Improving the Strength Characteristics of Red Clay Soil Using Waste Plastic Strips
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Date
2020-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Soil stabilization is the physical and chemical alteration of soils to enhance their physical
properties. Stabilization can increase the shear strength of a soil and control the shrink-swell
properties of a soil, thus improving the load-bearing capacity of a sub-grade to support
pavements and foundations. Stabilization can be used to treat a wide range of sub-grade
materials from expansive clays to granular materials. The cost of introducing traditionally
available stabilizers has increased in recent years which opened the door widely for the
development of other kinds of soil stabilizers such as plastics, bamboo etc.
The research is basically conducted by waste plastic strip and red clay soil found in KecheneRas
Desta
road.
The
significance
of
the
study
is
to
provide
alternative
stabilization
material
in
construction
industry.
The
objective
of
this
study
is
to
improve
the
strength
characteristics
of
soil
using the
stabilization
of
plastic
strips.
In this regard an attempt has been made to evaluate the effect of plastic strip as a stabilizer on
the geotechnical properties of red clay soil in stabilized form mainly strength and compaction
characteristics. The preliminary investigation of the soil to be stabilized shows that it belongs to
A-7-5 class of soil in the AASHTO soil classification system. Soils under this class are generally
of poor engineering use. Therefore, series of laboratory tests such as Atterberg limits, free swell
index, compaction, UCS and soaked and unsoaked CBR tests for different percentages of plastic
were performed. The soil was stabilized with plastic in stepped concentration of 0%, 0.5%, 1.5%,
2.5%, 3.5%, 5%, and 7.5% by dry weight of the soil.
The analysis shows slight improvement on the geotechnical properties of plastic stabilized soil.
The plastic strip is found to increase the unconfined compressive strength of the soil up to 5% of
plastic (75.01 kPa to 196.14 kPa) and CBR result of the red clay soil up to 2.5% (soaked CBR
from 3.5% to 5% and unsoaked CBR from 80.3% to 108.7%). Due to plastic’s light weight
property the MDD of the soil shows slight increase up to 2.5% of plastic from 1.4g/cm3 to 1.53
g/cm3, and as the ratio of the plastic increased in the clay soil the result decreases.
Description
Keywords
Red clay Soil, Plastic strip, Soil stabilization, Atterberg limit, Compaction, UCS, CBR value