CHAPTER ONE
INTRODUCTION
1.1 Background to the Study
In developing nations, similar to Nigeria, the construction sector is a vital area of the economy. It plays major in a country's economy, for example, Nigeria due to the transient pattern in national growth. The rapid growth in the country’s economy and population requires additional physical infrastructures to accommodate additional various component of the Gross National Product (GDP). These physical infrastructures include residential and commercial buildings, agricultural and health facilities to mention a few on the other hand requires the integration of engineering, project, and production management techniques (Ko, 2011) to provide.
More than 90% of physical amenities in Nigeria are being constructed using sandcrete blocks (Baiden and Tuuli, 2004). This makes sandcrete blocks a vital material in building construction. It is generally utilized in Nigeria, Ghana, and other African nations as load bearing and non-load bearing walling units. British Standard 6073: 1981 Part 1 characterizes a block as a masonry unit of bigger size in all measurements than indicated for bricks however no measurement ought to surpass 650mm nor should the height surpass either its length or six times its thickness.
Anosike (2011) postulate that Sandcrete technology or Block molding is turning into the foundation of infrastructural development of each country. Block molding industry is one of the biggest production areas of the construction sector in Nigeria. Practically every Local Government Area has at least one little or large scale block production factories. Block production is undoubtedly a lucrative business, if appropriately overseen. As of now, various block molding industries have sprung up in Nigeria to meet with the prerequisites of construction and infrastructural advancement as there are no laid down rules according to who is able to produce blocks for use in Nigeria (Uzoamaka, 1977; Oyekan and Kamiyo, 2008; Abdullah et al., 2012). Practically speaking, normal specialized skill, materials, tools, machinery and all fundamental frameworks are everything necessary to begin producing blocks either for private use or for business reason. Okoli et al. (2008) contend that part from manufacturers and entrepreneurs who are producing blocks carefully for business purposes, a lot of contractors and customers are likewise making blocks for use on their projects. Such contractors and customers utilize block makers; furnish them with every single vital material and logistics to deliver the block requirements of their building or infrastructural projects, with the sole point of limiting production cost and guaranteeing quality (Ogunsankin et al., 2011; Ko, 2011). Sandcrete blocks comprise of natural sand, water and binder. Oyetola and Abdulahi (2006) added that cement, as a binder, is the most expensive input in the production of sandcrete blocks. This has necessitated producers of sandcrete blocks to produce blocks with low OPC content that will be affordable to people and with much gain. The poverty level amongst West African Countries and particularly Nigerian has made these blocks widely acceptable among the populace so as to minimize the cost of construction works. The improper use of these blocks leads to microcracks on the walls after construction. The use of alternative cheaper local materials as stabilizer will greatly enhance the production of sandcrete blocks with the desired properties at low cost. It will also drastically reduce the cost of production and consequently the cost of construction works. A survey by raw materials research and development Council of Nigeria on available local building materials reveals that certain building materials deserve serious consideration as substitute for imported ones. Few of these materials includes: cement / lime stabilized bricks /blocks, sundried (Adobe) soil blocks, burnt clay bricks/ blocks, cast in-situ walls, rice husk ash (RHA), mud and straw, lime and stonecrete blocks.
A portion of the issues faced in the construction industry today can be connected to this masonry unit, which is a significant construction material. Low quality of building materials is one of the variables liable for the collapse of buildings. Hornbostel (1991) postulate that it is thusly basic to ensure that the production of blocks and bricks are standardized as well as regulated and enough supervised to guarantee quality.
Oyekan and Kamiyo (2011) added that this comes with incredible challenge in Nigeria because of the enormous size of the block producing industry combined with the way that a large portion of those involved with block production are not inadequately trained. Each industry has its own prospects and impossible to miss difficulties which whenever distinguished and suitably attended to will help achieve improvement for developmental purposes (Oyekan, 2001). Producing good quality block comes with a lot of difficulties and prospects. It is therefore important to identify these prospects and challenges with a view to improving and raising the standard of our block industry in Nigeria for the overall benefit of the construction industry. This study is therefore a research work on the factors that affect the quality production of sandcrete block in Nigeria.
1.2 Statement of the Problem
Deformities and varieties in construction products from standards is consistently an issue of worry in the construction industry in Nigeria, in spite of innovative technologies and quality education. The production of quality is a significant consideration in present day development. This is evident by clients’ increasing use of companies’ reputations for good quality work as a basis for choosing prospective contractors. The frequency of press reports of defective structures and the poor reputation of the construction industry for the quality of its products suggest that there are problems of quality control in Nigeria.
Examination and enforcement of standards are fundamental to the success of quality control implementation (Oakland 1991). The problem of quality control in Nigeria is compounded by serious lapses in inspection and enforcement of quality standards (as enshrined in technical specifications of contract documents). It is estimated that lack of quality control costs contractors between 15 and 20% of their annual turnover (Bezelga and Brandon 1991). Consultants and contractors seldom put in place quality assurance structures or assign technically competent staff to check, inspect, or take corrective measures towards meeting quality standards. The standards used are mostly old ones that have been adapted to suit local conditions. Portions of the Nigeria Building Code on sandcrete blocks were, for example, adapted from the BS 2028 (BSI 1975). These standards are rarely updated and the local industry still operates in the relevant era with old but suitable equipment. The use of old standards is therefore a normal practice in Nigeria among indigenous industries such as sandcrete block manufacturing.
In Nigeria, most contractors use aggregates and sandcrete blocks without regard to the source, properties, and quality. The quality of the input in any process has an immediate bearing on the nature of the product; thusly, this practice brings about structures constantly not standing the test of time (and real requirements, to the disappointment of many clients). The purpose of this study was therefore to investigate factors that affect the quality production of sandcrete block in Nigeria.
1.3 Objectives of the Study
The main objective of this study is to investigate the factors that affect the quality production of sandcrete block in Nigeria. However, the specific objectives are:
i) To examine the reasons for the low in the quality of sandcrete block production in Nigeria
ii) To establish the effects of good quality of sandcrete block on buildings in Nigeria
iii) To understand the strength and the durability properties of hardened concrete/sandcrete on buildings in Nigeria
iv) To determine the uses of quarry dust in concrete/sandcrete works
1.4 Research Questions
The following were considered to be the research questions that were provided answer to by this study.
i) What are the reasons for the low in the quality of sandcrete block production in Nigeria?
ii) What are the effects of good quality of sandcrete block on buildings in Nigeria?
iii) What are the strength and the durability properties of hardened concrete/sandcrete on buildings in Nigeria?
iv) What are the uses of quarry dust in concrete/sandcrete works?
1.5 Research Hypotheses
The following statements were considered to be the research hypotheses of this study:
i) There is no significant relationship between low in the quality of sandcrete block production and several collapsed buildings histories in Nigeria
ii) There is a significant correlation between good quality of sandcrete block and strong buildings in Nigeria
1.6 Significance of the Study
The study will provide additionally needed data on sandcrete block in Nigeria. It will also help in the use of quarry dust in block production. The mixes developed for block production will be of great help in assisting commercial block producers in meeting required strength targets. The models that will be developed will be of great assistance in mix design by forming the basis of trial mix designs, thus eliminating great experimental works and the high cost often associated with such ventures. It will serve as reference materials to students, scholars, and research analyst of construction industries, who have the interest further on this topic. More so, the findings of this study would contribute to the existing knowledge factors that affect the quality production of sandcrete block in Nigeria. By so doing, this study would serve as reference material for future research organization.
1.7 Scope of the Study
This work will be limited to the formulation of model equations for predicting the structural characteristics of sandcrete blocks with the sand partially replaced with quarry dust. This study centered on factors that affect the quality production of sandcrete block in Nigeria. More so, Lagos State was chosen for this study as it is considered to be the commercial centre of Nigeria.
1.8 Limitations of the Study
In the course of this research work, the researcher was confronted with series of problems which tends to limit the researcher pace at actualizing his research work. These limitations among others includes:
Finance: This research work requires a lot of financial commitment as it involves the researcher traveling to libraries outside the city of residence as well as meeting some contractors and manufacturers.
Time Factor: This is another impending factor that militates against the research work. The researcher is a student and under academic duress could not have ample time to carry out a thorough research on the subject matter.
Lack of Cooperation: Getting the necessary cooperation from some individuals so as to deduce important documents for the research work was a very big task to the researcher. Some information where either incomplete or denied by individuals who were the custodians of such information and documents.
Limited Materials: The subject matter is new and therefore there was limitation to materials from visited libraries has very little or no important materials on this research topic. Tactics in overcoming some of these limitations have thereby made this project to be a thing of success. Out of the limited cost of materials, available materials and textbooks were utilized. Some were borrowed from friends, libraries and lecturers while others were bought on installment. The scheduled time between leisure periods were managed in making fundamental study for this research. Time used was mostly at mid night.
