As rapid economic growth continues to generate substantial amounts of industrial waste from construction sites worldwide, finding environmentally responsible disposal methods has become an increasingly critical challenge. To combat this issue, governments are enacting stricter laws to prevent waste generation and ensure proper disposal of such waste. Liquefied soil stabilization, a technique popularized in the 1990s, has emerged as one approach to address this problem. By mixing construction-generated waste with cement or other solidifying materials, it can be repurposed as backfill for reinforcement and ground stabilization. Although liquified stabilized soil offers certain advantages, such as the ability to pump and pour the material efficiently over a site, it also poses drawbacks that hinder its widespread adoption. However, a team of researchers at Shibaura Institute of Technology (SIT) has recently made groundbreaking advancements that address these limitations.
Led by Prof. Shinya Inazumi from SIT’s School of Engineering and Science, the research team sought to overcome the existing structural and environmental limitations of liquefied stabilized soil. They achieved this by altering the solidifiers and thickeners used in the process. Traditionally, bleeding, the rise of water to the surface resulting in a loss in soil strength, has been a significant concern. However, the team successfully inhibited this phenomenon and maintained fluidity by introducing a cellulose-based thickening agent. Furthermore, they replaced the ordinary Portland cement (OPC) solidifier with earth silica-blast furnace slag powder (ES-B), which does not contain chromium. ES-B offers greater sustainability, as its components can be adjusted to control the rate of curing and enable homogenous mixing with soil, resulting in improved end product fluidity.
While studying the impact of the cellulose-based thickener, the researchers found that the strength of the liquefied stabilized soil remained unaffected, even with its addition. The thickener proved to be successful in completely suppressing bleeding and preventing soil component separation. The soil, when immersed in water, did not adversely affect its surroundings or exhibit any differences in reaction products. These findings demonstrate the potential for revolutionary improvements in the stability of building foundations, particularly in earthquake-prone zones.
The advancements made by the SIT research team in liquefied stabilized soils offer numerous benefits. Firstly, the environmentally friendly disposal of industrial waste can be facilitated, resulting in a significant reduction in the environmental impact of construction projects. By reusing waste material, the circularity of construction can be improved, leading to cost savings and enhanced efficiency. Moreover, this technology will accelerate ground improvement processes on construction sites, reducing construction timelines and increasing operational efficiency.
The breakthroughs achieved by the Shibaura Institute of Technology in the field of liquefied stabilized soil have the potential to revolutionize the disposal of industrial waste. By addressing the limitations of bleeding, fluidity constraints, and environmental concerns associated with traditional approaches, the research team has paved the way for more environmentally responsible construction practices. With the ability to improve building foundation stability, reduce environmental impact, and optimize operational efficiency, this innovative technology marks a significant step toward a greener, more sustainable future for the construction industry.