EFFECTIVENESS OF THE TREATMENT OF FINE-GRAINED LATERITIC SOIL USING  SUGARCANE BAGASSE ASH (SCBA) FOR  USE IN MODERN DAY CONSTRUCTION

EFFECTIVENESS OF THE TREATMENT OF FINE-GRAINED LATERITIC SOIL USING  SUGARCANE BAGASSE ASH (SCBA) FOR  USE IN MODERN DAY CONSTRUCTION

ABSTRACT

Sugarcane as an agricultural product is a readily available source of food for its sugar content.  However, Sugarcane Bagasse Ash (SCBA) is the bi- product formed at sugar industries from the burning of sugarcane after the sugar content has been extracted.  Sugarcane Bagasse Ash (SCBA) is a fibrous waste product containing mainly aluminum and silica, calcium ions to produce calcium aluminate hydrate (CAH) and calcium silicate hydrate (CSH) shown in the  pozzolanic reaction below. 

Ca²⁺ + 2(OH)^– + Al₂O₃ (clay alumina > CAH

Ca²⁺ + 2(OH)^– + SiO₃ (clay silica)) > CSH

Over the years, sugarcane has posed adverse hazardous environmental impacts due to the poor disposal methods. From research, sugarcane bagasse ash (SCBA) has been found to improve the stability and overall suitability of any type of soil for engineering (construction) purposes amongst other uses. 

During my project, 1%, 2%, and 3% sugarcane bagasse ash (SCBA) was mixed with equivalent proportions by weight of dry laterite soil.  

Results:

1. The liquid limit (LL) increased from 35% to 46% and gradually decreased to 41% with increase in sugarcane bagasse ash (SCBA) content.
2. The plastic limit (PL) increased from 22.5% to 28.3% and gradually increased to 32.9%.
3. The plastic index (PI) increased from 12.5% to 17.7% and gradually decreased to 8.1 with increase in sugarcane bagasse ash (SCBA) content.
4. The shear strength increased gradually I.e. C= 17KN/m² @ 20^o showing a relatively increased cohesion as angle reduced.
5. Moisture content remained relatively same between (17.5 – 19.2) % as dry density reduced from 1.738g/cm³ to 1.702g/cm³

The California Bearing Ratio (CBR) values increased gradually from 20.11% to 26.06%. Addition of increased SCBA content is however necessary to attain minimum CBR standard of 30%. (BS 1990).

KEYWORDS: Sugarcane, Sugarcane Bagasse, Sugarcane Bagasse Ash (SCBA),

Agricultural Waste, Stabilization, Treatment, Atterberg Limits ((Plastic (PL) & Liquid (LL) Limits) & Plastic Index (PI)), Shear Stress, California Bearing Ratio (CBR), Compaction, Fine-Grained Soil, Particle Size Distribution.

CHAPTER ONE

INTRODUCTION

1.1    BACKGROUND OF STUDY

Every Engineering structure has a lifespan. This is greatly influenced by the stability of the soil it is constructed on. For a soil to be stable and suitable for engineering purposes, it needs to effectively resist by evenly distributing lateral and vertical displacements and disturbances caused by induced stresses developed within the soil due to the structural pressure.

 

1.1.1 Soil Stabilization

The term ‘Soil stabilization’ is used to describe the application of necessary improvement tests and methods used to effectively predetermine and improve the engineering property of any type of soil by the addition of binder material (Sugarcane Bagasse Ash (SCBA), Cement, Lime) etc, chemical materials (calcium chloride) etc and mechanical (vibration) compaction. The engineering property of a soil are density, strength (shear, bearing), durability, degree of compaction, permeability, swelling, shrinkage etc.

The application of the methods of soil stabilization helps to improve the engineering properties of soil and as such effectively distributing the load over a greater surface area of the soil.

(Nasiru, 2019).

 

1.1.2 Laterite Soil

Soil is the topmost surface of the earth crust composed of accumulation of organic and inorganic substances such as minerals, gases, water, decomposed trees, leaves and organisms. It is primarily used as a foundation to support the growth of micro-organisms, trees, construction of Engineering structures etc.

 

A laterite or lateritic soil is a type of soil having both cohesive (silt and clay) and cohesionless (sand and gravel) property. It is primarily composed of compounds of aluminum (Al) and iron (Fe). It is formed by the weathering of parent rocks. It is found in hot and wet tropical regions of the world. Owing to its method of formation, it contains organic matters, sulphates, sulphides and carbon-dioxide resulting in the instability and less desirability of the soil for engineering uses. (K., et al., 2009).

 

1.1.3 Sugarcane, Bagasse & Sugarcane Bagasse Ash (SCBA)

1. Sugarcane is an agricultural product readily available in major tropical regions of the world. It is consumed domestically and industrially mainly for its sugar content.
2. Sugarcane Bagasse is the fibrous residue obtained after the initial extraction of the sugar content from sugarcane.

 

1. Sugarcane Bagasse Ash (SCBA) is the fine black ash obtained from the burning of sugarcane bagasse. Sugarcane bagasse ash (SCBA) is found to contain mainly aluminum (Al) and silica (Si) ions.

The burnt sugarcane bagasse was passed through B.S. sieve No. 200 (0.075mm) to obtain sugarcane bagasse ash (SCBA). This is done to meet the BS 1924 (1990) requirements.  

 

1.2     RESEARCH PROBLEMS

In considering a soil for engineering purposes (road, building, bridges) etc, the stability of the sub-grade level of that soil predetermine the life-span of such structure. However, in other to improve on the life-span and durability of a built Engineering structure, the soil it is to be being erected on should be tested and researched on and improvement methods should be adopted.

 

1.3     JUSTIFICATION FOR RESEARCH

1. Cost – The use of sugarcane bagasse ash (SCBA) compared to other stabilizers e.g. lime, cement is low cost effective.
2. Environment – The use of sugarcane bagasse ash (SCBA) as a stabilizer is effective since it is readily available as an agricultural waste.
3. Time – The use of sugarcane bagasse ash (SCBA) compared to other stabilizers e.g.

lime, cement is time effective since it is readily available.

 

By improving on the Engineering property of any type of soil found within the country using sugarcane bagasse ash (SCBA), there would be significant improvements on the lifespan and durability of constructed Engineering structures.

 

1.4     AIM AND OBJECTIVES OF RESEARCH

1.4.1 Aim of Research

I aim to determine the effectiveness of the treatment of fine-grained lateritic soil using Sugarcane Bagasse Ash (SCBA) for use in modern day construction.

 

1.4.2 Objectives of Research

Using sugarcane bagasse ash (SCBA) considering its availability as an agricultural waste and binder additive property, fine-grained laterite soil can be efficiently improved and stabilized.

My objectives are:

1. Determine the availability by volume in thousand metric tonnes of sugarcane production as an agricultural product.
2. Determine the suitability use of (1%, 2%, 3%) by weights of sugarcane bagasse ash (SCBA) content to mix and treat/stabilize fine-grained lateritic soil for the purpose of road, building construction.
3. Determine the overall socio, economic and environmental impact use of sugarcane bagasse ash (SCBA) as an agricultural product to treat soils for construction purposes.

 

1.5     PROBLEM STATEMENT

Generally, soil is strong and can bear direct imposed pressure and stresses but is so limited as such it should be treated/stabilized otherwise it could result in structural and infrastructure failures as experienced in recent years.

 

1.6     RESEARCH METHODOLOGY

The following methodologies was adopted during the research:

1. Literature review: Textbooks, research journals & papers were reviewed and used.
2. Laboratory Testing: Identification, analysis, sampling and testing was conducted on the collected materials to determine the stabilization effects.
3. Discussions: Using data and results, conclusions and recommendations was obtained.
4. Thesis compilation: The thesis was compiled using a, b, c above.

 

1.7     SCOPE OF STUDY

Prior to its use for engineering purposes, the degree of stability of soil should be determined by testing and improvement methods should be applied where necessary. Over the years, research and experiment such as Compaction, Consolidation, Atterberg Limits (Liquid Limits (LL), Plastic Limits (PL) and Plastic Index (PI)), California Bearing Ratio (CBR) have been conducted to determine the effectiveness of the treatment of fine-grained laterite soil using sugarcane bagasse ash (SCBA) for modern day construction.

EFFECTIVENESS OF THE TREATMENT OF FINE-GRAINED LATERITIC SOIL USING  SUGARCANE BAGASSE ASH (SCBA) FOR  USE IN MODERN DAY CONSTRUCTION