Papers
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Papers
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Caminhar como contributo metodológico do cocriar a cidade
A reflexão discute e propõe uma abordagem do ato de caminhar como método integrado e interdisciplinar para captar a experiência territorial das pessoas e, no campo do urbanismo, perspetivar a cidade. Atenta aos amplos benefícios do uso caminhado da cidade, às virtualidades do incrementar espaços caminháveis, ao caminhar como ato de resistência e assimilação estético-sensorial da cidade, o objetivo aqui é, todavia, abordar o caminhar como recurso metodológico de apreensão compreensiva, cocriativa e mais responsiva da cidade. A acuidade do caminhar advém aqui, por um lado, de um percurso etnográfico de investigação que, por outro lado, tem colaborado para insinuar sobre o interesse de uma maior ingerência didático-pedagógico que, em defesa de que se caminhe mais antes de intervir na cidade, assuma efetivamente o caminhar como um potencial método cocriativo do captar e fazer o espaço urbano.
Year: 2019
Number Pages:
12-19pp.
Author(s): Menezes, M.
: CES Contexto
Editor: CES-Centro de Estudos Sociais/UC-Univesidade de Coimbra
Volume:
24.
Keywords: Cocriação; Rua; Cidade; Urbanismo; Etnografia; Método; Caminhar
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CFD simulation of the aerodynamic sealing of plane jets
Abstract: Controlling air quality is of the utmost importance within today's buildings. Vertical air curtains are often used to separate two different climatic zones in order to reduce heat transfer. This research work proposes an air curtain aimed to ensure a proper separation between two zones, a clean one and a contaminated one, which is to be used together with an air extraction from the ?contaminated? compartment. A CFD parametric study was carried out in order to assess the optimal parameters for achieving the aerodynamic sealing of the air curtain. The software OpenFOAM was used to carry out the simulations. This paper presents the numerical validation of the computational fluid dynamics model for contaminant control applications and the final simulation results. Furthermore, it refers to the test results obtained in the framework of previous research, which were obtained in both small scale and full size testing, and demonstrates that the simulation results are coherent with the experiments. This research work shows that, when properly implemented, the air curtains provide the adequate aerodynamic sealing to maintain the air contaminants within the ?contaminated? compartment. The appropriate performance can be obtained for nozzle speeds as low as 1 m/s and for a nozzle thickness of 10 mm. The best performance is obtained when the extraction flowrate of the ?contaminated? compartment corresponds to the total flowrate entrained by the air curtain from the ?non-contaminated? side.
Year: 2019
Number Pages:
31-53pp.
Author(s): Dias, J.; Gogotsi, O.; Viegas, J.
: IOSR Journal of Engineering (IOSRJEN)
Editor: IOSR Journal of Engineering (IOSRJEN)
Volume:
Vol. 09, Issue 3.
Keywords: OpenFOAM; Air curtain; Contaminant control; Plane jets
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Combining embodied and operational energy in buildings refurbishment assessment
Buildings refurbishment is becoming a major trend in civil construction in Europe. At the same time Eu- ropean environmental and cultural commitments are being transposed to building and urban regulations. Energy efficiency and heritage safeguarding are two objectives of buildings refurbishment policies which do not always lead to the same refurbishment options. Energy efficiency assessment is not always suit- able to existing buildings in different local contexts and, while focusing on operational energy, it does not include embodied energy in buildings. This article calculates and combines embodied energy and operational energy, proposing a methodol- ogy for the assessment of building components life-cycle energy, suitable for the assessment of repairing and replacing scenarios. The methodology is applied to a case study, comparing walls repair or replace- ment and considering different scenarios of users requirements of thermal comfort. Results show the advantages of preserving building components and materials in terms of whole life cycle energy demand.
Year: 2019
Number Pages:
13p.
Author(s): Mourão, J.; Gomes, R.; Matias, L.; Niza, S.
: Energy & Buildings
Editor: Elsevier
Volume:
197 (2019).
Keywords: Operational embodied; Buildings refurbishment; End-of-life energy; Repair and replacement
Info
Comparative study of the effect of long-term ageing on the behaviour of bitumen and mastics with mineral fillers
This study aims to evaluate the effect of mineral fillers on bitumen ageing. Two different bitumens and four mastics were investigated in the unaged and long-term aged states, based on different properties (consistency, rheology, fatigue resistance and ductility). Mastics stiffened less due to ageing treatment than bitumens, especially with granite filler. However, the results of the performance tests were not definitive regarding the effect of the filler. Aged bitumen showed greater fatigue resistance and higher specific energy of ductile fracture than unaged bitumen, whereas the mastics showed minor variations in the specific energy of ductile fracture with ageing treatment, which is indicative of less ageing, but the fatigue resistance decreased significantly in mastics with one of the bitumens.
Year: 2019
Number Pages:
76-89pp.
Author(s): Carl, C.; Lopes, P.; Sá-da-Costa, M.; Canon Fallaa, G.; Leischner, S.; Micaelo, R.
: Construction and Building Materials
Editor: Elsevier
Volume:
225.
Keywords: Ductility fracture; Fatigue testing; Rheological properties; Ageing; Filler-bitumen interaction; Bituminous mastic
Info
Damage progression in rubble-mound breakwaters scale model tests, under a climate change storm sequence
This paper describes the two-dimensional (2D) physical model tests of a rock armor breakwater, performed at LNEC´s experimental facilities, under the framework of the HYDRALAB+ project. The aim of the present work was to evaluate damage evolution under future climate change scenarios, by using different damage evaluation techniques. The tested wave conditions simulated a storm sequence where two water levels (low water and high water) were considered, as well as an increase of the wave height. The water levels and the wave heights were chosen to simulate extreme events forecasted on climate change scenarios. Damage evaluation was based on the traditional counting method and on stereo-photogrammetric techniques. Test results are presented in terms of the damage parameter S and in terms of the percentage of removed armor units. The analysis is focused on the damage progression during the scale model tests, for the imposed storm sequence. The damage presents an oscillating behavior with two main damage areas corresponding to the active zones for each level, due to the variation of the water level between low-water and high-water. This behavior differs significantly from that found for the common storm sequences usually tested, where the water level does not change. Both measuring techniques lead to an intermediate damage of the cross-section breakwater. However, the damage parameter assessment with the stereo-photogrammetric technique allows a more versatile evaluation, since it is possible to characterize damage in representative zones of the cross-section
Year: 2019
Author(s): Fortes, C. J. E. M.; Lemos, R.; Mendonça, A. C.; Reis, M. T. L. G. V.
: Journal of Research on Engineering Structures and Materials (RESM)
Editor: MIM Research Group
Volume:
Vol. 5 Iss. 4.
Keywords: Stereo-photogrammetric techniques; Climate change; Rubble-mound breakwaters; Damage progression
Info
Demand scenario planning approach in water distribution systems of Portugal using regression techniques
This paper aims to develop and apply an approach for short-, medium- and long-term scenario planning. Construction of water demand scenarios is of the utmost importance for planning, design and operation of distribution systems, providing useful information to promote more efficient use of water resources. The proposed approach offers a new perspective for water utilities to obtain coherent and plausible descriptive scenarios as well as realistic water demand projections. This approach was applied to network sectors in existing water distributions systems, using extensive network flow data. Descriptive scenarios for water demand, considering trends and the uncertainties of the future, were obtained, together with improved Multiple Linear Regression (MLR) models, with the inclusion of the key variable temperature and by using historical billed consumption, socio-demographic and infrastructure data. In addition, water demand projections for short- and long-term periods were obtained through the inclusion of future trends in the MLR models. Results from MLR models show enhanced empirical relations between water demand variables and water consumption key factors. This approach was validated using different distribution systems and the results have demonstrated the efficiency of the developed models for the projection of water demand.
Year: 2019
Number Pages:
394-411 pp..
Author(s): Cabral , M.; Mamade, A.; Loureiro, D.; Amado, C; Covas, D.
: Water Policy
Editor: IWA Publishing
Volume:
Volume 21, nº2.
Keywords: Water distribution systems; Water demand scenarios; Scenario planning; Multiple linear regression models; Demand projections
Info
Development of a Multi Criteria Decision Analysis Model for Pavement Maintenance at the Network Level: Application of the MACBETH Approach
This paper proposes the application of the MACBETH approach for the development of a multi criteria value model to enable the prioritization of maintenance and rehabilitation interventions in the pavements of road networks according to technical, economic, and social aspects. A case-study design considering the Portuguese network was undertaken to illustrate the proposed approach. Using an interactive structuring process developed with the decision-maker, a set of five evaluation criteria related to maintenance costs, traffic, pavement condition, safety, and social equity were defined. The MACBETH approach was then used to build value functions and establish relative weights for the criteria. An application of the resulting model was made to a portfolio of possible intervention projects, prioritizing them according to the principle of benefit/cost maximization. The case-study demonstrated the application of the MACBETH approach and its suitability to solve the decision-making problem, thus proving the usefulness of this approach for road agencies with pavement management responsibilities.
Year: 2019
Number Pages:
1-10pp.
Author(s): Marcelino, P.; Antunes, M. L.; Fortunato, E.
: Frontiers in Built Environment
Editor: Frontiers
Volume:
5.
Keywords: Pavement management system (PMS); Decision-making; Maintenance & rehabilitation; Road & highways; Prioritization algorithm; MACBETH; Multi criteria decision analysis
Info
Discrete element modeling of the seismic behavior of masonry construction
Discrete element models are a powerful tool for the analysis of masonry, given their ability to represent the discontinuous nature of these structures, and to simulate the most common deformation and failure modes. In particular, discrete elements allow the assessment of the seismic behavior of masonry construction, using either pushover analysis or time domain dynamic analysis. The fundamental concepts of discrete elements are concisely presented, stressing the issues related to masonry modeling. Methods for generation of block models are discussed, with some examples for the case of irregular stone masonry walls. A discrete element analysis of a shaking table test performed on a traditional stone masonry house is discussed, as a demonstration of the capabilities of these models. Practical application issues are examined, namely the computational requirements for dynamic analysis.
Year: 2019
Author(s): Lemos, J. V.
: Buildings
Editor: MDPI
Volume:
2019, 9, 43.
Keywords: Masonry; DEM
Info
Dynamic behaviour of ancient freestanding multi-drum and monolithic columns subjected to horizontal and vertical excitations
Earthquakes represent one of the major threats to cultural heritage monuments, such as classical ancient columns. Understanding the behaviour and dynamic response of such historic structures is useful for the assessment of the conservation and rehabilitation techniques to be used for their preservation. The behaviour of ancient multi-drum and monolithic columns subjected to dynamic loads is characterized by highly nonlinearity since both rocking and sliding phenomena can occur. Analytical studies of multi-drum columns subjected to dynamic load is extremely complicated, if not impossible to perform. Nowadays, computational methods of analysis can be used to represent their dynamic response. Using a software based on the Discrete Element Method (DEM) of analysis, a typical ancient multi-drum and an equivalent in dimensions monolithic columns subjected to horizontal and combined horizontal and vertical harmonic excitations were modelled to identify the main factors affecting their stability. Different acceleration amplitude and frequency input records were applied and their role in the collapse/deformation mechanism was investigated. From the results analyses it was shown that novel structural analysis tools that extend traditional methods of structural assessment could allow engineers to understand the mechanisms that have allowed the surviving structures to avoid structural collapse and destruction during strong earthquakes.
Year: 2019
Number Pages:
39-57pp.
Author(s): Sarhosis, V.; Lemos, J. V.; Milani, G.
Editor: Elsevier
Volume:
120(2019).
Keywords: DEM; Masonry
Info
Ensaios em coluna-de-solo para avaliar o destino de poluentes de ETAR simulando condições de recarga controlada de aquíferos (SAT-MAR)
As metodologias de tratamento solo-aquífero (Soil-Aquifer Treatment ou SAT) são aqui estudadas como meio complementar para a remoção de contaminantes de águas residuais tratadas, com o propósito de melhorar a qualidade da água infiltrada em bacias para recarga controlada de aquíferos (Managed Aquifer Recharge ou MAR). Foram realizados ensaios em coluna com o solo da área anexa à ETAR de São Bartolomeu de Messines (Algarve) e analisados, na água de injeção e na água de saída, um conjunto de nutrientes, metais e compostos farmacêuticos. Foi possível observar a redução de alguns destes compostos (amónia, diclofenac e carbamazepina) e verificar a persistência de outros (boro, zinco, cobre, nitratos, gemfibrozil e naproxeno) após a percolação da água pelo solo.
Year: 2019
Number Pages:
78-86pp.
Author(s): Martins, T.; Leitão, T. E.; Henriques, M. J. A.
: Ribagua - Revista Iberoamericana del Agua
Editor: IAHR e WCCE
Volume:
Volume 6, nº 1.
Keywords: Contaminantes emergentes; Qualidade; Ensaios em coluna-de-solo; Tratamento solo-aquífero (SAT); Gestão da recarga de aquíferos (MAR)
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