Bamboo Deployable Structural Systems: An Exploration Study in Responding to Rapid Alteration Challenges

Abstract

the conventional notion of architecture and the built environment is that they are meant to be relatively static and final, once constructed according to the well prepared plans based on users’ needs and wants. That notion, however, overlooks the reality that change is inevitable during a building’s lifetime. That change arrives in the form of userrelated factors such as new or growing functional requirements and aesthetic aspirations. The change has affected and will continue to affect the dwelling habits, which in turn will affect the way the built environment is perceived and delivered. The conventional construction method that relies on the assumption of a static and ascertain future will find it difficult to sustainably and ecologically accommodate the changes. The transformable capability of architecture and the built environment, supported with the use of natural and renewable material, can offer a plethora of solutions to that contemporary challenge. The deployable structural system, which has the ability to transform from compact to predetermined configuration, offers a prospective opportunity to create building structures that can adapt to the necessity of both rapid and gradual alternations. Coupled with the use of bamboo, a notable renewable material, the promotion of deployable bamboo structure(s) will have a positive impact on the effort to realize the sustainable architecture. This research explored and compared four designs of deployable bamboo structures with planar and spatial scissor-like elements (SLE) systems. Through these experimental projects, the research aims to discover the application of the deployable structures with appropriate bamboo technology to meet the challenge of transformations of sizes and dimension in building; and the generated variations in building form, space and dimension. The research concludes that deployable bamboo structures with the SLE planar system have the size and functional adaptability to create more variants of building form, space, and dimension to the user’s flexibility. Meanwhile, the greatest potency of S-SLE is the compactness, because it has fewer additional elements and it even has self-locking mechanism. Keywords— sustainable architecture, deployable structure, bamboo, scissor-like element I. BACKGROUND The conventional notion of architecture and the built environment is that they are meant to be relatively static and final, once constructed according to the well prepared plans based on users’ needs and wants. That notion, however, overlooks the reality that change is inevitable during a building’s lifetime [1]. Change arrives in the form of userrelated factors such as new or growing functional requirements and aesthetic aspirations [2]. The other forms of change are related to what Andjelkovic defined as “sociallydemographic destabilization” to describe forced displacement of people by dramatic economic downturns, social clashes, wars, as well as disasters-both natural and man-made [3]. The above-mentioned changes have affected and will continue to affect the dwelling habits, which in turn will affect the way the built environment is perceived and delivered. The conventional construction method that relies on the assumption of a static and ascertained future will find it difficult to sustainably and ecologically accommodate the changes. The transformable capability of architecture and the built environment, supported with the use of natural and renewable material, can offer a plethora of solutions to that contemporary challenge. II. METHODS This research explores and compares four designs of deployable bamboo structures with planar and spatial scissorlike elements (SLE) systems. Through these experimental projects, the research aims to discover the application of the deployable structures with appropriate bamboo technology to meet the challenge of transformations in the sizes and dimension of buildings; and the generated variations in building form, space and dimension. A. Design Inclusive Research The four experimental designs were part of the research method that Horvath called “design inclusive research (DIR)” [4][5].The design process is considered as the essential activity in design-related research that Horvath proposed as a specific characteristic that discern academic research in this subjects from the other conventional scientific research conducted Horvath’s first phase of the DIR is the “Explorative Research Action” [5] in which researchers/designers conduct observation of phenomena and/or cases related to the particular research area(s) as stated in section I (Background). The researchers also complement the observation with exploration through theories and methods through literature studies on the research topic (Section III). A certain (design) problem(s) should be defined and hypotheses in the form of (design) criteria should be formulated as the outcomes of this phase. Copyright © 2019, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). 56 Advances in Engineering Research, volume 156 57 The second phase is the “Creative Research Action” [5] where the experimental design processes were conducted based on the criteria from the first phase. Researchers experimented with concepts and models as the means to test the formulated hypotheses/criteria. The variants were studied through scaled analog models which were subsequently evaluated based on the criteria. Potential variants were then proceeded to be developed into 1:1 scaled models or prototypes as described in Section IV and V. Afterwards, they were evaluated once again based on the same criteria to see how the performance differed from the scaled ones in order to verify and validate the hypotheses to produce useable knowledge on the specific topic of this paper, which makes it the third phase of Horvath’s DIR (Section VI). These two phases are also the focus of this paper. Fig. 1. Research Framework B. Limitation Based on the discussion at Point I.C about adaptability, the criteria used in this research are adjustability, extendibility, versatility, appropriateness, move-ability, refitability and recyclability (Fig.2). However, this paper limits itself within the context of three main aspects of the deployable structure system: first the adjustability, second the extendibility, and last the versatility, which are related to the aspect of spatial geometry. The conducted (design) studies on both aspects were discussed on the aspects of the structural system and structural module. The others, which related to construction technology, will be discussed later. The adjustability factor requires and evaluates the design variants in terms of their capacity to fulfill multiple possibilities of adaptation in the user’s needs and wants. This factor directed the (deployable) structural system aspect to have a compact stowed state that needs to be installed easily and work perfectly, with the smallest number of movements/actions possible by the user, while the structural module aspect was directed to offer the potential of providing various building shapes and/or forms through the arrangement of identical structural modules. The extendibility factor requires that the deployable structure system(s) has the capability to transfer loads acting on the building in its deployed state and other loads while being stowed or transported, which directed the design to have adequate structural redundancy. This factor also evaluates the structural modules’ capability of repetition along X, Y & Z axis, and the capability of the structural span’s adjustability. The versatility factor evaluates how both the deployable structural systems and their respective modules can offer degrees of adaptability in the spatial profile, spatial dimension, and grid system(s). The versatility factor posed the question how each variant can be easily adapted to the challenge of change in needs and functions that require alteration of spatial shape(s) and dimension(s) in future circumstances. Fig. 2. Research Limitation The other factors (appropriateness, move-ability, refitability and recyclability), which are related to technological aspects will not be discussed in this paper. Advances in Engineering Research, volume 156 58 III. LITERATURE STUDIES A. Bamboo as Structural Material Traditionally, bamboo as a construction material is wellknown in South Asia, East Asia and the South Pacific, because of its abundance. Although bamboo has been popular as construction material for the poor, the use of bamboo has intensified recently since people recognize its sustainable values. Bamboo has a very strong fiber that is regarded as one of the building material with high tensile strength at approximately 28,000 N per square inch, which is higher than steel [6]. Moreover, the compressive strength of bamboo is two times higher than concrete. The drawback of bamboo as a structural material, which has always been questioned, is the issue of durability against insect attacks and rot. Consequently, bamboo requires thorough material preservation before being used as a structural material. Durability can also be achieved through a good architectural design [7]: keeping bamboo from direct contact with the ground, providing good natural air flow, and protection from rain and sunlight through wide overhangs. B. Deployable Structures Deployable structure is one of the two classes of transformable structure [8][9], with the other class is known as kits-of-parts. The transformable structure as the general category itself can be defined as any structural system that is Fig. 3. Scissor-Like Element (SLE) Based on this simple generic composition, various modifications can be made to allow different movement patterns, planar SLE or spatial SLE as well. The combination of this basic module with other similar or modified generic modules at a certain connectin