Experimental Study on the use of Bamboo as Structural Reinforcements in RCC Structures

Bamboo is a natural material obtain from plants family. It is fast growing, light weighted, renewable and environment friendly. Bamboo material is very interesting topic in construction for research. Bamboo has good tensile strength; from a study it is found that tensile strength specific weight ratio of bamboo is twenty times more than that of steel. An experimental investigation of bamboo characteristics and bamboo as reinforcement in concrete study is carried out in this paper. Here we have focused on to identify water absorption in bamboo during curing period and flexure strength of bamboo reinforce beam, cracking pattern and other experimental value to step more towards bamboo as alternative to steel. Keywords—Bamboo, Reinforcement, flexure, compresssion, tension, naturally available construction material.


I. INTRODUCTION
In recent year, many researchers around the world have already begun to explore the use of low cost and low energy substitute construction materials. [1] Among the many possibilities for such substitutions Bamboo, which is one of the fastest growing plants, has great potential. [2] [4] Bamboo has been used in construction of bridges and houses for thousands of years in Asia. Bamboo takes less energy to harvest and transport. [3] Bamboo is hygroscopic material thats why it also absorbs moisture from surrounding hence determination of properties, improve over moisture absorption and bamboo reinforcement in concrete beam has been investigated by the authors in the lab and results are presented. [  Since Bamboo is a hygroscopic material having tending to absorb moisture from air and surroundings. In green concrete bamboo splints absorb moisture and swells, when the concrete becomes dry the bamboo splints contracts and creates spaces between the contacts, the bamboo-concrete bond strength decreases and member fails in bond. Hence water absorption is one of the main drawbacks of bamboo, when it is used as reinforcement in concrete so our main aim is to perform this test to find out percentage of water absorb by bamboo and percentage of volume increase.
We have taken six (WA1, WA2, WA3, W1, W2, W3) sample of bamboo specimen of 50*50mm2 and let it dry for 24hrs in an oven. After that the specimen was allowed to cool for 30 minute. 3 Specimen painted with water proof coating (W1, W2, W3) but remaining three were not. Calculation of dimension, weight was made initially. Then all the 6 samples were allowed to soak in water at normal temperature pressure.
Reading for changes in dimension and weight was made at every 24-hour interval for next 28 days.    Bamboo splints of 12*12mm2 were used as reinforcement. Bamboo splints were tied in frame of 55cm length and within 10*10cm2. Binding bar is use to tie. Since bamboo absorbs water so a moisture resistance paint was applied over bamboo splints. Bamboo reinforced concrete beam of 150*150*600mm3 were casted with clear cover of 25mm. For casting beam, we have used mix designed concrete grade of M25. After 28 days of curing, beams were subjected to standard Flexure test and the flexural strength was calculated. The experimental analysis is done for compressive strength of bamboo specimen. And it was found that compressive strength of bamboo specimen with node has greater strength than that of specimens without node this could be because of additional cross-sectional area at nodes and due to the dense mass present at nodes. Some of the specimen showed an ideal failure by cracking longitudinally but most of them showed a mixed mode of failure where in the specimen cracked as well as got crushed and buckled along length.
As per result an average ultimate tensile strength of bamboo splints is 160 MPa which is comparatively lower than the yield strength of structural steel i.e. 250MPa. But bamboo splints can resist sufficient tensile loads in a concrete flexure element. All the bamboo specimens shown brittle failure.
The water absorption value is decreased by using moisture resistant paint and can help in maintain strength and shrinkage and swelling problem.
Bamboo Reinforced Concrete Beam follows same pattern those in steel reinforcement elements. The ultimate moment is 50.733MPa i.e. good result for short building. After testing, cracks are developed at the mid span in beam i.e. flexural type failure.