Experimental determination of flexural strength of Bholuka bamboo (BambusaBalcooa) of Assam, India

Abstract

In everyday life bamboo occupies a prominent place and is extensively used for both structural and non-structural purposes. Being a material that compares favourably with timber in strength, bamboo is increasingly being used in many structural applications like posts, pole fencing, scaffoldings, house building, etc. Bamboo has been used worldwide in various construction works as an alternative to steel and wood as bamboo is more fibrous and has more tensile strength than steel. Possibilities of construction of boats with bamboo using traditional knowledge enriched with advanced techniques could be visualized and eventually local Bholuka Bamboo of Assam was found to be very useful for construction of the boat hull using the lower thick stem of the whole Bholuka Bamboo.The work investigates the bending strength of the locally grown Bholuka Bamboo. Lime water treated bamboo stems are shaped roughly into square logs by cutting arcs from two sides. Both circular and square section stems of gauge lengths over 300 mm are deflected in Universal Testing Machine (UTM). The direct bending strength test gives an ultimate breaking load and ultimate stress as 13.10kN and 4 MPa for the circular cross section whereas 15.85kN and 5 MPa for square cross section respectively. Three point bending test conducted on Instron-Dynamic UTM on specimens taken from freshly felled culms, preferably from the lowest section of the culm containing nodes at two ends. Half section of the total length of 345 mm is considered for the test. The flexural test for I-section beams of the bamboo yields a Modulus of Elasticity of 3762.94 MPa which is 87.5 % less than Charotar bamboo and 57.9 % less than Moso bamboo.