Artigos de Revista

Atendendo à exposição das comunidades humanas aos riscos ambientais de diversa natureza e intensidade disruptiva, num contexto de maior imprevisibilidade, as exigências que se colocam à sociologia não podem comprometer a sua primeira e essencial vocação para o estudo das desigualdades e da estratificação sociais. Com efeito, a análise dos processos de mudança social e as formas de estratificação social marcam de forma indelével os primeiros estudos da sociologia e vinculam o carácter da sua análise: desde os opúsculos de Augusto Comte à Divisão do Trabalho Social de Émile Durkheim ou às obras comprometidas de Karl Marx impõe-se uma visão objetivista sobre a evolução das sociedades e uma interpretação dialética dos processos de mudança social [1]. Metodologicamente saliente-se, aliás, os estudos pioneiros de Frederick Engels, curiosamente quase sempre alienado das referências sobre sociologia e, mesmo, de uma ecologia humana. Este desenvolveu uma apurada epidemiologia dos impactes da poluição ambiental, relacionando condições de trabalho e de saúde humana, tendo recorrido a entrevistas locais e a diversa documentação reunida sobre os bairros operários e a distribuição social das doenças [2].

Azulejos are part of Portugal

Na ilha da Madeira, existem vários reservatórios de água para diferentes fins, entre eles as albufeiras das barragens de Pico da Urze e da Portela. Estas infraestruturas têm em comum a particularidade de as características das formações geológicas vulcânicas ocorrentes e os materiais de construção das barragens não garantirem a estanquidade necessária para a retenção da água, tornando imprescindível o uso de geossintéticos na impermeabilização do corpo das barragens e das suas albufeiras. Na Barragem do Pico da Urze foi utilizado um geocompósito de impermeabilização (geomembrana de PVC termoacoplada a um geotêxtil) e na Barragem da Portela foi usada uma geomembrana de PEAD. A utilização destes materiais colocou alguns desafios ao nível da conceção e construção dos seus sistemas de impermeabilização. Neste artigo, apresentam-se os principais desafios enfrentados durante as fases de projeto e de construção dos sistemas de impermeabilização, que o Laboratório Nacional de Engenharia Civil acompanhou no âmbito de assessorias técnicas prestadas aos donos de obra.

Mortars are among the most important materials in building construction. They aregenerally obtained by mixing aggregates with an inorganic binder. The identification of mortar constituents,particularly the binder type in historic buildings, is one of the essential aspects of buildingconservation, considering that the new conservation materials must be chemically, mechanically,and physically compatible with the old masonries. Among other techniques used to characterisebinders, those related to optical and electronic microscopy are particularly important. Microscopyand combined techniques may be the key to this identification since the classic mineralogical andchemical-based identification approaches are not conclusive enough in investigating the types ofhydraulic binders in mortars. This work presents an analysis procedure to identify mortar binders bycombining EDS microanalysis and petrography. Mortar samples of known composition were usedas a reference for analyzing mortars from historic buildings. The proposed methodology made itpossible to identify the type of binder or a mixture of binders based on the identification of the binderfeatures by petrography together with analysis of the chemical composition of the paste by X-raymicroanalysis under a scanning electron microscope.

The evaluation of damage progression caused by wave action on physical models of rubble-mound breakwaters can be accomplished through two types of methods: quantifying the movements and falls of the resistant armor elements by visual inspection (the traditional, classical method) or determining the eroded volumes and depths between consecutive surveys of armor layers using sensors and photogrammetric methods (3D scanning methods). Of the latter, one may use techniques such as the so-called "Kinect", "Photogrammetry" and "LiDAR". The end-product of these techniques is, among others, point clouds, which allow obtaining three-dimensional surface models. In this paper, four of the latter techniques (3D scanning methods) are briefly described, and a comparison is made between them regarding their usability in current tests, their advantages and disadvantages, among themselves for a study case of the physical 3D model of the Ericeira breakwater. In evaluating survey quality across the four methods, RMSE (root mean square error) was employed to align obtained point clouds with ground control points (GCP). Notably, Photogrammetry, Kinect, and Azure techniques showed excellent RMSE values. Conversely, the LiDAR-derived-method cloud, using a smartphone with LiDAR sensor and 3dScanner app, fails to yield acceptable and accurate results for the research objectives of this paper.

Data of wave dissipation over vegetation fields was collected from laboratory flume experiments, fordifferent vegetation and wave conditions. An analytical model and a numerical model are applied to estimatethe wave dissipation obtained in the experiments, through the calibration of the bulk drag coefficient (CD).Results and conclusions will analyse and compare each model behaviour and obtained CD values.

The external envelope of buildings with reinforced concrete structures (RCS buildings) is usually subjected to various external environmental actions. Among these external environmental actions, hygrothermal actions are particularly relevant, mainly related to external temperature and humidity variations. These variations could negatively influence the hygrothermal behavior of that envelope and lead to problems related to an increased risk of material degradation of the external face of unreinforced masonry (URM) infill walls of the building envelope URM infill. In the survey of the degradation of these URM infill walls and of concrete elements, nondestructive evaluation (NDE), such as ultrasonic pulse velocity testing (UPV testing), had been used before. The main objective of the study is to assess the potential use of UPV testing in the evaluation of the influence of moisture content in the behavior of URM infill walls, and the methodology of the study consists, firstly, concerning the hygrothermal actions, which RCS buildings are subjected, which are here described summarily. An assessment is made of the most usual types of degradation of URM infill walls of the envelope of RCS buildings, mainly due to moisture and thermal effects in URM infill walls. UPV testing in the survey of the degradation of the external face of URM infill walls of the building envelope, essentially due to hygrothermal actions, is analyzed, based on an example of the use of UPV testing in a building façade. Subsequently, the potential use of UPV testing in evaluating the influence of moisture content in the behavior of URM infill wall is made, particularly with the use of UPV testing in a compression test of a masonry specimen with variable moisture content during the test. Their results are presented, followed by a discussion of these results, and finally by the conclusions of the study.

o obtain predictions closer to concrete behaviour, it is necessary to employ a particle model(PM) that considers contact softening. A bilinear softening contact model (BL) has been adoptedin PM studies. Several limitations in PM predictions have been identified that may be due to BLassumptions. For this reason, this paper compares BL predictions with those obtained with morecomplex models to assess if PM predictions can be improved. As shown, it is possible to calibrateeach contact model to reproduce the complex behaviour observed in concrete in uniaxial and biaxialloading. The predicted responses are similar, and the known PM limitations still occur independentlyof the adopted model. Under biaxial loading, it is shown that a response closer to that observed inconcrete can be obtained (higher normal-to-stiffness ratio of

Os dispositivos móveis inteligentes, como smartphones e tablets, tem revolucionado as nossas vidas e apresentam um elevado potencial de aplicação na monitorização de infraestruturas civis, incluindo ferrovias. Tais dispositivos, equipados com múltiplos sensores, oferecem uma complementaridade e alternativa económica e eficiente aos métodos tradicionais de monitorização, que são dispendiosos e exigem pessoal qualificado dedicado. Este tipo de dispositivos permite monitorizar vários parâmetros e transmitir dados para análise em tempo real, melhorando a segurança e a fiabilidade, nomeadamente do sistema ferroviário [1, 2]. Este artigo apresenta uma breve visão geral sobre o uso de sensores móveis e de baixo custo na monitorização do transporte ferroviário, como alternativa aos sistemas tradicionais, mais dispendiosos. Apresenta-se um exemplo de medição de acelerações com um smartphone a bordo de um veículo de passageiros, comparando os dados obtidos com os registos de auscultação de geometria de via por um veículo de inspeção dedicado. Estas novas abordagens permitem a deteção precoce de falhas na via, contribuindo para otimizar a manutenção, economizar custos e melhorar a segurança e conforto dos passageiros.

Carbon fiber reinforced polymer (CFRP) composites have shown desirable properties in aerospace, automotive,and construction industries. Focusing on the latter and in the context of strengthening existing structures, CFRPcomposites are typically bonded to concrete structures using epoxy adhesive as a bonding agent. To date, there isa lack of literature on the durability of both the CFRP composite and epoxy adhesive. In this regard, the durabilityof two different commercially available CFRP laminates and epoxy adhesives was assessed after exposure todifferent indoor and outdoor environments for up to 4 years. Experimental, numerical, and analytical studieswere conducted. In the latter, a new formulation was introduced to model water diffusion through the epoxyadhesive. The results from the experimental tests showed that water immersion substantially affected the twostudied epoxy adhesives, resulting in a reduction of approximately 60