Faculty of Engineering and the Built Environment (Research Outputs)

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Expert systems : the fifth generation -more than a genealogical pursuit
(University of the Free State, 1995-12) Muller, Marius M.
This paper describes the nature of Expert Systems and outlines their possible use in the field of building economics. Their usefulness in terms of quantification of uncertainty is also examined. It was found that the benefits of developing Expert Systems are tremendous, but that the success of Expert Systems would be determined by their acceptance by the general public.
Contractor's plant: whether to buy or to lease?
(University of the Free State, 1997) Muller, Marius M.
This article comments on the concepts of buying versus leasing in terms of decision-making theory regarding the procurement of contractor's plant. It was found that leasing offered the better option in the worked example presented herein, but that every plant buying or lease decision would have to be made individually on proven calculation and on merit. In hierdie ortikel word die bestoonde opsies behondel woorvoor die boukontrokteur te stoon kom wonneer hy toerusting oonskof. Die vroog is: moet hy huur of koop. Uit die voorbeeld wot hier oongehool word blyk dit dot huur 'n beter opsie bied. Dit is egter ook boie duidelik dot elke gevol meriete het en dus individueel bekyk moet word. Kostes moet teen mekoor opgeweeg word. verol met die kontrokteur se doelwit voor oe.
The role of education as an agent of change: a two fold effect
(1997) Muller, Marius M.; Hindle, R.D.
Several aspects of change to the procedures in the construction delivery process have been described in recent times, particularly those affecting building procurement systems. This paper describes the results of an investigation into one of the underlying causes of such change, particularly that which is affecting the traditional roles of the various parties that participate in the construction procurement process. It is proposed that one of the 'agents' of change is the product of tertiary education programmes that have been producing 'professional builders'. It describes how a new generation of builders, equipped with business skills and an inherent dissatisfaction with the traditional structure and procedures of the industry, are allowing leading construction companies to develop innovative construction marketing strategies and systems. These systems are based upon sound business practice, offer improved customer satisfaction and allow them to get closer to customers. In so doing they are taking over the roles of various built environment consultants who were principal agents and leaders in the traditional building procurement system.
How Rapid Urbanisation, Neighbourhood Management Affects Living Conditions. A Survey of Agege Local Government Area, Lagos, Nigeria
(Canadian Center of Science and Education, 2014-11-23) Ijasan, K.C.; Ogunro, V. O.
This paper explores the issues around urbanisation, neighbourhood degeneration and its effects on the living condition on the residents of Agege area of Lagos, Nigeria. This paper traces the historical background of the area, examines the meaning of neighbourhood degeneration and explores factors responsible for neighbourhood degeneration. The paper adopts quantitative data collection strategies of investigation, and compares these with past literature on the issue. From the survey of 120 households in the area, the study realized street hooliganism; destitution, bad roads and considerable inequality in the distribution of wealth as the greatest problems in the area. It concluded on the need for holistic approach by government to fast-track housing conditions improvement in the entire areas. Moreover, the redevelopment of the area needs to be community-led participatory planning where all stakeholders harness ideas that can be used to improve the present situation of the area.
Architectural education @ different scales: Symposium 2016
(University of the Witwatersrand, Johannesburg, 2018) Architectural Education Forum
Not available
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.
Minimising the risk of thermally induced cracking in mass concrete structures through suitable materials selection and processing
(Springer, 2018) Ballim, Yunus
The hydration of cement is an exothermic reaction which generates around 300 kJ/kg of cement hydrated. In mass concrete structures such as dams and large foundations, this heat of hydration causes a significant rise in temperature in the internal sections of the concrete. If thermal gradients between the internal sections and the near-surface zone of the concrete element are sufficiently large, the thermal stress can cause cracking of the concrete. This cracking may cause functional or structural problems in the operation of the structure. In order to minimise the potential for such cracking, it is necessary to minimise the rate and amount of heat that is evolved, particularly during the early period of the hydration process. This can be achieved by design engineers and concrete technologists through judicious selection and processing of concrete-making materials. This paper presents the observations and results obtained over a number of years from adiabatic testing of concretes, computational modelling of temperature development in large concrete structures and direct temperature measurements in actual structures, with a view to understanding the effects of concrete-making materials on temperature development in concrete. The paper considers the effects of different types of rock aggregates, different types of Portland cement, fineness of grinding of the cement, the addition of supplementary cementitious materials and variations in the concrete starting temperature on temperature development in a large concrete element over time. The results indicate that using a coarser ground cement, adding significant amounts of supplementary cementitious materials and cooling the concrete mixture before placing has a more significant effect in reducing the risk of cracking than varying the aggregate type of the Portland cement type.
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.
Optimizing Structures with Semi‑Rigid Connections Using the Principle of Virtual Work
(Springer, 2018-04) Elvin, Alex; Strydom, Johnnie
In this paper, the virtual work optimization method (VWOM) has been generalised to consider structures with semi-rigid connections. The VWOM is an automated method that minimizes the mass of a structure with a given geometry, multiple deflection criteria, and load cases while adhering to design code requirements. In the optimization process, members are selected from a discrete database to meet all strength and stiffness criteria. Connections are modelled using rotational springs, allowing some moment transfer. The rotational stiffness of each connection can be varied from rigid to pinned. The example of a pitched roof frame is used to explain the method. Two case studies are considered: (i) (i) a three-storey two-bay and (ii) a four-storey three-bay office building. The VWOM produced results up to 26.7% lighter than results in the literature. Furthermore, the structures were optimized for a range of rotational stifness, where all connections in the structure were assumed to have the same rotational stiffness. Characteristic jumps in the optimized mass versus rotational stiffness were observed.
Modelling spontaneous combustion liability of carbonaceous materials
(Springer Open, 2018-06) Onifade, M.; Genc, B.
This paper presents predictive models to determine spontaneous combustion liability of carbonaceous materials (coals and coal-shales) using statistical analysis. The intrinsic properties and spontaneous combustion liability index were determined by testing 14 coals and 14 coal-shales from Witbank coalfields, South Africa. The relationship between these intrinsic properties (obtained from proximate, ultimate and petrographic analysis) and spontaneous combustion liability indices (the Wits-Ehac Index and Wits-CT Index) were established. The influence of the intrinsic properties of coal-shales in relation to coal properties affecting spontaneous combustion has been established using a statistical method. The linear regression analysis indicates better linear relationships between some of the selected intrinsic properties and spontaneous combustion liability index and thus, identifies the major intrinsic factors affecting their liability toward spontaneous combustion. It was found that a definite positive or negative correlation coefficient exists between the intrinsic factors and spontaneous combustion liability. A set of models to predict the spontaneous combustion liability was derived. The best significant correlation along with the most appropriate model as indicated by R-squared values, the coefficient of correlations and standard error was used to predict the incident of spontaneous combustion.
The persistence and rise of master planning in urban Africa: transnational circuits and local ambitions
(Informa UK Limited, trading as Taylor & Francis Group, 2022-03-27) Harrison, Philip; Croese, Sylvia
Master plans have long been criticized by critical planners who have argued in favour of more strategic, collaborative and relational forms of spatial planning that can more adequately respond to local needs and realities, especially in the context of the global South. Rather than critiquing master planning, this paper seeks to interrogate its recent rise in urban Africa. Building on a review of international planning trajectories, the paper seeks to challenge dominant narratives in the Western literature around the rise and decline of master planning. Planning experiences from across the African continent illustrate how master planning was a limited practice under colonialism and emerged more strongly in early post-colonial years, while persisting through a quiet period of planning and proliferating in recent times. By exploring the diversity in the influences and approaches to master planning for new and existing cities in Africa over time, the paper positions master planning as the product of a complex array of transnational circuits and multiple local actors and ambitions which intersect across different scales. The study of master planning should therefore be considered as an important entry point into understanding and rethinking the contemporary politics of urban planning, implementation, and development in Africa.
The transcalar politics of urban master planning: the Japan International Cooperation Agency (JICA) in Africa
(Informa UK Limited, trading as Taylor & Francis Group, 2022-09-22) Croese, Sylvia; Miyauchi, Yohei
This article sheds light on the growing, but understudied role of the Japan International Cooperation Agency (JICA) in supporting the local production of master plans across the African continent as a tool for guiding long-term investments in urban development. To explore the multiple logics, actors and interests driving the conception, preparation and implementation of these plans, we approach urban master planning as a transcalar process, through which diverse investment, planning and governance arrangements are produced and mobilized in ways that transcend the city scale. We illuminate these dynamics by building on an analysis of the history of Japanese development cooperation and drawing on case studies of JICA master planning in Malawi, Ghana and Tanzania.
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, Bongi
This 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.
Investing in the Future: A Comparative Analysis of Green Technology Investments and Youth Unemployment in the US and South Africa
(Common Ground, 2024-05-14) Weaich, Malcolm; Weaich, Sherwyn; Simbanegavi, Prisca; Ndlovu, Pride
This study explores the nuanced relationship between sustainable investments, particularly from entities such as the United States (US), and their impact on unemployment trends in South Africa, contributing to discussions on sustainable development goals (SDGs). Utilizing a quantitative approach with data from sources such as the World Bank and Statistics SA, this study employs statistical and econometric methods to assess the socioeconomic consequences of international sustainability funding. The findings indicate a significant link between US sustainable investments and youth unemployment in South Africa, challenging and reinforcing existing research. It depicts that while foreign investments in green initiatives are crucial, they may inadvertently affect local employment negatively. This study recommends policy adjustments in both US and South African legislation to align foreign investments with SDGs, aiming to mitigate youth unemployment. This study underscores the importance of understanding the implications of international funding conditions on local economies, offering insights for policymakers and scholars to develop strategies that leverage sustainable investments for economic growth and employment opportunities. This study provides a fresh perspective on the dynamics between international investments and local unemployment, offering valuable insights for economic planning and policy formulation in South Africa and across other African nations.
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, Runming
Black 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.
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, Runming
Unbalanced 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.
Bibliometric review of social value in construction literature
(University of the Witwatersrand, Johannesburg, 2024-07) Laryea, Samuel; Kwasafo, Oscar Kwame; Mensah, Sarfo; Laryea, Samuel; Li, Baizhan; Essah, Emmanuel Adu; Mensah, Sarfo; Liu, Hong; Yao, Runming
The construction industry plays a leading role in the provision of infrastructure projects that promote not only the primary objectives for which a project is intended but also the secondary objectives which relate to wider socio-economic development and social value aspects, as shown in the International Organization for Standardization (ISO 10845…2022) 10845 family of standards for construction procurement. While most papers in the construction literature have focused on the primary objectives of infrastructure projects such as costs, time, and quality, relatively little attention has been focused on the secondary objective aspects like economic, environmental, and social sustainability objectives. There has been an increasing focus on the social value aspects of infrastructure projects in recent years. This trend seems likely to increase and directions for future research can be generated from examining the current literature. This paper examines 78 articles relating to social value in construction to explore current understanding and key emerging themes in this area. The 78 articles were identified through a systematic search in Scopus and Google Scholar, then analysed using temporal co-word analysis to generate four key bibliometric themes: social sustainability, social procurement, social value, and employment. Two preliminary conclusions are presented from the bibliometric review. First, while using the ‘social value’ terminology may show this as a relatively new concept flowing from the social sustainability discourse, earlier studies and practices in this area precede the ‘social value’ terminology and appropriate linkages to earlier knowledge should be properly established. Secondly, different terminologies are used to refer to the same concept, creating duplication and significant overlaps across the different terminologies. It would be necessary to consolidate and align the various terminologies for consistency.
Using dynamic BIM to improve construction safety culture
(University of the Witwatersrand, Johannesburg, 2024-07) Amiri, Mojtaba; Saghatforoush, Ehsan; Laryea, Samuel; Laryea, Samuel; Li, Baizhan; Essah, Emmanuel Adu; Mensah, Sarfo; Liu, Hong; Yao, Runming
Among the various studies that have addressed the application of BIM dynamics in domain of health and safety management, the lack of research regarding the impact of BIM dynamics on safety culture is clearly visible. These days, it is apparent that more and more construction technologies are currently being used for safety and health management. These technologies can be used in different construction applications to mitigate workplace hazards. Among these technologies, BIM and IoT has been shown to have significant potential in high-risk Environment, Health, and Safety (EHS) industries. Several researchers have started to explore the potential synergy between BIM and IOT. Dynamic BIM presents an influential pattern for applications to improve construction safety management. The main purpose of this paper is to demonstrate the necessity of research on the use of dynamic BIM in improving construction safety culture. Hence, the literature review method was used to identify the domains in which dynamic BIM has been applied. Prominent application domains in which dynamic BIM has been applied are construction operation and monitoring, facility management (FM), construction logistic and management, health and safety (H&S) management. Results show that no research has addressed the impact of dynamic BIM on safety culture. Therefore, research related to dynamic BIM and its impact on construction safety culture is necessary.
A Digital Skills Gap Analysis of Building Inspectors: The Case of The City of Johannesburg Metropolitan Authority
(University of the Witwatersrand, Johannesburg, 2024-07) Gethe, Faranani; Simbanegavi, Prisca; Awuzie, Bankole; Chiloane, Maruping Broderick; Laryea, Samuel; Li, Baizhan; Essah, Emmanuel Adu; Mensah, Sarfo; Liu, Hong; Yao, Runming
The utility of digital technologies in improving building inspection functions has been elucidated by relevant literature. However, the ability of building inspectors to deploy these technologies remains contentious as a paucity of studies, highlighting the digital capabilities possessed by these cohort has been observed. To bridge this gap, this study conducts a digital skills gap analysis of building inspectors in Johannesburg, South Africa. The study adopts a case study research strategy with a selected building inspectorate unit in South Africa’s Gauteng province serving as the case study. Data was elicited within case surveys, 41 building inspectors responded out of 70 total population sampling sent out. Data was analyzed using descriptive and inferential statistics in SPSS. Results show substantial levels of digital illiteracy among building inspectors in the City of Johannesburg yet little drive-in adoption of the digital technologies in conducting building inspections. It is clear from this study that essential competencies required for the adoption of digital technologies are not at the acceptable level for practical application in the case of Johannesburg. Besides elucidating the growing importance of digital technologies in the execution of building inspection functions in developing countries, the study provides considerable insight into the existence of a skills gap which limits the ability of building inspectors to engage in the increased uptake of these technologies.
Evaluating the new universities project outcomes using the PMBOK project performance domains
(University of the Witwatersrand, Johannesburg, 2024-07) Mosalaesi, Tsholofelo; Laryea, Samuel; Laryea, Samuel; Li, Baizhan; Essah, Emmanuel Adu; Mensah, Sarfo; Liu, Hong; Yao, Runming
The Project Management Institute (2021) PMBOK Guide seventh edition presents eight essential domains or activities that are crucial to ensure the success of a project. PMI (2021) defines these Project Performance Domains as a group of related activities that are critical for the effective delivery of project outcomes. The PMI’s new focus on performance and project outcomes marks a significant shift away from traditional project management tools and techniques. This paper uses the eight PPDs as a framework to determine the critical factors that enabled the success of the new universities project based on the eight domains. A completed project with comprehensive data was used for the analysis. Hence, data from the project close out report was analysed using the thematic analysis method to identify the key project performance practices that were formulated and implemented to successfully achieve the intended outcomes. The key success factors identified relate to the role of the client as a leader, stakeholder’s productive working relationship and the delivery of the project within 1% of the control budget. There may be a common assumption that all clients may employ project managers who may possess the skills to execute these critical functions successfully. However, this is not always the case on all projects, and there is also varying degrees of competency among project managers. Therefore, clients should ensure that those playing leadership roles in their projects are well equipped to perform these critical functions successfully as a condition to achieve better infrastructure project outcomes.