Faculty of Engineering and the Built Environment (Research Outputs)
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Item Making a mark: Wits School of Construction Economics and Management and Its Contribution to the Construction and Property Fields(University of the Witwatersrand, Johannesburg, 2024) Laryea, Samuel; Smit-Stachowski, Alexandra; Mphuti, BongiThis book is a historical account on the Wits School of Construction Economics and Management, its contributions and impact in society, which is very significant and leaves a positive impression of academic and industry development, despite historical hurdles. It looks at the past, present, and future of the School in the broader context of South African history and the overall development of the university. The process of writing this book has been both challenging and exciting with interesting discoveries about the academic disciplines and the growth trajectory of the School. It was challenging uncovering information from various sources within the university and external sources. It has also been an interesting process learning about the rich history and contributions of a key School within the university to the South African and global society. This book chronicles the careers of some graduates of the School who served in the highest leadership and management roles, and made an indelible mark in the construction industry locally and internationally. The School’s graduates have made substantial contributions to the growth and advancement of the South African construction and property sectors and their respective statutory councils including the South African Council for Quantity Surveying Profession (SACQSP), South African Council for Project and Construction Management Professions (SACPCMP) and the South African Council for the Property Valuers Profession (SACPVP). The School’s graduates have also played leading roles in major construction firms that have built some of the iconic buildings in South Africa and other parts of the world. In recent years, many of the School’s graduates are increasingly being recruited by firms in Europe, Middle East, Australia, and the US, indicating the quality of their education and their value to employers and the global construction industry. Through a meticulous search through the Wits university archives and available published material, a huge amount of history and contributions of the School could be produced in this book. As these sources spoke their minds, many of their quotes are produced verbatim - so we can appreciate their wisdom. When gaps emerged in the historical chronology, we turned to those who studied and taught at Wits in the various phases of our Faculty. The Alumni and past Academics took time from their busy schedules as many are still instrumental in building our country, to answer several questions and share their fondest memories and what they believe is the state of the industry currently. The original 15-page document has grown and developed, as has the School, into a fully-fledged manuscript of interviews, yet-unheard-of stories and a vibrant and vital document, to be read and shared widely. The story arc includes the factual history of the School of Construction and Economic Management from birth until now, and is peppered with amusing anecdotes and pictures. Students’ awards were mentioned, where the information was available. This also serves to remember the inspiring academics including Professors Harry Bell-John, Geoff Pearse, Doug Calderwood, Ronnie Schloss and the lecturers who led our current leaders in the fields of quantity surveying, construction management, building sciences and property development, onto the path they have carved, so they can make a mark. This story is filled with chutzpah, grit, determination, humour and a few mishaps, but proves without a doubt that the time spent by students at Wits and SCEM has resulted in lasting friendships, business savvy and in professionals in the built environment who are making their mark across the country, the continent and the world. This is their story and the story of the School of Construction and Economic Management.Item Time and frequency nexus among public debt, exchange rate, inflation, monetary policy rate and economic growth in Ghana(Elsevier, 2025-01) Owusu Junior, Peterson; Odoom, Absalom; Adu-Asare Idun, Anthony; Akorsu, Patrick KwashieThe debate about the influence of public debt on an economy has gained long-standing attention among policy-makers, regulators and academic scholars. The excessive expansion of Ghana’s public debt to GDP demands a fresh insight into the macroeconomic variables that are connected to economic growth. This study utilised wavelet techniques to investigate the nexus and effect of public debt, exchange rate, inflation rate, and monetary policy rate on economic growth in Ghana using monthly data from 2000 to 2022. Diks and Panchenko (2006) was used as a battery test for the wavelet results. We found a significant negative correlation between public debt and GDP at both short- and long-term frequencies, though there was no notable connection in the medium term. The causality analysis suggests a possibility of bidirectional causality between GDP and public debt in both the short and medium term. Interestingly, the COVID-19 pandemic had minimal impact on this relationship when comparing the pre-pandemic and during-pandemic periods. The only observed coherence (negative) between monetary policy and GDP occurred between 2000 and 2003, at low and medium frequencies. The WMCC results depicted that no variable was seen to lead or lag during the pandemic period however, GDP (exchange rate) reacted to shocks first (last) in the short run (long run) prior to the pandemic. The result of this research is crucial for policy implementation. The GDP-public debt negative nexus offers strong evidence for the government to make determined efforts to reduce external borrowing. The positive coherence of exchange rates and the public debt offers a strong incentive to the monetary authorities to make determined efforts to stop the rapid rise of exchange rates.Item Balancing urban regeneration to prevent displacement: a conceptual strategy for inclusivity in South Africa(Proceedings of the AfRES 2024 Conference, 2024-09) Gethe, Faranani; Simbanegavi, PriscaThe regeneration of urban areas and neighbourhoods plays a crucial role in mitigating urban decay and enhancing socio-economic conditions. However, conventional urban renewal initiatives often inadvertently perpetuate geographies of exclusion, chiefly through gentrification and displacement. This paper is aimed at devising effective urban regeneration strategies that prioritise social inclusivity while mitigating the negative impacts of gentrification and displacement of poor people. The study employed a literature and theoretical review approach, utilising published articles and documents to assess the impact of urban regeneration programs on poor communities. The outcomes include the identification of shortcomings in current urban regeneration strategies and the need to formulate more equitable approaches. This study's significance lies in its contribution to expanding knowledge on urban redevelopment, particularly in the developing world of the global south. Furthermore, it will inform policy development aligned with Sustainable Development Goal 11 (Sustainable Cities and Communities) of the United Nations, thus facilitating much-needed advancements in urban development policies.Item Comparing occupant satisfaction in Green versus Conventional Residential Real Estate in South Africa(Proceedings of the AfRES 2024 Conference, 2024-09) Masotya, Adam; Simbanegavi, Prisca; Weaich, Malcolm; Adewunmi, Yewande; Ndlovu, Pride; Gethe, FarananiThis study compares occupant satisfaction in green versus conventional residential real estate in South Africa. It investigates the benefits and satisfaction levels related to green developments, particularly in terms of energy savings and socio-economic Impacts. The research aimed to determine if there is a significant difference in occupant satisfaction between green and conventional residential developments. A quantitative approach was employed, utilizing stratified random sampling to survey 160 occupants from two developments: Crossberry Central (green) and Little Manhattan (conventional). Data was analysed using the Mann-Whitney U and Wilcoxon W tests due to non- normal data distribution. The findings indicate that occupants of green developments report significantly higher satisfaction levels. Key areas of satisfaction include air quality, utility savings, and environmental benefits. Green developments demonstrate higher levels of satisfaction regarding reduced utility bills, improved indoor air quality, and contributions to environmental conservation. The study concludes that green residential developments significantly enhance occupant satisfaction compared to conventional housing. This suggests a socio-cultural shift towards valuing sustainable living environments, emphasising the importance of promoting green building practices to improve both environmental and occupant well-being.Item Phase proportions, carbon equivalent, mechanical properties and their effect on material cost of railway axle steels(Springer, 2018-04) Klenam, D.E.P.; Chown, L.H.; Papo, M.J.; Cornish, L.A.Commuter trains with solid axle configuration are produced from medium carbon steel due to cost restrictions. High-speed trains have hollow axle configuration for reduced weight and are made from high strength low-alloy (HSLA) steels. The HSLA steels have higher amounts of C, Cr, Ni, Mo, V and Nb, and are more expensive than medium carbon steels. The effects of phase proportions, carbon equivalent (CE), yield strength and ultimate tensile strength (UTS) on material costs of existing railway axle steels were studied using Thermo-Calc. Medium carbon rail axle steels had higher Fe3C phase proportions than the HSLA steel rail axle grades. Higher affinity of Cr, Mo and V for C than Fe resulted in decreased cementite proportions. The HSLA steels had yield strengths above 370 MPa, and UTS above 750 MPa, with increased material cost above $3300 per ton. A scattered distribution was observed for the pearlite weight fraction and material costs, with most between $3200 and $3400. The yield and tensile strengths increased with increasing carbon equivalent and pearlite weight fraction. The data aided the selection and design of alloys with better mechanical and corrosion properties at reduced material cost.Item In vitro Evaluation of Porous borosilicate, borophosphate and phosphate Bioactive Glasses Scaffolds fabricated using Foaming Agent for Bone Regeneration(Nature Research, 2018) Erasmus, E. P.; Sule, R.; Johnson, O. T.; Massera, J.; Sigalas, I.In this work, glasses within the borosilicate borophosphate and phosphate family were sintered into 3D porous scaffolds using 60 and 70 vol. % NH4(HCO3) as a foaming agent. All scaffolds produced remained amorphous; apart from one third of the glasses which crystallized. All produced scaffolds had porosity >50% and interconnected pores in the range of 250–570 μm; as evidenced by μCT. The in-vitro dissolution of the scaffolds in SBF and changes in compression were assessed as a function of immersion time. The pH of the solution containing the borosilicate scaffolds increased due to the typical noncongruent dissolution of this glass family. Borophosphate and phosphate scaffolds induced a decrease in pH upon dissolution attributed to the congruent dissolution of those materials and the large release of phosphate within the media. As prepared, scaffolds showed compressive strength of 1.29 ± 0.21, 1.56 ± 0.63, 3.63 ± 0.69 MPa for the borosilicate, borophosphate and phosphate samples sintered with 60 vol. % NH4 (HCO3), respectively. Evidence of hydroxyapatite precipitation on the borosilicate glass scaffolds was shown by SEM/EDS, XRD and ICP-OES analysis. The borophosphate scaffolds remained stable upon dissolution. The phosphate scaffolds were fully crystallized, leading to very large release of phosphate in the media.Item An evaluation of the quantitative risk assessment simulation undertaken during the planning stage of mega-projects(University of the Witwatersrand, Johannesburg, 2024-07) Zwane, Sibongile; Schutte, David; Maila, Sue; Jones, Razaak; Laryea, Samuel; Li, Baizhan; Essah, Emmanuel Adu; Mensah, Sarfo; Liu, Hong; Yao, RunmingThis research examines how the absence of robust risk identification processes during the planning stage can significantly impact the quantitative risk assessment (QRA) outcomes and increase the likelihood of cost overruns in mega-projects in South Africa. By analysing specific mega-projects and their risk identification procedures, this study highlights the importance of a high-quality assessment of the QRA input stage in the context of these mega-projects. Through surveys and interviews with project managers and stakeholders, the study has provided deeper insights into the consequences of inadequate planning, such as project cost overruns and decreased project profitability. The research indicated that a robust risk identification process during the planning stage is pivotal in mitigating cost overruns in mega-projects in South Africa. Projects that prioritise structured methodologies involving all the relevant stakeholders and conduct comprehensive risk identification practices are better equipped to control project costs. The unanimous agreement on the significance of risk identification in cost overrun prevention emphasises its paramount importance. The findings will contribute to the risk management body of knowledge, offering valuable recommendations for improved risk identification and mitigation strategies to enhance project outcomes and positively impact project owners. Lastly, the paper sheds light on the nuanced landscape of risk identification, its impact on cost overruns, and the strategies for its improvement.Item Detecting and preventing unbalanced bidding in South African public sector construction(University of the Witwatersrand, Johannesburg, 2024-07) Tilese, Neliswa; Makhaga, Thendo; Mphahlele, Matjelele; Zungu, Zamageda; Laryea, Samuel; Li, Baizhan; Essah, Emmanuel Adu; Mensah, Sarfo; Liu, Hong; Yao, RunmingUnbalanced bidding in public sector infrastructure projects is a key challenge, involving the manipulation of unit prices without adjusting the overall bid. Unbalanced bidding increases the client’s financial risks and the likelihood of project abandonment by the contractor. Existing literature provides guidelines for detecting and preventing bid price imbalances but inadequately addresses the practical implementation and efficacy of these approaches. This research aims to evaluate the practices for detecting and preventing unbalanced bidding in the South African public sector against existing formal models. This qualitative case study employs semi-structured interviews with quantity surveyors from public sector clients in Gauteng, South Africa. The purposive, non-probabilistic sampling targets professionals with relevant expertise. A thematic analysis of the interview data reveals insights into the awareness, consequences, and practices associated with unbalanced bidding in the South African public sector. The study findings highlight the need for strengthened governance and accountability, more robust strategies for detection of unbalanced bidding, and enhanced education of practitioners to promote fair competition and ethical practices in awarding projects.Item The job satisfaction of black female quantity surveyors(University of the Witwatersrand, Johannesburg, 2024-07) Punungwe, Fungai; Terblanche, Rolien; Laryea, Samuel; Li, Baizhan; Essah, Emmanuel Adu; Mensah, Sarfo; Liu, Hong; Yao, RunmingBlack women face discrimination in the quantity surveying profession hence experiencing tension to balance their careers and life, which results in them not being satisfied with their jobs. The aim of this research is to assess the job satisfaction of black females in quantity surveying and examine if discrimination affects it. Data was collected through online interviews with Black females that are Quantity Surveyors. The results were analysed using thematic analysis to assess similarities in responses. Issues of harassment discrimination were significantly recognised through deep interviews with participants. The issue of job satisfaction of black female quantity surveyors is less explored in literature. The findings of this research can be used by bodies of knowledge and industry professional to improve measures on issues of inequality and alleviate any problems.Item Key barriers to green building implementation in South Africa(University of the Witwatersrand, Johannesburg, 2024-07) Mompati, Lerato; Mandlate, Mike; Kabini, Karabo; Nomvalo, Usiphe; Laryea, Samuel; Li, Baizhan; Essah, Emmanuel Adu; Mensah, Sarfo; Liu, Hong; Yao, RunmingDue to climate change, South Africa is faced with economic and health challenges. Adopting green building technologies reduces the amount of energy usage, however the implementation of green building in South Africa has been slow. This research aimed to identify the barriers on the implementation of green building and the methods that can be adopted to enhance the growth of green building in South Africa. A qualitative research method was be adopted. The open-ended interviews were conducted with built environment professionals. The main barriers of green building implementation are: initial high cost, lack of awareness, lack of incentives, and resistance to change. Recommendations to enhance the growth of green building practices in South Africa include: updating building codes, expanding training programs, fostering collaboration between the public and private sectors, offering financial incentives, promoting the re-purposing of existing structures, and using performance-based contracts. The paper has highlighted the key barriers of green building implementation in South Africa and developed a database of the relevant studies which can further guide future researchers, stakeholders and policymakers in this area.