Evaluation of bamboo for building elements satisfying housing criteria

Bamboo – identified as a Non Timber Forest Product (NTFP) – offering optimal mechanical properties for construction purposes, and at the same time little studied among contemporary building materials, is paradoxically most used in precarious housing. The use of natural resources within the context of sustainable development is nowadays considered a subject of vital importance, especially in the construction industry, considered as being the largest consumer of world energy. This work concerns itself with two fundamental contemporary issues: the use of natural resources as a contribution to sustainable development and precarious housing. The topic of housing among the different problems relating to the construction industry is one of the most critical in developing countries since poverty entails precariousness in various aspects of the habitat and particularly in housing. The aim of this thesis is to validate a construction element designed using bamboo as its main constituent. Therefore in the first part, before presenting the composite bamboo structure, the CBS panel (an element designed within the framework of this thesis), the theme of precarious housing in relation to bamboo is examined. A final part gives insight into the appropriation and application of the proposed CBS panel. The first part, devoted to the link between bamboo and precarious housing, analyses the problems concerning social housing in developing countries. To identify how bamboo's use for construction is related to the social habitat, precarious housing is evaluated on the basis of the world view and aspirations of inhabitants. This will help determine the challenges involved in the construction proposals put forward to reduce the complex problems of social housing in the South. In this search, the reality of intermediate cities is examined to obtain a better understanding of the urbanisation phenomenon of metropolises versus the deterioration of the rural habitat within the context of globalisation (Chapters 1 and 2). The second part is devoted to presenting the composite bamboo structure (CBS panel) carrying out simple four-point load bending tests resulting in values that guarantee the element's load-bearing capacity, establishing the existence of a composite behaviour between bamboo and concrete. An experimental study, allowing the interaction between bamboo and concrete to be identified, was carried out. The use of bamboo in construction is validated via mechanical tests, studying the mechanical properties of bamboo and identifying high tensile strength, and confirming the weakness of bamboo, a longitudinal separation parallel to the grain. The investigation contributes to improvement by means of fibre reinforcement: natural, such as jute, and artificial, such as glass fibre, with compression tests made parallel and perpendicular to the fibre (Chapters 3, 4, 5 and 6). The third part concerns the study of appropriation and application criteria, applied to the composite bamboo structure (CBS panel). This part contains theoretical elements and a descriptive study with qualitative methodology that explores appropriation by various populations of Latin America, all involved with a construction project. This revision confirms the hypothesis that social appropriation is a complex issue that includes cultural, social and psychological elements, which are part of the emerging phenomenon of human settlements in precarious areas. The production of social housing is based on the study of the relationship between bamboo, its morphology, its applicability as construction system and the spaces that can be generated. Consequently the different possible forms of housing are presented, developing details of connections between the housing elements, and their chain of production. Quality control is identified as being the most important stage to guarantee the final product. Failure to carry out this control would be to jeopardise the success of not only the CBS panel but also the use of bamboo as resource. We also demonstrate that appropriation of a technology for a target group must be considered not only in relation to this group, but also introduce its use to a superior target group, since the reference factor is important (Chapter 7).

New Vernacular Architecture as Appropriate Strategy for Housing the Poor

Sytse de Maat

Improving living conditions of the poor often involves a drastic change in lifestyle, in order to fit daily life into industrially produced dwellings. Slum rehabilitation programs replacing informal settlements with standardized mass housing, have often resulted in a mismatch of inhabitants and their built environment. Participation strategies meant to counter this problem, show little effect unless the user is in charge. What is the problem with development and participation? This chapter will discuss ‘housing the poor’ as a case to illustrate how industrialization and systemization are at odds with participation. We will consider two ways of producing housing: industrial mass housing, and informal settlement. The focus is on the connectedness of the user, the inhabitant, with his dwelling. It will lead to the observation that participation aims at meeting the diversity that is natural to human beings, whereas systemization requires and produces the opposite: uniformity. Moreover, the term user-participation implicitly states the user is an outsider participating in developers' projects, which after all are dominated by the interests of the construction industry. An Appropriate Technology - approach in housing the poor would benefit from a focus on user-building interaction as it taps directly into people’s most powerful resource: creativity. Western systemization is not the only route to improvement. Strategies based on vernacular are at least as effective, appropriate, and humanly sustainable.

Springer Verlag2012

New Vernacular Architecture as Appropriate Strategy for Housing the Poor

Sytse de Maat

Springer Verlag2012

Méthodologie multicritère d'aide à la décision pour le renouvellement urbain à l'échelle du quartier

Maria Gracia Riera Perez

The present work develops a new methodology for assessing urban renewal scenarios at the neighborhood scale. Entitled URBIUS, this methodology seeks to meet the needs of municipalities in terms of planning for the development of their urban built fabric. It is now widely recognized that the urban population growth, along with the increase in the use of private vehicles, has led to a generalized urban sprawl. This land use is not sustainable in environmental, social and economic terms. Because most European cities are in this situation, it appears necessary to bring new developments within the urban built fabric, in order to raise their density. However, to rely on densification alone is not sufficient in order to move towards a more sustainable urban environment and to attract new residents looking for quality living spaces. Therefore, the transformation of the city requires a holistic vision, integrating different objectives. In this perspective, the neighborhood scale has been identified as an operational scale which integrates both the specific objectives of stakeholders taking part in the making of the city and the broader objectives of the city itself. In this context, this work seeks to contribute to the inward development of the cities in a qualitative way, by providing URBIUS, a new methodology for assessing the sustainability of urban renewal strategies at the neighborhood level. Prior to the creation of this methodology, an operational definition of sustainable neighborhoods has been developed. This one includes six goals: to ensure the feasibility of the urban renewal strategy, to provide housing to all residents, to balance the supply of jobs and housing, to save energy resources, to upgrade the local natural resources and to promote the balance between density and urban quality. Hence, the methodology is structured following these six goals and declines them in criteria and indicators for the purpose of the assessment. For each indicator, both quantitative and qualitative, assessment thresholds are set: a limit value and a target value. These thresholds are used to assess the strategies positively if the value is better than the target value, negatively if it is worse than the limit value, and uncertain for values lying between the limit value and the target value. However, in order to adjust the assessment to the specific potential of a neighborhood, an adaptation technique has been developed based on a dynamic approach. The assessment thresholds are adapted depending on the evaluation of the existing state of the neighborhood and on its underlying trend, that is to say the assessment of the neighborhood at a given time whereas no special action is planned. Finally, the new methodology is tested on four neighborhoods taken as case studies. The chosen neighborhoods have all a good quality public transportation system, with potential for densification and capacity to provide quality living space. They are located in the canton of Vaud, Switzerland: Lausanne, Prilly, Echallens and Yverdon-les-Bains. This work highlights the potential of urban renewal strategies at the neighborhood scale in the process of the transformation of the city towards greater sustainability and the contribution of sustainability assessment methodologies. In this sense, URBIUS is a relevant methodology to assist and foster sustainable urban renewal. Now it is up to the key stakeholders to undertake such efforts in urban renewal in a concerted and sustained effort.

EPFL2016

Méthodologie multicritère d'aide à la décision pour le renouvellement urbain à l'échelle du quartier

Maria Gracia Riera Perez

EPFL2016