No. 36-21 Journal of Structural Engineering Vol. 36, No. 3, August-September 2009 pp. 164–171 Theoretical and experimental investigation on single and double bolted bamboo joint under axial tension I. P. Sonar , * and V. R. Siddhaye ** * Civil Engineering Department, Govterment Polytechnic, Malvan, Sindhudurg, Maharashtra 416 606, India. ** Applied Mechanics Department, Govterment College of Engineering, Pune, Maharashtra 411 005, India. Received 21 May 2008; Accepted 10 October 2008 Bamboo is the strongest known natural fiber material available abundantly in the world. Highest growing and yielding rate, resistance to weathering action, high strength to weight ratio make the bamboo a versatile material for temporary or semi permanent low cost construction. Considering physical and strength properties of bamboo, it can be used as the structural member for plane and space trusses such as truss, grid, dome, etc used as roof-supporting structures. Different types of bamboo joints for round bamboo have been suggested by researchers. Use of half splint bamboos as structural members and joints with mild steel plate as gusset is an innovative concept suggested by the first author. An extensive experimental program was undertaken by the author to determine various mechanical properties of (Dendracalamus Strictus) bamboo and to examine the behavior of single bolted connection of bamboo under axial tension. Based on the test results, further theoretical investigation on the development of double bolted bamboo joint is carried out. To verify the strength and efficiency of these bamboo joints under axial tension, specimens with double bolted joint were tested under axial tension and results are compared with theoretical values. It is observed that experimental load carrying capacity of the proposed member and joint is more than predicted value. Considering strength capacities of the suggested bamboo steel composite joint and member, it has enough potential by giving proper treatment to replace conventional steel angle sections for plane and space trusses for construction of temporary and semi-permanent structures. KEYWORDS: Structural use of bamboo; bamboo bolted connection under axial tension; bearing failure in bamboo joint. Bamboo as an Engineering Material Bamboo is the strongest known natural fiber material abun- dantly available in the country. Highest growing and yield- ing rate, resistance to weathering action, high strength-to- weight ratio make bamboo versatile building material for construction industry. It is not surprising that bamboo has been called nature’s fiber glass. Some research works 1-5 has been carried out on various aspects of low cost bamboo hous- ing which include bamboo reinforced slabs, beams, bamboo- crete wall panels and roofing elements. Many scientists 6-8 have carried out research work on durability aspects of bam- boo and they have suggested different techniques and meth- ods, coatings and materials to improve durability and life of bamboo. Janssen 3 in his paper has outlined the state of the art on durability, mechanical properties, housing, bamboo- reinforced concrete, etc. In his thesis, Janssen 3 describes the enormous efficiency of the material bamboo. With the avail- ability of advanced coating material and treatment methods, it is possible to improve durability and life of bamboo. The research activities so far have mainly been directed towards biological questions and to a lesser degree to the equally im- portant field of utilization. The limited research on the uti- lization aspects of bamboo is mostly properties oriented and not product oriented. Bamboo as Structural Member for Plane and Space Truss Janssen 3, 9 has stated that the use of bamboo in building is limited by a lack of knowledge of how to make joints in bamboo. Usually, joints in bamboo structures are compli- cated and labour intensive, and the structural safety is un- known. Only a few references have been published. Among the temporary structures, the scaffolding is well known. In summary, research is required on joints with an emphasis on strength, safety and simplicity. In the opinion of the au- thor, scientific research can considerably enlarge the oppor- tunities of traditional building methods related to use of bam- boo. Considering strength properties of bamboo, it has high potential to utilize as structural member for plane and space truss. A few research works has been carried out on bam- boo trusses and space frames. Some researchers 4, 9 have tried to use bamboo as a structural member for plane frames and  E-mail: ishwarpsonar@rediffmail.com (Discussion on this article must reach the editor before October 31, 2009) 164 JOURNAL OF STRUCTURAL ENGINEERING VOL. 36, NO. 3, AUGUST-SEPTEMBER 2009