In the quest for sustainable construction materials, researchers are turning to unlikely sources: agricultural waste. A recent study led by Abiodun Joseph Kilani from the University of South Africa’s Department of Civil & Environmental Engineering and Building Science has delved into the potential of locust bean and mango waste (LBW and MW) to reinforce concrete, offering a glimpse into a future where waste becomes a valuable resource.
The construction industry is under increasing pressure to reduce its carbon footprint, with cement production alone accounting for a significant portion of global CO2 emissions. Meanwhile, agricultural residues like locust bean and mango waste often end up in landfills, contributing to environmental problems. Kilani’s research, published in the journal ‘Discover Applied Sciences’ (which translates to ‘Discover Applied Sciences’ in English), explores the possibility of turning these wastes into pozzolanic materials that can enhance concrete’s properties.
The study reveals that LBW and MW are rich in pozzolans, with concentrations reaching up to 77.31% and 78.815%, respectively. Pozzolans are crucial in concrete production as they react with calcium hydroxide to form compounds with cementitious properties. “The incorporation of these agricultural wastes into concrete can potentially reduce the need for traditional cement, thereby lowering the industry’s carbon emissions,” Kilani explains.
The research shows that incorporating 30% pod ash from LBW accelerates the setting times of concrete, while 50% mango seed ash increases water absorption. However, the study also highlights some challenges. The compressive strength of concrete decreased by 10–84% with the addition of 5–50% LBW ash, and by 2.17–13.04% with 2–8% mango leave ash. Flexural strengths also saw reductions, although blending with other materials like eggshells showed promising results, increasing flexural strength and modulus of elasticity.
Despite these setbacks, the potential for innovation is significant. “The findings suggest that while LBW and MW may not be silver bullets, they can play a role in sustainable construction when blended with other pozzolan-rich materials,” Kilani notes. This could open doors for future research into composite materials that combine agricultural wastes with other sustainable resources, paving the way for greener construction practices.
For the energy sector, the implications are substantial. As the push for net-zero emissions intensifies, industries are seeking ways to reduce their carbon footprints. By incorporating agricultural wastes into construction materials, companies can not only cut costs but also contribute to a circular economy where waste is minimized, and resources are used more efficiently.
The study underscores the importance of continued research and development in sustainable materials. As Kilani’s work demonstrates, the path to greener construction is complex and requires a multifaceted approach. By exploring unconventional materials and innovative blending techniques, the industry can make strides toward a more sustainable future. The journey is just beginning, but the potential is immense.