ENEMS MICROSYSTEMS RESEARCH SPOT: soil stabilization

Showing posts with label soil stabilization. Show all posts

Tuesday, 17 January 2023

EFFECTS OF PALM KERNEL SHELL ASH ON SOIL STABILIZATION

EFFECTS OF PALM KERNEL SHELL ASH ON SOIL STABILIZATION

Abstract

The mechanical properties of soft clay soils encountered in construction works consist of unconfined compressive strength, stiffness, tensile strength, brittle behavior, ductility, and axial strain, undrained shear strength, elasticity, plasticity, permeability, porosity, shrinkage, durability. This known deficiencies have to be corrected by means of stabilization and palm kernel shell ash was used to modify this known characters of clayey soil, below is the summary of the test carried out in the laboratory. The presence of SiO2, presented the palm kernel shell ash as a siliceous material, possessing pozzolanic properties due its high SiO2, Al2O3, and Fe2O3 contents. The palm kernel shell ash was classified as a ‘class f’ fly ash due to the 10% (LOI) taken, in accordance with ASTM C618-92a.The clay soil was classified as an A-7-6(20), with the ’20’ indicating the group index of the soil. It was described by AASHTO as a clayey material and rated as a fair to poor soil. The group index of 20 described the soil as one having a low bearing capacity. From the sieve analysis test conducted a percentage of 91.1 passed through the 75um sieve. With a liquid limit of 77.8% > 50% it was identified as an organic soil, with a plasticity index of 50.1 it was identified as a highly plastic soil. A maximum dry density of 1.36kg/m3 at two different moisture content of 13.99% and 23.03% respectively but the optimum moisture content of 23.03% was taken. A CBR value of 9.25% unsoaked and 1.75% when soaked, for the natural condition of the soil,

that is, without the PKSA admixture., which failed to meet the minimum requirement stipulated by the Nigerian Highway Officials of 15% CBR, indicating that the material is inadequate as a subgrade material alone, at its free or natural state. With the addition of palm kernel shell ash at 3%, 6%, 9%, 12% and 15% optimum values of CBR were obtained for the unsaoked CBR, with values of 19.8% and

20.2% for PKSA’s at 9% and 12% respectively. An optimum value for the soaked sample was attained at a CBR value of 20.3% at 9% PKSA, with a simulated peak value from the statistical model, of 21% CBR at 10% PKSA though un- experimented. Therefore, giving 9% of PKSA as the optimum amount of PKSA additive required to stabilize this soil.

CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

Land based structure of any type is only strong as its foundation. For that reason, soil is a critical element influencing the success of a construction project. Soil is either part of the foundation or one of the raw materials used in the construction process. Therefore, understanding the engineering properties of soil is crucial to obtain strength and economic importance. One of the major reasons for structural failure particularly in pavement design is non-availability of generalized relevant data of the particular soil involved in the area of construction and how these soils respond to atmospheric, moisture and temperature. Cases under design of pavement strength have been recorded largely due to assumption of subgrade properties involved which resulted to failure. To be cost effective, pavement should be constructed over good subgrade materials therefore, remove early failure such as potholes, raveling, shoving, rutting and so on. The cost of construction material is often exorbitant, particularly when most of the materials have to be imported. It is preferable to construct with locally available material that may have limited durability but cost effective. Onyelowe (2016). It will be necessary to understand the rheology of clayey soils and also the stabilization processes in soil improvement.

These are the properties that determine deformation potentials of soils, treated or untreated. The rheology properties of the test soil are determined through laboratory study on the behavior of soils at failure. So it is the establishment of the maximum values beyond or below which a construction material is considered unstable.

In general, soft clay soils are expansive soils that require improvements in their mechanical properties to enable them meet the requirements to be used as foundation materials or hydraulically bound materials.

1.2 Significance and Importance of the Study

Due to the problems associated with expansive soils on engineering structures i.e. the deformation produced as a result of swelling and shrinkage of soils; it is necessary that a means of improving the structural qualities of the soil such as the compressive be devised.

It has been discovered that agricultural wastes such as Palm Kernel Ash (PKSA), Groundnut Shell Ash (GSA), Coconut Shell Ash (CSA), Saw Dust Ash (SDA) etc. have the ability to stabilize soils to an optimum for constructional uses. It will be wise to optimize the use of this agricultural waste in construction, after validating their reliability for constructional uses. Processed palm kernel shell ash (PKSA) is the ash produced from burning of palm kernel shell and it is a byproduct of palm oil mills.

The ash has pozzolanic properties that enables it as a partial replacement for cement and also plays an important role in soil stabilization as well as strength and durability of concrete.

Palm kernel shell ash has yet to be utilized to a great extent as a constructional material but blended palm kernel shells have been used to modify lateritic soils because of their good interlocking characteristics, low specific gravity and high porosity. Palm kernel shell ash will continue to be abundant, as industrial waste product will continually be created.

1.3 Research Aim and Objectives

The am of this study is to investigate the effect of palm kernel shell ash on soil stabilization. The specific objectives inc the following:

To produce PKSA and determine its chemical and elemental properties.
Determine the physical and engineering properties of the soil provided, and classify the soil.
Investigate the influence of Palm Kernel Shell Ash on the engineering properties of the soil sample.
Develop statistical models to relate the strength indices and determine the optimum Palm Kernel Shell Ash content (OPKSA) required for stabilizing the soil sample to meet requirement for constructional works.

1.4 Scope of Study and Limitation

This study is focused on, and limited to the use of Palm kernel Shell Ash on soil stabilization.

The Palm Kernel is the fruit of the oil palm plant (elaeis guineesm), grows naturally in West Africa where it is abundant in the wild and has developed into an agricultural crop.

The palm kernel shell, which is the crushed shell housing the palm kernel seed. It is an economic valuable tree that is wide spread throughout the tropics.

In Malaysia, oil palm plantations cover over 5 million hectares, and an annual production of oil palm kernel shell (OPS) as solid waste from 450 oil palm mills is more than 6 million tones. This large amount of OPS as a renewable green aggregate can contribute to overcoming the over dependence on the depletable resources of concrete production. The civil engineering projects are of a large scale; they need sustainable materials in order to gain a greater momentum of growth. The major technical characteristics of OPS solid waste must be primarily understood before each particular use, therefore, there is need to highlight the importance of OPS to be used in the construction industry. (Mannan 2017).

Monday, 16 January 2023

STABILIZATION OF BLACK COTTON SOIL WITH GROUNDNUT SHELL ASH USING BRITISH STANDARD LIGHT COMPACTION ENERGY

STABILIZATION OF BLACK COTTON SOIL WITH GROUNDNUT SHELL ASH USING BRITISH STANDARD LIGHT COMPACTION ENERGY

ABSTRACT

The study is a potential stabilization of black cotton soils in Gombe state using Groundnut Shell ash. Index properties of the natural soil showed that, the soil belongs to A-7-6 in AASHTO classification system and CH in USCS classification system. This indicate a poor soil for engineering use. Liquid limit and Plasticity index values of 83.36 % and 89.32 % respectively for the natural soil suggest that the soil is highly pastic. There was gradual decrease in the free swell to a minimum value of 2.91% at 10% GSA as compared to the natural value of 15.25%. The soaked CBR for the natural soil is 1.67% which increased to 2.17% at 10% GSA. This value fell short of specification requirement of the CBR value to be used as sub-base or base material. For the electrokinetic test, pH test, considerable increase to a peak value of 9.2 while the peak CEC is 70.50mol/kg at 0% GSA. The durability of samples determined in terms of resistance to lost in strength failed to meet the 80% resistance to loss in strength. This concludes that the groundnut shell ash cannot be used as stabilization for black cotton soil as stated by Stephen (2006) However, there was increase in strength for UCS of 21 days curing period from a value of 134kN/m² as compared to 313kN/m² for the unstabilized soil.

CHAPTER ONE

INTRODUCTION

1.1 PREAMBLE

Generally, lands with Black Cotton soils are fertile and very good for agriculture, horticulture, sericulture and aquaculture. Good irrigation systems exist, rainfall is high and people are affluent in these areas. Though black cotton soils are very good for agricultural purposes, they are not so good for laying durable roads. Good road network is a basic requirement for the all round development of an area. Unfortunately, poor road network is hampering the full fledged development of the otherwise prosperous areas. (Bhavanna Rao, 2005).

Application of solid waste (Groundnut Shell Ash) disposal for soil stabilization is a significant which serves various benefits to the environment. The term solid waste includes all those solid and semi solid materials that are discarded by the community. Improper management of solid waste causes adverse effects on ecology which may lead to possible outbreaks of diseases and epidemics. The over dependence on industrially manufactured soil improving additives (cement, lime etc) have kept the cost of construction of stabilized road financially high. This hitherto have continued to deter the underdeveloped and poor nations of the world from providing accessible roads to meet the need of their rural dwellers who constitute large percentage of their population which are mostly rural farmers. Furthermore, the World Bank has been expending substantial amount of money on research aimed at harnessing industrial waste products for further usage. (Oriola and Moses 2010).

Black cotton soils are expansive clays with potential for shrinking or swelling under changing moisture condition. The soils are formed under conditions of poor drainage from basic rocks or limestones under alternating wet or dry climatic conditions. They usually exhibit high shrink-swell characteristics with surface cracks, opening during the dry seasons which are more than 50mm or more wide and several mm deep. These cracks close during the wet season and an uneven soil surface is produced by irregular swelling and heaving. Such soils are especially troublesome as pavement sub-grades. (Osinubi, 1997)

Groundnut Shell is an agricultural waste obtained from milling of groundnut. In the world, the total hectare planted to groundnut is over 20 million hectares per year. It is estimated that over 2 million hectares are planted on groundnut in Nigeria. Groundnuts are mostly intercropped. Groundnut contains about 25% Protein and 45 to 50 % oil. The skins are high in Vitamin B. Groundnut can be decorticated by hand-operated decorticating machine. (NAERLS, 2009)

In this work, an exercise is done to utilize groundnut shell ash (GSA) to improve the engineering performance of Black Cotton soil which may be an economical solution of soil stabilization.

1.2 Justification of the Research

In Nigeria, and the world at large; the cost of constructing stabilized roads is financially high. This is apparently due to the over dependence on industrially manufactured soil improving additives (cement, lime etc). The high amount of money spent has continued to invalidate poor and underdeveloped nations of the world from making accessible roads available to meet the standard of their rural dwellers that constitute large percentage of their population. On the other hand, the safe disposal of waste products from industries and agriculture has been hitherto a challenging issue demanding urgent solution because of the decline effect of these materials on the environment and the hazardous risk it pose to the health of humanity.

Thus, it is greatly required to consider the use of agricultural waste (such as Groundnut Shell Ash- GSA ) in improving the engineering properties of the soil, in this case Black Cotton soil (BCS) when used in road construction will considerably reduce the cost of construction and as well as eradicate or reduce the environmental and hazardous risk of such wastes. Hence, this research is justifiable in the use of Groundnut Shell ash to stabilized Black Cotton soil.

1.3 AIM OF RESEARCH

This research is aimed at evaluating the possibility of utilizing groundnut shell ash (GSA) in the stabilization of black cotton soils.

1.4 OBJECTIVES OF THE RESEARCH

The following objectives are devised for this research work and are summarized below.

To investigate the pozzolanic properties of Groundnut Shell Ash.
To examine the physical and engineering properties of black cotton soil treated with various percentage of Groundnut Shell Ash (0% – 10%) using British Standard Light compactive effort.
To contrast between the engineering properties of natural black cotton soil and engineering properties of the treated soil.
To investigate the electrokinetic properties of virgin BCS treated with GSA
To carry out durability and strength assessment tests on natural and treated BCS

1.5 SCOPE AND LIMITATION OF THE RESEARCH STUDY

This research is focused on stabilizing black cotton soil treated with various percentage of Groundnut Shell Ash (0%, 2%, 4%, 6%, 8% and 10% by dry weight of soil). All these tests are carried out at their respective Optimum Moisture Content limited to British Standard Light Compactive effort.

STABILIZATION OF BLACK COTTON SOIL WITH GROUNDNUT SHELL ASH USING BRITISH STANDARD LIGHT COMPACTION ENERGY

ABSTRACT

The study is a potential stabilization of black cotton soils in Gombe state using Groundnut Shell ash. Index properties of the natural soil showed that, the soil belongs to A-7-6 in AASHTO classification system and CH in USCS classification system. This indicate a poor soil for engineering use. Liquid limit and Plasticity index values of 83.36 % and 89.32 % respectively for the natural soil suggest that the soil is highly pastic. There was gradual decrease in the free swell to a minimum value of 2.91% at 10% GSA as compared to the natural value of 15.25%. The soaked CBR for the natural soil is 1.67% which increased to 2.17% at 10% GSA. This value fell short of specification requirement of the CBR value to be used as sub-base or base material. For the electrokinetic test, pH test, considerable increase to a peak value of 9.2 while the peak CEC is 70.50mol/kg at 0% GSA. The durability of samples determined in terms of resistance to lost in strength failed to meet the 80% resistance to loss in strength. This concludes that the groundnut shell ash cannot be used as stabilization for black cotton soil as stated by Stephen (2006) However, there was increase in strength for UCS of 21 days curing period from a value of 134kN/m²as compared to 313kN/m² for the unstabilized soil.

CHAPTER ONE

INTRODUCTION

1.1 PREAMBLE

In this work, an exercise is done to utilize groundnut shell ash (GSA) to improve the engineering performance of Black Cotton soil which may be an economical solution of soil stabilization.

1.2 Justification of the Research

1.3 AIM OF RESEARCH

This research is aimed at evaluating the possibility of utilizing groundnut shell ash (GSA) in the stabilization of black cotton soils.

1.4 OBJECTIVES OF THE RESEARCH

The following objectives are devised for this research work and are summarized below.

To investigate the pozzolanic properties of Groundnut Shell Ash.
To examine the physical and engineering properties of black cotton soil treated with various percentage of Groundnut Shell Ash (0% – 10%) using British Standard Light compactive effort.
To contrast between the engineering properties of natural black cotton soil and engineering properties of the treated soil.
To investigate the electrokinetic properties of virgin BCS treated with GSA
To carry out durability and strength assessment tests on natural and treated BCS

1.5 SCOPE AND LIMITATION OF THE RESEARCH STUDY