In the heart of Nigeria, a groundbreaking study led by K. Ishola from the Department of Civil Engineering at Osun State University, Osogbo, is revolutionizing the way we think about road construction in regions rich in lateritic soil. The research, published in ‘Hybrid Advances’ (which translates to ‘Hybrid Progress’), focuses on the eco-friendly use of cashew leaf ash (CLA) to enhance lateritic soil for sustainable road pavement construction. This isn’t just about building better roads; it’s about building them smarter and greener, with significant implications for the energy sector and beyond.
Lateritic soil, abundant in tropical regions, is often challenging to work with due to its high clay content. Traditional methods of improving its properties for road construction can be energy-intensive and environmentally taxing. However, Ishola’s research offers a promising alternative. By incorporating cashew leaf ash into lateritic soil, the study demonstrates a significant improvement in the soil’s engineering properties.
The research involved adding CLA in varying concentrations to lateritic soil and conducting a series of tests, including Atterberg limits, compaction characteristics, California Bearing Ratio (CBR), and unconfined compressive strength (UCS). The results were compelling. “We found that increasing the CLA content reduced the Atterberg limits up to 4% CLA content,” Ishola explains. “The optimal compaction characteristics were observed at 6% CLA content, where the CBR values significantly improved.”
While the CBR values did not meet the thresholds required for base materials and cement-stabilized materials, the UCS values at 28 days were within the range suitable for sub-base use. This means that roads built with CLA-treated lateritic soil could serve as a robust sub-base, supporting the upper layers of the pavement. “This finding is particularly exciting for low-traffic road surfaces,” Ishola notes. “It opens up the possibility of using CLA as an additive in cement stabilization, reducing the need for traditional, energy-intensive methods.”
The implications of this research are far-reaching. For the energy sector, the potential to reduce the carbon footprint of road construction is significant. By using a locally available and renewable resource like cashew leaf ash, the need for energy-intensive materials and processes is diminished. This not only lowers operational costs but also aligns with global sustainability goals.
Moreover, the study’s findings could reshape future developments in road construction. As Ishola points out, “The regression analysis indicated robust connections amid experimented and predicted strength indices. This suggests that with further refinement, CLA could become a standard additive in road construction, particularly in regions with abundant lateritic soil.”
The study recommends using lateritic soil treated with 6% CLA and compacted at 28 days curing age for sub-base in flexible pavement construction. This approach not only enhances the soil’s engineering properties but also promotes sustainable and eco-friendly practices. As the world continues to seek innovative solutions for infrastructure development, Ishola’s research offers a beacon of hope, demonstrating that sometimes, the best solutions are right under our feet—or in this case, right under the cashew trees.