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A sustentabilidade do uso da madeira na construção

Coelho, Ana C.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Dissertação de Mestrado
Publicado em //2012 POR
Relevância na Pesquisa
26.43%
Dissertação de mestrado em Construção e Reabilitação Sustentáveis; O presente trabalho aponta ao objetivo geral de explorar o potencial do uso da Madeira na Construção, sob a perspectiva da sustentabilidade e dos atuais métodos de Avaliação de Ciclo de Vida (ACV). Apresenta-se um enquadramento preliminar, que pretende situar a madeira nas várias dimensões e linhas de orientação para a Sustentabilidade da Construção. Em seguida, avaliam-se as possibilidades e limitações das Avaliações de Ciclo de Vida de edifícios de madeira, através da sua aplicação a casos de estudo segundo duas diferentes abordagens: a primeira estabelece uma comparação (ambiental e económica) entre dois sistemas estruturais: madeira e aço leve; a segunda, quantifica exaustivamente os impactos ambientais de uma solução-base, que é de seguida sujeita a uma análise de sensibilidade para aferição de quais as variáveis que provocam as maiores variações nos resultados da ACV. Por fim, em resultado da experimentação efectuada, apresenta-se uma lista de contributos para a formulação de uma Metodologia de Avaliação da Sustentabilidade adaptada às particularidades dos edifícios de madeira.; This research work points to the main goal of exploring the potential associated with timber construction...

An overview on the seismic behaviour of timber frame structures

Vasconcelos, Graça; Lourenço, Paulo B.; Poletti, Elisa
Fonte: Tampone, Ruggieri and Zinno Publicador: Tampone, Ruggieri and Zinno
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 ENG
Relevância na Pesquisa
66.83%
Traditional timber frame walls are an important structural element of many buildings and are usually composed of vertical posts and horizontal beams with bracing diagonal elements. In Portugal the timber frame walls, known as frontal walls, are usually part of Pombalino buildings, which were introduced by the Marquis of Pombal, who was responsible for the reconstruction of Downtown Lisbon after the great earthquake of 1755, which partially destroyed the city. Given the increasing interest of the research community to this structural system, it is important to promote the discussion of the main findings that can contribute to the advance on the knowledge of the mechanical behaviour of timber frame buildings to seismic action. Therefore, this paper intends: (1) to give an overview of the different solution of timber frame structures in different countries with special focus on the frontal walls characteristic of Pombalino buildings; (2) provide some examples of the reasonable behaviour of timber frame buildings in past earthquakes; (3) to summarize the experimental research carried out in the recent years in analysis of the behaviour to in-plane cyclic loading.

Seismic performance of traditional half-timbered walls : experimental results

Poletti, Elisa; Vasconcelos, Graça
Fonte: Tampone, Ruggieri and ZInno Publicador: Tampone, Ruggieri and ZInno
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 ENG
Relevância na Pesquisa
26.34%
Half-timbered structures constitute an important cultural heritage of many countries, since they represent a typical anti-seismic construction adopted worldwide [1][2]; therefore, their preservation is of the utmost importance. Although recent earthquakes have pointed out the good seismic behaviour of this kind of structures, few experimental studies are available on the performance of traditional half-timbered walls and their retrofitting solutions and mainly only qualitative information is available of the seismic response of such structures. Due to this lack of information, an extensive experimental campaign was carried out, performing in-plane cyclic tests on real scale half-timbered and timber frame walls, adopting connections and dimensions encountered in real structures and considering different infill types (brick masonry and lath and plaster). Moreover, keeping in mind the great rehabilitation effort that has been carried out in recent years on such buildings, such in the case of the Portuguese Pombalino buildings in Lisbon, it is important to study the effect of strengthening on traditional timber-frame walls. To do this, retrofitting solutions have been applied to traditional walls and tested under cyclic loading. Both traditional and innovative techniques have been considered...

Characterization of the seismic behaviour of traditional timber frame walls

Poletti, Elisa
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Tese de Doutorado
Publicado em 20/12/2013 ENG
Relevância na Pesquisa
46.65%
Tese de doutoramento Engenharia Civil - Estruturas; Timber frame structures constitute an important cultural heritage of many countries, since they represent a typical anti-seismic construction adopted worldwide. Therefore, the preservation of these structures is of the utmost importance. Although recent earthquakes have pointed out the good seismic behaviour of this kind of structures, few experimental studies are available on the performance of traditional half-timbered walls and their retrofitting solutions. Aiming at filling this research gap and at better understanding the behaviour of these historic elements under seismic loads, an extensive experimental campaign has been carried out, performing in-plane cyclic tests on real scale half-timbered and timber frame walls, adopting connections and dimensions found in real structures and considering different infill types (brick masonry and lath and plaster). Moreover, considering possible damages caused by earthquakes, after the unreinforced tests, the walls were retrofitted and re-tested to compare the efficiency of the retrofitting solutions in terms of maximum load, ductility, cyclic stiffness, energy dissipation and equivalent viscous damping. Both traditional and innovative retrofitting techniques were adopted...

Mechanical characterization of traditional timber connections : experimental results; Caracterização mecânica de ligações tradicionais em madeira : resultados experimentais

Poletti, Elisa; Vasconcelos, Graça; Branco, Jorge M.; Koukouviki, A. M.
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Conferência ou Objeto de Conferência
Publicado em 15/10/2014 ENG
Relevância na Pesquisa
46.43%
Timber connections are an important part of a timber structure and a great variability exists in terms of types of connections and mechanisms. Taking as case study the traditional timber frame structures, the half-lap joint was selected. Connections play a major role in the overall behaviour of a structure, particularly when assessing their seismic response, since damage is concentrated at the connections. Therefore, an experimental campaign was carried out on traditional half-lap joints to assess their in-plane response, carrying out pull-out and in-plane cyclic tests. Subsequently, the connections were retrofitted using self-tapping screws, steel plates and GFRP sheets. In this paper, the experimental results are presented taking into account factors such as dissipated energy, damping and influence on the wall behaviour.; As ligações em madeira constituem uma parte importante das estruturas em madeira e existe uma grande variabilidade em termos de tipologia de ligações e mecânismos. Considerando como caso de estudo os edifícios com paredes de madeira tradicionais (paredes de frontal), foi adotada a ligação madeira-madeira. As ligações tem uma função fundamental no comportamento global da estrutura, em particular na analise sismica...

Full-scale experimental testing of retrofitting techniques in Portuguese “Pombalino” traditional timber frame walls

Poletti, Elisa; Vasconcelos, Graça; Jorge, Marco
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
Publicado em 25/11/2014 ENG
Relevância na Pesquisa
66.83%
Traditional timber frame walls are constructive elements representative of different timber frame buildings that are well known as one of the most efficient seismic resistant structures in the world. Timber frame walls were also used in the reconstruction of buildings of the old town of Lisbon after the earthquake of 1755 aiming at improving their seismic global behaviour. As it is important to preserve these structures, a better knowledge about their behaviour under seismic actions is important and can give some indications about possible retrofitting techniques to be used to improve the seismic performance. Due to the great rehabilitation effort currently carried out in many countries, a better understanding of retrofitting techniques is also needed. Therefore, this paper aims at providing a study on possible retrofitting techniques adopting traditional solutions such as bolts and steel plates. Static cyclic tests have been performed on retrofitted traditional timber frame walls in order to study their seismic performance. The experimental results showed the overall good seismic performance of steel plates and the more ductile behaviour of retrofitted timber frame walls with bolts.; Fundação para a Ciência e a Tecnologia (FCT)

Numerical study on the performance of improved masonry-to-timber connections in traditional masonry buildings

Araújo, Ana S.; Oliveira, Daniel V.; Lourenço, Paulo B.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
36.31%
This paper deals with a numerical study on the structural performance of masonry-to-timber connections in ancient buildings. The work is supported on an experimental campaign carried out at University of Minho, which aims at characterising a strengthening solution based on the use of injected anchors for the improvement of the connection between masonry and timber frame walls. The numerical study resorts to a detailed 3D finite element model, which reproduces the experimental test setup and proce- dure. The modelling approach adopted allows an accurate characterisation of the behaviour of all struc- tural elements, in terms of stress field and displacement distribution. The 3D model was validated against the available experimental results, which was then used to perform parametric analyses in order to eval- uate the influence of key parameters. Finally, simplified analytical approaches to estimate the strength capacity of injected anchors on masonry are presented and discussed.

An input on the characterization of timber frame structural system of tabique walls

Pinto, Jorge; Ribeiro, Sofia; Cunha, Vítor M. C. F.; Cristelo, Nuno; Lousada, José; Paiva, Anabela; Padrão, José; Varum, Humberto; Costa, Aníbal
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2014 ENG
Relevância na Pesquisa
66.79%
Tabique construction corresponds to a relevant Portuguese heritage. Urban and rural tabique construction exists all over the country. This traditional building technique started to be in disuse after the massive introduction of the reinforced concrete. Therefore, tabique buildings are already aged and, in general, they show signals of degradation. Recent research works have concluded that this degradation stage is essentially caused by the absence of a regular proper maintenance process. The fact that tabique buildings are mainly private property, that there are economical limitations and that there is still a lack of knowledge concerning this traditional building technique, have been the main reasons identified. In order to contribute solving this problem this paper intends to give an input on the characterization of timber frame structural system of tabique walls. In fact, a tabique building element is a structural system formed by a timber frame coated with an earthy render. The elements of the timber frame are nailed to each other. It has been noticed that there are different types of timber frames. Given technical information related to these alternative traditional structural solutions may be helpful in future rehabilitation processes. At the same time...

Robustness of timber structures in seismic areas

Branco, J.M.
Fonte: Universidade Nova de Lisboa Publicador: Universidade Nova de Lisboa
Tipo: Artigo de Revista Científica
Publicado em 20/06/2011 ENG
Relevância na Pesquisa
36.46%
Some of the properties sought in seismic design of buildings are also considered fundamental to guarantee structural robustness. Moreover, some key concepts are common to both seismic and robustness design. In fact, both analyses consider events with a very small probability of occurrence, and consequently, a significant level of damage is admissible. As very rare events,in both cases, the actions are extremely hard to quantify. The acceptance of limited damage requires a system based analysis of structures, rather than an element by element methodology, as employed for other load cases. As for robustness analysis, in seismic design the main objective is to guarantee that the structure survives an earthquake, without extensive damage. In the case of seismic design, this is achieved by guaranteeing the dissipation of energy through plastic hinges distributed in the structure. For this to be possible, some key properties must be assured, in particular ductility and redundancy. The same properties could be fundamental in robustness design, as a structure can only sustain significant damage if capable of distributing stresses to parts of the structure unaffected by the triggering event. Timber is often used for primary load‐bearing elements in single storey long‐span structures for public buildings and arenas...

Aerodynamic Load Characteristics Evaluation and Tri-Axial Performance Testing on Fiber Reinforced Polymer Connections and Metal Fasteners to Promote Hurricane Damage Mitigation

Canino-Vazquez, Iván R.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
36.39%
Damages during extreme wind events highlight the weaknesses of mechanical fasteners at the roof-to-wall connections in residential timber frame buildings. The allowable capacity of the metal fasteners is based on results of unidirectional component testing that do not simulate realistic tri-axial aerodynamic loading effects. The first objective of this research was to simulate hurricane effects and study hurricane-structure interaction at full-scale, facilitating better understanding of the combined impacts of wind, rain, and debris on inter-component connections at spatial and temporal scales. The second objective was to evaluate the performance of a non-intrusive roof-to-wall connection system using fiber reinforced polymer (FRP) materials and compare its load capacity to the capacity of an existing metal fastener under simulated aerodynamic loads. The Wall of Wind (WoW) testing performed using FRP connections on a one-story gable-roof timber structure instrumented with a variety of sensors, was used to create a database on aerodynamic and aero-hydrodynamic loading on roof-to-wall connections tested under several parameters: angles of attack, wind-turbulence content, internal pressure conditions, with and without effects of rain. Based on the aerodynamic loading results obtained from WoW tests...

Land use impact assessment in the construction sector: an analysis of LCIA models and case study application

ALLACKER KAREN JOSEE; SOUZA DANIELLE MAIA; SALA SERENELLA
Fonte: SPRINGER HEIDELBERG Publicador: SPRINGER HEIDELBERG
Tipo: Articles in Journals Formato: Online
ENG
Relevância na Pesquisa
26.34%
Purpose: Land use is a potentially important impact category in LCA studies of buildings. Three research questions are addressed in this paper: (1) Is land use a decisive factor in the environmental impact of buildings?; (2) Is it important to include the primary land use of buildings in the assessment?; and (3) How does the environmental performance of solid structure and timber frame dwellings compare when assessed using different available models for quantifying land use impacts? Methods: This paper compares several operational land use impact assessment models, which are subsequently implemented in an LCA case study comparing a building constructed using timber frame versus a solid structure. Different models were used for the different research questions. Results: The results reveal that different decisions may be supported by LCA study results, depending on whether or not and how land use is included in the assessment. The analysis also highlights the need to include the footprint of the building in the assessment and to better distinguish building locations in current land use impact assessment models. Conclusions: Selecting land use assessment methods that are most appropriate to the goals of the study is recommended as different models assess different environmental issues related to land use. In general...

A computer model for Chinese traditional timber structure: the Foguang Temple.

Cao, Dapeng
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado Formato: 3436680 bytes; 931824 bytes; 221827 bytes; application/pdf; application/pdf; application/pdf
Publicado em //2005 EN
Relevância na Pesquisa
36.47%
This thesis presents a study of an ancient Chinese timber structure- the main hall of the Foguang temple built in China in the Tang Dynasty (857), which is regarded as one of the most important temples in that period. The research represents a detailed digital model of the structural timber components and their connectivity. The research questions are: - Firstly, how to identify and represent the structural components, and the ways they are assembled. This is not covered in the few previous studies of the temple, which just offered brief introductions and general descriptions of the construction of the timber structure. - Secondly, how to create a digital model for such a structure where there is insufficient or incompatible information. These are common issues that arise in the simulation and representation of historic architecture. The outcome of the research is the presentation of a digital model that is much more detailed than previously existing representations. During the process, two concepts were developed and adopted: - Firstly, the concept of "building an ideal model". Rather than seeking the representation of the timber structure as built, the notion outlined in this thesis is to create an ideal digital model according to the vocabulary of structural components and the predefined spatial relations of their assembly connectivity. - Secondly...

Seismic behaviour of traditional timber frame walls: experimental results on unreinforced walls

Poletti, Elisa; Vasconcelos, Graça
Fonte: Springer Verlag Publicador: Springer Verlag
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
66.86%
Timber frame buildings are well known as an efficient seismic resistant structure and they are used worldwide. Moreover, they have been specifically adopted in codes and regulations during the XVIII and XIX centuries in the Mediterranean area. These structures generally consist of exterior masonry walls with timber elements embedded which tie the walls together and internal walls which have a timber frame with masonry infill and act as shearwalls. In order to preserve these structureswhich characterizemany cities in theworld it is important to better understand their behaviour under seismic actions. Furthermore, historic technologies could be used even in modern constructions to build seismic resistant buildings using more natural materials with lesser costs. Generally, different types of infill could be applied to timber frame walls depending on the country, among which brick masonry, rubble masonry, hay and mud. The focus of this paper is to study the seismic behaviour of the walls considering different types of infill, specifically: masonry infill, lath and plaster and timber frame with no infill. Static cyclic tests have been performed on unreinforced timber frame walls in order to study their seismic capacity in terms of strength...

Application of near surface mounted (NSM) strengthening technique to traditional timber frame walls

Poletti, Elisa; Vasconcelos, Graça; Jorge, Marco António Peixoto
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2015 ENG
Relevância na Pesquisa
66.65%
Timber frame buildings are well known as an efficient seismic resistant structure popular all over the world not only due to their seismic performance, but also to their low cost and the strength they offer. These constructions still exist today and it is important to be able to preserve them, so a better knowledge on their behaviour is sought. Furthermore, historic technologies could be used even in modern constructions to build seismic resistant buildings using more natural materials with lesser costs. A great rehabilitation effort is being carried out on this type of buildings, as their neglect has led to decay or their change in use and alterations to the structure has led to the need to retrofit such buildings; only recently studies on their behaviour have become available and only a few of them address the issue of possible strengthening techniques for this kind of walls. In this scope, an innovative retrofitting technique (near surface mounted steel flat bars) is proposed and validated on traditional timber frame walls based on an extensive experimental program. The results of the static cyclic tests on distinct wall typologies retrofitted with the NSM technique are herein presented and discussed in detail. The main features on deformation...

La madera en la construcción de entramados inclinados de viviendas unifamiliares. Situación actual en España; Timber in domestic roof construction. Present situation in Spain

González Rodrigo, Beatriz
Fonte: Consejo Superior de Investigaciones Científicas (España) Publicador: Consejo Superior de Investigaciones Científicas (España)
Tipo: Artículo
SPA
Relevância na Pesquisa
36.61%
La madera estructural está encontrando un nicho importante de mercado en la construcción de entramados inclinados de madera, impulsada por las normativas vigentes, las políticas gubernamentales y los nuevos productos y subproductos de la madera. En el presente artículo se presentan los diferentes sistemas constructivos en madera empleados en entramados inclinados, analizando su comportamiento estructural y determinando las ventajas y desventajas de cada uno de ellos. Se incide en los sistemas de entramado pesado de par e hilera y par y picadero, que son los que están teniendo una mayor acogida en la construcción de entramados inclinados en madera, frente al sistema de entramado ligero. Finalmente se compara el comportamiento térmico de los diferentes sistemas constructivos de madera presentados con el de un sistema tradicional de cubierta ventilada de teja curva cerámica sobre tabiquilla según el CTE (Código Técnico de la Edificación). En este análisis se comprueba que la madera tiene un comportamiento térmico igual al sistema tradicional de teja y en además permite abaratar en tiempos de montaje.; Structural timber is playing an increasing role in the market and construction of domestic roofs, pushed by existing regulations...

Choptank

Lush, Richard
Fonte: Universidade de Delaware Publicador: Universidade de Delaware
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
26.34%
Choptank or the J. Clayton Farm is situated on the east side of route 435, .65 miles south of its intersection with route 432. The house and related outbuildings stand amidst cultivated fields at the end of drive extending 400 feet east of route 435. The nominated area extends along the drive from route 435 in a rectangle back to a pond at the rear of the property, and from 200 feet north of the barn to 200 feet south of the main house.

Perceived obstacles to multi-storey timber-frame construction: an Australian study

Xia, B.; O'Neill, T.; Zuo, J.; Skitmore, M.; Chen, Q.
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
Publicado em //2014 EN
Relevância na Pesquisa
56.66%
The contemporary default materials for multi-storey buildings – namely concrete and steel – are all significant generators of carbon and the use of timber products provides a technically, economically and environmentally viable alternative. In particular, timber's sustainability can drive increased use and subsequent evolution of the Blue economy as a new economic model. National research to date, however, indicates a resistance to the uptake of timber technologies in Australia. To investigate this further, a preliminary study involving a convenience sample of 15 experts was conducted to identify the main barriers involved in the use of timber frames in multi-storey buildings. A closed-ended questionnaire survey involving 74 experienced construction industry participants was then undertaken to rate the relative importance of the barriers. The survey confirmed the most significant barriers to be a perceived increase in maintenance costs and fire risk, together with a limited awareness of the emerging timber technologies available. It is expected that the results will benefit government and the timber industry, contributing to environmental improvement by developing strategies to increase the use of timber technologies in multi-storey buildings by countering perceived barriers in the Australian context.; Bo Xia...

Timber frames as an earthquake resisting system in Portugal

Poletti, Elisa; Vasconcelos, Graça; Lourenço, Paulo B.
Fonte: Taylor & Francis Group Publicador: Taylor & Francis Group
Tipo: Parte de Livro
Publicado em //2015 ENG
Relevância na Pesquisa
56.53%
Timber frames are commonly adopted as a structural element in many countries with specific characteristics varying locally, in termsof geometry and materials.Their diffusion in Southern European countries is linked to their good seismic-resistant capacity, but only in the last decade interest has grown for this structural typology, and studies have been performed to better understand their behaviour. In this contribution, a brief state of the art on existing timber frame building typologies is presented, focusing on their seismic-resistant characteristics. Additionally, an overview of possible strengthening solutions, adopted both in practice, and tested experimentally are presented. Their performance when applied to walls and connections is also discussed.

Traditional timber frame walls: mechanical behavior analysis and retrofitting

Vasconcelos, Graça; Poletti, Elisa
Fonte: IGI Global Publicador: IGI Global
Tipo: Artigo de Revista Científica
Publicado em //2015 ENG
Relevância na Pesquisa
66.87%
Timber frame construction is characteristic of several historic city centres as well as of vernacular architecture in several countries around the world, either motivated by the availability of materials and construction traditions or by the need of reducing the seismic vulnerability of buildings, namely in south European countries, where this construction technique was adopted for seismic-resistance purposes. From past earthquakes, it has been seen that timber frame construction can be viewed as an interesting technology as it has exhibited a very reasonable behaviour when compared to other traditional construction techniques such as masonry walls. This chapter provides an overview of the main insights on the seismic performance of timber frame buildings from the evidences of past earthquakes and provides the main results of recent research focused on the in-plane cyclic behavior of timber frame walls with distinct geometrical configurations. Additionally, the main seismic performance indexes of timber frame walls, both unreinforced and retrofitted, are presented and discussed in detail.

Local seismic cultures: the use of timber frame structures in the south of Portugal

Ortega Heras, Javier; Vasconcelos, Graça; Rodrigues, Hugo; Correia, Mariana
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2015 ENG
Relevância na Pesquisa
46.61%
Given the fact that using timber frame structures has proven to improve the seismic behavior of vernacular architecture, as has been reported in past earthquakes in many countries, its preservation as a traditional earthquake resistant practice is important. This paper firstly intends to evaluate whether the use of timber frames as a traditional seismic resistant technique for vernacular architecture in the South of Portugal, traditionally a seismic region, is still active. Secondly, the city of Vila Real de Santo António was selected as a case study because it also followed a Pombaline development contemporary to the reconstruction of Lisbon. The plan included the provision of timber frame partition walls for some of the buildings and, thus, an overview of the type of constructions originally conceived is provided. Finally, the alterations done in the original constructions and the current state of the city center are described and the effect of these changes on the seismic vulnerability of the city is discussed.