Publications

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

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.

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

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.

Performance of traditional railway structure depends significantly on the behaviour of its support layers, particularly the ballast. This layer

Railway track designers and maintenance entities have long been pursuing for a robust and reliable method topredict the track

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.

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.

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.

In recent years, there has been an increasing interest in the application of machine learning for theprediction of pavement performance. Prediction models are used to predict the future pavementcondition, helping to optimally allocate maintenance and rehabilitation funds. However, few studieshave proposed a systematic approach to the development of machine learning models for pavementperformance prediction. Most of the studies focus on artificial neural networks models that are trainedfor high accuracy, disregarding other suitable machine learning algorithms and neglecting theimportance of models

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.

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.

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.

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

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.

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.

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.

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 (

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

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.

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.

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

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.

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.

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

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

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.

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

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.

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.

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.

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.

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.

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

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

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

No âmbito Programa de Investigação e Inovação do LNEC 2013-2020 (P2I) e inserido no Programa de ID&I do Departamento de Transportes (DT), o Núcleo de Infraestruturas de Transportes tem vindo a desenvolver um projeto de ID&I designado por

Executive SummaryInfrastructure is the backbone of our society. Citizens, companies and governments have come to rely on and expect uninterrupted availability of the road network. Climate change is an important topic within the context of designing, maintaining and operating traffic networks. Most transport infrastructure is intended to be available (in service) to the public for several decades. The life cycles of assets in transport are long enough to take the full strain that comes with climate change; however, climate impact is experienced on a small scale. Crops are destroyed by floods, timber is felled by heavy storms and infrastructure is devastated by various kinds of extreme events. The adaptation of road networks to a changing climate is one of the important issues that road authorities have begun to address and that needs to be further continued in the near future.The main objective of the Conference of European Directors of Roads (CEDR) Call 2012

The Mozambican Roads Administration (ANE) has embarked on a project to establish a Road Research Centre (RRC) in Mozambique aiming to provide the basis for improving the long-term capacity to undertake relevant, high quality research relating to the road sector of Mozambique. This project forms part of the Africa Community Access Programme (AFCAP), which is a research programme supported by the Department of International Development (DFID) of the Government of the United Kingdom and managed by Crown Agents Ltd on behalf of DFID. CSIR, in association with LNEC has been commissioned by Crown Agents to provide Technical Assistance for phase 2 A of the project, which aims to address institutional issues relating to the RRC, draft a strategic research plan and develop a 5-year business plan for the RRC. This monthly progress report dated January 2014 summarises progress made with the identification of the road research needs of Mozambique; the production of recommendations on the institutional structure of the RRC; the establishment of the Road Research Technical Committee (RRTC) and the Road Research Steering Committee (RRSC); and the drafting of the business and strategic research plans for the RRC. The activities planned for February 2014 are also presented.

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The Mozambican Roads Administration (ANE) has embarked on a project to establish a Road ResearchCentre (RRC) in Mozambique aiming to provide the basis for improving the long-term capacity toundertake relevant, high quality research relating to the road sector of Mozambique. This project formspart of the Africa Community Access Programme (AFCAP), which is a research programme supported bythe Department of International Development (DFID) of the Government of the United Kingdom andmanaged by Crown Agents Ltd on behalf of DFID. CSIR, in association with LNEC has been commissionedby Crown Agents to provide Technical Assistance for phase 2 A of the project, which aims to addressinstitutional issues relating to the RRC, draft a strategic research plan and develop a 5-year businessplan for the RRC. In this report, appropriate institutional structures for undertaking research arepresented. It addresses the following: (i) the Terms of Reference for a functioning Road ResearchSteering Committee (RRSC) and Road Research Technical Committee (RRTC), as well as an overview ofthe outcomes of the inaugural meetings of both of these committees; (ii) the institutional location ofthe RRC within the structures of ANE; (iii) the physical location of the RRC in Mozambique; (iv)laboratory support for a functioning RRC; and (v) Staffing of the RRC. All items, with the exception of thelast item (

No âmbito do Convénio de Cooperação entre o Laboratório Nacional de Engenharia Civil(LNEC) e o Programa de Capacitação dos Laboratórios de Engenharia dos PALOP eAdministração Pública de Timor-Leste 2013, realizou-se no Laboratório de Engenharia Civilde São Tomé e Príncipe (LECSTP) um curso subordinado ao tema

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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.

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.

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