Pre-Engineered Construction Using Bamboo Portal Frame
Mukul Gupta1, Suresh Bhalla2, Diwakar Bhagat3, Roger P. West4, Aarti Nagpal5 1
Former Undergraduate student, Department of Civil Engineering, IIT Delhi, New Delhi 110016;
[email protected] 2 Associate Professor, Department of Civil Engineering, IIT Delhi, New Delhi 110016 Email:
[email protected] 3 Research Scholar, Department of Civil Engineering, IIT Delhi, New Delhi 110016 4 Associate Professor, Department of Civil, Structural and Environmental Engineering, Trinity College, University of Dublin, Dublin 2, Ireland 4 Assistant Professor, School of Planning and Architecture, IP estate, New Delhi 110002
ABSTRACT This paper covers new advancements undertaken by Trinity College, University of Dublin, in collaboration with research group (BRG) at IIT Delhi in the area of sustainable construction. Bamboo is an eco-friendly construction material which is natural and grows quickly with fewer resources as compared to timber. The paper focuses on the development of bamboosteel fixtures to enable connections and weld ability, followed by testing of moderate capacity built up beams. A full scale bamboo portal frame has been fabricated and installed at IITD by assembling all the components as a proof-of-concept modular sustainable construction.
1. INTRODUCTION Bamboo is a versatile, strong, renewable and environment-friendly material. It is a member of the grass family, and the fastest growing woody plant on earth. Most bamboo species produce mature fibre in three to four years after sowing, much sooner than any tree species. It can grow on marginal and degraded land, elevated grounds, along field bunds and river banks, and can be harvested in 3 to 5 years cycles. It adapts to most climatic conditions and soil types, acting as a soil stabilizer, an effective carbon sink and aiding to counter the greenhouse effect (Bhalla et al., 2008). Although throughout the past, especially in India, it has been used in rural buildings, it needs to be characterized for strength and other properties. Also, scientific design approach needs to be developed on lines of concrete and steel before can be used in an economical fashion for widespread modern urban as well as rural construction. Recently, there has been rapid progress in this regard as a result of the ground breaking work done by the bamboo research group (BRG) IIT Delhi in collaboration with Trinity College, University of Dublin, Ireland. This paper briefly presents an overview of the recent developments in this front, starting from material characterization, and development of
scientific design methodology and development of pre-engineered modular components, both moderate and high capacity. 2. DEVELOPMENT OF STEEL-BAMBOO COMPOSITE CONNECTIONS Suitable steel-bamboo composite connections have been developed and characterized to impart weld ability to the built up columns and beams. The connection does not involve any drilling in the bamboo culm. The fixture is attached to the culm by tightening two half split pipe pieces using bolts tightened to a specific torque value, as illustrated in Fig (1). Several specimens of fixtures were tested in compression at varying torque values and steel clamps. The maximum ultimate strength achieved was 43kN for dry specimens, which gives an allowable axial load of 10.7 kN (considering a factor of safety of four), which is satisfactory for the particular design problem considered in the project (Gupta, 2014).
Figure 1: Steel-bamboo composite connections
3. DEVELOPMENT OF MODERATE CAPACITY BUILT UP BAMBOO BEAMS
A new type of built up beams consisting of bamboo culms tied together by half-split bamboo battens and steel clamps using steel fasteners have also been developed by BRC at IIT Delhi, as illustrated in Figs (2) and (3). Different combinations of clamping system were investigated experimentally. Experiments under two-point flexural loading were performed along with strain measurements at critical locations. The member could withstand a maximum load of 20 kN. The details of the experiments can be found in Gupta et al. (2014).
Figure 2: Strain gauge locations on built-up bamboo beams
Figure 3: Two point loading on built-up bamboo beam
4. DESIGN AND FABRICATION OF PRE-ENGINEERED BAMBOO PORTAL FRAME A pre-engineered bamboo portal frame was analyzed and designed for wind and dead loads. All the frame components after proper experimentations, were assembled together to fabricate full scale bamboo portal frame at IIT Delhi. The complete erection process can be visualized through video link available at: http://web.iitd.ac.in/~sbhalla/video.html.
(a)
(b)
Figure 4: (a) Pre-engineered bamboo portal frame. (b) Proposed model. Possible applications of this system include construction of cattle sheds, ware houses and rural industrial sheds. They can also possibly be employed to construct stylish activity centres in colleges and commercial hubs, a typical artistic impression of one such centre is shown in Fig. (4). Wind load analysis of a typical frame can be accessed from the related project reports Gupta (2014) and Chauhan (2012).
5. CONCLUSIONS This paper has presented new developments undertaken by BRC at IIT Delhi in collaboration with Trinity College, University of Dublin. Suitable steel fixtures have been developed to impart connect ability to the members, including welding. Built-up bamboo beams have also been developed through rigorous experimentation. A complete full scale bamboo frame has been fabricated. The entire fabrication can be carried out in a workshop in rural settings and the final fabrication be done with fast speed at the site using the principles of pre-engineered construction. The technology has immense potential for countries like India which have large wastelands and suitable climate where bamboo species can be easily cultivated.
6. REFERENCES 1) Bhalla, S., Gupta, S., Puttaguna, S. and Suresh, R. (2008), “Bamboo as green alternative to concrete and steel for modern structures”, J. Env. Res. & Dvpt., Vol. 3 (2): 362-370. 2) Bhagat, D., Gupta, M. and Bhalla, S. (2013), “Composite bamboo junction elements for structural applications”, Proc. Innovative Techniques in Civil and Environmental Engineering (SITCEE-2013), 05-06 June, Jawaharlal Nehru University, New Delhi(Published in special edition in the Int. J. of Civil Engg. & Appls.), Vol. 3(7):3641. 3) Chauhan (2012), “Analysis and design of bamboo based cowshed”, B. Tech. Project, Department of Civil Engineering, IIT Delhi. 4) Gupta, M., Bhagat, D. and Bhalla, S. (2013), “Design and strength analysis of steelbamboo fixtures for pre-engineered bamboo portal frame”, Proc. Innovative Techniques in Civil and Environmental Engineering (SITCEE-2013), 05-06 June, Jawaharlal Nehru University, New Delhi (Published in special edition in the Int. J. of Civil Engg. & Appls.), Vol 3 (7):42-46. 5) Gupta, M. (2014), “Engineered bamboo structures for sustainable construction”, B. Tech. Project, Department of Civil Engineering, IIT Delhi.
