Publications

As descontinuidades dos maciços rochosos influenciam o seu comportamento mecânico e hidráulico e consequentemente as obras neles construídas. Este trabalho descreve o desenvolvimento e aplicação de uma técnica de digitalização das superfícies de descontinuidades rochosas que recorre a uma mesa digitalizadora, visando contribuir para a compreensão dos mecanismos de contacto e desgaste. As superfícies numéricas obtidas são analisadas usando parâmetros geo-estatísticos que podem ser comparados com parâmetros semi-empíricos, como o JRC, permitindo quantificar a evolução da rugosidade após ensaios mecânicos de compressão ou deslizamento. Os resultados deste trabalho permitiram ainda a geração de descontinuidades que poderão ser usadas futuramente em modelos micromecânicos de partículas para simular o comportamento mecânico e hidráulico de descontinuidades.

In railways Ground Penetrating Radar (GPR) studies, the evaluation of materials dielectric properties is critical as they are sensitive to water content, to petrographic type of aggregates and to fouling condition of the ballast. Under the load traffic, maintenance actions and climatic effects, ballast condition change due to aggregate breakdown and to subgrade soils pumping, mainly on existing lines with no sub ballast layer. The main purpose of this study was to validate, under controlled conditions, the dielectric values of materials used in Portuguese railways, in order to improve the GPR interpretation using commercial software and consequently the management maintenance planning. Different materials were tested and a broad range of in situ conditions were simulated in laboratory, in physical models. GPR tests were performed with five antennas with frequencies between 400 and 1800 MHz. The variation of the dielectric properties was measured, and the range of values that can be obtained for different material condition was defined. Additionally, in situ GPR measurements and test pits were performed for validation of the dielectric constant of clean ballast. The results obtained are analyzed and the main conclusions are presented herein.

The objective of this laboratory study is to investigate the relationship between the geometrical and physical properties of filler and the consistency of filler

At railway bridge approaches the track stiffness may vary rapidly and often differen-tial settlements take place between the stiff structure and the approach section of thetrack. These differential settlements lead to uneven track pro

Após alguns anos em que o transporte ferroviário teve um declínio acentuado, ultimamente temvindo a assistir-se, em vários países, à modernização de linhas férreas antigas, nomeadamente procedendo àreabilitação da via-férrea. Vários desses casos referem-se a vias que se pretende que venham a servir essen -cial mente o transporte de mercadorias. Durante a reabilitação das vias férreas existem vantagens técnicas,económicas e ambientais em manter, se possível, os materiais existentes, em particular a camada de balastroferroviário contaminado com solos finos, sob as novas camadas de reforço. Este trabalho apresenta resultadosde estudos realizados com o objetivo de reabilitar uma via-férrea para o transporte de mercadorias, localizadaem África. Para além da caracterização realizada in situ, construíram-se trechos experimentais para testardiversas soluções estruturais para reabilitação da plataforma ferroviária e realizaram-se modelações numéricasda via, contemplando essas soluções. Os resultados dos estudos permitiram concluir que é possível levar acabo o reforço estrutural da plataforma, de forma eficiente, em termos técnicos e económicos.

Railway tracks degrade faster at transition zones to railway bridges. In modern lines, back

In railway lines, transition zones between different track support conditions normally evidence higher degradation rates,thus requiring additional maintenance to ensure safety and service quality. Studies based on numerical simulations indicatethat under sleeper pads (USP) can minimise those degradation rates. The study presented herein focuses on the in

O Laboratório Nacional de EngenhariaCivil (LNEC) e o Instituto Superior Técnico(lSn têm estado a desenvolverum projeto de investigação, apoiado pelaFundação para a Ciência e Tecnologia (FeD,a concretizar ao longo de três anos, intituladoSUPREMA - Aplicação Sustentável de Resíduosde Construção e Demolição (RCD) emInfraestruturas Rodoviárias, que pretendecontribuir para a generalização da aplicaçãosustentável de RCD em pavimentos rodoviários,através da melhoria do conhecimentorelativo ao desempenho do comportamentomecânico e ambiental destes materiais, quandocolocados como agregados em camadasnão ligadas de pavimentos.O principal resultado esperado com o desenvolvimentodeste projeto é a elaboraçãode recomendações práticas para projeto econstrução de pavimentos rodoviários com autilização de RCD, que incluirão um guia paraa aplicação de misturas betuminosas fresadascomo materiais granulares não ligados em camadasde sub-base e de leito de pavimento.Assim, no âmbito do presente projeto foiconstruído um trecho experimental no novoEcoparque do Ambigroup, presentementeem construção e destinado a atividades de reciclagemde materiais com diferentes origens(máquinas elétricas e eletrónicas, madeira,construção e demolição), localizado na zonasul da área metropolitana de Lisboa, Seixal,contemplando a aplicação de diferentes RCDnas camadas não ligadas, devidamente instrumentadase cujo comportamento se pretendeobservar ao longo do tempo.

Railway tracks frequently show higher degradation rates at transition zones from earthworks to bridges, or to other structures. In order to guarantee the safety and comfort of passengers, this aspect results in higher maintenance costs and disturbs railway operations. The behaviour of transition zones is rather complex and its poor performance has been mainly attributed to variations in the vertical stiffness of the track and to differential settlements. These two aspects amplify the dynamic loads of the trains and cause further track degradation. The Portuguese railway network manager has reported the poor structural behaviour of a few transition zones in some of its lines, which constrain train operations and present high maintenance costs. Thus, a research project is currently underway aiming at contributing to a better understanding of the phenomena that occur at transitions, and at optimizing their design for conventional and high-speed railway lines. In this article, we present some aspects of this research project, namely: a review on the design of backfills for transition zones; a comparison between numerical models found in the literature that were used to study the problem; some results obtained during the construction (characterization of materials and layers) and operation of the line.

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The construction activity usually generates large amounts of waste from different sourcesand processes. Due to the increasing shortage of space for landfill implementation and thecosts associated with waste control regulations, derived from its ever increasingenvironmental protection requirements, the most desirable alternative is the reduction ofconstruction and demolition waste volumes by means of their reuse and recycling.A research project, SUPREMA - Sustainable Application of Construction and DemolitionRecycled Materials (C&DRM) in Road Infrastructures, is being developed by the NationalLaboratory for Civil Engineering (LNEC), and by the University of Lisbon (IST). This projectseeks to contribute to the sustainable implementation of C&DRM in road pavements byimproving the knowledge of the physical, mechanical and environmental behaviour of thesematerials when placed as aggregates in unbound pavement layers.Besides a general presentation of the research project and the construction procedures of atest pit structure where four different materials were applied, this paper presents someresults related to the characteristics of the studied materials, supported by laboratory and byin situ tests performed with the FWD in the test pit structure. It was concluded that allmaterials demonstrate an acceptable structural performance.

The utilization of recycled materials has obvious environmental and economicbenefits that contribute for a more sustainable construction and rehabilitation of roadpavements. Despite the fact that many studies have already focused on the reusing of recycled materials, further research is always important to achieve a deeper knowledge on materials and technologies and to increase the confidence of road owners and construction companies for the use of these materials. This is the case of reclaimed asphalt, it is also a material with an enormous potential to be used in

O Laboratório Nacional de Engenharia Civil (LNEC) e o Instituto Superior Técnico (IST) estão adesenvolver desde 2010 o projeto de investigação SUPREMA

Às misturas betuminosas do tipo

In order to facilitate the sharing of national experiences on dismantling and recycling of road and road related materials, the three-year Direct-Mat project was initiated in January 2009, within the EU 7th Framework Program Transport. The project addresses the recycling of unbound, hydraulically-bound and asphalt road materials as well as other materials not commonly recycled in roads. Among these technologies, this paper focuses specifically on cold in-place recycling, which is considered a very promising technique from the environmental point of view, since it allows for the reuse of reclaimed asphalt as well as for energy savings and reduction of harmful emissions.The results obtained so far have shown that some European countries have already acquired experience with cold in-place recycling, but this has largely been done in isolation. Therefore, the practice at national level can differ significantly from one European country to another, and although some research has already been done, further efforts should be made in order to optimize the use of cold in-place recycling.In the framework of this project a Best Practice Guide (BPG) was prepared. This was aimed at issuing recommendations for cold in-place pavement recycling in order to offer the highest added value. This paper highlights some recommendations included in the BPG on the following topics: pavement characterization, mix design, production, application, curing process, mix performance.This paper is based on the work carried out within Direct-Mat project, which involved partners from 15 participating countries. Therefore, it reflects the views of its participating members.

O nível de exigência imposto às modernas vias-férreas pressupõe um adequado desempenho da sua substrutura, nomeadamente no que se refere à resposta resiliente e às deformações permanentes. Neste trabalho são apresentados os resultados de um estudo realizado sobre dois agregados britados, com o objetivo de avaliar a sua adequação para serem aplicados em sub-balastro ferroviário. Para além da caracterização laboratorial tradicional, realizaram-se ensaios triaxiais de carga cíclica, sobre provetes de grandes dimensões, com granulometria integral, para avaliar o comportamento resiliente, em diversas condições de estado e sob distintas solicitações, assim como as deformações permanentes acumuladas durante um milhão de ciclos de carga. Em face dos resultados obtidos, concluiu-se que pode não ser adequado continuar a proceder à seleção de geomateriais para utilizar nas camadas de apoio de vias-férreas, em particular no sub-balastro, recorrendo apenas a ensaios tradicionais, como é prática corrente.

The evaluation of the railway track condition represents one of the mostsignificant parts of maintenance planning. Generally, only the track geometry ismeasured and then, during the maintenance process, the parameters of the tracklayout are restored, through tamping and levelling processes. Nevertheless, oneof the main causes of track geometry deterioration is related to the track-bedcondition. An evaluation of track stiffness can contribute to identify foundationproblems and to adopt adequate maintenance actions.In order to identify structural problems, a continuous monitoring of the trackthrough non-destructive load tests can be performed. The Falling WeightDeflectometer (FWD) equipment is commonly used to evaluate pavement´scondition and, due to its advantages, has been recently used also for railwayplatform evaluation. Thus, various FWD tests were performed during theconstruction of a new railway section, designed for high speed traffic. Three testcampaigns were undertaken on different months, aiming to study the climateeffect, and also different load levels were applied on each test point, in order toanalyse the non-linear response of the track-bed layers to load level.Based on the FWD tests results, the elastic moduli of the track-bed layers areback-calculated and, consequently, the stiffness variation along the track can beestimated. This enables the identification of possible settlements caused byfoundation.The main results obtained so far are presented in this paper, together withproposals for future developments.

The rational use of materials to be applied in the supporting layers of railway tracks is an important aspect that can contribute to reducing the life cycle cost of such infrastructures. In recent renovation and new rail track construction projects carried out in Portugal, a sub-ballast layer has been typically implemented in the track structure, using unbound granular materials (UGM). This layer and the characteristics of the materials play a fundamental role in the track behaviour. Nevertheless, there is a lack of consensus worldwide on the requirements established for such materials. In Portugal and in other countries, very stringent requirements based on empirical tests have been adopted, making it difficult to find materials that fulfil such requirements. There is also evidence that some of these materials, which do not comply with all those requirements, can still be considered as appropriate for sub-ballast. Within the scope of this study, the construction of a new railway section was supervised. During construction, it was difficult to obtain the desired quantity of granite material for the 30 cm thick sub-ballast layer that would fulfil the requirements and still comply with the contract deadline. In alternative, another structural solution was used that considered the replacement of the bottom 15 cm of granite material sub-ballast layer by limestone material which did not comply with some empirical requirements. In order to study the feasibility of this change, evaluate its consequences and establish new quality assurance indicators to be adopted afterwards, several studies were developed, such as in-situ characterization and cyclic triaxial load tests on different UGM. The studies performed and the results presented in this paper show that, taking into account a mechanistic approach, some materials that do not comply with all requirements based on empirical tests might be adequate to be applied in the sub-ballast layer.

Most transport infrastructures, including road and airport pavements, include bituminous mixtures which allow a3 good performance and an adequate durability under ordinary service conditions.4 Due to the need to improve the performance of railways, allowing a more durable high-speed lines and a5 maintenance cost reduction, several studies to promote the use of new materials, mainly through the incorporation of6 bituminous mixtures as sub-ballast layer have been developed, instead of the classical section, which only includes7 granular setting beds.8 The present work aims to characterize the mechanical behaviour of bituminous mixtures in order to be applied in9 railway infrastructures.10 As a methodology to study the mechanical behaviour of the bituminous mixtures, laboratory repeated loading tests11 were performed, namely four-point bending tests (4PBT) to determine stiffness and fatigue behaviour, and cyclic12 triaxial compression tests to evaluate the permanent deformation behaviour.13 The fatigue behaviour of the studied bituminous mixtures was evaluated by the 4PBT, with controlled strain and the14 application of a sinusoidal loading with different frequencies, according to the European Standard EN 12697-24.15 The permanent deformation behaviour of the bituminous mixtures was analyzed with the cyclic triaxial compression16 test, by subjecting the samples to a static confinement stress through the application of vacuum and applying a17 rectangular cyclic axial pressure stress, according to the European Standard EN 12697 -25.18 For this study several samples were cored from a physical model built at LNEC

Identification and diagnosis of railway track problems of the supportinglayers is essential to achieve efficient maintenance and safe trainoperations [1]. Nowadays, maintenance interventions consist ofperforming different operations such as levelling and tamping of thetrack, based on the measured geometric parameters. Although theseactions restore the track design geometry, they do not solve substructurerelated problems. Thus, a better maintenance policy should be adoptedso that structural problems can be identified and solved earlier, forexample by using non-destructive tests [1,2] during monitoring surveys.The ground penetrating radar (GPR) is a non-destructive technique thatallows the evaluation of the infrastructure condition almost continuously,enabling, besides the measurement of thickness of layers, theidentification of changes in the structure and material condition along thetrack [2].This paper presents some GPR tests performed for railway evaluation,both during construction and during service life. The objective was tostudy different possible applications of this technique to railway tracks.Some of the results obtained are presented in this paper, together withthe calibration procedures performed. Moreover, future research lines areaddressed, with the aim of improving the GPR testing methodology and,in this way, to optimise the assessment of the track condition.

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

The main objective of the COST Action 354

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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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