Habtamu Teshome

Bule Hora University, Ethiopia

Title: In Bio-Based Self-Healing Concrete: Effect of Nutrient Components of the Media on Mechanical Properties and Environmentally Friendly Concrete Development

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Biography

Habtamu Miju holds a Bachelor of Science degree in Construction Technology and Management from Wollega University, Oromia, Ethiopia, and later pursued my Master of Science in Construction Project Management at Parul University, Gujarat, India. Over the past decade, he had the privilege of serving as a lecturer at Bule Hora University, where he also taken on various administrative responsibilities. This experience has allowed him to grow not only as an educator but also as a contributor to the academic and professional development of students and colleagues alike. 

Currently, he is pursuing a PhD in Civil Engineering with a specialization in Structural Engineering at Andhra University, Visakhapatnam, India. Skilled in research and analysis, he foster collaboration among faculty while mentoring students to explore career pathways, ensuring meaningful learning experiences and academic success. The next step in his educational journey reflects his continued passion for learning and advancing knowledge in the field of structural design and construction. He is always eager to connect with others who share similar interests and goals.

Abstract

To meet the growing global demand for concrete, more durable and eco-friendly alternatives are needed. About 7% of all human-caused CO2 emissions come from cement production. Integrating bacteria into concrete can prolong its lifespan, improve durability, and promote the sustainability of the concrete. Traditional crack repair methods, such as epoxy injection, grouting, drilling, plugging, and gravity filling, are time-consuming, require additional maintenance, and have a negative environmental impact. The objective of the present study was to evaluate bacteria as self-healing agents by investigating their capacity to seal cracks via calcium carbonate (CaCO3) production, as well as the influence of organic nutrient media, particularly the content of carbon and nitrogen. The impact of bacteria and nutrient media was evaluated by fabricating three concrete variants and curing them in four distinct environments: water, nutrient broth, bacteria-nutrient solution, and bacteria-sprayed control specimens. The properties, including setting time, strength, acid and sulfate resistance, chemical composition, bacterial viability, and microstructure (analysed via scanning electron microscopy [SEM] and energy-dispersive X-ray [EDX] spectroscopy), were evaluated at various ages over time. The results demonstrate that the organic nutrient medium hurts the setting, hydration, and mechanical properties of the concrete, whereas the bacteria-infused mixtures remain unaffected. After 28 days of curing, bacterial specimens treated with bacterial nutrient solution exhibited strength enhancements of 32.5% (compressive), 29.78% (flexural), and 20.3% (tensile), while media admixture-treated concrete demonstrated strength declines of 38.4%, 34%, and 42.4%, respectively, compared to the control concrete. Bacteria admixture-treated (BAT) concrete and bacteria-spray-treated concrete exhibited superior resistance to H2SO4 and MgSO4 compared to the control concrete. Additionally, bacterially treated samples showed higher levels of carbon, nitrogen, and CaCO3, along with effective repair of 3mm cracks. Bacterial spores remained inactive in small pores (<1µm) until stimulated by cracking, indicating significant potential for self-healing concrete. This suggests that using bacterial spores as a self-sealing agent holds enormous potential.