In the quest for sustainable construction materials, a team of researchers led by G.H.M.J. Subashi De Silva from the Department of Civil and Environmental Engineering at the University of Ruhuna in Sri Lanka has made a significant breakthrough. Their study, published in the journal *Next Sustainability* (which translates to *Sustainability Tomorrow*), explores the potential of eggshell ash (ESA) in enhancing the performance of high-volume rice husk ash (RHA) cement mortar. This innovative approach not only supports the circular economy but also promises to revolutionize the construction industry.
The research focuses on the pore refinement, early strength gain, and durability properties of mortar when ESA is added to high-volume RHA. “Adding ESA into high-volume RHA mortar increases early strength gain, with 110% strength activity index at 7 days of the mortar,” explains De Silva. This means that structures built with this enhanced mortar can achieve greater strength in a shorter period, a critical factor for commercial construction projects.
One of the most compelling findings is the significant improvement in durability. Mortar with 10% RHA and 5% ESA showed a 17.3% reduction in water absorption and a 49% improvement in acid resistance compared to conventional mortar. “Mortar with 15% RHA and 5% ESA showed superior performance over the control mortar, enabling 20% cement replacement,” adds De Silva. This not only reduces the environmental impact but also lowers production costs, making it an attractive option for the energy sector.
The study also delved into the chemical composition of the materials. Compounds like SiO2 and CaO enhanced the pozzolanic reaction, leading to denser CSH gel formation. This pore refinement contributes to the strength and durability of the mortar. “SEM images revealed denser CSH gel formation, indicating a pore refinement and strength developments,” notes De Silva.
In addition to experimental examinations, the researchers employed machine learning models to predict the compressive strength of ESA-RHA mortar. Among the models, Random Forest regression performed the best, providing accurate predictions that can guide future research and commercial applications.
The implications of this research are far-reaching. By reducing the reliance on traditional cement, which is a significant source of carbon emissions, this innovative mortar supports sustainable construction practices. “High-volume RHA, with ESA in mortar is not just environmentally beneficial (less clinker), but also technically superior performance in early strength gain, pore refinement and durability performance, supporting sustainable circular economy policies,” concludes De Silva.
As the construction industry continues to seek sustainable and cost-effective solutions, this research offers a promising path forward. The integration of ESA and RHA in mortar production could become a standard practice, benefiting both the environment and the economy. With the support of machine learning models, the industry can optimize the use of these materials, ensuring consistent and superior performance.
This study, published in *Next Sustainability*, highlights the potential of circular economy principles in the construction sector. As the world moves towards more sustainable practices, innovations like these will play a crucial role in shaping the future of the industry.