Artigos de Revista
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Artigos de Revista
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Optical Measurement of Planar Deformations in the Destructive Mechanical Testing of Masonry Specimens
This paper addresses the planar measurement problem in the destructive mechanical testing of masonry specimens, describing the proposed optical measurement solution. The adopted affine geometrical camera model is described as well as its experimental implementation using a digital camera and a measurement referential traceable to the International System of Units (SI). Experimental results from non-destructive tests are presented and discussed, including measurements obtained from the use of classical contact instrumentation. Measurement estimates and uncertainties related to the quantified mechanical properties are also shown.
Ano: 2020
Autor(es): Lages Martins, L.; Mera Marques, A.; Ribeiro, A.; Candeias, P.; Veiga, M. R.; Ferreira, J.
Revista: applied sciences
Editor: MDPI
Volume:
Vol. 10, issue 1.
Keywords: Optical measurement; Deformation; Masonry specimens; Destructive testing
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Performance assessment of 23 wastewater treatment plants - a case study
Water systems and particularly wastewater treatment may only improve or keep high-quality service if their performance is continuously measured and benchmarked against peers. This paper presents a casestudy developed under the Portuguese Initiative on Water Quality, Treatment and Energy (iEQTAWWTP), involving 7 water utilities, and focused on the performance assessment of 23 urban wastewater treatment plants (WWTPs) covering a wide range of treatment sequences and capacities (700-54000 m3/ d). An earlier developed system of key performance indicators (KPIs) with reference values was used to assess the plants
Ano: 2020
Número Páginas:
9 pp..
Autor(es): Silva, C.; Rosa, M. J.
Revista: Urban Water Journal
Editor: Taylor & Francis Online
Volume:
Volume 17, Issue 1.
Keywords: Sludge; Energy; Performance indicators; WWTP; IEQTA
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Pilot Studies and Cost Analysis of Hybrid Powdered Activated Carbon/Ceramic Microfiltration for Controlling Pharmaceutical Compounds and Organic Matter in Water Reclamation
This paper addresses the enhanced removal of pharmaceutical compounds (PhCs), a family of contaminants of emerging concern, and effluent organic matter (EfOM) in water reclamation by powdered activated carbon/coagulation/ceramic microfiltration (PAC/cMF). Four chemically diverse PhCs are targeted: ibuprofen (IBP), carbamazepine (CBZ), sulfamethoxazole (SMX) and atenolol (ATN). Pilot assays (100 L/(m2 h), 10 mg Fe/L) run with PhC-spiked sand-filtered secondary effluent and 15 mg/L PAC dosed in-line or to a 15-min contactor. They showed no PAC-driven membrane fouling and +15 to +18% added removal with PAC contactor, reaching significant removals of CBZ and ATN (59%
Ano: 2020
Número Páginas:
13 pp.
Autor(es): Viegas, R.M. C.; Mesquita, E.; Campinas, M.; Rosa, M. J.
Revista: Water
Editor: MDPI
Volume:
Volume 12, nº1.
Keywords: Water reclamation; Pharmaceutical compounds; Microfiltration; Hybrid membrane processes; Cost analysis; Contaminants of emerging concern; Ceramic membranes
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Probabilistic structural analysis of São João Bridge based on the on-site study of the time-dependent behavior of concrete
This article aims to present a procedure to take into account the variability ofthe time-dependent behavior of concrete on its structural effects, evaluatedfrom the study of creep and shrinkage based on experimental data obtainedon-site. For this purpose, the S~ao Jo~ao Bridge, a railway bridge built in Porto,Portugal in 1991, is presented as a case study. S~ao Jo~ao Bridge is a railwaybridge crossing the river Douro. It is a prestressed concrete structure, with atotal length of 1,028 m, including the main span of 250 m, two side spans of125 m, six approaching spans on the left river bank, and three approachingspans on the right river bank (Porto). During bridge construction, a comprehensivestructural health monitoring (SHM) system was set up, as well as anon-site study of time-dependent behavior of concrete. This study was based oncreep 15 specimens and 15 shrinkage specimens, prepared simultaneously withsome segments of the deck, using the same material, and it was kept runningduring almost 20 years. The results of this study were treated statistically andused as random variables in a probabilistic analysis of the time-dependentbehavior of the bridge. After a brief description of the mentioned on-site studyand the bridge SHM system, the paper presents the procedure followed on thebridge numerical probabilistic analysis. Finally, the values computed by thenumerical model are presented and compared with the experimental valuesprovided by the SHM.
Ano: 2020
Número Páginas:
11p.
Autor(es): Oliveira Santos, L.; Xu, Min; Virtuoso, F.
Revista: Structural Concrete
Editor: Structural Concrete - Wiley Online Library
Volume:
2020.
Keywords: structural health monitoring; experimental data; creep and shrinkage; probabilistic structural analysis; time-dependent behavior of concrete,
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Proposta de lei de aderência entre varões de aço e betões com baixa dosagem de ligante com agregados naturais/reciclados
O betão com baixa dosagem de ligante (LBC - low binder concrete na denominação anglo-saxónica) e o betão com baixa dosagem de cimento com agregados reciclados (LCRAC - low cement recycled aggregate concrete ) são alterativas eco-eficientes ao betão de cimento Portland com agregados naturais por apresentarem um menor impacto ambiental. Para contribuir para o estudo da viabilidade de aplicação estrutural do LBC e do LCRAC, apresentam-se neste artigo os resultados obtidos numa campanha experimental de ensaios de arrancamento (pull-out tests), realçando o desempenho obtido ao nível da relação entre a tensão de aderência e o deslizamento do varão de aço. Os resultados experimentais foram comparados com as propostas de previsão existentes e apresenta-se uma primeira proposta de lei para descrever a relação tensão de aderência-deslizamento, considerando a compacidade, os agregados reciclados, o diâmetro do varão e a respetiva área relativa das nervuras transversais. A influência positiva da compacidade na aderência foi validada através da comparação dos resultados obtidos com os resultados decorrentes da proposta existente no Model Code 2010.
Ano: 2020
Número Páginas:
14p.
Autor(es): Pereira, T.; Louro, A. S.; Costa, H.; Júlio, E.
Revista: Revista Portuguesa de Engenharia de Estruturas
Editor: LNEC | Divisão de Divulgação Científica e Técnica
Volume:
Série III, n.º 14.
Keywords: Relação tensão de aderência-deslizamento; Aderência varão-betão; Elevada compacidade; LCRAC; LBC; Sustentabilidade
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RAF resilience assessment framework - a tool to support cities' action planning.
Urban areas are dynamic, facing evolving hazards, having interacting strategic services and assets. Their management involves multiple stakeholders bringing additional complexity. Potential impacts of climate dynamics may aggravate current conditions and the appearance of new hazards. These challenges require an integrated and forward-looking approach to resilient and sustainable urban development, being essential to identify the real needs for its achievement. Several frameworks for assessing resilience have been developed in different fields.
Ano: 2020
Número Páginas:
64 pp..
Autor(es): Cardoso, M. A.; Brito, R.; Pereira, C.; Gonzalez, A.; Stevens, J. R.; Telhado, M.
Revista: Sustainability
Editor: MDPI
Volume:
Volume 20, Issue 6.
Keywords: Cities; Urban services; Climate change; Urban resilience; Resilience assessment
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RAF Resilience Assessment FrameworkA Tool to Support Cities Action Planning
Urban areas are dynamic, facing evolving hazards, having interacting strategic services and assets. Their management involves multiple stakeholders bringing additional complexity. Potential impacts of climate dynamics may aggravate current conditions and the appearance of new hazards. These challenges require an integrated and forward-looking approach to resilient and sustainable urban development, being essential to identify the real needs for its achievement. Several frameworks for assessing resilience have been developed in different fields. However, considering the focus on climate change and urban services, specific needs were identified, particularly in assessing strategic urban sectors and their interactions with others and with the wider urban system. A resilience assessment framework was developed directing and facilitating an objective-driven resilience diagnosis of urban cities and services. This supports the decision on selection of resilience measures and the development of strategies to enhance resilience, outlining a path to co-build resilience action plans, and to track resilience progress in the city or service over time. This paper presents the framework and the main results of its application to three cities having diverse contexts. It was demonstrated that the framework highlights where cities and urban services stand, regarding resilience to climate change, and identifies the most critical aspects to improve, including expected future impacts.
Ano: 2020
Número Páginas:
49 pp..
Autor(es): Cardoso, M. A.; Brito, R.; Pereira, C.; Gonzalez, A.; Stevens, J. R.; Telhado, M.
Revista: Sustainability
Editor: MDPI
Volume:
Vol 12 Issue 6.
Keywords: Cities; Urban services; Climate change; Urban resilience; Resilience assessment
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RainfTrends over a Small Island Teleconnected to the North Atlantic Oscillation - the Case of Madeira Island, Portugal
For improving sustainable water resources management and planning at local andregional scales, specifically in small islands, long-term and recent rainfall trends due totemporal shifts in major climatic drivers should be investigated based on dense and longrunningground data series
Ano: 2020
Número Páginas:
4449-4467pp.
Autor(es): Espinosa L. A.; Portela, M. M.
Revista: Water Resources Management
Editor: Springer
Volume:
volume 34.
Keywords: North Atlantic oscillation index; Teleconnection; Madeira Island; Small island; Rainfall trends
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Re
The main objective of the study was to evaluate the durability of a crushed concrete aggregate, processed from construction and demolition waste and an inert siderurgical aggregate for construction, processed from electric arc furnace steel slag, with a view to boosting their re-cycling, minimizing the consumption of non-renewable natural resources and preserving the capacity of landflls. Both recycled aggregates were selected based on their high availability worldwide and to be generally associated with suitable engineering properties. However, in many cases, their acceptance by the end-users continues to be very low. One reason for continuing this distrust is the lack of knowledge about the durability of both materials. In natural aggregates, durability has been considered as an important mechanical property in the evaluation of their performance, but it has not been studied in recycled aggregates; so, slake durability tests were carried out. Their durability was compared with the behaviour of two reference natural aggregates, a basalt and a limestone. To complement the durability results obtained, macropetrographic and micropetrographic examinations as well as physical characterizations were performed. The results of the tests showed that, under the test conditions adopted, both recycled aggregates present durability which foresees their use in civil engineering applications.
Ano: 2020
Número Páginas:
1699
Autor(es): Roque, A. J.; Rodrigues, G.; Silva, A. P.
Revista: Journal of Material Cycles and Waste Management
Editor: Springer
Volume:
22.
Keywords: Laboratory tests; Reference natural aggregates; Recycled aggregates; Steel slag; Construction and demolition waste; Durability
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Rede de partilha de entidades gestoras de sistemas urbanos de água (iCITAGE.net)
Na última década tem-se consolidado em Portugal a adoção, pelas entidades gestoras de serviços urbanos de água (EG), de processos de gestão patrimonial de infraestruturas, de gestão de energia e de perdas de água em sistemas de abastecimento e de controlo de afluências indevidas em sistemas de drenagem. Neste contexto, o LNEC tem promovido diversos projetos colaborativos, genericamente designados por iniciativas (PASt21, iGPI, iPerdas, iAFLUI e iEQTA). Estes projetos têm demonstrado ser diferenciadores para as EG participantes, designadamente pelas oportunidades de partilha entre EG e com instituições de I&D. Mesmo após terem iniciado o seu percurso nestes processos, as EG são frequentemente confrontadas com desafios à sua internalização, à consolidação das metodologias ou até à integração dos vários planos setoriais desenvolvidos em cada temática. Por forma a dar resposta a esta necessidade, o LNEC promoveu em 2018-2019 a Rede de Partilha (iCITAGE.net), que se destinou a apoiar as EG na definição de ações para ultrapassar barreiras na implementação, monitorização, revisão e interligação dos seus diversos planos de gestão. No artigo apresentam-se os princípios de funcionamento da rede de partilha e os principais desenvolvimentos da iCITAGE.net, destacando-se os impactos e resultados do projeto.
Ano: 2020
Número Páginas:
10 pp..
Autor(es): Brito, R.; Loureiro, D.; Cardoso, M. A.; Santos, L.F.; Almeida, M. C.
Revista: Revista Águas & Resíduos
Editor: APESB
Volume:
série IV n.º 6.
Keywords: Rede de partilha; Perdas de água; Gestão patrimonial de infraestruturas; Afluências indevidas
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