In the vast landscape of China’s infrastructure projects, particularly high-speed railway construction, a significant challenge has emerged from an unlikely source: red mudstone. This prevalent geological material, often encountered during slope excavation and tunnel construction, has long posed disposal and environmental management issues. However, a groundbreaking study led by KONG Kunfeng, published in the journal Engineering Science and Technology, offers a promising solution to this persistent problem.
Red mudstone, while abundant, is notoriously susceptible to weathering, fragmentation, and water-induced disintegration. These properties have limited its use primarily to subgrade fill material. However, KONG’s research delves into the potential of lime modification to enhance the strength characteristics of red mudstone, opening up new possibilities for its application.
The study reveals that the shear strength of red mudstone fill material is significantly influenced by its degree of saturation. “The cohesion of red mudstone fill material initially increases with degree of saturation but subsequently decreases, reaching its peak near the optimum water content,” KONG explains. This “peak effect” suggests that red mudstone achieves higher shear strength in a relatively dry state, a crucial finding for engineering applications.
Moreover, the research highlights the transformative effects of lime stabilization. After treatment, the cohesion of saturated red mudstone fill increases by more than 6.5 times, and the internal friction angle improves by over 1.4 times. This significant enhancement in shear strength not only mitigates water-induced softening but also reduces excessive settlement, a common issue in subgrade construction.
The implications of this research are vast, particularly for the energy sector. As infrastructure projects continue to expand, the efficient use of materials like red mudstone becomes increasingly important. By improving the strength characteristics of red mudstone through lime modification, construction projects can reduce waste generation, expand application scenarios, and contribute to waste reduction, pollution control, and resource efficiency.
KONG’s findings also shed light on the microscopic level changes in red mudstone after lime treatment. Scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), and X-ray diffraction tests (XRD) reveal that lime treatment maintains the particle integrity of red mudstone, forming a three-dimensional interlocking framework that strengthens interparticle bonding. This microscopic insight is crucial for understanding the long-term stability and durability of lime-stabilized red mudstone fill material.
The study’s implications extend beyond immediate engineering applications. As high-speed railway construction continues to boom, the need for sustainable and efficient materials becomes paramount. KONG’s research provides a roadmap for future developments in this field, offering a practical solution to a long-standing problem. By leveraging lime modification, the construction industry can not only improve the performance of red mudstone but also contribute to a more sustainable and environmentally friendly future.
This research, published in Engineering Science and Technology, marks a significant step forward in the field of construction materials. As the industry continues to evolve, the insights gained from KONG’s study will undoubtedly shape future developments, paving the way for more innovative and sustainable practices.
