Artigos de Revista
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Impact of Water-Repellent Products on the Moisture Transport Properties and Mould Susceptibility of External Thermal Insulation Composite Systems
External Thermal Insulation Composite Systems (ETICS) are constructive solutions widely used to increase the thermal insulation in new and retrofitted buildings. However, these systems can present several anomalies due to their constant exposure to weathering agents and anthropic factors. Water is generally the major cause of degradation. Thus, the application of water-repellent products can minimize the appearance of anomalies and increase the durability of the systems. Inthis paper, acrylic-based and siloxane-based hydrophobic products were applied to ETICS, with the aim of assessing the compatibility, effectiveness, and durability of these products. The moisture transport properties and mould susceptibility were assessed through laboratory tests on untreated and treated specimens. The durability of the hydrophobic treatments was also evaluated through artificial aging tests (heat-cold and freeze-thaw cycles). Results show that the protection products generally decreased water absorption, slightly decreased the drying rate, and presented adequatewater vapor permeability. After aging, the products still had reasonable effectiveness and, with one exception, improved the water vapor diffusion of the systems. Additionally, ETICS underwent an alteration in the finishing coat (possible modification of the porosity) due to the aging cycles. No clear linear correlation was found between the contact angle values and water absorption results,evidencing the influence of other factors related to the composition of the water-repellent products.
Ano: 2021
Autor(es): Roncon, R.; Borsoi, G.; Parracha, J.; Flores-Colen, I.; Veiga, M. R.; Lina Nunes
Revista: Coatings
Editor: MDPI
Volume:
11 (5): 554.
Keywords: Durability; Mould susceptibility; Moisture transport properties; Water-repellency; Hydrophobic protection; ETICS
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Impact of Water-Repellent Products on the Moisture Transport Properties and Mould Susceptibility of External Thermal Insulation Composite Systems.
External Thermal Insulation Composite Systems (ETICS) are constructive solutions widely used to increase the thermal insulation in new and retrofitted buildings. However, these systems can present several anomalies due to their constant exposure to weathering agents and anthropic factors. Water is generally the major cause of degradation. Thus, the application of water-repellent products can minimize the appearance of anomalies and increase the durability of the systems. In this paper, acrylic-based and siloxane-based hydrophobic products were applied to ETICS, with the aim of assessing the compatibility, effectiveness, and durability of these products. The moisture transport properties and mould susceptibility were assessed through laboratory tests on untreated and treated specimens. The durability of the hydrophobic treatments was also evaluated through artificial aging tests (heat-cold and freeze-thaw cycles). Results show that the protection products generally decreased water absorption, slightly decreased the drying rate, and presented adequate water vapor permeability. After aging, the products still had reasonable effectiveness and, with one exception, improved the water vapor diffusion of the systems. Additionally, ETICS underwent an alteration in the finishing coat (possible modification of the porosity) due to the aging cycles. No clear linear correlation was found between the contact angle values and water absorption results, evidencing the influence of other factors related to the composition of the water-repellent products. ....
Ano: 2021
Autor(es): Roncon, R.; Borsoi, G.; Parracha, J.; Flores-Colen, I.; Veiga, M. R.; Lina Nunes
Revista: Coatings
Editor: MDPI
Volume:
2021.
Keywords: ETICS; hydrophobic protection; water-repellency; moisture transport properties; mould susceptibility; durability
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Impacto de afluências indevidas no consumo energético em instalações elevatórias em sistemas de drenagem urbana.
As afluências indevidas são identificadas como um dos principais problemas dos sistemas de águas residuais e pluviais, levando a diversos problemas de desempenho dos mesmos, como sejam a ocorrência de inundações, a diminuição da eficiência hidráulica e energética, entre outros. A atuação no controlo de afluências indevidas perspetiva oportunidades de melhoria do desempenho em várias dimensões incluindo a componente de eficiência energética. Neste artigo desenvolve-se esta temática numa perspetiva de avaliação do desempenho de instalações elevatórias (IE) embora considerando o sistema como um todo. A metodologia adotada consiste em efetuar a análise de sensibilidade de um sistema separativo de águas residuais para cenários de ocorrência de afluências indevidas à rede, de modo a avaliar o impacto no consumo de energia e noutras variáveis relevantes do sistema. O caso de estudo utilizado consiste numa adaptação do caso de estudo real correspondente ao sistema de drenagem de águas residuais da Bacia da Venteira, Amadora. A finalidade é aferir uma abordagem para tratar esta temática de modo mais geral com base no caso de estudo referido, de forma a contribuir para a sensibilização para a adoção de metodologias operacionais e de monitorização que permitam ter dados para fazer uma gestão mais racional da energia nestes sistemas. As conclusões são genericamente aplicáveis a qualquer sistema separativo de águas residuais.
Ano: 2021
Número Páginas:
12 pp.
Autor(es): Jorge, C.; Almeida, M. C.; Covas, D.
Revista: Águas & Resíduos
Editor: APESB
Volume:
2021b série IV nº9.
Keywords: Sistemas de drenagem; Instalações elevatórias; Eficiência energética; Avaliação de desempenho; Afluências indevidas
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In-plane structural performance of dry-joint stone masonry Walls: A spatial and non-spatial stochastic discontinuum analysis
In this study, the in-plane structural behavior, capacity, and performance of dry-joint stone masonry walls (DJSMWs)and the effects of the vertical stress level on these factors are investigated via a stochastic discontinuumanalysis that considers the material uncertainty. A discontinuum type of analysis is performed based on thediscrete element method (DEM), where each stone masonry unit is explicitly represented in the computationalmodel. To better simulate the cracking and shear failure modes within the stone units, a coupled fracture energybasedcontact constitutive model is implemented into a commercial discrete element code, 3DEC. First, theproposed modeling approach is validated by comparing to experimental findings in literature. Then, theapproach is used to explore the failure mechanism and the force
Ano: 2021
Autor(es): Pulatsu, B.; Erdogmus, E.; Lourenço, P.; Lemos, J. V.
Revista: Engineering Structures
Editor: Elsevier
Volume:
242.
Keywords: Estruturas de alvenaria
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Incorporation of Natural Fibres in Rendering Mortars for the Durability of Walls.
One of the main functions of renders, together with the overall aesthetic appearance of the building, is the protection of the walls against external aggressive actions, such as water, salts solutions, erosion, and mechanical impacts. However, some anomalies of renders may drastically hinder their protection ability. In fact, cracking, high water permeability, and loss of adherence to the substrate of renders limit their barrier effect and favour the exposure of the substrate to external actions. The incorporation of fibres in mortars is commonly pointed out to reduce their cracking susceptibility, due to the probable enhancement in tensile strength and ductility of the composite. The use of lime in substitution of the part of the cement binder is seen as a method to reduce the modulus of elasticity and therefore enhance the resistance to cracking due to drying shrinkage. Therefore, this study investigates the wall protection-related properties of natural fibre-reinforced renders with cement-lime as a binary binder at 1:1:6 volumetric ratio. With this purpose, wool, coir, and flax fibres are used at 20% by total mortar volume and the water behaviour, cracking susceptibility, and adherence to the substrate of the mortars are assessed. Specifically, the water absorption by capillarity, drying rates, permeability to water under pressure, adherence strength, and shrinkage are evaluated. In order to evaluate the renders
Ano: 2021
Número Páginas:
82.
Autor(es): Veiga, M. R.; Brito, J.; Pederneiras, C.
Revista: Infrastructures
Editor: MDPI
Volume:
6, assunto 6.
Keywords: durability; natural fibre-reinforced mortar; cement-lime mortars; sustainability; render
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Influence of Zwitterionic Buffer Effects with Thermal Modification Treatments of Wood on Symbiotic Protists in Reticulitermes grassei Clément
The majority of thermal modification processes are at temperatures greater than 180
Ano: 2021
Número Páginas:
15p.
Autor(es): Duarte, S.; Lina Nunes; Kr
Revista: Insects
Editor: MDPI
Volume:
12, 139.
Keywords: Reticulitermes grassei; Wood; Tricine; Thermal modification; Termite gut; Symbionts; Bicine
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Inovação nos corredores e zonas de passagem domésticas
Neste artigo, dedicado à temática da circulação doméstica e depois de uma pequena introdução muito dedicada ao sublinhar dos outros aspetos essenciais no seu desenvolvimento para além das matérias funcionais, abordam-se, de um modo bastante informal e acompanhado por imagens de novas soluções habitacionais, os seguintes subtemas frequentemente associados ou desejavelmente associáveis à ampla matéria da circulação doméstica: escada doméstica considerada como elemento "plástico" de habitação; circulação doméstica intensamente embebida/integrada no espaço habitacional; circulação doméstica desenvolvida e tratada como verdadeiro elemento "protagonista" de uma habitação; escada doméstica desenvolvida e tratada como "elemento central" de habitação; circulação doméstica desenvolvida e tratada como "elemento central" de habitação.
Ano: 2021
Número Páginas:
12p.
Autor(es): Baptista Coelho, A.
Revista: Infohabitar
Editor: GHabitar - Associação Portuguesa para a Promoção da Qualidade Habitacional (GHabitar APPQH)
Volume:
Infohabitar, Ano XVII, n.º 789
Keywords: infohabitar; circulações domésticas; arquitectura; habitação
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Integrated InSAR and GNSS monitoring subsystem for an arch dam and reservoir banks
Interferometric synthetic aperture radar (InSAR) is a cost-effective method for displacement measurement at dams and reservoir banks, and is especially relevant for structures without embedded equipment or rarely monitored. However, the lack of redundant observations prevents the determination of a posteriori variances for InSAR measurements, which limits the uptake of the InSAR technology for structure monitoring. This paper presents a methodology for the integration of persistent scatterer interferometry (PSI) and Global NavigationSatellite System (GNSS) displacement measurements. Double differences between PSI and GNSS data are used as observations in a redundant network connecting the points of interest, with GNSS data used to constrain PSI measurements. This procedure allows the determination of adjusted displacements and a posteriori variances at all network points. Maximum uncertainty of 3 mm was achieved for displacementsalong the SAR sensor line-of-sight at both the dam and its surrounding slopes. The proposed method is of interest for monitoring purposes, because it allows displacement measurement at both the structure and its surroundings, together with the displacement uncertainty, which aids decision makers in the planning of maintenance operations for the whole area influenced by the dam.
Ano: 2021
Número Páginas:
12p.
Autor(es): Roque, D.; Lima, J. N.; D. Perissin; Falcão, A. P.; Lemos, J. V.; Fonseca, A. M.
Revista: Journal of Surveying Engineering
Editor: American Society of Civil Engineers
Volume:
147(3).
Keywords: Uncertainty assessment; Slope; Dam; GNSS; InSAR; Data integration; Monitoring system
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Integrative analysis of multimodal traffic data: addressing open challenges using big data analytics in the city of Lisbon
Worldwide cities are establishing efforts to collect urban traffic data from various modes and sources. Integrating traffic data, together with their situational context, offers more comprehensive views on the ongoing mobility changes and supports enhanced management decisions accordingly. Hence, cities are becoming sensorized and heterogeneous sources of urban data are being consolidated with the aim of monitoring multimodal traffic patterns, encompassing all major transport modes
Ano: 2021
Número Páginas:
13-64pp.
Autor(es): Lemonde, C.; Arsénio, E.; Henriques, R.
Revista: European Transport Research Review Journal
Editor: Springer
Keywords: Mobilidade inclusiva; Transporte público; Cidades inteligentes; Ciência dos dados; Mobilidade sustentável; Multimodalidade
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Introdução à sala-comum doméstica
Neste artigo, dedicado à temática geral de um adequado desenvolvimento das salas-comuns domésticas, faz-se, de início, um enquadramento e uma breve introdução geral ao tema; passa-se, depois, para uma abordagem às grandes opções e às associações mais frequentes nas salas-comuns; registando-se, a seguir, os usos e hábitos considerados mais frequentes naqueles espaços da habitação; seguindo-se a consideração dos
Ano: 2021
Número Páginas:
14p.
Autor(es): Baptista Coelho, A.
Revista: Infohabitar
Editor: GHabitar - Associação Portuguesa para a Promoção da Qualidade Habitacional (GHabitar APPQH)
Volume:
Infohabitar, Ano XVII, n.º 796
Keywords: infohabitar; sala-comum; arquitectura; habitação
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