School of Built Environment (SBE) Collections
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ItemAn investigation into the impact of super plasticiser dosage on the compressive strength of cement concrete(Makerere University, 2025)Polycarboxylate ether (PCE) has long been used as a superplasticiser (SP) in the production of high-strength concrete. However, new SP products are frequently released into the market with various compositions, leading to different dosage requirements and concrete properties. The purpose of this study was to determine the effect of SP dosages of 0.1,0.2,0.3,0.4, 0.5,0.6,0.7,0.8,0.9, and 1 litre per 50kg of cement on concrete performance. The study assessed the material properties of cement concrete ingredients, created mix designs for 20MPa, 25MPa, and 30MPa, and produced 297 concrete cubes using varying superplasticiser dosages to investigate the impact of Master Glenium 3889 superplasticiser on concrete compressive strength. Using a plasticiser in the mix reduced the required quantity of cement, thereby reducing the overall cost of the constituent materials by an average of 8%. Laboratory experiments on fresh and hardened concrete properties were conducted and compared to a control normal concrete using the slump test and compressive strength. A thorough analysis was performed in MATLAB R2024a, using the best slump values and compressive strength without concrete defects as the criteria for determining the optimal dosage. The results showed that, with a constant water-cement ratio, increasing the SP dosage resulted in increased workability and compressive strength for the various concrete grades when compared to normal mixes. From the experimental results obtained, it has been found that the optimal SP dosages for G20, G25, and G30 were between 0.6 litres and 0.8 litres. This is because these dosages resulted in the highest attainable compressive strength while also providing the best workability. The results showed a significant improvement in the properties of concrete after using superplasticisers to achieve the highest compressive strength while maintaining high workability.
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ItemGeometric and hydraulic parameter correlations with cross pipe culvert extension requirements in road rehabilitation works( 2025)Highway rehabilitation often results in modifications to the existing embankment geometry and roadway prism, necessitating the extension of cross-pipe culverts to maintain hydraulic and geometric continuity. These extensions are commonly determined through subjective judgment or rule-of-thumb methods, causing design inconsistencies, project delays, and cost overruns. The absence of scientifically established literature guiding the quantification of culvert extension lengths limits a replicable and consistent approaches for extension length determination. This study develops and validates a predictive, data-driven framework that integrates Digital Terrain Model (DTM)–derived parameters with analytical and hydraulic principles to quantify culvert extension lengths and improve design-stage consistency. Using the Alwii–Nebbi corridor (Uganda) as a case study, Digital Terrain Models (DTMs) derived from topographic surveys were integrated with roadway geometry to extract governing variables—shoulder elevation (Z), invert elevation (V), lateral offsets (Xz, Xv), embankment slope (S), culvert gradient (g), diameter (Ø), and wall thickness (t)—across 61 culvert sites (122 inlet/outlet cases). From the roadway–embankment–culvert cross-section, explicit closed-form expressions for upstream (Lu) and downstream (Ld) extensions were derived, with √(〖(g〗^2+1)) capturing barrel inclination and (S ± g) distinguishing inlet/outlet configurations. Terrain analysis revealed corridor variability (Z−V ≈ 2.0–3.5 m; Xv ≈ 5.0–6.5 m) and diagnostic negative extensions indicating regrading needs rather than pipe addition. Validation showed strong agreement between analytical predictions and DTM-measured lengths (R² > 0.9; low RMSE) and hydraulic adequacy under design flows (Hw/D ≤ 1.2 via HY-8). Sensitivity and correlation analyses identified vertical separation ΔZV = Z − (V + Ø + t) and lateral placement (Xv − Xz) as dominant controls; Xv offers the most actionable field lever for fine-tuning lengths. Descriptive statistics indicated a modest downstream bias (mean Ld ≈ 1.64 m vs. Lu ≈ 1.45 m; Δ ≈ +0.19 m) with typical extensions between 1.0 and 2.0 m, supporting modular sizing (1.0–1.5–2.0 m) while retaining site-specific optimization. The study contributes a reproducible, terrain-sensitive, and hydraulically verified framework suitable for specification adoption. It recommends institutionalizing the DTM → analytical sizing → HY-8 check workflow in design manuals and Terms of Reference (ToRs). Future research should focus on evaluating the structural performance of culvert extension joints and joint treatment during installation, and on integrating the developed equations into civil engineering platforms such as AutoCAD Civil 3D, ArcGIS, and HY-8 to enable automated optimization in culvert extension planning.
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ItemAssessing the impact of community involvement in the urban design processes : case study - Wamala ward - Nansana Municipal Council physical development plan 2020-2025 project(Makerere University, 2025)The purpose of this research was to evaluate the impact of community involvement in the urban design processes in Wamala Ward, Nabweru Division, Nansana Municipal council. Community participation has been regarded as the force in creating spaces that are more responsive to community needs and priorities, ensuring most effective neighborhood plans resulting from informed residents collaborating with local authorities. This study delves into evaluating how involving the community in the urban design processes impact the design outcomes. Effective community engagement is guided by key principles such as inclusivity, transparency, and accountability, and can lead to a range of benefits, including improved public health, increased social cohesion, and enhanced economic development. This study was based on key 3 objectives i.e. to examine the level of community involvement in the design and implementation of the Wamala Ward detailed Physical Development Plan, to identify the major barriers limiting effective community participation in urban design processes, and to analyze how community input influences decision-making in the urban design process outcomes. The study’s main focus was Wamala Ward being one of the areas of priority for the implementation of the Physical Development Plan for Nansana Municipal council. The primary attraction in Wamala Village is the Wamala Tombs, which serve as the burial site of Ssekabaka Suuna II, the 29th king of Buganda. This site is not only significant for its historical value but also for its architectural features. The tombs are housed within a large grass-thatched hut adorned with intricate designs made from reeds, symbolizing the unity of Buganda's clans. Visitors can learn about the life and reign of Kabaka Suuna II, who ruled from 1836 to 1856 and was known for his despotic rule and significant contributions to trade by welcoming Arab traders into Buganda. The impact of community engagement in urban planning on sustainable development is a subject of growing significance as cities grapple with the challenges of rapid urbanization. This study delves into the multifaceted relationship between community involvement in the planning process and the achievement of sustainable development goals. By examining case studies and assessing the outcomes of participatory initiatives, the research aims to shed light on the effectiveness and implications of community engagement in shaping urban environments that are both socially inclusive and environmentally sustainable. Contemporary planning theories acknowledge the value of community participation in the development processes of our built environment, suggesting that community involvement has the potential to achieve a more sustainable outcome. Research in this field indicates that citizen participation can generate trust, credibility and commitment regarding the implementation of policies. This paper investigates tools to measure the effectiveness of public participation and their influence on urban development processes. Based on a literature review, a framework of indicators was developed, which has been used to analyse the community participation process in the development of the ‘Greater Christchurch Urban Development Strategy’, a collaborative initiative to develop a growth strategy for the Christchurch region in New Zealand. Results from this case study suggest that there is a relationship between the various indicators and the main findings can be summarized as follows: (i) Most sectors of the community appear to have an interest in their built environment and urban planning processes, provided that their involvement is encouraged by stimulating information and expertise is provided to support their contributions. (ii) Although no conclusions on the motivation of the various participants in the process were reached, the professionals involved appear to have a strong interest in networking and the sharing of expertise. (iii) A commonality in the views of the public was observed, with a focus on the ‘big picture’ rather than selfinterests. (iv) Collaborative planning was experienced as an effective technique for consensus building between professionals. (v) The quality of resources and allocation of time appear to be influential in a community participation process. (vi) Indications were given that process and product outcomes should not be evaluated separately.
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ItemAn assessment of land use/land cover changes and their impact on the urban heat island effect dynamics : a case of Kampala City(Makerere University, 2025)Urbanization in African cities poses significant environmental challenges, including Urban Heat Island (UHI) effects. The accumulation of anthropogenic heat in cities exacerbates this issue, posing serious health risks to the public. This study investigates the UHI trends associated with LULC changes at a local scale, residents’ heat perceptions, and coping strategies to guide planning interventions for improved UHI mitigation and adaptation. The study employed a mixed-method research design. Quantitatively, Kampala’s landscape was classified into homogenous LULC zones based on thermal properties. The UHI trends were analyzed using LST data from Landsat imagery for the years 2005, 2014, and 2023, while LULC changes were assessed through change detection analysis. The relationship between UHI and LULC was examined using the ANOVA tests, boxplots, and grid analyses. Furthermore, local perceptions and behavioral responses were assessed through face-to-face interviews using closed-ended questionnaires and key informant interviews. Findings revealed an expansion of UHI-affected areas from 58% of Kampala city’s landscape in 2005 to 72% in 2023, driven by the observed increase in built-up areas and a decline in natural cover. The built-up LULC zones were associated with the highest UHI values, while natural cover zones had the lowest. The increase in UHI was significantly correlated with urban expansion, densification, and vertical enhancement. Compact high/mid-rise, compact low-rise, lightweight low-rise, and large low-rise zones experienced the highest UHI effects. Nakivubo I, Nakulabye I, Kamwokya II, and the civic center were selected for the heat perception and behavioral response survey. Most respondents (82%) perceived urban heat as increasing and greatly impacting their daily lives, but lacked awareness of its causes. Coping strategies included staying hydrated (81%) and using electric fans/air conditioners (21%), alongside opening windows, wearing light clothes, frequent bathing, and shading. Challenges encountered included increased electricity and water bills, water scarcity in the informal settlements, exposure to water-borne diseases, and limited space for greening. Based on the LULC zone, heat perceptions, and expert recommendations, the study proposes planning strategies for enhanced UHI adaptation and mitigation. Short-term strategies include public awareness campaigns and planning for cooling centers, while long-term measures focus on urban greening, increasing city albedo, and innovative building designs. These findings provide insights for urban planners, policy makers, and public health officials to foster a more resilient and sustainable Kampala city.
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ItemRedevelopment of Agule B fish landing site in Kumi District 2023–2033(Makerere University, 2025)Agule is located in Kumi District in Eastern Uganda, approximately 17kmfromkumitown. It is found Kumi Sub county, Omatege Parish and in Agule village. It is bordered by Okichira village to the East, Aipany to the West. The area has a tropical climate with two (2) rainy seasons in the year. The winds blow from the East to West with the wind strength depending on the season. However, the strong dry winds are usually experienced in a dry season. Agule has a relatively flat terrain with, lake bisina in the area and the swamp