Ethiopia Institute of Technology- Mekelle

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Start date: 2020

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    Sustainable Sisal Fibers Reinforced Cement Composites: Development, Characterization, and Mechanical Performance for Wall Applications
    (Mekelle University, 2025-06-13) Meselu Zewdu
    Sisal fibers, extracted from Agave sisalana plants, are abundantly available in Tigray region of Ethiopia. This study investigates the potential of NaOH-treated sisal fibers as sustainable and costeffective reinforcement in cement composites. C-25 concrete and Grade 42.5R cement was used, and mix proportions determined using the ACI method. A water-to-cement ratio of 0.56 was adopted to achieve the target slump range of 75 -100 mm, ensuring adequate workability. The experimental investigation focused on sisal fiber-reinforced cement composites with varying fiber lengths (10 mm, 15 mm, and 20 mm) and contents (1 %, 2 %, and 3 % by weight of cement). The fibers were treated with sodium hydroxide (NaOH) to enhance their interfacial bonding with the cement matrix. Mechanical properties, including compressive, split tensile and flexural strength, were evaluated at 7 and 28 days of curing. To determine the optimal mix configuration, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was employed. SolidWorks software was also used to model the testing setups, providing detailed visualization of loading and specimen arrangements. The optimal mix was identified at 28 days as the composite containing 15 mm fiber length at 2 % content, which achieved the highest tensile strength (4.10 Mpa), compressive strength (31.6 Mpa), and flexural strength (5.4 Mpa). These findings confirm that NaOH-treated sisal fiber can enhances the mechanical performance of cement composites and offers a promising, eco-friendly alternative for both structural and non-structural wall applications.
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    The Potential of Alkali-Treated Sisal Fiber/Granite Reinforced Hybrid Composites for Automotive Semi-Trailer Loading Floor Applications
    (Mekelle University, 2025-06-13) Semere Ayahuney
    Natural fiber reinforced composites offer a sustainable alternative in the composite industry due to their low density, high specific strength, and eco-friendliness. Sisal fibers, abundantly grown in northern Ethiopia, are attractive for their low cost and favorable mechanical properties but are limited by their inherent weaknesses in mechanical strength, water absorption resistance, and durability. This research focuses on enhancing these properties in sisal/polyester composites for automotive applications, specifically for a semi-trailer loading floor. The study investigates the efficacy of alkali (NaOH) treatment of sisal fibers and hybridization with granite powder as a filler to improve mechanical performance and water resistance. Experimental evaluations determined that a composite with 30 wt.% alkali-treated sisal fibers and 5 wt.% granite powder (E8) exhibited the best overall mechanical properties (tensile, flexural, compressive, and impact strengths) and significantly reduced water absorption. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was employed to select this optimal composite formulation from various alternatives. Subsequently, a Genetic Algorithm (GA) was used to optimize the design of a sisal/granite hybrid composite loading floor, achieving an approximate weight reduction of 64.3% compared to a conventional steel counterpart. Finite Element Analysis (FEA) validated the optimized design, confirming a peak stress of 43.9 MPa and a minimum factor of safety of 2.19 in the most critical ply, meeting the design constraints. The maximum deflection was 1.459 mm, well within serviceable limits. The findings demonstrate the potential of alkali-treated sisal/granite polyester composites as a lightweight, durable, and sustainable material for semi-structural transport applications.
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    Investigation of Ceramic Tile Waste as Partial Replacement of Cement in concrete
    (Mekelle University, 2024-11-08) Tsegay Kassahun Gebreegzabihe
    The construction industry's rapid growth coupled with increasing environmental concerns and necessitates sustainable practices. The study investigates grinded ceramic tile wastes as a partial replacement for cement for C-30 concrete grade having an aim to feel material scarcity and enhance sustainability in the construction industry. After the concrete ingredients test, mix design of C-30 concrete grade was prepared and concrete cube specimen with 0%, 5%, 10%, 15%, 20%, 25% and 30% of ceramic tile wastes in place of cement were casted, cured and tested for compressive and flexural strength. The experimental test results have revealed, an increase in the proportion of grinded ceramic tile waste in concrete production decreases workability. In terms of strength, both compressive and flexural strengths initially increased with ceramic tile waste, peaking at 10% replacement with a compressive strength of 40.26 MPa and a flexural strength of 4.31 MPa at 28 days. Beyond 10%, both strengths declined indicating that while moderate ceramic waste enhances concrete strength but excessive replacement negatively impacts performance. And the cost analysis revealed that incorporating ceramic waste significantly reduces the cement cost. It can therefore be concluded that in areas where cement scarcity or high costs are prevalent, the partial replacement of cement with grinded ceramic tile waste in concrete is a viable and sustainable alternative. The use of ceramic waste at optimal levels can improve strength properties and offers significant cost advantages while contributing to waste management and reducing the environmental impact of construction activities.
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    Investigation the Causes of Delay and its Impact on Urban Road Projects in Shire Town –Tigray
    (Mekelle University, 2025-02-21) Goitom Tsehaye
    In construction, the word "delay" refers to something that happens later than expected, according to schedule, specified in the contract or beyond the date agreed by the parties to deliver the project and one of the most common issues considered during implementation of construction projects. Construction delays have an impact on more than just construction industry, but also an Influence on the overall economy of a country like Ethiopia. Relative Importance Index (RII) analysis was used to test the agreement between different groups of respondents participated in the questionnaire survey, and to rank the most causative factor of delay in urban road projects in case of shire town. This project identified thirty nine (39) causes of delay. There were forty (40) valid Questionnaires which received back from Contractors, Consultants, and employer. The objective of the project is to investigate the causes of delay and their impacts in construction of urban road projects in case of shire town. The causes of delay were grouped in to seven (7) as client related delays, consultant related delay, contractor related delay, material related delay, equipment related delay, Labor related delay and external related factors or outside the Control of Either Party to the Contract. The project study identified and ranked the top or most causative factor for delay in urban road construction projects are: Lack of construction materials with relative important index (RII) of (0.85). Escalation of materials prices with relative important index (RII) of (0.845). Force majeure with relative important index (RII) of (0.84). Material market instability with relative important index (RII) of (0.825). Poor communication and coordination with other parties with relative important index (RII) of (0.805). Inaccurate time estimate with relative important index (RII) of (0.77). Inaccurate site investigation with relative important index (RII) of (0.77). Lack of construction machinery with relative important index (RII) of (0.76). Poor quality of construction materials with relative important index (RII) of (0.74). Improper project feasibility study with relative important index (RII) of (0.715). Poor Communication and coordination with other parties with relative important index (RII) of (0.705). Conflicts between contractors and firm members with relative important index (RII) of (0.70). Economic, financial and environmental impacts have been found the most impacts of delay with relative important index (RII) of 0.93, 0.925 and 0.845 respectively.
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    Assessing the Impact of Improper Sidewalks on Pedestrian Safety and Level of Service in Mekelle City
    (Mekelle University, 2025-07-22) Kibrom Weldu
    Pedestrian safety is a vital yet often neglected aspect of urban development in rapidly growing cities like Mekelle, Ethiopia. This study examines how improper sidewalk conditions, such as narrow, obstructed, and poorly maintained paths affect pedestrian safety and the Pedestrian Level of Service. A mixed-methods approach was used to comprehensively assess pedestrian conditions in Mekelle City. Quantitative data collection involved measuring sidewalk widths, counting pedestrians, and conducting structured surveys to evaluate safety, usability, and infrastructure quality. Physical assessments also identified common obstructions like vendors, utility poles, and parked vehicles. PLOS was evaluated using the Highway Capacity Manual, considering factors such as surface condition, lighting, and crossing points. Complementing this, qualitative data were gathered through field observations and open-ended survey responses to capture pedestrian experiences, perceptions of safety, and challenges such as poor lighting, unmarked crossings, and obstructed walkways, especially during nighttime travel. The findings show that most sidewalks are narrower than the recommended 1.2 meters and often obstructed by vendors, poles, or construction materials, making them unsafe. PLOS ratings ranged from C to E, indicating poor walking conditions. Over half of respondents felt unsafe, mainly due to poor lighting, inadequate crossings, and lack of maintenance. This study concludes that Mekelle's pedestrian infrastructure significantly hinders walkability and compromises safety. Recommendations include adopting international design standards, enforcing clear regulations to prevent sidewalk encroachment, and incorporating inclusive urban design principles in future planning. These insights provide essential guidance for urban planners and policymakers aiming to create safer, more accessible pedestrian environments in Mekelle and similar urban contexts.
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    Sustainable Design and Development of ceiling board from waste garment fabric reinforced composites with sisal fiber
    (Mekelle University, 2025-06-13) BRKTI MERDU
    This study focuses on converting textile waste into a useful resource by utilizing it in to new product which is ceiling boards. The textile waste materials were collected from a local textile factory, MAA Garment. And it combined with sisal fibers as reinforcement with unsaturated polyester matrix. These recycled materials can be used to successfully develop composite materials that exhibit high strength, rigidity and ideal weight ceiling board applications. Different structural configurations were prepared with a 30/70% fiber-to-polyester resin ratio using randomly oriented cut waste fabrics: SSS (S1), SFS (S2), FSF (S3), and SSS (S4). The materials were mixed manually in the fabrication process. Demonstrating waste fabric and sisal fiber hybrid polyester composite laminates can effectively replace gypsum ceiling boards which offering notable environmental benefits and promoting the recycling of waste into functional construction materials are the two key goals of this research. Samples were prepared via the hand lay-up method, with fiber-to- polyester resin weight ratio 30/70%. And the sisal fiber were treated by alkali to enhance interfacial adhesion and remove impurities. Those treatment of fiber leads to enhance mechanical and physical properties of the laminate. This laminate pass through a series of experimental tests to evaluate the compressive strength, tensile strength, flexural strength, impact strengths, density, and water absorption rate. Finally the laminate shows good mechanical properties especially in flexural, tensile strength and water absorption. The optimized laminate achieved a 29% reduction in weight compared to gypsum boards, reducing from 12 kg to 8.49 kg. According to literature-based optimization, the water absorption of the laminate was only 5%, which represents a 54.5% reduction compared to lightweight cement boards, 50% compared to gypsum ceiling boards, and 44% compared to fiber cement boards (DORCK brand). To determine the optimal laminate configuration, the TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method was employed. The analysis revealed that the F-S-F (S3) layup was the most effective. This optimal laminate, arranged in a 90°–45°–90° orientation, was further optimized using a Genetic Algorithm (GA) in MATLAB and its performance validated through re-analysis in ABAQUS software.
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    EVALUATION OF SUSTAINABLE URBAN MOBILITY IN THE CITY OF MEK’ELE
    (Mekelle University, 2020-06-28) Yoseph Solomon
    Currently, cities are looking for all round transport sustainability. Nevertheless, urban transportation can create a problem on economic, social and environmental aspect of the city. Up on observation residents have complaint on the fare for local transportation, vehicles noise disturbance and services provided by public transport. This thesis indexed eleven urban sustainable transport indicators. Based on the indexed results of the tool, SWOT analysis is conducted. The study also sought to identify the remedial measures that should be undertaken to mitigate the problems. The study area is defined to be Mek’ele city. The sustainable urban mobility indicators are assessed through a procedure that requires various method of data collection and data processing. World Bank backed online software was used after data legitimizing and confirmation was made between Tigray Construction Road and Transport Bureau and the world councils of urban sustainable development headquarter at Geneva, Switzerland. The indicator, access to mobility service, is based on percentage of people living within a radius of 400 meters from a public transport stops. Fatalities were considered as the number of deaths per annum per 100,000 inhabitants. For mobility space usage, area of roads, open parking, service areas and petrol stations were considered. Length of road network with sidewalks, with bike lanes, in zone 30 (km/h) and total length of city road network were served as input for the indicator of opportunity for active mobility .The social aspects such as, access for mobility impaired groups, comfort and pleasure, commuting travel time and security is indexed using structured questionnaire as part of the tool. For noise hindrance, sound measurements were taken. Affordability of public transport for the poorest quartile is measured by GDP and population’s lowest quartile income as a data. The sustainability for Mek’le city transport system is 4.93/10, suggesting weak sustainable mobility conditions for the city‘s transport system. The SWOT analysis has the prospects of being used in policymaking, defining strategic directions and the implementation of measures towards the fulfilment of sustainable urban mobility in the city of Mek’ele.
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    Estimating Traffic Congestion Costs for selected Road of Mekelle City
    (Mekelle University, 2020-06-28) Wahd Solomun
    Traffic congestion is a problem which occurs on road network characterized by slower speed, longer trip time due to excessive vehicles from different direction. Traffic congestion have a negative impact on society such as late reach to work place by increasing travel time, on health by creating stress, mentality and physical discomfort, increasing fuel consumption and air pollution. Mekelle is one of the fastest growing city in Ethiopia. Accordingly, traffic congestion is growing extremely in the city and results time wastage on travel and other direct and indirect effects on the society. This study is concentrated on two selected intersection the first one is four leg signalized intersection which is found around commercial bank of Ethiopia, main branch and the second one is four leg intersection which is found around Relief Society of Tigray in this intersection traffic light is not functional for about two years but after data collection performed the traffic signal was maintained and the intersection become signalized. Then again traffic volume data was conducted at signalized case. The main objective of this study is to estimate traffic congestion costs for selected intersection of Mekelle city and to suggest the possible counter measure for the problem. Primary and secondary data was collected to accomplish the study objectives. Primary data traffic volume, vehicle occupancy, signal timing, geometric data and daily labor cost was collected. The traffic volume count was made using video recording starting in the morning peak time 7:00AM-10:00AM, at noon time 11:00 AM-2:30 PM and the evening peak time 4:30 PM- 7:30 PM at 15 minutes interval was done for both intersections. The vehicles were counted by type passenger car, bus and small and medium truck vehicles. The average vehicle occupancy was collected based on traffic engineering vehicle occupancy data collection manual. After the data was collected data analysis was made. Delay at the intersection was analyzed using SYNCHRO software. Then using the collected data and delay annual peak hour cost of traffic congestion in both intersection was estimated. The cost of congestion consists travel time cost, fuel consumption cost and cost of co2 emission gas due to excess fuel usage. The result is found about (5,339,609.37ETB annual peak hour cost) at CBE four leg signalized intersection, (3,789,746.99ETB annual peak hour cost) at REST four leg unsignalized intersection, and (3,181,684.41ETB annual peak hour cost) at REST four leg signalized intersection. Annual peak hour travel time cost represents the opportunity costs of wasted time on congested intersection which shows the largest category at CBE intersection found about 4,311,552.5ETB nearly 81% of total cost of the intersection, at REST unsignalized is about 3,116,165ETB about 82% of cost of intersection and REST signalized have 2,618,690.9ETB about 82% of total intersection cost. Meanwhile annual peak hour cost of fuel is the second contributor to the overall cost of congestion with 1,009,870.3ETB at CBE, 661,988.9 ETB at REST unsignalized intersection and 552,987.4 ETB at REST signalized intersection which is about 18% of the total cost. On the other hand annual peak hour emissions costs is the least contributor to the overall cost of congestion and estimated about 18,186.57ETB at CBE intersection, about 11,611.09ETB at REST unsignalized intersection and 10,006.11 ETB at REST signalized intersection. The cost of congestion result shows the effect of congestion is highly concentrated on the travel time of public transport users’ means 78% of the travel time cost is for the public transport users.
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    Pavement management system development for Mekelle city road network and prioritization of roads for maintenance based on their performance index
    (Mekelle University, 2020-06-28) Hadush Hagos
    Pavement represents an important asset which is a pillar for the economy of one nation and this demands well-organized asset management. In Mekelle city, intensive investment has been made on constructing and maintaining roads at a network level. The current maintenance strategy followed by Mekelle city municipality is reactive. It responds to a problem after it has occurred. Instead of providing preventative maintenance at an early stage, roads are left until much more expensive reconstruction is needed and this maintenance delay will induce rising cost. This, in turn, causes spending a large amount of money to maintain extensively distressed pavements. The network needs great caution through periodic evaluation of pavement conduction and timely maintenance to keep the network operating under an acceptable level of service. This research work is intended to develop web-based flexible pavement management system software for Mekelle city road networks which will support the local road agency on road maintenance decisions. The developed decision supporting tool software compiles the basic components of a pavement management system using MySQL as a database creating quarry language and PHP software creating platform. The components of the pavement management system are framed as input data, analysis part and reporting tool for the outputs of the analysis section. The software uses road inventory data, road condition assessment data, road section data, and road traffic survey data as input. Storing all this data on its database the software utilizes those data to make pavement performance evaluation analysis employing the pavement condition index as a performance indicator. A case study of 6 km main access road segmented to eight sections was inspected to analyze the proposed pavement management system software. Finally, the software reports the results of the analysis part in the form of road Id, pavement condition index, rating scale, repair alternatives, and maintenance strategy as end results of the analysis for each road on the network then a priority for maintenance is made based on PCI value. In addition to this, the developed system can perform life cycle cost analysis for each road on the network employing net present value as economic evaluation criteria. According to the analysis result of the developed software, Alula Street i.e. form commercial bank of Ethiopia to Romanat roundabout is with least pavement condition index value, a PCI value of 11.17, a rating scale of very poor, and the corresponding maintenance strategy is reconstruction.
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    Three-Dimensional Finite Element Analysis of Dowel-Concrete Contact Stresses In JPCP Using Abaqus 6.14.
    (Mekelle University, 2020-09-21) Goytom Gidey Desta
    Jointed Plain Concrete Pavements (JPCPs) are the most common and applicable type of rigid pavement in road and airfields. Yet, it has been very common to see JPCP failed at transverse joint, globally. Study of dowel-concrete contact interface behavior and induced concrete contact stresses at this interface has received significant attention in recent years because of its relevance to overcome transverse joint problem and design effective doweled joints in JPCP. However, most of the previous studies relied on simplifying assumptions that neglected the exact dowel concrete interface behavior. With the above context, this thesis addresses a numerical analysis of contact stresses and strains at dowel-concrete interface and load transfer efficiency (LTE) in JPCP by means of FEM. So as to attain this objective, a nonlinear 3D-FEA was performed using a commercial software package, ABAQUS (6.14). Moreover, theoretical calculations were done based on friberg‟s closed form solution for verification of the FEA result, and a slight difference was achieved. The analysis was made to understand the effect of transverse joint parameters on dowel-concrete contact stresses and LTE. According to the outcome of this thesis, the decreasing of friction value that represents dowel-concrete bonding form 1 to 0.05 resulted decrease in bearing stress and LTE by 0.66% and 0.69%. Also, as the concrete weight increased by 28.57% (from thickness of 250mm to 350mm), the bearing stress decreased by 3.05% and LTE increased by 0.69%, for the 15.78% increase in dowel bar weight, the bearing stress decreased by 12.5% and LTE increased by 2.56%, for the change in joint width form 10mm to 12mm the bearing stress increases with 3.45% and the LTE decrease about 0.86%, for 46.67% increase in axle load, the bearing stress increased by 60.90% and LTE decreased by 5.23%, for 96.5% increase in stiffness of the base course (from 350MPa. to 10,000MPa.) the bearing stress decreased by 60.90% and LTE increased by 7.93%. In addition, for a change in modulus of dowel support from 4.07MPa/m to 6MPa/m, the bearing stress increased by 0.79% and LTE by 1.22%. Form effect of dowel bar misplacement, for the 30mm vertical misplacement a single bar misplacement produced 2.66% higher bearing stress and 0.76% less in LTE than two bars. In general, it can be concluded that a 3D-FEM is a promising approach for modelling JPCPs.