Faculty of Engineering, Technology, Applied Design & FineArt (FETADFA)
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Browsing Faculty of Engineering, Technology, Applied Design & FineArt (FETADFA) by Subject "Concrete"
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Item Restricted Assessing the Effect of Accelerators and Retarders on the Early-Age Compressive Strength of Concrete.(Kabale University, 2024) Gumoshabe, EdgarAccelerating admixtures affect the rates of reactions between cement and water to give an overall increase in the hydration rate. Retarding admixtures on the other hand slow down the hydration rate. Thus, the use of accelerators in concrete provides a shortening of setting time and/or an increase in early strength development and retarders increase the setting time and reduce early strength development. In this project, the issues of slow down and uncontrolled rapid setting and hardening of concrete or addressed by the use of accelerating and retarding admixtures (Calcium Chloride and Citric Acid respectively) in concrete. Calcium chloride and citric acid were added in four samples, with quantities of 1%, 1.5 %, 2%, and 2.5% by weight of cement, which were taken as mix -1 and mix -2. The concrete samples were tested 1, 3, 7, and 28 days of Compressive strength. The concrete specimens were laid for M25 grade of concrete.Item Restricted Assessing the Effect of Cassava Peel Flour as an Admixture on the Properties of Concrete.(Kabale University, 2024) Opiyo, Junior RonneyThis research investigated the effect of Cassava Peel Flour (CPF) as an admixture on the properties of concrete. A chemical analysis was conducted on CPF, along with tests on the properties of coarse and fine aggregates. Concrete mix designs were prepared following the American Concrete Institute (ACI) method. Initial and final setting time tests were performed by incorporating CPF in varying proportions (0%, 1%, 2%, 3%, 4%, 5%, and 6%) by weight of cement. The results revealed that the addition of CPF delayed the setting time of the cement paste. As the CPF dosage increased, both the initial and final setting times were extended, with the highest delay at 6% CPF, showing an initial setting time of 150 minutes and a final setting time of 435 minutes, compared to 55 and 245 minutes, respectively, at 0% CPF. This demonstrates that CPF is an effective retarder. A consistency test was conducted using the same CPF dosages, resulting in consistencies ranging from 27.4% at 0% CPF to 63.1% at 6% CPF. The slump test for a design slump of 7.5 cm showed that slump values decreased slightly with increased CPF dosage immediately after mixing but increased 30 minutes after mixing, indicating CPF’s impact on workability over time. Compressive strength tests were conducted on cubes (150x150x150 mm) at 7, 14, and 28 days. At 7 days, compressive strength decreased with increasing CPF dosage, from 15.2 MPa at 0% CPF to 10.3 MPa at 6% CPF. However, at 14 and 28 days, compressive strength increased with CPF addition up to 2%, after which further CPF dosage resulted in a decrease in strength. This suggests that while small amounts of CPF can enhance compressive strength over time, excessive amounts may weaken the concrete.Item Restricted Assessing the Effect of Partial Replacement of Fine Aggregates in Concrete with Iron Ore Tailings in Kigezi Sub-Region.(Kabale University, 2024) Musasizi, AllanThis study aimed to assess the strength properties of concrete produced using IOT as partial replacement of the natural sand as fine aggregates. IOT is a waste product of iron ore mineral that is abundantly available in some regions and has the potential to be used as a sustainable alternative to traditional fine aggregates. In this research, the mixture, C15, was designed with 10%,25%, and 50% of IOT, natural fine aggregates and natural coarse aggregates. Properties considered included: workability, unit weight and compressive strength. Test results indicated that in all cases, IOT concrete gave high compressive strength than the conventional concrete. In conclusion, this study suggests that IOT can be used as a viable alternative to partially replace traditional fine aggregates in the production of concrete with acceptable strength properties for structural applications in pavement and floor slabs. Further research should however be carried out to investigate the durability and performance of IOT-based concrete.Item Restricted Assessing the Impact of Utilization of Dairy and Hospital Waste Waters on Engineering Properties of Concrete.(Kabale University, 2024) Bahati, AugustineThe hardening of cement gives strength and durability to concrete. The quality of mixing water may affect the setting, hardening, and strength of the concrete. Great control of the properties of cement and aggregates is exercised, but the control of the quality of water is often neglected. The suitability of a particular source of water for making concrete can be checked by casting concrete cubes using water under question and comparing its 7 days, 14 days, and 28 days strength. If the compressive strength is up to 90 percent, the source of water may be accepted. The aim of the present study was to know the effect of chemical, physical,l, and biological parameters in mixing water on different engineering properties of concrete. This work was carried out for a mix of 25-grade concrete to study the effect of the use of Potable (tap water), dairy waste water, and hospital wastewater on the strength development of concrete at 7, 14, and 28 days and fresh concrete properties. From the results, it is observed that Potable water resulted in good strength properties and is more workable compared to dairy and hospital waste water samples. There was also an increase of 29.2% in compressive strength when compared to dairy wastewater and 36.8% when compared with hospital wastewater. Dairy and hospital wastewater samples did not meet the requirements for use in concrete production.Item Restricted Comparative Study of the Effect of Pumice Sand, River Sand, and Quarry Dust as Fine Aggregates on the Unit Weight of Concrete.(Kabale University, 2024) Niyonzima, RichardConcrete is a widely used construction material, and its properties can be influenced by a variety of factors, including the unit weight of aggregates used in the mix. One of the key components of concrete is the aggregate, which is typically made up of sand and gravel or crushed stone. The unit weight of aggregates can have a significant impact on the performance of the concrete. It can affect the strength, permeability, and durability of the mix. Different types of fine aggregates can result in different concrete properties, making it important to study and understand the influence of unit weight on the behavior of concrete. Therefore, this study was made by will be used and use of pumice sand, river sand, and quarry dust on the performance of concrete. The aggregate C20 grade of concrete was designed and tested. The experimental investigation was conducted on both fresh and hardened concrete such as workability, density, compressive strength, particle size distribution, water absorption, and fineness modulus. Concrete cubes were cast and soaked in a curing tank for 7 days, 14 days, and 28 days.Item Restricted Comparison of Hand Crushed and Machine Crushed Coarse Aggregates on Concrete.(2024) Ingabire, PeaceThis research aimed at determining the difference in compressive strength of concrete of the same mix design produced by hand and machine-crushed coarse aggregates and the effect of the two types of coarse aggregates on compressive strength on concrete was investigated. The same source for both machine and hand-crushed coarse aggregates was considered so that the aggregates have the same physical and mechanical properties. Properties of concrete compounds such as water and cement were kept constant and no admixtures were used. Mix design for two types of coarse aggregates with the help of the design of normal concrete mixes by H.C. Erntroy and R.E. Franklins was conducted. Test cubes for fresh concrete were crushed after 7, 21, and 28 days of well-cured and stored conditions according to BS 1881 to obtain the compressive strength. Comparisons on compressive concrete strength were made between concrete made with hand and machine-crushed coarse aggregates and recommendations that suit the conditions at hand.Item Restricted Effect of Partial Replacement of Cement with Clay on the Compressive Strength of Concrete.(Kabale University, 2024) Vudriko, Ivan DradiThis study investigated the impact of partially replacing cement with clay on the compressive strength and physical properties of concrete. The primary objective is to explore sustainable alternatives to cement in concrete production by using locally available clay while ensuring that the performance of the modified concrete remains within acceptable standards. Clay was introduced at varying percentages (0%, 5%, 10%, 15%, 20%, and 25%) by weight as a replacement for cement in the mix. Tests were conducted to assess the slump, wet density, bleeding, and compressive strength of concrete specimens at 7, 14, and 28 days of curing. The results indicate a decrease in workability and compressive strength with increasing clay content, though up to 10% replacement showed acceptable performance for non-structural applications. The study concludes that a 10% clay replacement is a viable and sustainable option for reducing cement usage without significantly compromising concrete strength. This research provides valuable insights into sustainable construction practices and proposes guidelines for the partial substitution of cement with clay. Recommendations are made for further studies to explore the use of additives or supplementary cementitious materials that could enhance the pozzolanic activity of clay, thereby improving the compressive strength of concrete with higher clay content.Item Restricted Effect of Water-Cement Ratio on Compressive Strength of Concrete with Granite Stone-Dust and Scoria.(Kabale University, 2024) Mukisa, NathanThere is always a need to test concrete for several properties before it is used at a construction site. This process is not only time-consuming but also takes additional resources in terms of labor and materials. This research was conducted to determine the standard mix design ratio for concrete with scoria aggregates for class C25/20. Stone dust (granite) was used as fine aggregates and ordinary Portland cement (CEMI 42.5N) was used as a binder. The research was initiated with the collection of materials like scoria aggregates from Kisoro, and granite stone dust from Kiyoora. Both scoria and granite were tested for a number of physical properties which aided in the determination of a trial mix design. The concrete which was prepared was tested for fresh and hardened properties. The results for compressive strength of cubes (150x150x150mm) were obtained after 3, 7, 14, and 28 days of curing. The optimum water-cement ratio for class C25/20 was found to be 0.52 depending on the average compressive strength of 26.3Mpa after 28 days of curing.Item Restricted Investigating the Civil Engineering Properties of Concrete Produced from Construction and Demolition Waste.(Kabale University, 2024) Mukungu, Eric TimothyThis study explored the potential of using Recycled Concrete Aggregates (RCA) and Recycled Brick Fragments (RBF) as sustainable alternatives to natural aggregates in concrete production. The investigation focuses on the workability, compressive strength, and density of concrete mixes with varying proportions of RCA and RBF, ranging from 0% to 100% replacement. The results show that increasing RBF composition decreases workability and compressive strength, while RCA exhibits better performance. The optimal mix is achieved with 10% RBF and 90% RCA, attaining target of 20MPa. The density of all mixes falls within the normal weight concrete range. This research demonstrates the feasibility of using RCA and RBF in concrete production, offering a promising solution for sustainable construction practices.Item Restricted Investigating the Impact of Concrete Class on the Strength-Density Relationship of Concrete.(Kabale University, 2024) Asiimwe, PiusThis study evaluated the impact of concrete class on the relationship between strength and density, aiming to enhance understanding and optimization of concrete performance. The investigation focused on key objectives: assessing the physical properties of materials used in concrete mix design, performing mix designs for various concrete classes, identifying parameters influencing density in different classes, and analyzing the relationship between concrete density and compressive strength.Item Restricted Investigating the Performance of Epoxy Concentrations in the Self-Healing of Concrete.(Kabale University, 2024) Manzi, Evans EvalistConcrete, a fundamental construction material, is susceptible to various forms of damage (cracking). Formation of cracks may result due to the shrinkage effects during curing and mechanical loading which deteriorate the concrete performance especially in terms of durability aspect. Traditional methods of repair often involve human intervention and significant costs. In recent years, the concept of self-healing concrete has gained traction as a potential solution to mitigate the impact of cracks and enhance the longevity of structures. Self-healing concrete by using bacteria as a healing agent had gained interest among researchers. In contrast, this research delves into the intricate relationship between epoxy concentrations and the self-healing capabilities of concrete, aiming to provide comprehensive insights into optimal concentrations and their implications for construction. The experiment involved varying epoxy concentrations, ranging from 0% to 15%, in concrete mixes. Critical parameters, such as slump, compressive strength at 28 days, and microscopic structure after crack induction, were meticulously analyzed. The objective was to understand how epoxy, known for its adhesive and cohesive properties, influences the mechanical properties and self-healing potential of concrete. The experimental setup aimed to simulate real-world scenarios where concrete structures may be exposed to external stresses leading to cracks. The results revealed a consistent decrease in slump as epoxy concentrations increased, indicating a reduction in concrete work-ability. Notably, the compressive strength at 28 days exhibited a fascinating trend. At 5% epoxy, there was a modest increase in strength, while the optimal concentration of 10% demonstrated a significant enhancement. However, concentrations beyond the optimum (15% epoxy) led to a decline in compressive strength. The experiment's pivotal phase involved crack induction to assess self-healing capabilities. At 10% epoxy concentration, the compressive strength increased after crack induction. Microscopic analysis further corroborated these findings, revealing signs of self-healing within the concrete matrix. This enhancement suggested a unique healing mechanism associated with the optimal epoxy concentration.