Geotechnical Properties of Cocopeat Soil

This assignment delves into the geotechnical behavior of cocopeat soil. It outlines procedures for conducting standard penetration tests (SPT) to determine soil density and shear strength, and oedometer tests to analyze consolidation characteristics. The document explains the significance of these tests in understanding the engineering properties of cocopeat soil.

Engineering Behaviour of Clay Reinforced with Cocopeat 1
ENGINEERING BEHAVIOUR OF CLAY REINFORCED WITH COCOPEAT
An Experimental Paper on Cocopeat By
Student’s Name
Name of the Professor
Institutional Affiliation
City/State
Year/Month/Day

Engineering Behaviour of Clay Reinforced with Cocopeat 2
ABSTRACT
This paper is about the engineering behaviour of the clay soil reinforced with cocopeat. The
cocopeat is a fibre that is naturally found in the coconut’s husks. The process of extraction of
the fibre from the husks of the coconut produces 100% natural cocopeat. The clay used in this
experiment was a natural clay gotten from the site of Sungai Kebun Bridge with the plasticity
index of 15.9%, plasticity limit of 22.5%, and liquid limit of 38.4%. The clay soil then
underwent processes such as crushing and drying followed by sieving which will only allow
425 μm to pass through. The samples of clay soil which were reinforced with numerous
inclusions of the cocopeat that is 2.5%, 2.0%, 1.5%, and 1.0% and of diverse sizes of 30mm,
20mm, and 10mm were tested with an aim of determining the impacts on consolidation
behaviour as a result of the cocopeat inclusion.

Engineering Behaviour of Clay Reinforced with Cocopeat 3
INTRODUCTION
Background Information
Soil can be defined as the particles of minerals that have been formed through the process of
rock weathering. The clay soil is characterized by low permeability because of its high water
holding capacity. It is for this reason why the clay soil possesses great challenges to the
construction and engineering industries globally and it is not recommended for carrying or
holding heavy loads of any construction above the soil.
Problem Statement
The major reason behind the ground improvement is to enhance the features of the soil. Some
of the methods of ground improvement include vibrated compaction, vertical drains, lime
stabilization, grouting, and soil reinforcement. Through stabilization of the condition of clay
soil, the issue of settlement can be barred. The swelling and shrinkage of the soil can be
minimized hence leading to the increase in its stability specifically for the work of
construction (Akhtar, 2013).
Aims and Objectives
The major aim of this study is to investigate the behaviour of the non-reinforced and
cocopeat-reinforced and clay soil through undertaking the consolidation test. This study will
portray how the characteristic of soil consolidation is effected by the cocopeat inclusion. For
this study to be achieved, the following are some of the objectives put in place:
i. To examine the characteristics of the clay soil in agreement to BS 1977
ii. To determine the experimental to determine the impacts of cocopeat on maximum
moisture content and optimum dry density.
iii. To evaluate a suitable method of installation of cocopeat in clay soil.
iv. To carry out numerous consolidation test through:
a) Variation in the percentage of cocopeat inclusion
b) Variation of the length of the cocopeat.

Engineering Behaviour of Clay Reinforced with Cocopeat 4
v. To analyse the numerous series test done to evaluate the impacts of length and
inclusion on the behaviour of clay soil.
LITERATURE REVIEW
The earlier research on soil reinforce with cocopeat and the effects of consolidation of clay
are analysed in this section which majorly focuses on the techniques, techniques, and end-
results of the research in relation to the effects on the soil and different categories of cocopeat
inclusion.
Characteristics of Cocopeat Reinforced Cohesive Soil
The content of the cocopeat used were in the range of 0 to 1% with an extra 0.2% of the dry
weight of clay soil and with dimensions of 10mm, 15mm, and 20mm. The sample preparation
was performed by random mixing and distribution of cocopeat on top of the clay soil with the
addition of water (Chegenizadeh, 2014). The results of the experiment above realized the
figure below:
The results above portrays that 0.6% of the cocopeat content is the least value of compression
index (Cc). Fig 2 below shows the consolidation curves for the clay soil unreinforced and the
clay soil with cocopeat:

Engineering Behaviour of Clay Reinforced with Cocopeat 5
The Effects of Cocopeat on the Strength and CBR Value of Clay Soil
By using cocopeat of 0.1 mm diameter and 5 mm of length, the compression test which is not
confined with different content of cocopeat proportion of 1%, 2%, and 3% with the ratio of
the aspect of 50 being maintained were performed. The results of undrained compression test
obtained from the experiment are as shown in figure 3 below:
The results above portrays that the soil’s strength was greater in the soil possessing reinforced
cocopeat than the virgin soil (Choudhry, 2014). There was also an improvement of shear
strength of the soil up to 2% inclusion of cocopeat, but after this, the strength reduces as
portrayed in fig above. The results of CBR Test is as shown in figure 4 below:
Behaviour of Strength of Clay Soil Reinforced with Cocopeat
The Tri-axils test, direct shear box, and unconfined compression were performed with an aim
of determining the behaviour of the strength of the soil. The experiment on tri-axils test
shows that there is an improvement in the behaviour of stress-strain of the soil as portrayed in
fig 5 below:

Engineering Behaviour of Clay Reinforced with Cocopeat 6
The shear strength of the clay soil reinforced with cocopeat increases with 0.4% of the
cocopeat added and then begin to decrease as portrayed in the results of the Tri-Axial test
below:
There is an increase in the cohesion value of the clay soil due to an addition of cocopeat. It is
also clear that when the content of cocopeat was increased for the test of unconfined
compression, the compression strength initially increased and then begin to decrease as extra
cocopeat is added (Estabragh, 2010). The optimal length of cocopeat was found to be 10mm
and 15mm and the optimum inclusion was 0.2% and 0.3%.
SUMMARY
Table 1
Table 1 portrays the consolidation factor and shear strength of the unreinforced and cocopeat
reinforced clay soil:
(Kaniraj, 2014)

Engineering Behaviour of Clay Reinforced with Cocopeat 7
Table 2
No
.
Authors
and Year
Material
Fibre
Performed
Test
Sample Preparation Outcome
1 (Kaniraj,
2014)
(Maher,
2012)
(Naeini,
2012)
Cocopeat Tri-axial
Test
Direct shear
box test
Series: 0%, 0.5%,
1.0%, 1.5%, 2.0%, and
2.5%
Length: 10mm, 15mm,
and 20mm
In Tri-axial test, the rise in cocopeat rises
the stress failure and main principle gain
strength with 150 aspect ratio of the
cocopeat.
Indirect shear box test, the strength of
cocopeat rises up to the inclusion of 0.4% at
20mm length and 100 aspect ratio was
optimum.
2 (Vasan,
2017)
(Torgersonb,
2015)
Cocopeat California
Bearing
Ratio Test
Unconfined
Compression
Test
Diameter: 0.1mm
Length: 5mm
Series: 1%, 2%, and
3%
In both the tests, the optimum cocopeat
content was 2% without any significant
increase after 2%, this is due to the poor
interlocking amongst soil particles and
elements of cocopeat. When additional
cocopeat was added, there was no variation
observed.
3 (Suits,
2011)
(Shukla,
2016)
(Pradhan,
2013)
Cocopeat Test of one-
dimensional
consolidatio
n
Length 10mm, 15mm,
and 20mm
The Cc optimum value at the cocopeat fibre
content of 0.6% and fibres of coir of 0.8%.
This is due to extra contact between the
cocopeat inside the clay chance making it
dormant
METHODOLOGY
From the literature review, the extra analysis and investigations on the performance of
cocopeat inclusions on clay are to the evaluated depending on the techniques and procedures
which will be discussed in this section.
Material Used
Natural Clay
The clay used in this experiment was a natural clay gotten from the site of Sungai Kebun
Bridge with the plasticity index of 15.9%, plasticity limit of 22.5%, and liquid limit of 38.4%.
The clay soil then underwent processes such as crushing and drying followed by sieving
which will only allow 425 μm to pass through. The minerals of clay can be defined
geologically be defined as phyllosilicate possessing tetrahedral and octahedral sheet

Engineering Behaviour of Clay Reinforced with Cocopeat 8
arrangements. In the process of structural arrangements formation by layer, the spaces
between layers amid the sheets of octahedral-tetrahedral that is stacked may be filled or
empty with water cations or molecules. The water holding capability of clay soil is high and
this provides the soil with an additional feature of low permeability which leads to swelling
that can result in soil expansion hence becoming weak (Naeini, 2012).
Cocopeat
Cocopeat is a natural fibre gotten from the husks of coconut and can be white or black in
colour. A coconut that is mature have brown cocopeat and are usually thick, resistant to
abrasion and strong while white cocopeat gotten from husks of mature coconut are readily
available, tough, durable, resistant to fungi and rot, and are not affected by moisture. The
cocopeat extracted from the husks of mature coconut were divided into three dissimilar
lengths of 30mm, 20mm, and 10mm to be utilized in the experiment and possess a mean
diameter of 0.4mm (Choudhry, 2014). The divided cocopeat was then mixed randomly with
clay soil to ensure a homogenous spread of the mixture as shown below:
Testing Equipment
Consolidation and compaction by the use of oedometer are the dual experiments to be done in
this assessment. This section describes the equipment used in testing with an aim of outlining
the analysis and procedures after the test to get the results and for advance discussion.
Compaction

Engineering Behaviour of Clay Reinforced with Cocopeat 9
The compaction of soil is critical before proceeding with the test of consolidation.
Compaction minimizes the amount of air in the sample of soil through packing the particles
of soil closer. The procedure of compaction test is as explained below. The mould is first
cleaned by the use of the brush (Maher, 2012). The mass of mould is measured with the base
using electronic balance. 150 ml of water measured using measuring cylinder is then added to
the 3kg of the sample of soil. Water and soil are then mixed by the use of spatula until a
homogeneous mixture is achieved.
The soil surface is then pressed and secured under the rammer machine. The rammer is then
set to 27 blows and the machine is then started for the compaction of soil to begin. The
procedure is repeated by the addition of extra layers of soil until three layers are compacted
with 27 blows. The collar should then be unlocked and lift up. The soil should then be
removed from the mould by taking approximately 100g of the sample for the determination
of the moisture content. Two samples are then engaged for every soil sample to get the
moisture content value (Kaniraj, 2014).
Oedometer
An oedometer is an instrument used in determining the soil characteristics. It is consolidation
test of one-dimension with two-drainage where specifically perpendicular load is applied to
the stress. Soil consolidation is when the extra pore pressure of water is dissipated out of the

Engineering Behaviour of Clay Reinforced with Cocopeat 10
soil through the bottom and top porous disk. The consolidation behaviour of cocopeat was
analysed by carrying out the experiment in accordance with BS 1377. The soil sample
preparation is the disc form were compacted inside a ring of consolidation as shown below:
A porous disk that is clean is inserted firmly into the cell and then filter paper at the top. A
ring of consolidation possessing the sample is then positioned top right of the filter paper and
the second paper for filtering positioned at the sample’s top. After the cell of oedometer is
ready, the unit is assembled and the load cell’s height adjusted to about 1mm on the cell’s top
cap. Water is then allowed inside the cell and the following parameters obtained; the
compression index (Cc), the coefficient of permeability (k), the coefficient of volume
compressibility (mv), and coefficient of consolidation (cv) (Kaniraj, 2014).
The value of mv calculated will be used in determining the coefficient of permeability of soil
k which can be determined by the eqn 5:

Engineering Behaviour of Clay Reinforced with Cocopeat 11
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