Faculty of Engineering and the Built Environment (ETDs)
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Item Exploring rapid development in emergency relocations in the South African context: a case study of Nellmapius Extension 21 in Mamelodi, Tshwane(University of the Witwatersrand, Johannesburg, 2020) Mahlangu, Phumuzile Nicoline; Huchzermeyer, MarieThe upgrading of informal settlements has been at the centre of upgrading in South African cities. While the government advocates for phased in situ upgrading of informal settlements, in some settlements upgrading is not possible thus making relocation the only option. While some cities may create Temporary Relocation Areas as guided by the Emergency Housing Programme, the City of Tshwane has managed to create a permanent relocation area for a relocated community in its jurisdiction. Using a series of interviews with community members, their leaders and a City official, this research report looks at how the City managed to create a permanent relocation area in Nellmapius Extension 21, being the study area. The findings of the paper are that the City has managed not only to develop the area but it did so rapidly. This paper reports on how rapid development happened in Nellmapius Extension 21 reporting on the potentials and limitations of rapid development, and what it could mean for South AfricaItem Thermo-mechanical processing and testing of titanium alloys for potential dental applications(University of the Witwatersrand, Johannesburg, 2022-12) Nape, Kgetjepe Tlhologelo; Chown, Lesley H.; Cornish, LesleyNew titanium alloy compositions were identified for potential dental implants on the basis of having two-phase microstructures for good mechanical properties and by avoiding problematic elements to increase biocompatibility. The Thermo-Calc program with the TTTI3 (TT Ti-alloy) database was used to calculate new Ti compositions, without toxic Al and V as alloying elements. The aim was to mimic the α+β phase proportions in Ti-6Al-4V and Ti-10.1Ta-1.7Nb-1.6Zr (TTNZ) (an analogue for Ti-6Al-4V). Copper (Cu = 1, 3, 5 and 10 wt%) was varied to give the Ti2Cu phase, which gives good hardness and antibacterial properties. A cost analysis was done and the less expensive Ti-6Nb-4Zr-xCu and Ti-8Nb-4Zr-xCu (x = 0 and 5 wt%) compositions were selected for experimental work. The samples were made by arc-melting and prepared for microstructural studies to understand the influence of alloying elements, and to compare with the commercial Ti-6Al-4V and reported Ti-10.1Ta-1.7Nb-1.6Zr (TTNZ) alloys. Hot deformation of the as-received Ti-6Al-4V and TTNZ alloys was investigated, using a Gleeble 3500® Thermo-mechanical Simulation Facility, at 850°C and 950°C and strain rates of 0.1 s-1 and 10 s-1. The as-cast Ti-6Nb-4Zr-xCu and Ti-8Nb-4Zr-xCu (x = 0 and 5 wt%) alloys comprised αTi and βTi, with Ti2Cu once Cu was added, although EDX indicated some inhomogeneity. The XRD analyses identified αTi and small amounts of βTi with solid solution (shifted peaks), with some Ti2Cu. The Ti-8Nb-4Zr alloy (285 ± 7 HV) had similar hardness to Ti-6Nb-4Zr (280 ± 13 HV), and was considered the better alloy. Adding 5 wt% Cu increased the hardness due to Ti2Cu. With the Gleeble, deformation at 950°C and 10 s-1 led to a finer Ti-6Al-4V microstructure, whereas finer Ti-10.1Ta-1.7Nb-1.6Zr (TTNZ) microstructures occurred at 850°C and 10 s-1. The XRD of all deformed Ti-6Al-4V and Ti-10.1Ta-1.7Nb-1.6Zr samples indicated αTi and βTi, with shifted βTi peaks. The Ti-6Al-4V (324 ± 9 HV) deformed at 850°C and 0.1 s-1 had higher hardness than both deformed TTNZ samples. Higher flow stress were obtained at higher strain rate (10 s-1) and lower temperature (850°C). The Ti-6Al-4V alloy had higher flow stress than the TTNZ alloy. Therefore, the TTNZ alloy was considered better, due to its lower flow stress, which indicated better formability. The new alloys had similar hardnesses to Ti-6Al-4V, and were higher than for TTNZ, suggesting that they might have similar properties to Ti-6Al-4V.Item Influence of copper on the corrosion and mechanical properties of Grade 4 titanium for biomedical applications(University of the Witwatersrand, Johannesburg, 2022-12) Hadebe, Nomsombuluko Dayanda Elizabeth; Cornish, Lesley; Chown, Lesley H.; Smit, Melanie; Mwamba, AlainThis study assessed the effect of Ti2Cu and its proportions on the corrosion resistance, and compared the results to Grade 4 commercially pure titanium. The Thermo-Calc program with the TTTI3 (Ti-alloy) database was used to predict the phases. Materials Studio software was used to model the crystal structures and XRD patterns of the phases of Ti-Cu alloys. Ti-Cu samples with 0, 5, 15, 25, 33, 40, 47 and 50 wt % Cu were produced. Composition, microstructures, phases, hardness and corrosion resistance were studied in the as-cast and annealed conditions (750° and 900°C water quenched). The CP Ti samples comprised basket-weave acicular microstructures. The Ti-5Cu samples comprised lamellar (αTi) and Ti2Cu phases. The Ti-15Cu, Ti-25Cu and Ti-33Cu alloys comprised (αTi) dendrites and sparse eutectic of Ti2Cu and (αTi). The ((βTi) dendrites decomposed to (αTi) and Ti2Cu, and could not be retained due to insufficient fast quenching. The Ti-40Cu and Ti-47Cu samples had minor titanium oxide dendrites which solidified first and then Ti2Cu nucleated on them and grew as dendrites, surrounded by the Ti2Cu + TiCu eutectic. In the Ti-50Cu sample, TiCu was the true primary phase and grew as needles, and was subsequently surrounded by a coarse TiCu + Ti2Cu eutectic. No Ti3Cu phase was observed. The microstructures of the as-cast alloys agreed with the Cu-Ti phase diagram of Ansara et al. (2021) and Dyal Ukabhai et al. (2022) with the congruent formation of Ti2Cu, as well as no Ti3Cu. The addition of copper to titanium increased the hardness, while annealing decreased the hardness of the Ti-Cu alloys. Addition of copper above 5 wt % Cu and annealing decreased the corrosion resistance of the samples, but since copper ions in liquid solutions promote the antimicrobial activity, some corrosion is necessary to allow the copper ions to be available. The corrosion tests showed that the corrosion rates obtained were very low, below 0.13 mm/y, which is an acceptable corrosion rate for biomaterial applications. Ti-5Cu showed the best corrosion resistance.Item What are the Lessons that can be Drawn from International Experience on Sustainable Transport for Johannesburg? Case Study: Berlin, Germany(University of the Witwatersrand, Johannesburg, 2024-02) Ngoma, Ralph Thabiso; Sihlongonyane, MfaniseniThis study unravels the performance of sustainable transport in two vastly different and unique spatial contexts, which have developed from comparable historical landscapes. The transport performance in the city of Johannesburg, South Africa and the city of Berlin, Germany is assessed respectively, to note the effectiveness of the transport modes individually and collectively. It is not a comparative study, but rather a study seeking to understand the actualisation of the concept ‘sustainable transport’ in Johannesburg. The problem statement is asking how the nuanced applicability of sustainability in transport can inform transport plans. The nuanced applicability of sustainability must inform transport plans, so that the vision of sustainable transport is strategically applied in the Johannesburg city plans and those of the other cities in the global south. There is a set of criteria that was adapted to assess the performance of transport in the respective cities, thereby extracting valuable lessons for Johannesburg. The qualitative method of study was used to gather the required data, through case studies, desktop research and unstructured discussions. The report argues for innovative and context sensitive approaches to conceptualising sustainable transport in the cities of the global south, and this is informed by the growth strategy of the respective cities. It is noted that transport and land use are co-dependent, therefore sustainable cities are those that integrate all the elements of sustainability in development plans. The results speak to planners and policy makers to have a nuanced view of transport, thus developing forward-looking frameworks to address sustainability as postulated by UN Habitat goals. The goal is to improve mobility in the city and keep abreast with new innovative approaches to unpacking ‘sustainable transport’ in literature, to inform the ever-growing sustainable, resilient and inclusive cities of the global south.Item Socio-economic Perspectives in the Redevelopment of Hostels in South Africa: A Case of Wolhuter Hostel, Jeppestown(University of the Witwatersrand, Johannesburg, 2020-11) Madonsela, Thando Kwenza; Sihlongonyane, MfaniseniHostels in the South Africa context are synonymous with the migrant labour system. The dominant feature of these pre-democratic hostels is that they catered for single-sex employees as opposed to worker families. This contributed to the destruction of the social fabric in terms of culture, traditions, and the destruction of the black families at large. In post-democratic South Africa, Hostel accommodation continues to paint a grim picture within our human settlement’s spaces. Socio-economic difficulties manifest themselves in mostly inadequate living conditions or poor housing circumstances that are largely conditioned by the unequal and distorted access to opportunities. To this day, most hostels that are not yet redeveloped or refurbished continue to present images of dirty menacing buildings associated with a public stigma of notoriety. This research study explores socio-economic perspectives in the redevelopment of hostels in South Africa. The study will consist of an interface between theoretical foundations, and empirical evidence. This research, data collection was sourced both from primary and secondary sources. Qualitative investigative methods were used to get an in-depth understanding of the subject. The research follows a case-study approach, that of Wolhuter Hostel, Jeppestown in Gauteng and undertook interviews of sixteen hostel dwellers plus a fucus group discussion. The study makes recommendations on policy reforms such introducing more responsive programmes in human settlements. It is also aimed at introducing an improved approach to the planning and redevelopment of the hostels by strengthening neighbourhood and precinct planning. The study contributes to the understanding and insight on hostels and their redevelopment and considering socio-economic perspectives in human settlements planning and development.Item Re-Urbanization Restoration of urban space through the narrative of the context of Tzaneen(University of the Witwatersrand, Johannesburg, 2024-02) Mohale, Koketso Emmanuel; Daskalakos, ChristosA study of abandoned buildings in a small town such as Tzaneen with a lack of concerns about Green Building and environmental consciousness. Evidence of old malls abandoned for newer and fashionable shopping centers with no sign of regenerating and renewing the abandoned economy. This leaves room for informal traders to operate in these abandoned spaces, leading to a decrease in property value within the economic hub of the Town. This project will be investigating the different methods of urban regeneration and exploring theories in relation to Sustainability, Environmental Ecology, and green design, to come up with a solution that could help in regenerating abandoned urban spaces. By exploring the current activities that are on the site, this project will further look at options to have an inclusive program of the informal trader as part of the solution to creating a well-balanced and vibrant economic hub.Item Navigating the Existential: A Sacred Anchor for the Liminal Identities of Johannesburg South’s Diasporic Youth(University of the Witwatersrand, Johannesburg, 2024-02) Moodley, Priyan; Bahman, DirkThe story of Johannesburg South is one that begun with the city itself, a by-product of the scar of the mining belt. Through an influx of diasporic communities, it grew and morphed into a place of diverse cultural editing. One that created a youth which was born into landscapes of sacred and cultural juxtapositions and multiplicities. The result is a diasporic melting pot of existential redefinitions and liminal identities, all in flux in this ever-changing landscape, requiring anchorage and rootedness in all the shifting. Through understandings of transliminality, diasporic theory, sacredness and phenomenological existentialism, this thesis aims to give form, materiality and atmosphere to spaces in which temporal meanings of ritual and event can be held and the layering of sacred and secular multiplicities can be evoked. To answer the question of how anchorage can be created for the sacred redefinitions and temporal meanings of the liminal diaspora of Johannesburg South.Item A Symphony of Sakina: Using mosque design to facilitate community development in Mooiplaas(University of the Witwatersrand, Johannesburg, 2024-02) Jaffer, Raeesah; Janse van Rensburg, ArianeThis research report studies Mooiplaas Informal Settlement in Pretoria, South Africa. The research first discusses the developmental challenges of this marginalised community and then investigates ways in which informal settlements can be developed. It explores the design and application of a Mosque complex, focusing on its potential to facilitate community development. Mooiplaas has a growing Muslim population, and a Mosque is a fundamental requirement to facilitate prayer. The Mosque is further investigated to understand its significance and functionality in community settings throughout history. Previous developmental initiatives undertaken have not reached full potential to holistically address the needs of the Muslim and non-Muslim communities in Mooiplaas. Thus, this research investigates ways the Mooiplaas community can enhance resilience and sustainability by applying the Mosque complex as a fundamental instrument for future development initiatives. The proposed Mosque can facilitate social and economic upliftment within the settlement by providing spiritual development and education and promoting social cohesion.Item Waste Not, Plant, Rot: A wastewater treatment centre that produces sustainable resources in Norwood, Johannesburg(University of the Witwatersrand, Johannesburg, 2024-02) Glanville, Robyn Alice; Stone-Johnson, BrigittaThis research investigates the delivery of essential resources - water, energy, and food around Orange Grove and Norwood, Johannesburg, where all three aspects are threatened by pollution and inaccessibility. Drawing upon permaculture and biomimicry principles, the study explores localized resource management in neighbourhood nodes to address the pressing issue of sustained inequality in South Africa. Focusing on a wastewater treatment plant and an aquaponic farm in Orange Grove, Johannesburg, the project aims to generate sustainable materials, produce, clean water, and energy while fostering spatial and social justice opportunities through community engagement and learning.Item Mwana Wevhu (Child of the soil): Enhancing subsistence cotton farming through education with production creating employment opportunities in Marondera, Zimbabwe(University of the Witwatersrand, Johannesburg, 2023) Mafemba, Simbarashe A.; Kirkman, DeborahCotton plant production in Zimbabwe has witnessed a concerning decline. This cash crop, crucial for the country’s economy, has unfortunately become a harbinger of poverty among diligent farmers. Nonetheless, there is a glimmer of hope on the horizon with the adoption of sustainable farming practices, including the use of organic seeds, which can reduce pesticide usage and water requirements, potentially revitalizing cotton production. Marondera, an agricultural hub, predominantly relies on subsistence farming methods to cultivate this labor and capital-intensive cash crop. Regrettably, these methods have proven inefficient for achieving profitability, ultimately pushing farmers further into poverty. The objective of my research is to delve into the realm of cotton farming, seeking avenues to enhance its viability and sustainability, thereby empowering farmers and fostering employment opportunities within associated industries. Cotton cultivation presents a multitude of job prospects, particularly during the processing phase. As part of my architectural intervention, I aspire to design a community Research Centre in Marondera. This center will serve as a knowledge hub, equipping cotton farmers with the expertise and techniques needed to cultivate the crop efficiently and sustainably. A pivotal aspect of the design will be the incorporation of vernacular architecture and locally available materials, ensuring that the architecture aligns with the practical needs of the local population it serves.