- Title
- Developing a circular-economy-based construction waste minimisation framework for Nigeria
- Creator
- Ogunmakinde, Olabode Emmanuel
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2019
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- The construction industry plays a significant role in developing and developed nation’s growth. It has been criticised as unsustainable because it impacts negatively on the environment and makes onerous demands on natural resources. Therefore researchers, policy makers, governments and non-governmental organisations have recognised the need to promote sustainable construction. Nigeria, one of Africa’s fastest-growing economies and the most populous, is endeavouring to implement sustainable practices. Its construction industry is viewed as lacking sustainable construction approaches such as waste management. The industry is heavily dependent on natural resources and its activities contribute to environmental degradation. A number of studies have identified high volumes of waste and this has highlighted the need for alternative approaches to the current traditional method of construction linked to the linear economy. The circular economy is a concept that integrates material repair, reduction, reuse, and recycling. Although the circular economy has not been applied in Nigeria, it has been adopted in the manufacturing, steel, and agricultural sectors in countries like China, Scotland, and Finland, while others are considering its adoption. The circular economy requires a holistic approach to be effectively and efficiently mainstreamed. Despite its advantages, there has been little investigation of its adoption for the Nigerian construction industry. The aim of this study is to develop a circular-economy-based construction material waste minimisation framework for Nigeria with a view to achieving sustainable construction. The objectives are, first, to identify types, causes, and methods of disposal for material waste. Second, to investigate the awareness, attitudes, and perceptions of Nigerian building construction firms to material waste minimisation. Third, to investigate current approaches to material waste minimisation at the design, procurement, and construction phases. Fourth, to investigate the extent to which the 3R principle has been adopted. Fifth, to identify policies or legislative measures and implementation methods for waste minimisation. Finally, to develop a circular-economy-based construction waste minimisation framework and investigate readiness for its adoption by Nigerian building construction firms. This study is founded on literature about construction waste management, the Nigerian construction industry, construction processes and phases as well as sustainable construction. The concept of the circular economy, including its origins, definitions, principles, characteristics, approaches, drivers, challenges, and benefits have been reviewed. The foundations of the circular economy and theoretical perspectives underpinning its integration have also been reviewed. This study has been viewed from a pragmatic philosophical stance that encourages the use of methods appropriate for the problem. A convergent parallel mixed methods approach was employed to obtain primary data from building construction firms in Lagos, Nigeria. Using a concurrent triangulation design, data obtained from a questionnaire survey were triangulated with data from semi-structured interviews and direct observation. Secondary data were collected via a traditional literature review. Quantitative data were analysed using SPSS. The tests conducted are the relative importance index analysis, factor analysis, Kruskal-Wallis test, and the Spearman’s rank correlation. Qualitative data were analysed through thematic analysis using NVivo 11 to identify key themes, relationships, coding, and sorting into categories. To ensure reliability and validity of the questionnaire data, a Cronbach’s Alpha test was conducted, with a result of 0.83 indicating good reliability and validity. A rigorous process, including a review of the research problem, design, and interview questions, as well as six rechecks of interview transcripts, ensured reliability and generalisability of the qualitative data. Findings suggest that concrete, timber products, and offcut tiles are the main types of waste generated in the Nigerian construction industry. The causes of these types of waste at the design, procurement, and construction phases are design changes, substandard materials, and quality of supervision, respectively. Nigerian building construction firms demonstrate a high level of awareness of the effects of material waste, while exhibiting positive attitudes to waste minimisation. However, their perceptions vary, although the majority perceived environmental protection as an important factor for waste minimisation. The relationships between the Nigerian building construction firms’ awareness, attitudes, and perceptions indicate that these are influenced by their perceptions. Furthermore, the study reveals that design for material optimisation is the design approach most frequently embraced to minimise waste, while design for reuse and recycling is the least frequently used. The most significant procurement approach adopted by the Nigerian building construction firms is to purchase durable materials. A factor analysis of procurement approaches was conducted, and two factors labelled “act green” and “buy green” were extracted. For construction approaches, stock control, effective team work, and avoiding excavation of unnecessary soil were identified as the most important processes, while factor analysis of construction approaches yielded three factors, namely: strategies, techniques, and operations. These approaches to waste minimisation differ among medium and large-scale construction companies. Additionally, the research has revealed reuse of formwork and scaffolding as the most significant approach of the 3Rs principle (reduce, reuse, and recycle). A factor analysis of the 3Rs approaches to waste minimisation yielded three factors, labelled “reduce”, “reuse”, and “recycle”. Site waste management planning is considered by Nigerian building construction firms as the most important policy to minimise waste. Two factors labelled “recommended” and “required” policies were extracted from the factor analysis of policies and regulations for ease of description and understanding. The key implementation methods are policy and education/training of the construction workforce. However, more than half of the firms surveyed do not have an organisational policy on waste minimisation, while 89.3% were keen to adopt a new waste minimisation method. Following these findings, a circular-economy-based construction waste minimisation framework was developed based on the diffusion of innovation theory. The framework consists of five sections, which are: identification of waste minimisation needs, assessment of existing minimisation measures, policy identification and formulation, identification of implementation methods, and evaluation of the proposed framework. This study has established a framework that can be used as a baseline for waste minimisation in the Nigerian construction industry while contributing to gaps identified in the body of knowledge. Adoption of the framework by Nigerian building construction firms and the Nigerian construction industry in general has the potential to reduce waste generated and landfilled. Recommendations are made for policy, training and education, changes in organisational culture and attitudes, best practices, and research and development. The study concludes by identifying future research areas.
- Subject
- circular economy; construction waste; construction industry; legislative measures; 3Rs; waste minimisation; Nigeria; design approaches; procurement approaches; construction approaches; relative importance index; exploratory factor analysis; convergent parallel mixed methods
- Identifier
- http://hdl.handle.net/1959.13/1407524
- Identifier
- uon:35738
- Rights
- Copyright 2019 Olabode Emmanuel Ogunmakinde
- Language
- eng
- Full Text
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