Center for Materials Engineering

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Browsing Center for Materials Engineering by Author "Anteneh Wodaje (PhD)"

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    Optimizing HighRange Water-Reducing And Retarding Admixtures: Substituting Gluconate With Sugarcane Molasses For Sustainable Concrete Production In Ethiopia
    (Addis Ababa University, 2025-02) Petros Abebe; Anteneh Wodaje (PhD)
    The construction industry is a critical sector in Ethiopia’s economy, yet it faces persistent challenges due to foreign currency shortages that limit the import of essential raw materials, including chemical admixtures. High-range water-reducing and retarding admixtures (Type G) are widely used in concrete production to enhance workability and setting time. However, the reliance on imported gluconate as a retarder increases costs and project delays. This study investigates the feasibility of substituting gluconate with sugarcane molasses, a locally available by-product of Ethiopia’s sugar industry, to develop a cost-effective and sustainable alternative. A series of experiments were conducted with varying molasses concentrations (2.5%–4.5%) in combination with Sodium Naphthalene Formaldehyde (SNF). Workability was assessed using slump tests at 0, 30, 60, and 120 minutes. Compressive strength was evaluated at 1, 3, 7, and 28 days, with density measurements performed on hardened concrete samples. Results showed that increasing molasses content significantly improved slump retention, with a 60mm increase at 120 minutes when 4.5% molasses was used. However, early compressive strength (1-day and 3-day) decreased, while 7-day and 28-day strengths improved, demonstrating molasses' effectiveness as a set retarder. The findings indicate that molasses can serve as a viable alternative to gluconate in Type G admixtures, reducing dependence on imported materials and lowering costs. The study recommends further field trials, optimization of molasses concentration, and policy support for local admixture production to enhance Ethiopia’s construction sector
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    Value added Consumer Product from Finished Leather Waste Incorporated with Bamboo Fiber for better Strength Property
    (Addis Ababa University, 2023-10) Aster Mekasha; Anteneh Wodaje (PhD)
    Finished leather waste is one of the most highly generated solid wastes. However, there is no proper utilization of these huge amounts of waste. So preparation of leather boards from finished leather waste is economical and helps in reducing environmental pollution, and also incorporating the plant fibers into leather board enhances its mechanical properties. In this research different treatment methods, such as water retaining, alkali treatment, and the combination of water and alkali treatment was used for the extraction of bamboo fiber. Then 5% alkali treatment was the optimum result for this research. After that fiberized finished leather waste mixed with the plant fibers in various proportions of 0, 1%, 5%, 10%, and 15% were used to prepare the composite leather board. Two different types of binders, mainly urea formaldehyde and fevicol synthetic in the proportion of 10%, 15%, 25%, 35%, and 45%, were used for the study. Here also 15% was optimum for both formaldehyde and favicon resin binder. The prepared leather board were characterized using the following techniques: Fourier transform infrared spectroscopy (FTIR), thermal stability (TGA), scanning electron microscope (SEM), tensile strength, water adsorption and desorption, flexing index, chromium six, and formaldehyde content. The results show that plant fibers improve the strength property of leather boards. Among the composite leather boards, composite board with 10% bamboo fiber with 15% urea formaldehyde, and fevicol synthetic resin show better strength property. However, the strength property of urea formaldehyde is better than that of fevicol binder. Therefore, this composite leather board can be used as a raw material for the preparation of leather goods (as a reinforcing material), false roofing, foot wear (insole board), mouse pads, interior decorations, and wall partitioning. The study also envisions the production of cost-effective composite, by converting the waste into wealth and thereby simultaneously reducing environmental pollution.