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
