AAU Institutional Repository (AAU-ETD)
Addis Ababa University Institutional repository is an open access repository that collects,preserves, and disseminates scholarly outputs of the university. AAU-ETD archives' collection of master's theses, doctoral dissertations and preprints showcase the wide range of academic research undertaken by AAU students over the course of the University's long history.
How to Submit Your Work
The repository contains scholarly work, both unpublished and published, by current or former AAU faculty, staff, and students, including Works by AAU students as part of their masters, doctoral, or post-doctoral research
- All AAU faculty, staff, and students are invited to submit their work to the repository. Please contact the library at your college.
You may contact digirep@aau.edu.et.with any questions about the repository
Colleges,Institutes in AAU-ETD
Select a college,institute to browse its collections.
Recent Submissions
Assessment of Construction Equipment Replacement Decisions (A Case Study: Addis Ababa City Road Authority)
(Addis Ababa University, 2025-06-01) Gebeyehu Teka Mitiku; Solmon Sertse (PhD)
Assets typically deteriorate with age, which raises operating and maintenance (O&M) expenses and lowers salvage values. Additionally, there may be more recent assets available for replacement that are more effective and better performance.Public and commercial organizations that own fleets and/or
specialized equipment must therefore make decisions about when to replace them on a regular basis. Unfortunately, prior studies have highlighted the issue of agencies failing to replace their equipment on time. This problem is made worse in public contracts since, due to their service-oriented nature, there is no way to determine whether the equipment is profitable (economical).Therefore, the main purpose of this study is to investigate equipment replacement policies, procedures, and techniques of Addis Ababa City Road Authority. It also examines the obstacles of on time replacing of outdated equipment.To achieve this the study applied mainly the following information gathering tools i.e.; questionnaire, road construction equipment fleet record inventory (RCEFRI), document review and indepth interview.Accordingly The results indicated that the work objectives, safety, and management goals were found to be the most influential qualitative factors affecting the decision of equipment replacement, while Maintenance cost, downtime cost, and capital/purchasing cost are among the top quantitative factors that are considered while making a decision to replace equipment.Researcher conducted replacement analysis using minimum cost method. Sample of nine (9), thirteen (13), and eleven (11) to heavy machinery, machinery and light weight machine and vehicles respectively were taken from population of Road equipment The result indicated that 21, 63% equipment are beyond their economic life .the previous replacement history of AACRA indicated that increasing maintenance and repair cost is the leading factor of replacement. on the other hand among 784 AACRA equipment 56% are 15 years and above.In this sense it is necessary for the authority to take action to utilize approaches to optimize equipment replacement decision. The research also suggest that AACRA must
evaluate equipment’s cost(Maintenance ,downtime cost…), performance (workout put….) and risk (accident,CO2 Emission…) factors and must replace equipment’s based on economical replacement analysis .
Key word: Equipment replacement decision, replacement factors, economic life,replacement analysis and on time replacement.
Assessment of Structure Plan Violations and Mitigation Strategies in Nifas Silk Lafto Sub-City, Addis Ababa
(Addis Ababa University, 2025-06-01) Zelalem Tamru; Berhanu Woldetensae (Associate professor)
Addis Ababa has been experiencing rapid urbanization that has profound impact leading to structure plan violations that undermine the envisaged city’s development. Nifas Silk Lafto SubCity, as one of the expansion area has been facing such viloations and related challenges such as unauthorized land use changes, encroachment on green areas, noncompliance with building height regulations, and obstruction of road rights-of-way. These violations reflect weak governance and socio-economic pressures that compromise the city’s structural plan and longterm livability. This study assessed the extent, causes, and impacts of such violations, and explored possible mitigation strategies. A mixed-methods design was applied, combining descriptive surveys with qualitative and quantitative approaches. Data were gathered from 120 respondents through questionnaires, interviews, and field observations, supplemented by secondary sources. It used analytical tools that included frequency distributions, percentages, tables, charts, and spatial mapping. The findings indicate that rapid urbanization, population pressure, weak institutional capacity, and corruption are the main drivers of plan violations. Some of the outcomes include shrinkages in green space coverage, reduction in right-of-way spacxe and violstions of the building height regulations. It is then recommended to strengthen institutional and legal frameworks, enhance enforcement mechanisms, and apply technological tools such as GIS and other applicable monitoring tools. monitoring. Moreover the promotion of community participation, awareness campaigns, and transparent governance are also beneficial in mitigating plan violations.
KeyWords: Land use violation, Building height violation, Road plan violation, Green area encroachment.
Impacts of water quality on the Compressive Strength of Concrete: Case of Banteyiketu, Betel, Bulbula and Mekanisa rivers in Addis Ababa
(Addis Ababa University, 2025-01-01) Aklesia Dereje; Tilahun Derib (PhD)
Addis Ababa is a water stressed city and it does not meet the demand of domestic water. On the other hand, there are aggressive constructions all over the city that need abundant water. In most of the areas, the construction has used piped water supply which adds an additional burden to the city’s water distribution system. So, it is very important to consider alternative water supply for the construction industry. So, one of the possible sources is river water. In Addis Ababa, about 10 rivers flow through the city at various locations. The rivers have different capacities and quality levels. This research investigates the impact of using water from various rivers in Addis Ababa on the comprehensive strength of concrete. The study aims to identify key water quality parameters that influence concrete performance and assess the suitability of Addis Ababa river water for construction purposes. Water samples were collected from four distinct locations namely Bantiketu, Betel, Bulbula and Mekanisa taking into consider the river flow rates. Laboratory tests were conducted to evaluate parameters including pH levels, suspended and dissolved solids, and chemical composition. The results were compared with a control sample using potable water and analyzed against ASTM and ACI standards. The findings reveal that river water quality varies across sampling points, with Banteyiketu and Mekanisa exhibiting the cleanest water suitable for concrete mixing. Although Betel (P3) showed higher acidity and nitrate levels, requiring caution and potential treatment, all samples generally fell within permissible limits for concrete use. The Bulbula sample demonstrated the highest compressive strength, while the other samples also showed acceptable performance by the 28th day. This research concludes that with proper quality control, river water can serve as a viable alternative source of water for concrete production in Addis Ababa, addressing local water scarcity challenges. Building a three-story structure consumes water equivalent to the daily needs of 442–883 people or residents in 3–6 condominium blocks. This emphasizes the need for sustainable water management in urban construction.
Key words: Construction, compressive strength, water quality, Addis Ababa Rivers,
Development of Pavement Management Performance Model: A Case Study of Ethiopian Roads Administration
(Addis Ababa University, 2025-06-01) Seble Deginetu Bogale; Asregdew Kassa (PhD)
According to United Nations Economic Commission for Africa “Road safety performance review of Ethiopia (2020)” Sustainable and vibrant transport systems can lead to long-term economic growth. If designed well, transport facilitates access to opportunities, education, medical services, and goods, and improves overall quality of life. Around $45 billion worth of road infrastructure has been destroyed over the previous 20 years due to poor maintenance, according to a World Bank study conducted in 85 developing nations. Less than $12 billion might have been spent on preventive maintenance to avoid this loss (Harral and Faiz, as cited by Regassa, 2015). This study's primary objectives are to evaluate the Ethiopian Road Administration's present pavement management practices and develop a pavement performance prediction model. A case study has been employed as a research methodology to carry out the investigation. Pavement condition assessment reports, document examination, and observation are the methods used to acquire data using regression analysis. The study's findings indicate that the road sector pavement management directorate planned and arrange strategies for timely maintenance of defective road but in reality the maintenance activity done after the road condition become sever condition. Which lead huge maintenance expense instead this loss could have been averted with less preventive maintenance cost. Performance models are used in pavement management systems (PMSs) to forecast pavement performance in the future by correlating pavement distress with traffic volume, age, traffic load, climate condition etc. But the study limited to correlating pavement distress with age of pavement as the other constraints (traffic volume, climatic condition, traffic load etc.) are not available during the study. The regression analysis model's result shows the maximum percentage difference between the actual and anticipated pavement distress is 4.2%, making it a good starting model. Ultimately, by reducing the most significant issues that are unique to the city, this study offers the municipal administration a logical way to enhance its road pavement management practices. By forecasting the road's future state, the pavement performance model is also anticipated to assist the local administration in carrying out prompt maintenance on damaged roads.
Key Word: Road pavement Management, Pavement Performance Prediction Model, Pavement
Spatial dynamics and morphological relations in the emergence of urban forms in Dire Dawa
(Addis Ababa University, 2024-09-01) Samuel Asfaw Zelelew; Zegeye Cherenet Mamo (Asstociate Professor)
This dissertation delves into the morphogenesis of Ethiopian cities, focusing on Dire Dawa. Leveraging Conzen's morphological evolutionary technique, the study conducts a meticulous physical examination of Dire Dawa's morphology, augmented by maps and detailed interviews to reconstruct its early spatial organization. Exploring the sustainability of land-use transformations, the research scrutinizes consequences of formal and organic planning interventions. Analyzing land-use mix and open space ratio across six cases from three morphological periods, a declining trend in mixed-land use intensity is observed, particularly at the plot scale. Moreover, a shift from the historic core to the periphery correlates with reduced mixed-land use intensity at the neighborhood level, emphasizing challenges in maintaining sustainable urban form. To address this, integration of principles from organic development and formal planning is advocated, emphasizing the importance of balanced mix of uses. Furthermore, the study investigates spatial transformation events and emergent urban forms in Dire Dawa, examining interplay between formal planning intervention and spontaneous developments. Utilizing Spacematrix software, the research identifies dominance of point-type low-rise developments in organically developed areas, contrasting with prevalence of block-type low-rise and mid-rise forms in plan-driven developments. Rising trends in floor space index and spatial coverage patterns indicate growing concern for space efficiency and sustainable development, particularly in outlying areas. However, density of street network in organically developed portions surpasses formally planned areas, highlighting relevance of organic development concepts. Lastly, the dissertation examines correlation between street width and land use patterns, elucidating impact of street hierarchy on land use intensity across different developmental periods. Utilizing mixed-methods case study design, four land use categories are identified and their relationship with street width evaluated. Findings underscore variability of this connection based on morphological periods and urban planning interventions, advocating for well-designed land use policies accommodating both formal and informal developments.
Keywords: Morphological evolution, Urban morphology, Sustainability, Land-use transformation, Spatial dynamics, Street hierarchy, Dire Dawa, Ethiopia.