In the heart of Ethiopia, a civil engineer is stirring up the concrete industry with a brew of innovation and sustainability. Fikreyesus Demeke Cherkos, from the Department of Civil Engineering, has been exploring the potential of coffee and rice husk ash as partial cement replacements, and the results are percolating through the construction world.
Cherkos’ research, published in the journal ‘Advances in Materials Science and Engineering’ (translated from the original Arabic), delves into the mechanical, durability, and microstructural properties of concrete infused with these agricultural byproducts. The findings could revolutionize the energy sector’s approach to construction, offering a more sustainable and resilient alternative to traditional concrete.
The environmental impact of concrete production is a pressing concern, with cement manufacturing accounting for a significant chunk of global CO2 emissions. Cherkos saw an opportunity in the mountains of coffee and rice husks generated annually, transforming these agricultural wastes into valuable construction materials.
Rice husk ash (RHA) and coffee husk ash (CHA) have shown promise as supplementary cementitious materials, enhancing concrete’s strength and durability. However, their combined effects on concrete properties have remained largely unexplored—until now.
Cherkos designed a C-25 concrete mix, replacing portions of cement with RHA and CHA in varying proportions. The results were striking. “The optimal mix of 10% RHA and 5% CHA improved compressive strength by 5.04% and 7.87% at 28 and 56 days, respectively,” Cherkos explains. This mix also enhanced flexural and split tensile strengths, indicating a more robust and resilient concrete.
But the benefits don’t stop at strength. Durability tests showed that a combination of 15% RHA and 5% CHA significantly reduced water absorption and improved sulfuric acid resistance. This suggests a denser microstructure, a crucial factor for concrete’s longevity, especially in harsh environments like those often found in energy sector projects.
The implications for the energy sector are substantial. Concrete is a staple in energy infrastructure, from power plants to wind turbines. A more durable, sustainable concrete could extend the lifespan of these structures, reducing maintenance costs and environmental impact.
Moreover, the use of agricultural byproducts like RHA and CHA could create new revenue streams for farmers and reduce waste. It’s a win-win for both the construction and agricultural sectors.
Looking ahead, Cherkos’ research opens the door to further exploration. How might other agricultural byproducts fare as cement replacements? Could these materials be used in other construction applications? The possibilities are as vast as they are exciting.
As the construction industry grapples with sustainability challenges, Cherkos’ work offers a refreshing brew of innovation. It’s a testament to how thinking outside the box—and looking into the coffee cup—can yield groundbreaking results. The energy sector would do well to take note, as the future of construction could very well be brewing in Ethiopia.