Artigos de Revista

Transition zones between embankments and bridges or tunnels are examples of critical assets of the railway infrastructure. These locations often exhibit higher degradations rates, mostly due to the development of differential settlements, which amplify the dynamic train-track interaction, thus further accelerating the development of settlements and deteriorating track components and vehicles. Despite the technical and scientific interest in predicting the long-term behavior of transition zones, few studies have been able to develop a robust approach that could accurately simulate this complex structural response. To address this topic, this work presents a three-dimensional finite element (3D FEM) approach to simulate the long-term behavior of railway tracks at transition zones. The approach considers both plastic deformation of the ballast layer using a high-cycle strain accumulation model and the non-linearity of the dynamic vehicle-track interaction that results from the evolution of the deformed states of the track itself. The results shed some light into the behavior of transition zones and evidence the complex long-term response of this structures and its interdependency with the transient response of the train-track interaction. Aspects that are critical when assessing the performance of these systems are analyzed in detail, which might be of relevance for researchers and practitioners in the design, construction, and maintenance processes.

Resumo: Understanding how climatic and anthropogenic drivers will influence coastal lagoons is fundamental to guarantee their preservation and sustainability. The Ria Formosa (coastal lagoon, South coast of Portugal) is a very important ecosystem that supports diverse economic activities in the region. The 3D coupled hydrodynamic-biogeochemical model SCHISM was validated and used to assess the influence of climate change and anthropogenic pressures on the water quality of the Ria Formosa. Five scenarios were simulated: reference scenario (S0), mean sea level rise (SLR) of 0.5 m (S1), increase of the air temperature of 1.68 °C (S2), increase of the outflow from the wastewater treatment plants (WWTP) by 50% (S3) and a combined scenario (S4). Results suggest that SLR of 0.5 m promotes an increase of 0.5

External Thermal Insulation Composite Systems (ETICS) have been extensively used for either new constructions or building facades retrofitting in the last decades. These systems can provide improved thermal performance to the building envelope. However, their long-term durability remains a pervasive concern, with some systems presenting relevant anomalies after few years from their application. The durability assessment of ETICS is defined by the EAD 040083-00-0404 guideline, which stated an accelerated ageing procedure based on the hygrothermal and freeze-thaw behaviour. Nevertheless, further important environmental urban conditions, such as UV radiation and atmospheric pollutants, as well as bio-susceptibility, are not envisaged in the guideline. This paper presents the results of an experimental campaign with the aim of evaluating the durability of the rendering system of several commercially available ETICS exposed to an innovative accelerated ageing procedure, which consists of hygrothermal cycles, UV radiation and air pollutants (SO2) exposure. Physical and chemical-morphological tests were carried out prior and after each ageing cycle in order to evaluate the durability of ETICS. Biological susceptibility to moulds was also assessed. The experimental results showed that both surface hardness and surface gloss decreased after the combined effect of the hygrothermal, UV, and SO2 ageing cycles, whereas an increase of surface roughness was observed. Substantial colour change for all systems after the ageing procedure was observed, confirming aesthetic alteration. Traces of biological growth were detected on the systems after ageing and the contact angle decreased after the hygrothermal cycles, indicating a lower surface hydrophobicity of the systems.

External Thermal Insulation Composite Systems (ETICS) have been extensively used for either new constructions or building facades retrofitting in the last decades. These systems can provide improved thermal performance to the building envelope. However, their long-term durability remains a pervasive concern, with some systems presenting relevant anomalies after few years from their application. The durability assessment of ETICS is defined by the EAD 040083-00-0404 guideline, which stated an accelerated ageing procedure based on the hygrothermal and freeze-thaw behaviour. Nevertheless, further important environmental urban conditions, such as UV radiation and atmospheric pollutants, as well as bio-susceptibility, are not envisaged in the guideline. This paper presents the results of an experimental campaign with the aim of evaluating the durability of the rendering system of several commercially available ETICS exposed to an innovative accelerated ageing procedure, which consists of hygrothermal cycles, UV radiation and air pollutants (SO2) exposure. Physical and chemical-morphological tests were carried out prior and after each ageing cycle in order to evaluate the durability of ETICS. Biological susceptibility to moulds was also assessed. The experimental results showed that both surface hardness and surface gloss decreased after the combined effect of the hygrothermal, UV, and SO2 ageing cycles, whereas an increase of surface roughness was observed. Substantial colour change for all systems after the ageing procedure was observed, confirming aesthetic alteration. Traces of biological growth were detected on the systems after ageing and the contact angle decreased after the hygrothermal cycles, indicating a lower surface hydrophobicity of the systems.

This paper addresses the viscoelastic behaviour of a commercially available cold-curing structural epoxy adhesive, under different preparation, curing and hygrothermal conditions. The main parameters studied were the preparation method (influence of the degassing and the temperature of the initial curing), the creep stress level, and the hygrothermal conditions. Tensile creep tests last up to 2400 h. Test results revealed that the preparation method has great influence on the tensile properties of the adhesive, particularly on the viscoelastic response where degassing and curing at 20

The effects of a farm of bottom-fixed oscillating flaps on the wave propagation in Almagreira beach (Portugal) are evaluated. The SNL-SWAN (Sandia National Laboratories, Simulating WAves Nearshore) numerical model is validated from 2010 to 2018 against Nazaré wave buoy data and run for 19 years to characterize the wave resource and identify the most common and energetic sea states. By varying number (10 to 100) and configuration of wave energy converters (WECs) an optimal array is identified. Model sensitivity to two methods of determining the transmission coefficient, OBCASEs 1 and 3, is studied by analyzing changes in significant wave height, period and direction. OBCASE 1 overestimates the effects of the farm on the waves and changes result higher in the lee of the array with an increasing number of devices. As a future work OBCASE 2 and 4 will be compared to OBCASE 1 and 3.

This paper presents and discusses the application of a novel energy balance scheme for assessing energy efficiency in wastewater systems. The energy balance is demonstrated with a Portuguese real-life case study, using mathematical modelling to estimate the different energy components and to compute two energy efficiency indices. The total inflow intrinsic energy can represent a significant amount (>95%) of the total energy used in systems mainly composed of gravity sewers. The total input energy is significantly (four-times) higher in the wet season than in the dry season, mostly due to undue inflows (e.g., direct rainfall and infiltration). The potential for energy recovery strongly depends on the available head and flow rate at the delivery point, being 0.01 kWh/m3 in the current case, with a project payback period of 4 years. The energy balance components and the respective energy efficiency indices strongly depend on the considered reference elevation. Thus, a unique regional reference elevation is recommended in the calculations.

Neste artigo, dedicado à temática do vestíbulo de entrada na habitação, faz-se, de início, uma introdução geral aos espaços domésticos, seguindo-se um enquadramento da temática do vestíbulo e dos aspetos considerados motivadores para o seu uso.Depois abordam-se diversas opções de vestíbulo, as associações formais e funcionais e os hábitos considerados interessantes nas soluções de vestíbulos domésticos e os problemas mais correntes que aí se detetam e as respetivas questões levantadas (dimensionais e outras)Por fim aborda-se a temática do vestíbulo doméstico em termos de respetivas novidades, dúvidas e tendências (ex., trabalho em casa, uso por idosos).

No artigo desenvolve-se uma reflexão ainda, de certa forma, introdutória e estruturadora sobre o interesse da exploração e do subsequente aprofundamento de uma razoável variedade de propostas organizativas para as zonas e subzonas da habitação, numa perspetiva diretamente ligada ao que se considerar serem os desejáveis equilíbrios dimensionais/funcionais e de privacidade/convívio na habitação.Desenvolvem-se, sequencialmente, algumas considerações sobre o equilíbrio com que se distribui o espaço na habitação e as respetivas consequências na adequação aos tipos de família e de modo de vida.No artigo consideram-se e comentam-se diversas situações-tipo, designadamente, em termos do papel dos quartos no que se refere ao referido equilíbrio entre espacialidade/funcionalidade e privacidade/convívio domésticos, mas também no que se refere à relação entre cozinha e sala comum e à presença espacial e funcional das zonas de entrada e circulação domésticas.