APPLICATION OF BAMBOO FIBER AS SUB GRADE SOIL REINFORCEMENT CASE OF ELGO TOWN

Abstract

Naturally existing soil at a construction site may not always be suitable for foundation of different structures such as buildings, bridges, highways and dams. Soils at in-situ conditions may behave very loose indicate high deformation, instability and compressibility. These can produce structural and non-structural defects. To solve such problems, soil improvement is necessary in order to make stable and strengthen such soils. For this research work, the sample soils were collected from Elgo town from six test pits with the depth of 60 cm below natural ground level after the removal of site clearance. The percentage of fiber used to stabilize the loose soil were 0.5%, 0.75%, 1% and 1.25% weight of dry soil and the lengths of fibers were 10 mm 20 mm 30 mm and 40 mm. The general objective of this research is to investigate the use of bamboo fiber as subgrade soil reinforcement. Test results indicate that the increase of OMC and CBR values as the increase of fiber content and fiber lengths. Inversely the result of MDD is decrease as the increase of fiber content and length. The maximum dry density reduces from 1.86 g/cm3 at 0% bamboo content to 1.71 g/cm3 at 1.25% bamboo content whereas the OMC increases from 17.9% un- reinforced sample to 22.83 % at 1.25% bamboo reinforced soil sample. The effect of reinforcement length on MDD and OMC are decreasing from 1.86 g/cm3 to 1.71 g/cm3 and increasing 23.8 g/cm3 respectively for fiber length ranged from 0 mm to 40 mm. The results of CBR test results indicate the inclusion of content and length of fiber reinforcement. The maximum value of CBR test results for 1 % bamboo content at 0 mm, 10 mm, 20 mm, 30 mm and 40 mm fiber length are observed as 12.2, 13.31, 13.34 and 13.36 respectively. The optimum content of reinforcement on which the maximum CBR value obtained is 1%. This significant increase of CBR value will make minimum thickness of pavement. Keywords: Bamboo, Fiber, Stabilization, Subgrade, Reinforcemen