Artigos de Revista

Trata-se da possibilidade de juntar e dividir compartimentos e espaços, da escolha entre ter mais compartimentos mais pequenos ou menos compartimentos maiores e, finalmente, da separação entre zonas mais sociais ou mais íntimas.

This paper is a review of the most recent and relevant achievements (from 2001 to 2013) on the development of organic–inorganic hybrid (OIH) coatings produced by sol–gel-derived methods to improve resistance to oxidation/corrosion of different metallic substrates and their alloys. This review is focused on the research of OIH coatings based on siloxanes using the sol–gel process conducted at an academic level and aims to summarize the materials developed and identify perspectives for further research. The fundamentals of sol–gel are described, including OIH classification, the interaction with the substrate, their advantages, and limitations. The main precursors used in the synthesis ofOIHsol–gel coatings for corrosion protection are also discussed, according to the metallic substrate used. Finally, a multilayer system to improve the resistance to corrosion is proposed, based on OIH coatings produced by the sol–gel process, and the future research challenges are debated.

O mundo doméstico retoma, hoje em dia, uma importância que talvez só tenha tido no mundo antigo, quando habitar e trabalhar profissionalmente se conjugavam, com frequência, nos mesmos espaços de habitar, condição que, entre outros aspetos, tinha exigências específicas de adequada integração e proximidades urbanas; exigências estas que talvez hoje, também, devam ser devidamente reconsideradas.

A major concern of coastal engineering is not only to access the damage to coastal structures by severe wave overtopping, but also the hazard imposed to users. Local hazard is often associated to the volume of overtopping water per unit of time (called overtopping discharge). Despite two decades of intensive research, it is yet not fully clear to practitioners what is the best method to compute the discharge parameter and its application on the assessment of local hazard. This work provides insight into the overtopping characterization in rubble mound breakwaters, by distinguishing different methods to assess hazardous overtopping. Fieldwork was conducted over a tidal cycle in a breakwater located at Albufeira Harbour (South coast of Portugal) under storm conditions (Hso~ 3 m; Tp ~ 9 s). Mean overtopping discharges were calculated from field measurements of flow depths and velocities at the breakwater slope armour and at the impermeable crest. Two different velocities were calculated: overtopping leading-edge velocity and overtopping peak velocity. The two methods provided similar results, with higher velocities occurring during high-tide (between 2 and 10 m/s). Mean overtopping discharges at the beginning of the impermeable crest ranged between 0.2 and 0.8 l/s/m. Under the measured hydrodynamic conditions, the breakwater offers risk to all types of pedestrians.Additionally it is shown that field measurements compare relatively well with empirical prediction methods (for the overall analysed overtopping events), namely the corrected NN_OVERTOPPING2 neural network tool. Besides contributing to the overall database on wave overtopping in coastal structures, the presented results can also be used for calibration and validation of overtopping evaluation methods (empirical formulae, artificial neural networks and numerical and physical models).

This work evaluates the influence of binder:aggregate ratio on the mineralogical and mechanical properties of air lime–metakaolin mortars. Mineralogical analysis showed that binder:aggregate ratio affects the extent of carbonation and pozzolanic reactions with curing. The pozzolanic reaction occurs mostly at lower curing times (28 days), while, at higher curing ages, carbonation reaction is mostly dominant. The exceptions are mortars with 1:1 (air:- lime) volumetric ratio with 30% and 50% MK in which the pozzolanic reaction is still dominant. The reduction in the mechanical resistance of some compositions observed from 28 to 90 days is related to the calcium aluminate hydrate instability in the presence of free lime. This instability is expected to disappear after the total consumption of free lime, either by pozzolanic or carbonation reaction.

The European Union Water FrameworkDirective aims to protect inland surface waters, transitionalwaters, coastal waters, and groundwater and achieve certainenvironmental objectives through the implementationof programs of measures specified in river basin managementplans (RBMPs). For that purpose, information systemshave been identified as a priority tool for managingwater resources effectively and efficiently, within theprocess of characterization and modelling of quantitativeand qualitative aspects of groundwater bodies, also consideringthe projected climate change scenarios. This paperaddresses some of the innovative issues developed inPortugal for RBMPs, exemplified for the Tagus and for theWest RBMPs, e.g. modelling groundwater rechargeassessment under climate change scenarios projected for2071

Divulgação internacional da missão e das atividades da Comissão Portuguesa de Geotecnia Ambiental (CPGA) da Sociedade Portuguesa de Geotecnia (SPG) junto dos membros da Sociedade Internacional de Mecânica dos Solos e Engenharia Geotécnica.

In Portugal, volcanic rocks are commonly used as concrete aggregates for concrete in Madeira and Azores Islands and in a lesser extent in the Mainland. Nonetheless, the information about the potential alkali-silica reactivity of Portuguese volcanic rocks is rather scarce. In order to ful ll this lack of information and in the scope of a Portuguese research project, four volcanic aggregates from the Portuguese Mainland and Madeira Archipelago were investigated. For this purpose petrographic characterization (polarizing microscopy complemented by bulk chemical analysis and scanning electron microscopy with energy dispersive detector) along with expansion laboratory tests were carried out. In this paper, results of the investigation are presented aiming to establish a possible correlation among the results from the used methods.

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Nas últimas décadas o número de infraestruturas em concreto afetadas por processos expansivos, nomeadamente por reações álcalis-agregado (RAA), tem motivado o desenvolvimento de estudos por todo o mundo. Em Portugal cerca de 30 pontes e grandes barragens encontram-se danificadas por RAA, o que tem obrigado a dispendiosas obras de reparação ou de substituição. A forma mais eficaz de prevenir a RAA é o conhecimento adequado da reatividade do agregado aos álcalis, o que exige a utilização de ensaios que permitam um correto diagnóstico. Neste artigo apresentam-se os resultados de caraterização obtidos em cerca de 40 agregados portugueses de diferentes mineralogias, e extraem-se conclusões acerca da aplicabilidade dos vários ensaios. Esta abordagem visa a melhoria do monitoramento da reatividade aos álcalis de agregados para concreto e das medidas preventivas contra a ocorrência da RAA em futuras construções.