LITERATURE REVIEW

2.1 INTRODUCTION

Our focus in this chapter is to critically examine relevant literature that would assist in explaining the research problem and furthermore recognize the efforts of scholars who had previously contributed immensely to similar research. The chapter intends to deepen the understanding of the study and close the perceived gaps.

Precisely, the chapter will be considered in two sub-headings:

Conceptual Framework

Theoretical Framework and

Empirical Studies

CONCEPTUAL FRAMEWORK

The Construction Industry in Nigeria

In the first decade after independence in Nigeria, modern construction which was referred to as the temp was at a low ebb. Only urban areas had the modern constructions which were considered the seat of the government as it marked the change or transition in the nation's growth. Hence, economic activities were on a low ebb owing to the 1967-1970 civil war. Wahab and Alake (2007) in their work stated that from 1971 and 1975, the company observed activities triggered by rehabilitation and re construction of programs incidental from the massive destruction in the course of the civil war. Property investment was largely trending, by 1974, the year's growth in the industry was 269.40%. “In Nigeria in the late 60's and early 70's the oil boom witnessed the emergence of indigenous and foreign companies into the industry” (Ogunbiyi 1998). Conversely, there was a little drop in the industry development which got more obvious as years passed from 1976 to 1980. The Nigerian construction industry emerged from Public Works Department (PWD), it transited into the federal ministry of works. The three tiers of government, the local, state and federal award 70% of the construction contracts project while the remaining 30% is left in the hands of private section. “The construction company project plays a very important role in the economy of Nigeria”. Akindoyeni (2004) “states that in technologically advanced countries, 20% of the Gross Domestic Product (GDP) is accounted for by the construction industry and which account for 12% of the labor force”. “He concluded that Nigeria is yet to reach the state of gladness over the issue, the company is still in charge of 61 percent of the Gross Domestic Product (GDP) and hires up to 20 percent of the work force”. The pattern of process is seen as the most prevalent required in Nigeria. Indigenous contractors are described as such owned and controlled by Nigerians according to (Idoro 2007). He described expatriate as multinational contractor’s workers and private firm normally jointly owned by both a Nigerian and expatriates but mainly headed by expatriates. Oladapo (2007) states that the construction company in Nigeria is of two types, viz;: Organized formal sector and Unorganized information types. The organized formal sector consists of both foreign and indigenous industries, these are further grouped into large, medium and small firms in accordance with their levels of capitalism and yearly income.

MATERIAL WASTAGE

According to Ekanayake,& Ofori, (2004) any material apart from earth material which needs to be transported elsewhere to the construction sites or used within the construction site itself for the purpose of land filling, incineration, recycling, reusing, or composting rather than the intended specific purpose of the project due to material change excess non use, or noncompliance with the specifications or being a byproduct of the construction process is regarded as construction waste. Shen,& Tam, (2002) defined building material wastage as the difference between the value of materials delivered and accepted on site and those properly used as specified and accurately measured in the work after deducting the cost saving of substituted materials transferred elsewhere in which unnecessary cost and time may be increased by the material wastage.

Al-Hajj,& Hamani, K. (2011) see construction waste as the difference between what was purchased and what was actually used. Waste is any surplus or unwanted material persistently causing environmental issues and global warming Nagapan, S., Abdul-Rahman, I., Asmi, A., Memon, A.H. & Latif, I. 2012). Construction waste can have a significant impact on cost, time, quality and sustainability, and also on the success of projects [Nagapa et’al 2012].

PHASES OF CONSTRUCTION WASTE

There are majorly two phases of construction waste which are the pre-construction phase and construction phase.

The pre-construction phase of a project

This phase includes events ranging from the feasibility phase to the phase of award. These comprise the practicability, scheme design, outlined proposal, bills of quantities, estimation, detail design, etc. If these phase are not well controlled, it could result in waste-generation and overruns the cost of the project (Ashworth, 2008). Therefore, it is good to also recognize the causes of construction waste that will give rise to overrun of the construction at this phase.

The Construction Phase of a project

This phase start from building on site to final handover to client and worker profession, improvement of deficiencies and conclusion of construction supplies and balance of the closing financial records (Ashworth, 2008). Nevertheless, this part of study would place emphasis on building connected matters. It can be deduced from the study that identifying causes and its correlation of waste provides clear advantage to the environment and the construction company in economic aspect.

FACTORS THAT INLUENCE MATERIAL WASTAGE IN BUILDING SITE

The causes of construction material waste can be measured and evaluated using a large number of construction phase related factors such as:

design and documentation

materials procurement and management

site management practices and site supervision including environmental conditions.

DESIGN

Design as one of the causes of material wastage involves three parties.

The first set is related to designers and client’s requirements; the people who consider the functional requirement of the building. The second set is related to construction team and contractors; people who consider the buildability and maintainability of the building. The third set is related to the site supervisors and the site operatives; people who are directly involved in the art of putting the raw materials together to form the building envelop.According to Ghanim, A. B. (2014) a change in a structure which has already been constructed will result to partial demolition, thereby generating material wastage. And this is supported by Fanira et’ al (1998) who reported that design changes are most significant source of construction waste.

MATERIALS PROCUREMENT AND MANAGEMENT

There is a growing consensus within the built environment in Nigeria that building materials account for over 50% of the total cost of a building project (Akinkurolere and Franklin, 2005). It therefore follows that wastage of material will lead to increase in total cost of building project. This assertion is supported by Teo et al. (2009) who opined that building material wastage on construction sites contributes to cost overruns. This implies that in-depth review, identification of causative factors of waste, assessment of these factors and any improvement in material wastage management on construction sites will enhance the cost performance of projects in Nigeria.Teo et al. (2009) observed that extra construction materials are usually purchased due to material wastage during construction. Previous studies from various countries have confirmed that waste represents relatively larger percentage of production. Tam et al. (2007) in a study in the United Kingdom reported an additional cost of 15% to construction project cost overruns as a result of material wastage. Bossink and Brouwers (1996) stated that material wastage accounts for between 20-30% project cost overruns. It is therefore glaring that the economic losses from construction material waste could pose a great threat to the economic growth of a nation.

SITE MANAGEMENT PRACTICES AND SITE SUPEVISION

According to Enshassi, A., (1996) adequate site supervision and control is the most effective strategy for minimizing materials waste in building sites in Nigeria. In the same vein, Fanira et’ al (1998) confirmed that site supervisors and engineer are the most important personnel for material control on site. In buttressing this view,Odusami, K.T., Oladiran, O.J. and Ibrahim, S.A. (2012) assert that site supervision and control is probably reason why materials waste generation levels differ from one building site to the other.Meghani et’el (2011) suggested that to reduce waste, there should be strict supervision and control of materials, creating an awareness of consequences of waste and educating staff, intensifying security, effective site management and improving storage facilities as toping the major measures to reducing wastage on site.Other factors that influences material wastage includes the following:

Design (Frequent design changes and poor design)

Poor materials handling on site

Poor coordinated documents

Poor strategy for waste minimization

Poor site conditions

Theft and vandalism

Poor quality and non-availability of equipment

Poor materials storage system

Waste resulting from poor packaging, delivery and transport

Time Pressure

Poor procurement management (wrong purchasing order – quality, number, time of order)

Site Management

Inclement weather

Long project duration

Use of unskilled labour.

Lack of workers' awareness and training on waste management practices

Traditional construction methods (labour intensive nature),

Lack of incentive for contractors to improve their practices

Poor and insufficient implementation of waste management plan

Poor segregation

WAYS TO CURB MATERIAL WASTAGE

There are few measures for managing materials in building project and curb wastage. In order to achieve good materials management on building project Calistus (2013), opine that the following areas have to be taken very seriously i.e. Training of management and other staff, Inventory control of materials on site, Ensuring proper planning, monitoring and control.

Alwi, Hampson, and Mohammed (1999), recommend the following effective management of building projects which includes:

Management, supervision and administration of sites,

Provision of adequate storage of materials,

Proper usage of materials,

Materials schedule for the contract on hand,

Materials delivery,

Provision and accessibility site layout, Attention to weather conditions.

Training of both management and other staff:

Vivian (2006), opine that it is necessary to provide education and training to encourage and promote the benefit in reuse, recycling and reduce the material consumption; however, cost saving for reuse and reduce the material consumption is difficult to measure, in which the material can be reuse and reduce the consumption for several times. Lingard (2000), observe that it is more effective to provide training and education among staff, and involve employees’ participation in implementing waste management and pointed out that employees’ participation could only be effective with genuine support from management.

Inventory control of materials on site:

Abdul-Rahman (1994) affirms that it involves taking note of the use and inventory of materials on site and recordings i.e. the loading and off-loading, transit and handling of materials. It is recommended that arrangements be made for materials to arrive on time. When a construction material is delivered to a site, it should be checked for damage, quantity, quality and specification. Kapot (2010) stated that this involves physical control of materials, preservation of stores, minimization of obsolescence and damage through timely disposal and efficient handling, maintenance of stores records, proper location and stocking. Stores are also responsible for the physical verification of stocks and reconciling them with book figures. The inventory control covers aspects such as setting inventory levels, ABC analysis, fixing economical ordering quantities, setting safety stock levels, lead time analysis and reporting. Ensuring proper planning, monitoring and control:

Mohamed (2006) describe construction site management practice as the process of determining, analyzing, devising and organizing all resources necessary to undertake construction project. It also includes monitoring and controlling the planned actions towards successful project delivery. Some of the specific activities include the production of a Gantt-chart, network analyses, method statements, resource leveling, progress reports and exception reports. The core element of planning is the establishment of a programme which reflects the planning process in relation to real time (Griffith and Watson, 2004), construction planning is the total process of determining the method, sequence, labour, plant, and equipment required to undertake a building project. All but the simplest tasks require planning in order to be accomplished with the best utilization of time and resources (Chimay, 2006)

Management, supervision and administration of sites: Supervision is the direction of people at work and management is the planning and control of the work process on construction site, supervision, management and administration of site are gradually spread over the earth because it is a more efficient way of accomplishing work (Alwi, et al, 1999). All work requires the coordination of effort; this is accomplished by giving workers assigned tasks and assigned time in which they are to accomplish these tasks, but instruction is not is not enough. A clear, specific instruction on what is to be done, monitor the worker in the course of their efforts. Jimoh, (2012), this is the arrangement on construction sites that lends to effective information dissemination and exchange. Information such as correspondences, minutes, labour allocations, payroll, progress reporting, notices or claims, instruction, drawing register and technical information does flow among stakeholders, for processing and further actions during and after project construction.

Provision of adequate storage of materials:

Kasim (2005), Material storage on site requires close attention in order to avoid waste, loss and any damage of materials which would affect the operation of the construction project. Proper material storage system must be designed to accommodate the loads of the materials to be stored; the sensitive environmental needs for different materials to be permanently stored and preserved; the functional, efficiency and safety of the visiting public and operating personnel; and the protection of the materials from fire, water and man-made threat (Pat, 1991).There must be a proper storage facilities provided for materials on site, some materials are usually not stored in shed or locked up building, also double handling of materials because of improper or indecision about the proper storage facility constitute to waste. Old stock must be available for use after a fresh delivery is made and these materials must be placed in such a way that damage would not be done to it by human activities or traffic on site. Bagged materials such as cement should be stored in a place that is free from moisture.

Proper usage of materials: Phu and Cho (2014), describes usage of materials is the flow component that provides for their movement and placement. Material usage can be defined as the provision of proper handling techniques either manually or mechanically for the components held on site during construction process. Adequate care must be taken to prevent wastage when working with materials on construction project, the assembly of installation process involves the practical incorporated into the project of materials depending on how the skills of the workmen involved. Materials on job site at times may have had a little defect due to poor storage or poor quality on the part of the manufacturer.

Materials schedule for the contract on hand:

Kelvin (2013), It has been established that preparation of a good materials schedule helps a long way in solving the problem of material handling on site. This is prepared at the contract stage of building contract by an estimator and also by the contractor in order to know accurately how much material to mobilize the site. This entails accurately detailed type, the size of materials and all other possible information regarding the required materials and the quantities and date on which it should be delivered. Materials schedules are valuable to buyer for ordering and also to site supervisor to ensure that materials when delivered are allocated or unloaded at or for the projects or building elements for which they are specified ordered productivity (Plunkett 1994). Project schedules should establish guidelines as to when and how the project should be executed, schedule requirements need to be communicated and properly managed throughout the entire project. The purpose of scheduling is to organize and allocates the resources of, equipment and labor with the construction projects tasks over a set period of time.

2.2 Theoretical Framework

For the purpose of this work,the researcher used the theory of waste management to justify the review.

Waste Management Theory

The Theory of Waste Management, as differentiated from waste management practice, represents a more in-depth account of the domain and contains conceptual analyses of waste, the activity upon waste, and a holistic view of the functions and goals of waste management.Thus the theory specified on the need to recycle solid waste at building sites and following the above listed waste management practices.

2.3 EMPIRICAL STUDIES

Akinolurere et’al (2005) carried out an Investigation into Waste Management on Construction Sites in South Western Nigeria. The study focused on the dangers posed by material waste in the construction industry, ways of minimizing construction waste, ways of keeping proper site records for accountability sake. And recommend effective waste management measures. This research adopted questionnaires to collect data from construction professionals, and employed tables and statistical indices for the data analysis. The study revealed that material wastage increase the cost of construction project and reduce contractor‟s profit. And attributed construction was to poor management and lack of effective waste management awareness. The study recommended that construction waste management should be recycled and reused. And through giving incentives to workers for proper handling, material wastage is reduced; and trained personnel should be used as supervisors. Wahab (2011) evaluated waste control measures in construction industry in Lagos, Nigeria. The study assessed the forms, causes and factors incidental to waste and measures to effectively control construction waste. The study adopted questionnaire, interview and site visit to collect it data from construction professionals. Study used Relative Important index, frequency and percentages to analyze its data. The study reported that factors incidental to waste, design variation are caused by last minute client requirement; cost of construction materials was major factor influencing construction materials selection; and construction cost factor leads to method of construction. The study revealed that most firms do not calculate waste indices which could assist them to determine the amount of waste generated, and no proper sorting exercise of waste during construction. Also, most firms do not incorporate “waste management plan” in their tender documents. To control waste, designers should coordinate dimensions between materials specified and those procured, proper material handling, storage and usage were advocated and that “waste management plan” should be incorporated in tender submission of contracting firms. Babatunde L (2012) carried out a study on Quantitative Assessment of Construction Materials Wastage in the Nigerian Construction Sites. The study‟s purpose was to quantitatively assess construction materials wastage in construction sites with a view to providing background information at the design stage on allowable percentage of construction materials waste that will enhance construction project delivery. The study used structured questionnaires to collect data from construction professionals in Abuja municipal, Nigeria. The study analyzed its data using average, percentage and relative significant index (RSI). The study found out that the most type of waste on construction site is theft and vandalism, cutting waste, transit waste and application waste. The study concluded that 15.32% are construction materials waste in the Nigerian construction sites; and recommended 15- 20% allowance for all types of construction materials waste in Nigeria.