Flexural behaviour of large scale concrete elements reinforced with bamboo

Author: Maritim, Nelson Kipkemboi

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : MSc

Year: 2004

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Civil engineering ; Concrete ; Bamboo ;

Pages: 153

Advisors: Antony Monda/Raphael N Mutuku

Abstract:

This research study is on bamboo culms as an alternative material for concrete reinforcement in low cost housing. In this research the commonly found bamboo species in Kenya Arundiraria Alpina was used to reinforce concrete beams, which were then subjected to flexural test. Other tests like tensile, compression, shear, pull-out test of bamboo and steel in concrete were also done in order to understand the basic properties of bamboo as a reinforcement material. Various tests such as compression, tension splitting and flexural testing prisms were also conducted on the concrete, in order to ensure that the concrete used met the required standard. The strength tests of bamboo obtained and those of previous investigations carried out by other researchers depict bamboo to be a fairly strong material that can be used as a substitute for steel reinforcement. The mean tensile strength of seasoned bamboo is 197.61 Nzmm' and 251.28 Nzmm? for bamboo with and without nodes respectively. The average composite strength of bamboo reinforced concrete beams is 105.5 Nzmm- at 28 days, which is about a half the actual tensile strength of seasoned bamboo. The average Elastic modulus of bamboo is 23.31kN/mm2 for seasoned bamboo and the mean interfacial bond strength of quarter bamboo in concrete is 1.99 Nzmm? at 28 days, which is about 25 % that of structural steel in concrete, which was determined as 7.78 Nzmm- at 28 days. The results show that splitting of bamboo reinforcement into different shapes ???improves the interfacial bond because the newly exposed surface is rougher than the outer surface. Also, it is noted that arranging bamboo reinforcement splits with their concave facing upwards (HBU and QB) enhances bamboo reinforcement stiffness than those with their concave facing downwards (HBD) and whole bamboo culm (FB). This resulted to higher composite strength in HBU and QB reinforced concrete beams than those ofFB and HBD reinforced concrete beams. It is concluded that the use of splitted longitudinal aligned continuous bamboo in the reinforcement of concrete gives rise to significant improvement of the mechanical properties of concrete. The recommendation is made that bamboo pieces with an average width of 20mm and with their concave part facing upwards, could be used to reinforce concrete beams.