Introduction

Lateritic soil comprises of any type of zonal soils that is formed under humid tropical forest vegetation. Lateritic soils are usually granular in size, dark reddish brown in color and commonly found in the leached soils of the humid tropics and is formed under weathering systems that cause the process of laterization (Helgren and Butzer, 1977; Gidigasu,1976). Laterites are formed from the leaching of parent sedimentary rocks (sandstones, clays, limestone); metamorphic rocks (schists, gneisses, peridotites); and mineralized protores (Tardy, 1997), leaving the more soluble ions to be predominately iron and aluminium. The aluminum rich representative of lateritic soils are bauxites (Akinwumi and Aidomojie, 2015). Lateritic soil has high plastic clay which may lead to cracks and ultimately damage on roadways, structural foundations, embankments, pavement as well as other structures. It is therefore imperative that their properties and actions are studied and soil stabilization techniques are subsequently employed in order to improve its quality (Mohd Yunus et al., 2015).

According to Hostler, (1964) soil stabilization can be defined as the changing of soils in order to enhance their physical properties. Additionally, soil stabilization increases the shear strength of a soil and can possibly control the shrink-swell properties of a soil, which consequently improves the load bearing capacity of the soil so as to support foundations and pavements. Furthermore, Makusa, (2012) described soil stabilization is the process of chemically or mechanically improving soil properties. It is done to achieve soils with better and desirable engineering properties as well as increase soil performance. The American Society for Testing and Materials (ASTM) stated that soil stabilization important as it increases the strength of existing soil so as to improve its capacity to bear load, also it improves soil permeability and increases the resistance and protection of soil to weathering process (wind, erosion and rain), improved mechanical qualities, better attraction between particles which decrease the porosity and changes in volume due to moisture changes, as well as traffic utilization (Obianyo, Onwualu and Soboyejo, 2020).

According to (Thagesen, 1996), soil stabilization can be done either mechanically or chemically. Mechanical stabilization involves blending different grades of soils and materials to obtain a required grade. Chemical stabilization involves blending the natural soil with chemical agents. Several blending agents have been utilized to obtain different effects in previous and recent times. The most commonly adopted agents are Portland cement, lime and asphalt binders. In cases when the stability of a soil cannot be obtained mechanically by combining soils and/or materials, it is best to stabilize the soil chemically by adding cement, lime, bituminous materials or special additives. Cement stabilization is mostly utilized in road works, especially in cases of high moisture content of the sub grade. Calcium hydroxide (slaked lime) is the mostly used for stabilization in the case of lime. Calcium oxide (quick lime) may be more effective in some cases; but quick lime is corrosive and can attack equipment which may cause severe skin damage to persons handling it. The effectiveness of stabilization is dependent on the ability to obtain uniformity in blending the various materials. The method used for soil stabilization is determined by the amount of stabilization required as well as the conditions encountered on the site. Additionally, accuracy in soil description and classification are important for selecting the correct materials and procedures.

Eggshells and animal bones are agricultural waste materials generated from farms, poultries, bakeries, fast food restaurants, homes and other food waste centers. These materials in most cases are not properly handled and they litter the environment and ultimately causes environmental pollution. In the increasingly popular efforts of waste to wealth creation, the conversion of eggshells and bones to beneficial engineering material is brilliant. Eggshell which constitutes about 11% of the total weight of the whole egg contains about 91% of calcium carbonate CaCO? (Kingori, 2011). Since the dominating compound in egg shell is calcium carbonate, during incineration to ash the calcium carbonate will decompose into calcium oxide and carbon dioxide (Okonkwo, Odiong, and Akpabio, 2012). Bone is a type of waste, gotten from animals and its production is over millions of tons in the world today. The utilization of bone ash for road construction such as in rigid pavement is advantageous to the environment. It reduces waste management cost and environmental contamination. Also, farmers and abattoir workers can make profit from the sales of these materials and which consequently leads to more production of these materials (Olutaiwo, Yekini, Ezegbunem, 2018).

Problem Statement

Modifying the engineering properties of soils is vital in making soil used for civil engineering (especially in geotechnics) constructions sustainable in cases of problematic or less quality soils. Problematic soils are either removed and replaced by a good quality material or treated using mechanical and/or chemical stabilization. The notable increase in the price of engineering materials have open researchers’ eye to several other materials that are accessible, cost viable and environmentally friendly which can be locally sourced. Laterite is one of these locally available materials which can be useful in engineering practices. However, due to its low cation exchange capacity and high clay content, cracks and consequently damage on pavements, roadways and building foundations, occurs when it is used. Therefore, the need for stabilization of lateritic soils arises (Ko, 2014). The high dependence of engineers on industrially manufactured conventional stabilizers such as cement, lime etc., have made the cost of construction of stabilized road high (Musa and Mohammed, 2015). Hence, in order to reduce the cost and still maintain the soil strength for the intended purpose, the use of locally sourced domestically and agriculturally discovered environmentally friendly materials are used as stabilizers (Vukicevic et al., 2019).

Environmental pollution and degradation are a major danger to the sustainability of human race (Maurya et al., 2020). Bones and eggshell are dispersed about in many African countries. They could be found in meat markets, abattoirs, poultries, landfills and generally domestic waste, which causes problem to both man and the environment. This is therefore the reason why this study seeks to utilize eggshell and bones ash for stabilizing lateritic soil.

Aim and Objectives

The aim of this research is to determine the effect of egg shell and bone ash as stabilizers on lateritic soils used for road construction.

The objectives of the research work are;

• Objective 1: To investigate the physical and chemical properties of eggshell powder and bone ash as stabilizers to laterite.
• Objective 2: To evaluate the physical and chemical properties of laterite.
• Objective 3: To determine the effect of eggshell powder and bone ash on the engineering properties of lateritic soil. The engineering properties to be investigated for include moisture content, soil classification (AASHTO and USCS), Atterberg limits, maximum dry density (MDD), optimum moisture content (OMC), California Bearing Ratio (CBR), Unconfined Compressive Strength (UCS), and specific gravity.
• Objective 4: To juxtapose the result of using eggshell powder and bone ash as stabilizers on laterite with conventional stabilizers such as cement and lime.

Research Questions

The identified research questions for this project are provided below:

• What are the physical and chemical constituents of eggshell powder and bone ash?
• What makes them a suitable stabilizer?
• What is the method of application of these stabilizers to laterite?
• How do they influence the physical, chemical and engineering properties of laterite?
• What properties of laterite can these stabilizers alter (increase or decrease)?
• Can these stabilizers used to augment or replace expensive conventional stabilizers?

Deliverables

The deliverables of this project are a project report, and results of the stabilized soil. The laterite soil would be tested according to the industry standard. Tests for moisture content, sieve analysis and hydrometer test, compaction test (for determining maximum dry density (MDD) and optimum moisture content (OMC)), specific gravity test, Atterberg limits test, CBR test, and Unconfined Compressive Strength (UCS) test would be carried out. Also, the report should contain complete documentation of the laboratory experiment procedure from start to finish, how various process variables and results were gotten, as well as the period of time and instruments used for the tests.

Relevance

This project focuses on investigating the effect of using eggshell and bone ash as stabilizers for laterite to either augment, reduce or replace the use of conventional chemical soil stabilizers.

Methodology

This project focuses on secondary research, laboratory experiments and process analysis. They are discussed below:

Secondary research

The secondary research in this project will utilize a systematic approach (Johnson et al., 2016) to review the works of literature. The steps involved in the systematic review of the literature are provided below:

• Step 1: Identify the research questions that can be used for the project.
• Step 2: Identify the keywords that should be used to research the works of literature.
• Step 3: Extract the journals and books that are appropriate for this project.
• Step 4: Write the literature review chapter.

Laboratory experiments

The laboratory experiments would cover a large part of this project. They would be carried out in stages, and as such described below;

• Stage 1: Collecting eggshell and bone from the market and food waste collection centers.
• Stage 2: Preparing the stabilizers (cleaning, drying, burning, and grinding)
• Stage 3: Collection and classification of lateritic soil
• Stage 4: Developing an appropriate process route and optimal equipment arrangement for an efficient process setup for the tests.
• Stage 5: Carrying out the several tests simultaneously on the raw lateritic soil sample and the stabilized lateritic soil sample using eggshell and bone ash.
• Stage 6: Result testing, analysis and evaluation.

Process Analysis

The totality of the process would be analyzed and this would also occur in stages;

• Stage 1:  Process Testing
• Stage 2:  Process Control
• Stage 3:  Process Optimization

Evaluation

The risk assessment conducted for this project is provided in the table below:

Table 1:  Risk assessment

Schedule

Table 2: Project Plan

References

Akinwumi, I.I and Aidomojie, O.I. (2015) “Effect of Corn cob Ash on Fine Geotechnical Properties of Laterite Soil Stabilized with Portland Cement” International Journal of Geomatics and Geosciences Vol. No 3.

Gidigasu, M. D.  (1976). “Laterite Soil Engineering - 1st Edition,” https://www.elsevier.com/books/laterite-soil-engineering/gidigasu/978-0-444-41283-6.

Helgren D. M. and Butzer K. W., (1977). “Paleosols of the Southern Cape Coast, South Africa: Implications for Laterite Definition, Genesis, and Age,” Geogr. Rev., vol. 67, no. 4, p. 430. doi: 10.2307/213626.

Hostler F. S., (1964). “Soil Stabilization,” Ind. Eng. Chem., vol. 56, no. 4, pp. 27–33. doi:10.1021/ie50652a005.

Johnson, D., Deterding, S., Kuhn, K.A., Staneva, A., Stoyanov, S. and Hides, L., 2016. Gamification for health and wellbeing: A systematic review of the literature. Internet interventions, 6, pp.89-106.

Kingori, A.M (2011), A Review of the uses of Poultry Eggshell and Shell Membranes, International Journal of Poultry Science, Vol 10, No 11, Page no. 908-912.

Ko T. H. (2014). “Nature and properties of lateritic soils derived from different parent materials in Taiwan,” Sci. orld J., vol. 2014, pp. 1–4. doi: 10.1155/2014/247194

Makusa G. P., (2012). “State of the Art Review of Soil Stabilization Methods and Materials in Engineering Practice.”

Maurya, P., Ali, S., Ahmad, A., Zhou, Q., da Silva Castro, J., Khane, E. and Ali, A., 2020. An introduction to environmental degradation: Causes, consequence and mitigation. Environmental Degradation: Causes and Remediation Strategies, pp.1-20.

Mohd Yunus, N., Yung, Y., Teck Wei, N., Abdullah, N., Mashros, N. and Abdul Kadir, M., 2015. Shear Strength Behaviour of Canlite-Treated Laterite Soil. Jurnal Teknologi, 72(3). pp. 91–97. doi: 10.11113/jt.v72.4019.

Musa, A. & Mohammed M. (2015). “Improvement of Deficient Soils in Nigeria Using Bagasse Ash”.

Obianyo I. I., Onwualu A. P., and Soboyejo A. B. O., (2020). “Mechanical behaviour of lateritic soil stabilized with bone ash and hydrated lime for sustainable building applications,” Case Stud. Constr. Mater., vol. 12. doi: 10.1016/j.cscm. 2020.e00331.

Okonkwo, U. N.; Odiong, I. C. and Akpabio, E. E. (2012)’’ The Effects of Eggshell Powder on Strength Properties of Cement-Stabilized Lateritic’’, International Journal of Sustainable Construction Engineering & Technology (ISSN: 2180-3242) Vol 3, Issue1.

Olutaiwo A.O, Yekini O, Ezegbunem I.  I. (2018) “Utilizing Cow Bone Ash (CBA) as Partial Replacement for Cement in Highway Rigid Pavement Construction,” Int. J. Civ. Eng., vol. 5, no. 2, pp. 13–19.

Tardy Y. (1997) “Petrology of Laterites and Tropical Soils” A. A. Balhema

Thagesen, B. (1996). Tropical rocks and soils in Highway and traffic engineering in developing countries: B, Thagesen, ed. Chapman and Hall, London.

Vukicevic, Mirjana, Milos Marjanovic, Veljko Pujevic, and Sanja Jockovic. 2019. "The Alternatives to Traditional Materials for Subsoil Stabilization and Embankments" Materials 12, no. 18: 3018. https://doi.org/10.3390/ma12183018

Last updated: Jan 05, 2022 10:04 AM