In the quest for sustainable construction practices, a groundbreaking study led by Mudassir Mehmood from the State Key Laboratory of Metal Mining Safety and Disaster Prevention and Control in Maanshan, China, and the School of Resources and Safety Engineering at Chongqing University, has introduced a novel approach to stabilizing expansive soils. This method not only addresses the challenges posed by these problematic soils but also contributes to the circular economy by recycling industrial by-products.
Expansive soils, known for their high potential for expansion and contraction, have long been a nuisance to civil infrastructure. Traditional stabilization methods, such as using cement or lime, have proven effective but come with a significant environmental cost. “The production of these conventional stabilizers substantially increases global carbon dioxide emissions and energy requirements,” Mehmood explains. “Therefore, there is an urgent need to develop sustainable alternatives that enhance soil performance while minimizing environmental impact.”
The study, published in *Case Studies in Construction Materials* (translated as “典型案例集” in Chinese), proposes a sustainable composite reinforcement scheme that combines enzyme-induced carbonate precipitation (EICP), sisal fiber (SFs) reinforcement, and iron ore tailings (IOts). This innovative approach aims to treat expansive soil through laboratory testing and response surface modeling (RSM).
The results are impressive. Utilizing the experimental and validated optimal mix (0.75 mol/L EICP + 0.53 % SFs + 11.7 % IOts) reduced swelling pressure by approximately 98% while increasing the unconfined compressive strength by around 262%. Additionally, cohesion improved by 78%, the angle of internal friction by 172%, and the Unsoaked California Bearing Ratio (CBRunsoak) from 2.4% to approximately 26%. The soaked California Bearing Ratio (CBRsoak) also saw a significant increase from 1.7% to around 20% after 28 days of curing.
Mehmood’s team also confirmed synergistic microstructural interactions through SEM and EDS analyses, resulting in a highly reinforced soil composite. The RSM model showed good agreement with the experimental results, with errors controlled within ±5%, validating the robustness of the model.
This research holds significant implications for the energy sector, particularly in areas where expansive soils are prevalent. By reusing mining waste and utilizing renewable fibers, this approach demonstrates a low-carbon, cost-effective, and scalable stabilization strategy that enhances infrastructure resilience. “This method not only addresses the immediate challenges of expansive soils but also aligns with broader environmental goals,” Mehmood adds. “It’s a win-win situation for both the construction industry and the planet.”
As the world continues to grapple with the impacts of climate change and the need for sustainable practices, this study offers a promising solution that could shape future developments in the field. By embracing such innovative approaches, the construction industry can move towards a more sustainable and resilient future, ultimately benefiting the energy sector and beyond.