In the frost-prone expanses of Jilin Province, China, construction crews face a persistent challenge: the unstable subgrade of carbonate saline soils. But a new study led by Wenhua Wang from the Department of Civil Engineering offers a promising solution, demonstrating how lime stabilization can significantly enhance pavement performance in these troublesome soils.
The research, published in the *Advances in Civil Engineering* (translated from Chinese as “Advances in Civil Engineering”), systematically explores how lime dosage and moisture content interact to influence key pavement performance indicators. “We found that the optimal lime dosage shifts depending on the moisture content,” Wang explains. “This is crucial for mixture design and construction control in the region.”
The study reveals that while the maximum dry density (MDD) decreases with increasing lime dosage, the unconfined compressive strength (UCS) exhibits a more complex relationship. At a moisture content of around 16%, UCS peaks at a 9% lime dosage. However, as moisture rises to approximately 18%, the optimal dosage shifts to between 5% and 7%. This finding underscores the importance of precise moisture control during construction.
Moreover, the California bearing ratio (CBR) shows an approximately linear relationship with lime dosage, suggesting that even modest additions can meet subgrade requirements. “A small amount of lime can make a big difference,” Wang notes. This is particularly significant for the energy sector, where stable subgrades are essential for the construction of pipelines, power lines, and other critical infrastructure.
Microscopic analysis using scanning electron microscopy with energy-dispersive spectroscopy (SEM–EDS) provides further insights. The study shows that lime stabilization transforms the soil’s fabric from a “particle–void dominated” structure to a continuous, foil-like network of calcium silicate hydrate (C–S–H) with minor portlandite. Higher lime dosages or moisture contents tend to produce plate-like crystals and connected pores, which are less favorable for densification and durability.
The implications of this research are far-reaching. For the energy sector, understanding these interactions can lead to more efficient and cost-effective construction practices. “By optimizing lime dosage and moisture content, we can enhance the stability and durability of subgrades, reducing maintenance costs and improving overall project outcomes,” Wang says.
As the energy sector continues to expand into challenging terrains, this research provides a valuable guide for engineers and construction professionals. By leveraging these findings, they can design more resilient infrastructure, ensuring long-term stability and performance. The study not only advances our scientific understanding but also offers practical solutions for real-world applications, shaping the future of construction in problematic soil regions.