Artigos de Revista

External renders based on air lime are used in historical buildings as decorative and protective coats. They act as sacrificial layers, particularly exposed to climatic actions and mechanical and environmental impact. They generally present good cohesion and adhesion to the background, although often suffering some degradation as detachments, superficial cracks or

In this paper the efficiency of two organic corrosion inhibitors, a migratory and an admixture inhibitor, was evaluated by electrochemical techniques in solutions simulating the interstitial electrolyte of concrete and on concrete slabs exposed to natural environmental conditions over a five-year period. From obtained results, the usefulness of the two products is discussed aiming its application in new structures to prevent chlorides induced corrosion and as a curative method for repairing reinforced concrete structures contaminated with chlorides and affected by reinforcement corrosion.

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The goal of this paper is to simulate the interaction of stress waves and rock fractures in a particle micromechanical model. Stress waves travelling in fractured rock masses are slowed down and attenuated by natural heterogeneities, voids, microcracks and, above all, by faults and fractures. Considerable laboratory and theoretical investigation have uncovered the major aspects of this phenomenon, but models that cover the core mechanisms of the wave propagation in rock masses are necessary to investigate aspects of wave

The paper addresses two complex case studies of modal and structural identification of monuments in Portugal: the Clock Tower of Mogadouro and the Church of Jero´nimos Monastery, in Lisbon. These are being monitored by University of Minho with vibration, temperature and relative air humidity sensors. Operational modal analysis is being used to estimate the modal parameters, followed by statistical analysis to evaluate the environmental effects on the dynamic response. The aim is to explore damage assessment in masonry structures at an early stage by vibration signatures, as a part of a health monitoring process that helps in the preservation of historical constructions. The paper presents the necessary preliminary dynamic analysis steps before the monitoring task, which includes installation of the monitoring system, system identification and subsequent FE model updating analysis, automatic modal identification and investigation of the influence of the environment on the identified modal parameters.

Tidal inlets and embayments constitute navigation routes and they control thestability of adjacent shorelines and the exchanges of water, sediment and dissolvedmaterial between the ocean and back-barrier lagoons. Tidal inlets are thus of critical and growing socio-economical and environmental importance worldwide. They are oftenexceptionally dynamic, due to the combination of tide- and wave-driven processes. Thisintense dynamics drives fast and large morphological changes, which make their behaviorhard to predict and their sustainable management difficult to achieve. To address thisproblem, the development of morphodynamic modeling systems has emerged over thelast decade as the most promising perspective to understand their behavior and predicttheir evolution. Morphodynamic modeling systems, whose development and successfulapplication to tidal inlets has been growing over the last decade, couple a set of modulesto simulate hydrodynamic circulation, wave propagation, sediment transport and bottomevolution.This chapter provides in introduction a synthesis of the existing quantitative methods to investigate tidal inlets and points out the advantages and limitations of morphodynamic modeling systems compared to physical, empirical and analytical models. The next section describes the main principles of morphodynamic modeling systems and explains how the different modules are coupled together. The following section illustrates through three selected applications the capabilities of morphodynamic modeling systems tosimulate morphological changes of tidal inlets at various time scales, but also toinvestigate the mechanisms that control their development. The final section providessome conclusions and perspectives regarding the morphodynamic modeling of tidalinlets.

O desenvolvimento e a actualização ou adaptação de normas tem grande importânciana clarificação e uniformização de critérios e métodos utilizados na concepção, noprojecto, na construção (incluindo a selecção e o controlo de qualidade de materiais e de equipamentos), na operação, na manutenção e reabilitação dos sistemas urbanos de água.O presente artigo tem por objectivo apresentar a actividade que tem vindo a ser desenvolvida recentemente no âmbito do grupo de trabalho europeu TC 165 /WG 22, e dorespectivo grupo espelho CT 90 / SC 2 / GT 22, que se aplica a sistemas públicos deáguas residuais e de águas pluviais.

Durante a produção, transporte e distribuição de água para consumo humano, a água entra em contacto, com diversos produtos de construção, tais como tubagens, componentes e acessórios, revestimentos, selantes, reservatórios, contadores, torneiras, etc, os quais podem ser constituídos por materiais diversos, sendo de destacar: cobre, aço inox, ferro, chumbo, cloreto de polivinilo (PVC), polietileno (PE), polipropileno (PP), betão, resinas epóxi, etc. Nos processos de tratamento de água para consumo humano, são utilizados produtos químicos (como, por exemplo, para coagulação/floculação, desinfecção e oxidação, ajuste de pH e dureza, regeneração de resinas de permuta iónica) e meios de suporte (como, por exemplo, para filtração e adsorção). Em ambas as situações, importa garantir que os níveis de impurezas e de substâncias tóxicas que eventualmente possam ser transferidos para a água sejam inferiores aos estabelecidos em documentos Normativos ou estabelecidos na legislação em vigor.Apresenta-se nesta comunicação, o actual enquadramento legal e normativo existente anível nacional e comunitário, para os produtos químicos usados no tratamento de água para consumo humano e para os produtos de construção que fiquem em contacto coma água.