1.1 Introduction
Palm kernel shells (PKS) are organic waste products that are left behind after the crude oil and nuts have been extracted from the oil plant. In Nigeria, PKS has been used for fuel in homes and industries. On the other hand, the drive for light-weight concrete and economic benefit of PKS over conventional aggregates has prompted the replacement of granite with palm kernel shells, Oyejobi et al. (2012). The role of coarse aggregate in concrete is central to this report. While the topic has been under study for many years, an understanding of the effects of coarse aggregate has become increasingly more important with the introduction of high- strength concretes, since coarse aggregate plays a progressively more important role in concrete behavior as strength increases.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
In normal-strength concrete, failure in compression almost exclusively involves debonding of the cement paste from the aggregate particles at what, for the purpose of this report, will be called the matrix-aggregate interface. In contrast, in high-strength concrete, the aggregate particles as well as the interface undergo failure, clearly contributing to overall strength As the strength of the cement paste constituent of concrete increases, there is greater compatibility of stiffness and strength between the normally stiffer and stronger coarse aggregate and the surrounding mortar. Thus, microcracks tend to propagate through the aggregate particles since, not only is the matrix-aggregate bond stronger than in concretes of lower strength, but the stresses due to a mismatch in elastic properties are decreased. Thus, aggregate strength becomes an important factor in high-strength concrete.
Alsalami et al. (2018) produced light-weight concrete with partial replacement of cement, sand and gravel. Cement, sand and gravel were replaced with 20% date palm kernel shell ash, 10% crushed palm kernel and 10% palm kernel shell respectively. This mix resulted in high performance concrete with density of 1850 kg/m3 and 45 MPa at 28 days curing age. The high strength could be as a result of super-plasticizer and silica involvement in the mix. Mohammed et al. (2012) structured cement content and water-cement ratio for 450 kg/m3 and 0.45 for mix proportions of 1:1.60:0.96 and 1:1.53:0.99 respectively. The study reported strength value that was greater than 15 MPa, workability of over 20 mm with density range between 1800 and 1900 kg/m3. As seen from the mix proportions, the sand and gravel ratios were close unlike the conventional mix design; hence, the low content of coarse aggregate might result in the uneconomical mix. Bediako et al. (2016) carried out experiment on calcined clay with partial replacement at 10–30% by weight for cement.
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Use of Eggshell Powder and Palm Kernel Shell as Substitute for Fine and Coarse Aggregate in Concrete Production.
1.3 Statement of Problems
Investigation revealed that eggshells may be contaminated with bacteria, such as Salmonella enteritidis. To avoid the risk of food poisoning, make sure to boil eggs before eating their shell. Natural calcium supplements may contain relatively high amounts of toxic metals, including lead, aluminum, cadmium and mercury (Healthline, 2021).
However, the amounts of these toxic elements in eggshells tend to be lower than in other natural calcium sources, such as oyster shells, and are generally not a concern. To prevent the risk of injury or infection, eggshells should be boiled and ground into powder before you eat them. Eggshell powder can be made at home using a pestle and mortar. Others have reported using a rolling pin or a blender and a sieve to sift out larger particles. They are also concerned that excessive intake of calcium may cause health problems, such as kidney stones, and potentially raise the risk of heart disease (Healthline, 2021).
1.4 Aim and Objectives of Study
The aim of the study is to investigate the Use of Eggshell Powder and Palm Kernel Shell as Substitute for Fine and Coarse Aggregate in Concrete Production. In achieving this aim, the following specific objectives were set out as follows:
- To determine the raw palm kernel shells used as coarse aggregates in Concrete Production
- To identify the raw Eggshell Powder shells used as coarse aggregates in Concrete Production
- To assess the factors affecting the Fine and Coarse Aggregate Substitution in Concrete Production
1.5 Significance of Study
This study will be of immense benefit to researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.6 Scope of the Study
The study focuses on the Use of Eggshell Powder and Palm Kernel Shell as Substitute for Fine and Coarse Aggregate in Concrete Production. This work is restricted only to the use of prepared samples of egg shell and palm kernel shell as pH enhancers.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).
…
