Masters Degree Dissertations

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12504/84

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Investigation into the collapse potential of subbase material in the tropics region case study: the greater Kampala metropolitan area
(Kyambogo University (Unpublised work), 2025-10) Mbwali, Mary Christine
Road construction in tropical regions such as the Greater Kampala Metropolitan Area (GKMA) faces persistent challenges from hydro-consolidation, which can weaken subbase layers and compromise pavement durability. This study aimed to evaluate the collapse potential of subbase materials in the GKMA and recommend measures to enhance their performance for sustainable road infrastructure. Representative samples were subjected to physical-mechanical tests [Maximum Dry Density (MDD), California Bearing Ratio (CBR), Atterberg limits and Particle Size Distribution (PSD)], chemical analysis (chloride, sulphate, and pH content) and conventional oedometer testing under wetting conditions to determine hydro-consolidation behavior. The oedometer test results showed that subbase soils at Natural Moisture Content (NMC) exhibited medium to high collapse potential, exceeding 3% under higher applied stresses, indicating susceptibility to hydro-consolidation when saturated under load. However, samples compacted at Optimum Moisture Content (OMC) displayed collapse potentials below 2%, demonstrating that proper compaction significantly reduces collapse risk. These results confirm that collapse potential is stress-dependent and highlight the importance of achieving optimum moisture content during construction to enhance subbase stability. Based on the findings, the study recommends further evaluation of subbase materials under higher applied stresses to better simulate traffic conditions, expanding investigations beyond the GKMA to capture broader geological variability, and examining other road failure mechanisms such as drainage efficiency and construction practices. Overall, this research provides a practical evidence base on hydro-consolidation behavior of subbase materials, enabling engineers and policymakers in Uganda to design, construct, and maintain pavements that are durable, resilient, and cost-effective in tropical environments.
Effects of land use patterns on microplastic concentration and distribution in river Rwizi, Mbarara district
(Kyambogo University (Unpublished work), 2025-09) Kemigisha, Mariam
Microplastic pollution has become a pressing global environmental challenge, threatening aquatic ecosystems. In Mbarara District, growing industrial development, agricultural and urban activities, and poor waste management practices, contribute to the release of microplastics into River Rwizi. These plastic particles, typically less than 5 mm in size, largely originate from degradation of discarded plastics and can enter the food web through ingestion, biomagnification, and bioaccumulation. This research aimed to study the concentration, characteristics (colour, size, shape and polymer type), and distribution of microplastics in River Rwizi, with emphasis on the role of surrounding land use activities. Samples of water and sediments were obtained from nine purposively selected sites based on predominant land-use types, representing agricultural (upstream), urban/built up (midstream), and forested (downstream) land use types. Sample preparation involved sieving, drying, density separation, and filtration. Microplastics were then identified using stereomicroscopy and analyzed for polymer composition using FTIR spectroscopy. Land use mapping was conducted using Sentinel-2 satellite and supervised classification in ArcGIS, followed by ground truthing with a handheld GPS. Data analysis used IBM SPSS Version 29.0, while Pearson correlation and regression modeling were used to assess the influence of land use on microplastic concentrations. Results revealed that all samples collected contained microplastics. Concentrations in water samples ranged from 0.117 to 0.883 particles per liter, while sediments contained 0.012 to 0.132 particles/Kg. Built up and agricultural areas recorded higher concentrations of microplastics than forested areas. Fibers were the most common shape, most prevalent in built up land use, while blue particles were the most frequent colour. Most particles fell within 0.5–1.0 mm size range, suggesting they originated from larger plastic debris. Polyethylene and Polypropylene emerged as the dominant polymers identified across all land use categories. These findings demonstrate that land use patterns strongly influence microplastic pollution in River Rwizi. The study recommends improved waste management practices, promotion of alternatives to single-use plastic packaging materials, strengthening community awareness and policy interventions to reduce plastic pollution, and strengthening plastic recycling initiatives.
Investigating the effect of activating agents on removal of lead ions from water using activated rice husk carbon
(Kyambogo University (Unpublished work), 2025-11) Kamukama, Ivan
Activated carbon is very important in treating polluted water. Carbon can be produced from locally sourced agricultural waste. This helps in reducing the amount of agricultural waste in the environment. This study investigated the effect of activating agents on removal of Pb2+ ions from water using activated rice husk carbon. Chemical activation method was used where rice husk carbon (RHC) was impregnated with chemical activating agents before heating. Three distinct activating agents were used namely; potassium hydroxide (KOH), phosphoric acid (H3PO4) and zinc chloride (ZnCl2). RHC activated with a 7.5% concentration of KOH using 5g/L adsorbent showed 99.9% efficiency in removing lead ions, almost achieving complete elimination. RHC activated with 1% ZnCl2 while using 20g/L adsorbent demonstrated 98.5% removal efficiency, just 1.36% less than the RHC activated with 7.5% KOH. RHC activated with 2.5% H3PO4 while using 20g/L adsorbent showed 84.1% removal efficiency, making it least effective among the three agents tested at their optimal levels. Despite achieving removal efficiencies of 98.5% and 84.1%, RHC activated with ZnCl2 and H3PO4, respectively, required a higher adsorbent dosage (20 g/L), indicating lower effectiveness compared to KOH-activated carbon. KOH activation created a highly porous and rough surface with a well-developed network of interconnected pores. On the other hand, ZnCl2 and H3PO4 resulted in less aggressive pore formation and different surface morphologies, leading to less interconnected and less rough porous structures. It was observed that the uptake of Pb²⁺ ions by activated RHC aligns more accurately with the Langmuir isotherm model.
Performance of green silver Nano particles using Psidium guajava leaves for adsorption of lead from water
(Kyambogo University (Unpublished work), 2025-11) Kihumuro, Josephine
This research examined the effectiveness of green silver nanoparticles (AgNPs) produced from aqueous extracts of three varieties of Psidium guajava leaves (white, orange, and red fruit mesocarp) in adsorbing lead (Pb²⁺) ions from contaminated water. The study assessed antioxidant activity, characterized nanoparticles, and analysed adsorption performance across different dosages (0.1–1.0 g) and contact durations (5–25 minutes). White guava extract demonstrated the highest antioxidant activity, achieving 83.85% 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging. Additionally, AgNPs from all varieties displayed spherical morphology as observed through Scanning Electron Microscope (SEM), with white guava derived AgNPs exhibiting uniform distribution of the NPs in the matrix. Adsorption experiments demonstrated a maximum Pb²⁺ removal efficiency of 83.16% at a dosage of 0.6 g and a contact time of 20 minutes for white guava AgNPs, while orange and red had 81.53 and 78.35 % respectively. Clay filters infused with AgNPs demonstrated a Pb²⁺ removal efficiency of 99.59% (composite filter), surpassing the performance of unmodified clay, which achieved 91.62% removal. The research findings indicate that white guava derived from AgNPs possess significant antioxidant capacity and adsorption affinity, presenting a viable approach for heavy metal remediation, with prospective applications in point-ofuse water treatment technologies. It is recommended to optimise the ratios of hybrid nanoparticles and conduct field validation in real-world conditions.
Investigation of the impact of ancillary roadworks on road safety in Uganda : a case of Kampala – Jinja road
(Kyambogo University (Unpublished work), 2025-08) Ssebuliba, Isaac
The 1949 Geneva Convention on road traffic put in place a unified approach to promote road safety and development of international road traffic. This coupled with the Global Sustainable Development Goals (SDGs), the United Nations Agenda 2030, African Union Agenda 2063, have had a great impact on ensuring safety on the world’s roads. However, road safety for Low Developed Countries like Uganda is still a challenge, despite the adoption of the country’s Vision 2040 and the launching of the National Road Safety Action Plan (2021-2026). A study to investigate the impact of ancillary roadworks on road safety in Uganda, a case of Kampala – Jinja road was conducted, with an aim of establishing a relationship between Road Signs, Road Marking, Guard Rails, Humped and Rumble Strips, Road Lights, Walkways and Service lanes with Road Safety. This study therefore used correlation research design supported by cross sectional survey design with qualitative and quantitative approaches for interviews and questionnaires respectively. Primary data were collected from 30 field traffic officers, 19 drivers, 03 Officers in Charge (OC) traffic police stations, 36 road engineers, 01 Inspectorate of Vehicles (IOV), 01 Regional Traffic Officer (RTO) and 12 market leaders, all within the study area, whereas secondary data were extracted from accident data from Uganda Police. Questionnaire data were analysed with SPSS version 24.0. The interview data was analysed using content analysis. Results indicated that 61% of installed informatory signs, 53% of the installed regulatory signs and 40% of installed warning signs still existed on the road and others were missing which exposes road users to risk of accidents. Guardrails were still existing but some had rusted and others covered with grown grass, making them not visible to road users. Majority of road accidents were serious, accounting for 159 (47.8%) cases, followed by 130 fatalities (39.2%) and 43 (13.0%) minor accidents for the period from 2017 to 2022. A relationship between the independent variables and dependent variable, (βeta) of the study was made. Results of correlation analysis indicated that all ancillary road works were significant except road signs, yet regression results indicated that road marking (βeta = 0.207, p-value = 0.029), guardrails (βeta = 0.186, p-value = 0.045) and humps and rumbles strips (βeta = 0.260, p-value = 0.028) have a positive significant effect on the road safety unlike road lights, road signs, walkways and service lanes which were insignificant. Field inspections together with traffic police officers within the study area, identified 14 blackspots with high annual frequency of accident occurrence in the section between Lugazi and Kitigoma village. It is concluded that road marking, guardrails and humps and rumbles strips significantly affect road safety. The study recommended that construction of humps and rumble strips of moderate size, visible road marking with higher retro reflectivity and strong guardrails, can help in ensuring road safety with support of enforcementof traffic laws of Uganda.
Investigating the effect of occupational safety and health measures on the cost of construction works in Uganda : a case Nakawa division, Uganda
(Kyambogo University (Unpublished work), 2025-10) Eluru, John
The Occupational Safety and Health Act of 2006 was enacted by the Government of Uganda as one of the strategies taken to enhance the welfare and health of workers on construction sites. It was important to investigate if the occupational safety and health (OSH) measures had a good effect. Design, progressive and incident reports were reviewed before considering over 500 respondents from 24 bungalow construction sites across Nakawa Division. Questionnaires and interview guides were distributed to site workers. Among those considered, only 216 valid questionnaires and interview guides from 10 construction sites were returned from respondents that were randomly considered from class category A-3, A-4 and A-5 of indigenous construction companies. Frequency and percentage tables were used to analyse the data. The findings show that the cost associated with OSH measures recorded the Safety Investment Ratio (SIR) of 0.71%. The cost incurred due to construction accidents recorded the Accident Loss Ratio (ALR) of 0.47%. The overall effect of OSH measures was 1.18%, which was considerably low. This result indicates that, despite the fact that 77% of construction workers experience accidents, indigenous construction companies do not make significant investments in occupational safety and health. Adherence to OSH was difficult with negligence, manual lifting and shortage of personal protective equipment (PPE) as the major causes. There is need to invest more on OSH measures in order to minimize the costs implications of sickness and death associated with accidents. It was recommended that the effect of OSH measures needs to be investigated on sites with fatal injuries. Fire protection and chemical storage too need to be investigated in Uganda. The study was limited to only Nakawa Division. Research on the effect of occupational safety and health measures on cost needs to also be conducted in other Divisions in Kampala and cities within Uganda. More studies should be conducted on innovative technology on safety and health measures at construction sites in Uganda. These findings are significant in the formulation of safety and health regulations and in the application of occupational safety and health measures.
Enhancing labour productivity through job-site training on building sites in Uganda : a case of Arua city
(Kyambogo University (Unpublished work), 2025-09) Econi, Kenneth Yikii
Labour productivity is a critical determinant of construction project performance directly influencing timelines, cost efficiency and overall quality outcomes. In developing countries like Uganda, the building sites often struggles with low productivity levels due to inadequate workforce skills, inefficient work practices and limited access to structured training programs. In Arua City, evidence from multiple building sites indicate that these challenges manifest in significant delays, substandard workmanship and cost overruns. According to the Uganda Bureau of Statistics (2022) and the Uganda Manufacturers Association (2022) reports, 68% of manufacturing firms in Uganda report difficulties in finding technically skilled workers highlighting a critical skills gap that undermines productivity and efficiency. This study investigates the role of jobsite training in enhancing labour productivity on building sites aiming to identify the most significant factors influencing training effectiveness and workforce performance while proposing strategies to optimize outcomes. A mixed-method approach is adopted, collecting quantitative and qualitative data from 94 workers across fourteen sites and is analyzed using SPSS version 23. Findings reveal a moderate positive correlation between job-site training and labour productivity with training method, recruitment criteria and trainee motivation identified as the most influential factors for training effectiveness while manpower, management and motivation emerge as the primary determinants of labour productivity across worker trades on site. A predictive regression model with R² value of 80.2% is developed to design, assess and predict the effectiveness of job-site training on building sites. An on-site training framework is developed and validated demonstrating productivity improvements across all trades including carpenters by 18.06%, non-trade workers by 15.95%, welders by 13.94%, painters by 9.72%, electricians by 6.24%, plumbers by 2.93% and masons by 2.65%. The study recommends that job-site training programs carry out systematic needs assessment to align training content with site-specific requirements. Priority should be given to training methods and manpower management as they have the greatest impact on training effectiveness and worker productivity on building site. The regression model and training framework should be adopted as practical tools for planning and evaluating training programs. Finally, the study recommends apprenticeship and role-playing as the most effective methods for knowledge transfer on building sites.
Investigating spatial variation of Arsenite concentrations into river Awoja, physiographic determinants and treatment options
(Kyambogo University (Unpublished work), 2025-09) Ecodu, Michael
The 2030 agenda of the United Nations placed a high priority on addressing water quality challenges. Many towns and cities are supplied with water from rivers. Depending on the human activities on the catchment, the water from the river can be characterized by the presence of Arsinite. It is important to quantify Arsenite to guide in planning for the water treatment. In this study, several points were selected within River Awoja catchment. Rainfall runoff was sampled at selected locations and concentrations of Arsenite was determined from a laboratory. To explain the spatial variation of Arsenite concentrations, analysis of land categories was conducted. The potential of rice husk as Activated Carbon in removing Arsenite was investigated. The concentrations of Arsenite ranged from 20.21mg/L to 27.57mg/L against WHO standards of 0.01mg/L indicating the need to treat the water given the substantial level of pollution with Arsenite. The linear relationship between physiographic characteristics and Arsenite-based land categories of barren land, grassland, settlement, cropland, waterbody, wetland and woodland characterized in terms of coefficient of determination (R2), yielding R² values of 0.80, 0.84, 0.86, 0.76, 0.62, 0.76 and 0.61, respectively. The efficiency of Arsenite removal using rice husks as Activated Carbon improves as dosage and contact time increase. This study demonstrated that Arsenite concentration at sampled points is higher than the WHO limit and that Activated Carbon has the potential to remove Arsenite with efficiency of about 78%.
Climate change impacts on precipitation extremes: potential and perceived implications for water resources management across Uganda
(Kyambogo University (Unpublised work), 2025-11) Ebalu, Moses
Water resources are increasingly being affected quantitively by climate change impacts. This requires carefully planned adaptation measures. This study investigated climate change impacts on precipitation extremes indices, including the annual maximum series (AMS), Severe dry spell (MDS1). Climate Forecast System Reanalysis (CFSR) was used to characterise historical precipitation conditions. Output from the eight General Circulation Models (GCMs) was used to project climate change signals for the 2050s, 2070s, and 2090s. Bias of a GCM output over the historical period (1985-2014) was assessed in terms of the ratio of observed to the model’s output. The best result, indicating no bias, would be indicated by a ratio of 1. The perception of water users in the various Water Management Zones (WMZs) across Uganda was assessed. The AMS over the study period 1985-2014 ranged from about 45 mm/day to nearly 55 mm/day in Victoria and Upper Nile WMZs, respectively. The biases in reproducing observed AMS ranged from 0.06 (for MPI-ESM1-Ham in Kyoga WMZ) to 0.82 (for INM-CM5 in Victoria WMZ). The best performance was exhibited by ACCESS-CM2 being the sole exception, demonstrating nearly accurate AMS estimation in the Victoria WMZ with a bias of about 1.01. Future projections of AMS under SSP245, SSP370, and SSP585 scenarios predict decreasing AMS in the Upper Nile WMZ (up to about 16% decline by 2090s) but increasing in Victoria WMZ up to about 60%. A survey (using questionnaire administered to water users of sample size n = 737) revealed that about 60% of respondents observed reduced precipitation, with approximately 48.1% expecting further declines. Nearly half (49.7%) cited extreme disruptions in rainfall timing, leading to agricultural losses and income reduction. Findings from both GCMs and the assessment of perceptions of water users show the need for carefully planned climate change adaptation in the various WMZs.
A comparative analysis on effectiveness of traditional and prism approach in project management on building construction : case of Enabel Uganda
(Kyambogo University (Unpublished work), 2025-10) Bikey, Francis Xaviour
Projects integrating Sustainable Methods (PRiSM) approach is critical in successful achievement of sustainability in project management on building construction projects. Building projects face complex challenges of balancing economic, social and environmental factors in their lifecycle for sustainability in constructions. Traditional approach caters majorly economic aspects neglecting social and environmental which are undertaken by PRiSM which is adopted by ENABEL necessitated this study to determine its effectiveness. The study establishes the environmental, social, and economic contribution of the PRiSM and traditional approaches on building construction projects. The descriptive research design with both quantitative and qualitative approach was adopted. The questionnaires were administered to 279 respondents to identify critical factors for Traditional and PRiSM approaches where Spearman was applied. The study interviewed 25 participants to identify strategies for improvement of PRiSM. SPSS version 24.0 developed mean where ranking was done to determine the critical factors using factor analysis. Results indicated that PRiSM approach ensured that employees and suppliers are satisfied with timely completion of project which cater for economic motive with two critical factors of stakeholders’ involvement and time management as well as quality design, environmental aspect was realized through harvesting of rainwater and protection of ecosystem to control pollution, social factors involved uptake of government intervention to prevent HIV/AIDs and provision of good working conditions. Traditional approach emphasizes profits, environment consider occupation management and social factors support use of local material and protection of ecosystem. Other findings indicated that PRiSM and traditional have moderate sign relationship (r= 0.571) on economic motives and negative relationship for environmental and social factors. Construction projects should adopt PRISM with inclusive participation of stakeholders in decision making, monitoring and evaluation and compliance on eco-system conservation regulations under an institutional framework. PRiSM approach emphasizes sustainability throughout project lifecycle with potential shift to reduce risk which lead to long-term value creation in construction industry.
Analysis of the effects of different types of welding electrodes on the integrity of Smaw-welded recycled steel in Uganda
(Kyambogo University (Unpublished work), 2025-11) Banura, Pascal
The mechanical performance of welded joints in Shielded Metal Arc Welding (SMAW) of recycled steel are significantly influenced by the type of electrode used. Different welding electrodes produce varying mechanical and microstructural properties in the weld because each electrode introduces distinct thermal and metallurgical conditions during welding. This study examined the effects of different welding electrodes (E6013, E7018, and E7024) on the hardness, tensile strength (breaking load), and microstructural characteristics of SMAW-welded recycled steel with the aim of determining the optimal electrode for achieving a balance between strength, hardness, and ductility. Rockwell hardness tests, tensile strength tests, and microstructural examinations were performed on welds made on steel samples obtained from three steel manufacturers in Uganda. The findings revealed that the E6013 electrode produced welds that exhibited moderate hardness across all steel manufacturers while E7018 electrodes produced the highest breaking load (78.4kN) indicating superior tensile strength and ductility; whereas E7024 electrodes produced welds that exhibited the highest hardness value of 63.9 HRB but with lower breaking load (28.2kN) suggesting a more brittle nature. Furthermore, microstructural analysis confirmed that E7018 welds had fine-grained acicular ferrite and bainite which enhanced toughness while E7024 welds displayed coarse martensitic structures which increased hardness but reduced ductility. The results suggest that E7018 electrodes are ideal for load-bearing structural applications whereas E7024 electrodes are better suited for applications where hardness is prioritized over toughness. Although this study provides valuable insights into electrode selection, further study is needed to explore the effects of welding parameters, long-term durability, and alternative welding techniques to enhance the performance of SMAW-welded recycled steel.
Evaluating the mechanical performance of Kukui seed shells as coarse aggregates in light weight aggregate concrete
(Kyambogo University (Unpublished work), 2025-11) Bagombeka, Ancel
Uganda’s population growth, currently at 3.2% (UNhabitat, 2016), has increased the demand for residential, commercial, and industrial buildings. Concrete constitutes nearly 60% of construction materials on building sites (Aytekin et al., 2022), and aggregates contribute 70–85% of its total weight (Cement and Concrete Association of Australia, 2002). This places pressure on existing natural aggregate sources, creating the need for sustainable alternatives. Lightweight aggregates offer a potential solution, yet kukui seed shells (an organic and waste-derived option) have never been studied in the Ugandan context, despite their potential contribution to sustainable construction. This study adopted a combined experimental and numerical methodological framework to evaluate the suitability of kukui seed shells as lightweight aggregates. Mechanical characterization of the shells was followed by an experimental program in which normal aggregates were partially replaced with kukui seed shells at 25%, 50%, 75%, and 100% for both Half Seed Shells and Quarter Seed Shells. The resulting concrete mixes were assessed through mechanical and water absorption, Fire resistance and Thermal conductivity performance tests, while serviceability behaviour was analysed using ANSYS finite element simulations. The shells demonstrated satisfactory Aggregate Impact Value (AIV), Aggregate Crushing Value (ACV), Los Angeles Abrasion (LAA), and soundness performance. Increasing the replacement percentage led to reductions in density, compressive strength, flexural strength, splitting tensile strength, and thermal conductivity. Quarter Seed Shell mixes generally outperformed Half Seed Shell mixes. Based on overall performance, a 50% replacement using Quarter Seed Shells is recommended, yielding a compressive strength of 25.1 MPa, thermal conductivity of 1.6 W/mK, and reduced density of 2,112 kg/m³, making it a viable lightweight concrete option for sustainable construction in Uganda.
Investigating the impact of Ruti Abattoir wastewater effluent on River Rwizi water quality
(Kyambogo University (Unpublised work), 2025-11) Atugasha, Den
The rapid population growth in developing countries including Uganda has increased food demand leading to high demand of meat from abattoirs. The abattoirs generate substantial amounts of solid waste and wastewater effluent during their operations. The discharge of untreated abattoir effluents into the environment leads to water pollution due to the high organic load to the environment. This study aimed at investigating the impact of Ruti abattoir wastewater effluent on the water quality of River Rwizi. Water samples were collected at the abattoir, downstream and upstream the point where the abattoir effluent enters River Rwizi. The samples were tested for total nitrogen and phosphorus, biological oxygen demand (BOD) and chemical oxygen demand (COD). Heavy metals such as nickel, arsenic, copper, chromium, iron, and mercury were also tested. The abattoir wastewater to open environment and flows to River Rwizi that increases COD levels of river water. The mean COD values at the abattoir 604.9±153.9 mg/l, upstream 83.0±3.1mg/l and downstream 252.3±61.4 mg/l. The COD level was above the National Environment Management Authority recommended water quality limit of 70mg/L. The use of raw and activated carbonised rice husks for the treatment of nitrate phosphate-polluted water studied. COD removal efficiencies increased with increase in contact time 5, 15 and 20 minutes were 79, 88, and 91%, respectively. Furthermore, COD efficiencies for dosages 1, 2, 3, 4 and 5 g were 52, 65, 72, 74 and 91% respectively. Secondly, carbonised activated rice husks at dosage of 5 g and 20 minutes contact time in reducing COD. The study calls on the abattoir to improve on their wastewater management techniques and community to improve on existing water treatment methods used.
Procurement planning on construction project performance: factors affecting infrastructure projects in Kampala city
(Kyambogo University (Unpublised work), 2025-11) Asio, Martha Okiring
The procurement process involves recognizing the demands of a project, outlining its specifications, and securing the right contractors that are crucial for finishing a construction project successfully in terms of cost, schedule, and quality. In Uganda, there have been issues with procurement in terms of accountability, scheduling conflicts, and budget overruns in construction projects. This study looked at the effect of procurement planning and how it influences the success of construction projects. Procurement planning was studied as an independent variable to determine its effect on project performance. The dependent variable in this study was project performance, which was assessed based on time, cost, and quality using a descriptive survey research design. The data was collected from construction clients, contractors and consultants through questionnaires. The study findings established that contemporary procurement within construction projects incorporate planning phase prior to the initiation of bidding. Despite the implementation of these measures during the planning stage, a notable discrepancy exists as numerous construction projects experience delays, and cost overruns. The survey reveals a strong agreement on the necessity of assessing client needs at 78% and material assessment at 86% during the planning stage. It emphasizes the necessity for all stakeholders to synchronize these elements before the commencement of the bidding process, as they profoundly influence project cost, construction timeline, quality of the final deliverables, and overall customer satisfaction.
Experimental and numerical investigations of fire resistance of a hybrid slab
(Kyambogo University (Unpublised work), 2025-09) Asiimwe, Ronald Wilfred
In Uganda, there has been a growing use of hybrid slabs which include timber steel and concrete within floor systems. On the 26th of September 2022, the government of Uganda through the minister of works and transport issued a ban on building houses with hybrid slab floor systems until enough studies have been done to deem it safe as a construction method. Therefore, there was a need to conduct an experimental and numerical investigation on the performance of the hybrid slab when subjected to a fire. The experimental and numerical model parameters and specifications considered were obtained from the baseline study carried out on buildings, designers and contractors employing the use of hybrid floor systems in Uganda. A 4x3m slab model was built on a construction site in Katta, Wakiso district. The model was constructed with a 75mm concrete topping cast on expanded metal lathe fixed, on top of 100x100mm Eucalyptus grandis beams, spaced 600mm cc which were simply supported on I-beams top flanges. The I beam were supported by SHS 75x75x5mm columns at the ends. The I-beams were spaced 2000mm perpendicular to the 4m side. Burnt clay brick wall were constructed around the perimeter of the structure to keep the heat in. Three openings were constructed on the 4m side and two openings were constructed on the 3m side. Due to the unavailability of the large laboratory furnaces to carry out the experiment, a natural fire was considered as the fire scenario to be used for experimenting following Eurocode specifications. It was observed from the experimental setup that hybrid slab could with stand a natural fire for more than one hour with the ability to maintain its load carrying capacity. Numerical simulation was done using ABAQUS-CAE a Finite Element Model programme. Natural fire curve, ECPC, ASTME119 and ISO 834 fire curves were used for numerical simulation. The numerical natural fire curve observations were consistent with the experimental results. The hybrid slab therefore meets the east African code recommendations of one hour fire resistance without collapse based on natural fire tests and therefore can be used as a construction method. The ability of the slab to withstand fire action will depend among other factors the composite action between the timber and concrete therefore an investigation of the degree of composition between the timber and concrete was be determined considering three-inch wire nails and expanded metal lathe as shear connectors. Four test samples were cast according to Eurocode 4 for each of the connectors. A Universal Testing Machine (UTM) was used to test the samples under monotonic loading, and linear variable displacement transducers (LVDTs) were used to measure slip. It was determined that both the nails and expanded metal lathe create partial composite action between the concrete and timber elements.
Investigating the dewaterability and resource recovery potential of distillery wastewater using sawdust and charcoal dust as conditioners
(Kyambogo University (Unpublised work), 2025-09) Angom, Hedina
Discharge of untreated distillery wastewater has a high impact on human and environmental health. One of the critical stages in its management is dewatering. However, understanding the dewatering characteristics of distillery wastewater is a grey area as minimal research has been done on it. This research evaluated the characteristics of distillery wastewater from various sources to identify any variations, its dewatering potential, enhancement of dewatering using conditioners and its resource recovery potential. The research was undertaken using laboratory measurements and experiments to determine the wastewater characteristics and dewaterability. Dewatering performance was measured in terms of capillary suction time (CST), and turbidity of supernatant after natural and mechanical settling. The findings of this study showed that distillery wastewater characteristics were very significant in pH (3.56-6.32) p=0.017, EC (4.22-34.77mS/cm) p=0.002, COD (63,800-148,680mg/L) p=0.004 and turbidity (18,700-45,500NTU) – p=0.167. Dewatering was noted to be CST (30-5512.64s) p=0.140 and turbidity of supernatant (14,700-87,500NTU) p=0.046. Enhancing dewatering using conditioners showed CST (60.56-9047.04s) p=0.452, 0.012, 0.207 and turbidity of supernatant (4.37-93,500NTU) p=0.002, 0.013, 0.788 with better performance observed after treatment with charcoal dust. Based on the Nitrogen (31-121mg/L), Phosphorus (195-757mg/L), Potassium (4580-13449.15mg/L) and TVS/TS ratio (0.76-0.91) values, distillery wastewater showed potential for resource recovery. Distillery wastewater needs to be treated to protect human and environmental health. Strict measures should be put in place to ensure adherence to standards for discharge into the environment.
Exploring the impact of managers’ supervisory styles on workers’ performance in private sector building projects in Uganda : a case study of Mbarara city
(Kyambogo University (Unpublished work), 2025-03) Agaba, Abel
In Mbarara city, construction projects have been characterized by delayed completion and poor-quality projects. This study sought to explore the impact of managers’ supervisory styles on workers’ performance in private sector building projects in Mbarara City. The study was motivated by the fact that an audit by the Government Accountability Office found that while the USMID project achieved an average score of 77.5% there were gaps in contract management and project performance in Uganda. Construction managers, other construction workers, experts, and owners of construction projects constituted the study population. A cross-sectional survey design was used under descriptive research design. Data was collected from a sample size of 246 using questionnaires and interview guides as data collecting tools. The descriptive and inferential statistical analyses of the data made use of the Pearson correlation coefficient and statistics from regression analysis. The results showed that different supervisory styles were in use, mostly reflecting democratic, autocratic, transformational, and to a much lesser extent laissez-faire type. The employees demonstrated excellent achievement by performing to the best of their abilities, starting work consistently, and successfully completing tasks to ensure customer pleasure. The correlation analysis indicated a statistically significant association between a manager's supervisory styles and worker efficiency i.e. (r=0.249**, p=0.000˂0.05), suggesting that managers in Mbarara city's private construction projects should rely on supervisory styles to raise staff performance. Regression analysis results showed that manager’s supervisory styles account for up to 6.2% of the variance in employee performance (adjusted R2 =0.062), implying that to a large extent, manager’s supervisory styles alone have less influence on the workers’ performance, with other factors like; level of motivation, welfare, level of training, remuneration, safety concerns, conflicts among workers, influencing their performance by 93.8%. In conclusion, the majority of employees value democratic supervisory practices, which are represented in managers consulting with employees before making decisions and promoting discussion of sensitive topics
Investigating the effect of leachate from solid wastes management plant on surface water quality in Mbale
(Kyambogo University (Unpublished work), 2024-09) Alunyu, Denis
This study investigated the effect of leachate from solid wastes composite plant on River Namatala water quality in Mbale City. Data was collected on the amount of solid wastes generated per day within Mbale city. Concentrations of water pollutants in the leachate produced from the decomposed solid wastes were tested in the laboratory. Possibility of treating lead as a pollutant using low cost adsorbent was explored. The results indicated that 273.5 tons of solid wastes are collected per day and deposited at the wastes management plant. Of this total, biodegradable and nonbiodegradable wastes constituted 84.4% and 15.6%, respectively. The concentrations or values of water pollutants especially total phosphorus, chemical oxygen demand, total nitrogen, lead and electrical conductivity from the leachate were higher than the limits recommended by the World Health Organisation (WHO).The heavy metals such as copper, iron, nickel, silver, chromium had lower values compared to maximum acceptable limit set by WHO. However, heavy metals should not be ignored as they are potential sources of pollution to nearby environments. The differences in the means of upstream and downstream pH, iron, chromium, lead, copper, total nitrogen, total phosphorus concentration and electrical conductivity were statistically significant (p < 0.05) while nickel, silver chemical oxygen demand, biochemical oxygen demand were statistically not significant (p >0.05).Raw avocado seeds had a higher lead removal efficiency (93.97%) compared to activated avocado seeds (89.7%). The households in Mbale city should be sensitized on the need for separation of wastes into biodegradable and nonbiodegradable. Water from River Namatala should be first treated before its domestic use.
Assessing occupational safety and health hazards at workplaces in Uganda : a case of four engineering materials testing laboratories
(Kyambogo University (Unpublished work), 2024-06) Lusundo, Fred Moses
Workplaces in Uganda are mandated to satisfy the requirements of the Occupational Safety and Health Act (OSHA), 2006 regarding the Occupational Safety and Health of workers. Despite of the above, many workplaces in Uganda including Engineering Materials Testing Laboratories have continued not to satisfy the above requirements. Although different strategies to manage OSH risks have been devised and several entities like Safety committees and Ministry of Gender Labour and Social development (MoGLSD) empowered by the act to ensure compliance of work places, OSH in engineering materials testing laboratories has remained a challenge; thereby exposing staff and visitors to the laboratories to serious OSH hazards including physical injuries and long-term health risks like cancer. It is these compliance gaps that this study is set to examine, using the case of Engineering Materials Laboratory (EML), Central Materials Laboratory (CML), Geotechnical Foundation Services Ltd (GFS) and Geotechnical Engineering and Technology Laboratory Ltd (GET). The study used both quantitative and qualitative research designs. Quantitative data collection was supported by the use of questionnaires with closed ended questions administered to 60 respondents and then qualitative data, by use of an interview guide. The study findings indicate that for all laboratories, risks due to chemical hazards ranked highest, followed by risks due to accident hazards. Risks due to physical hazards ranked third for EML as opposed to risks due to ergonomics and psychosocial factors that ranked third for CML, GFS and GET. Risks due to ergonomics and psycho-social factors ranked lowest for EML as opposed to risks due to physical hazards factors that ranked lowest for CML, GFS and GET. Consequently, the assessment of the level of compliance to Uganda’s OSH regulatory framework indicated that GET, GFS, EML and CML were 88%, 83.4%, 79.7% and 76% compliant respectively, implying that there are still gaps in the implementation of OSHA, 2006. In conclusion, the study attributes these gaps to inadequate financial resources allocated for OSH operations and laxity in implementing OSH management strategies by the various key players among others.
Assessing occupational safety and health hazards at workplaces in Uganda : a case of four engineering materials testing laboratories
(Kyambogo University (Unpublished work), 2024-07) Lusundo, Moses Fred
Workplaces in Uganda are mandated to satisfy the requirements of the Occupational Safety and Health Act (OSHA), 2006 regarding the Occupational Safety and Health of workers. Despite of the above, many workplaces in Uganda including Engineering Materials Testing Laboratories have continued not to satisfy the above requirements. Although different strategies to manage OSH risks have been devised and several entities like Safety committees and Ministry of Gender Labour and Social OSH in engineering materials testing laboratories has remained a challenge; thereby exposing staff and visitors to the laboratories to serious OSH hazards including physical injuries and long-term health risks like cancer. It is these compliance gaps that this study is set to examine, using the case of Engineering Materials Laboratory EML), Central Materials Laboratory (CML), Geotechnical Foundation Services Ltd (GFS) and Geotechnical Engineering and Technology Laboratory Ltd (GET). The study used both quantitative and qualitative research designs. Quantitative data collection was supported by the use of questionnaires with closed ended questions administered to 60 respondents and then qualitative data, by use of an interview guide. The study findings indicate that for all laboratories, risks due to chemical hazards ranked highest, followed by risks due to accident hazards. Risks due to physical hazards ranked third for EML as opposed to risks due to ergonomics and psychosocial factors that ranked third for CML, GFS and GET. Risks due to ergonomics and social factors ranked lowest for EML as opposed to risks due to physical hazards factors that ranked lowest for CML, GFS and GET. Consequently, the assessment of the level of compliance to Uganda’s OSH regulatory framework indicated that GET, GFS, EML and CML were 88%, 83.4%, 79.7% and 76% compliant respectively, implying that there are still gaps in the implementation of OSHA, 2006. In conclusion, the study attributes these gaps to inadequate financial resources allocated for OSH operations and laxity in implementing OSH management strategies by the various key players among others.

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