of machine learning applications for solving some standard pavement management problems, providing insights into the application of machine learning to transportation infrastructure management systems. The studies successfully demonstrated the potential of machine learning applications for pavement management systems. It showed that machine learning is applicable to various transportation asset management problems, such as condition assessment, performance prediction, and decision support, and that it is able to outperform some of the analytical techniques currently used. Overall, this research work finds that machine learning is a promising tool for transportation infrastructure management systems.
Year: 2020
Author(s): Marcelino, P.
Keywords: Pavement Management Systems.; Decision Support Systems; Prediction Models;; Machine Learning; Transportation Infrastructure Asset Management
Info
Transition zones in railway tracks: An experimental and numerical study on the structural behaviour
The railway track continually degrades over its life cycle. This has negative consequences for maintenance and availability of the lines and is particularly evident at locations with abrupt changes in the track
Year: 2014
Author(s): Paixão, A.
Keywords: Dynamic train-track interaction; Numerical modelling; Instrumentation and monitoring; Cyclic load triaxial tests; In situ characterisation; Degradation of the track geometric quality; Backfill design and construction; Under sleeper pads; Transition zones; Railway track
Info
Renovação de plataformas ferroviárias. Estudos relativos à capacidade de carga
Esta dissertação pretende ser um contributo para o desenvolvimento de uma metodologia de abordagem do problema da renovação de plataformas ferroviárias em serviço, em particular no que se refere à avaliação da capacidade de carga e técnicas de reforço. A referida metodologia foi desenvolvida com o objectivo de apoiar os projectos de renovação das vias férreas.Os principais aspectos abordados são os mecanismos que contribuem para a degradação das vias férreas, a caracterização
Year: 2005
Author(s): Fortunato, E.
Keywords: Ensaios in situ; Modelação física; Modelação numérica; Ensaios laboratoriais; Renovação de caminho de ferro; Capacidade de carga; Deformabilidade da via férrea; Fundação da via férrea; Balastro; Linha férrea
Info
Deformações permanentes de misturas betuminosas em pavimentos rodoviários
Nas últimas décadas tem vindo a verificar-se, em Portugal bem como no resto do mundo, umacentuado crescimento do volume de tráfego rodoviário e das cargas transportadas pelos veículospesados. Tem-se observado, igualmente, um aumento das exigências funcionais, relacionadas com asegurança e conforto do utente das infra-estruturas, a par das preocupações de carácter ambiental, oque conduz à necessidade de pavimentos rodoviários cada vez mais resistentes e duráveis.Consequentemente, tem-se vindo a recorrer a soluções de pavimentação que envolvem maioresespessuras de camadas betuminosas o que implica uma maior parcela de contribuição docomportamento deste tipo de materiais no desempenho das estruturas de pavimentos. Daqui decorre,entre outros aspectos, uma crescente preocupação com a deformação permanente deste tipo demateriais. Esta situação é também sentida em diversos países, nomeadamente nos países europeus,no Canadá e nos Estados Unidos da América.O presente trabalho tem como objectivo contribuir para um melhor conhecimento do comportamentoà deformação permanente de misturas betuminosas aplicadas em camadas de desgaste depavimentos rodoviários, possibilitando o estabelecimento de metodologias e de critérios de avaliação,que conduzam à selecção de materiais adequados às exigências actuais. Como principais aspectosabordados referem-se a caracterização do comportamento viscoelástico destes materiais, através daexecução e interpretação de ensaios laboratoriais com aplicação de cargas repetidas, que simulemas condições observadas in situ, e a modelação do comportamento à deformação permanente dasmisturas.É analisado o fenómeno da deformação permanente, bem como a sua forma de manifestação naestrutura do pavimento
Year: 2002
Author(s): Freire, A. C.
Keywords: Modelação do comportamento estrutrual; Ensaios de simulação em pista de laboratório; Ensaios decompressão uniaxial estático; Ensaio de compressão uniaxial de cargas repetidas; Modelos reológicos; Comportamento viscoelástico; Deformação permanente; Caracterização laboratorial; Misturas betuminosas
|
|
Relatório Científico
Info
The way forward for pavement performance indicators across Europe COST Action 354 Performance Indicators for Road Pavements Final Report
The main objective of the COST Action 354
Year: 2008
Number Pages:
72p.
Author(s): Antunes, M. L.; LITZKA, Johann; LEBEN, Bojan; LA TORRE, Francesca; WENINGER-VYCUDIL, Alfred; KOKOT, Darko; Mladenovic, Goran; BRITTAIN, Stuart; VINER, Helen
Keywords: Performance indicators for road pavements
Info
MISTURAS BETUMINOSAS DE ALTO MÓDULO Aplicação na Beneficiação da EN 14, entre Chantre e Trofa
N/A
Year: 2007
Number Pages:
137pp.
Author(s): Antunes, M. L.
Info
COST 334 - Effects of wide tyres and dual tvres task group 3 - Pavement wear effects - Mechanistic approach for rutting - Stage 4
N/A
Year: 2000
Author(s): Quaresma, Luis.; Ferreira, P.; Batista, A. L.
Info
COST 334 - Effects of wide tyres and dual tyres task group 3 - Pavement wear effects - Mechanistic approach for rutting - Stage 2
N/A
Year: 2000
Author(s): Quaresma, Luis.; Ferreira, P.; Freire, A. C.; Batista, A. L.
|
ICT
Info
NOVAS SOLUÇÕES DE SUPERSTRUTURA DE VIA PARA A ALTA VELOCIDADE FERROVIÁRIA - Comparação com a via balastrada tradicional
As crescentes exigências impostas ao transporte ferroviário e a necessidade de o tornar num sistemade transporte mais competitivo, têm levado ao desenvolvimento de novas soluções de via-férrea.Estas novas soluções constituem inovações tecnológicas de via-férrea que diferem da via balastradatradicional na utilização de diferentes materiais e métodos construtivos. Apostam fortemente naredução da necessidade de conservação e renovação da via, o que se traduz na diminuição doscustos associados à sua operação, assim como no aumento da disponibilidade da linha.Assim, estas soluções apresentam uma melhor resposta a velocidades de circulação cada vez maiselevadas e a maiores volumes de tráfego, que tendem a conduzir a maior deterioração da via e aconsequentes maiores custos de conservação e renovação. Em comparação com a via tradicional,estas soluções podem ser mais vantajosas, no que se refere à segurança, a aspectos ambientais, àgestão da operação e a custos globais, quando se considera o ciclo de vida da infra-estrutura.Embora estas tecnologias tenham vindo a ser testadas e aplicadas em alguns países, desde há váriasdécadas, em particular no Japão, só mais recentemente diversos países demonstraram especialinteresse pela sua aplicação. Face a estas vantagens, tem-se verificado actualmente uma crescentetendência para a adopção destas novas soluções, sobretudo para as linhas de alta velocidade,particularmente na Europa e Ásia Oriental.Dentro deste contexto, e tendo em conta a previsível integração de Portugal na Rede Europeia de AltaVelocidade, desenvolveu-se o presente estudo com o objectivo de apresentar diversas soluções devia-férrea que estão disponíveis e compará-las com a solução tradicional de via balastrada.O estudo incide na descrição de concepções de via-férrea não tradicionais, como a via sem balastro ea via de apoio misto, fazendo-se especial referência às principais vantagens e desvantagens da viasem balastro, face à solução tradicional de via balastrada, e à experiência da sua aplicação.Apresenta-se ainda uma síntese da situação actual da aplicação destas novas soluções em paísesque apostaram fortemente nas redes de alta velocidade.Do estudo desenvolvido conclui-se que, para novas linhas de alta velocidade, estas soluções podemser bastante atractivas, como alternativa à via balastrada tradicional.Os autores agradecem a todas as entidades e pessoas a título individual a autorização expressa paraa publicação das ilustrações apresentadas neste estudo, encontrando-se estas devidamentereferenciadas.
Year: 2009
Author(s): Paixão, A.; Fortunato, E.
Keywords: Comboios de alta velocidade; Novas tecnologias; Infra-estrutura ferroviária; Via férrea
Info
Current state of the re-use of waste materials in geotechnical works in Portugal
The reuse of recycled materials in geotechnical works has awakened a growing interest in the last few years in Portugal. A committee (GT-VROG) within the Portuguese Geotechnical Society (SPG) was created recently for analysing the current state of this kind of use and for promoting it nationwide. As part of the activities of the group, a national survey within producers of waste materials and potential users in geotechnical works was carried out, and a national seminar was organised within the framework of the activities of the TC-3 of theISSMGE, in order to discuss the present situation in the country and the best ways to develop the reuse of this kind of materials in geotechnical applications. The seminar had the participation of representatives of the different entities interested on the subject (producers, users, administration and research centres), as well as of invited foreign specialists from other European countries. Taking advantage of the results of these activities, the current state of the use of recycled materials in geotechnical works in Portugal is presented and analysed next.
Year: 2006
Author(s): Fortunato, E.; Santayana, F.; Roque, A. J.
Keywords: Recycled waste materials; Reuse of materials; Geotechnical works
|
|
Outro
Info
Guia para a reciclagem de misturas betuminosas a quente em central
N/A
Year: 2009
Number Pages:
4pp.
Author(s): DT / NIRA; DG / NGEA; DM / NB
Keywords: Reciclagem de material; Mistura betuminosa a quente
Info
Guia para a utilização de agregados reciclados em camadas não ligadas de pavimentos
N/A
Year: 2009
Number Pages:
4pp.
Author(s): DT / NIRA; DG / NGEA; DM / NB
Keywords: Reciclagem de material; Pavimento rodoviário; Camada do pavimento; Agregado para estrada
Info
Guia para a utilização de agregados reciclados grossos em betões de ligantes hidráulicos
N/A
Year: 2009
Number Pages:
8pp.
Author(s): DT / NIRA; DG / NGEA; DM / NB
Keywords: Reciclagem de material; Agregado grosso; Agregado para betão
Info
Guia para a utilização de materiais reciclados provenientes de resíduos de construção e demolição em aterro e camada de leito de infra-estruturas de transporte
N/A
Year: 2009
Number Pages:
4pp.
Author(s): DT / NIRA; DG / NGEA; DM / NB
Keywords: Aterro; Infra-estrutura de transporte; Reutilização de material de construção; Demolição de obra; Reciclagem de material; Agregado de detrito de obra
Info
MBR-BMB® MISTURAS BETUMINOSAS PARA PAVIMENTOS RODOVIÁRIOS E AEROPORTUÁRIOS
N/A
Year: 2008
Number Pages:
12pp.
Author(s): D. TRANSPORTES
|