ENEMS MICROSYSTEMS RESEARCH SPOT: 2023 at 10:06AM

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).

Tuesday 17 January 2023

EFFECTS OF PALM KERNEL SHELL ASH ON SOIL STABILIZATION

EFFECTS OF PALM KERNEL SHELL ASH ON SOIL STABILIZATION