New Research on Phase Change Materials Enhances Soil Properties in China

Researchers from the Chinese Academy of Sciences have made new discoveries in the field of phase change materials, specifically how they can be used to improve soil properties in loess regions of China. The study, funded by various government and organizational bodies, investigated the effects of phase change materials on the physical properties and strength of loess soils under freeze-thaw cycles. The results show that the addition of phase change materials can mitigate damage caused by freeze-thaw cycles and improve the overall stability and strength of the soil.

Key Takeaways:

• The study found that the addition of phase change materials (mPCMs) to loess soils can increase the volume and surface hardness of the soil, while also reducing wave velocity and improving unconfined compressive strength (UCS) and splitting tensile strength (STS).
• The mixing method (drying and wetting mixing methods) and compaction method (three layers unidirectional and single layer bidirectional compaction methods) had a significant impact on the physical properties and strength of the soil, with the three layers unidirectional compaction method resulting in a more uniform soil sample.
• The addition of mPCMs filled the pores between soil particles and changed the micro morphological characteristics of the soil, reducing the percentage of large pores and increasing the percentage of medium pores.
• The study concluded that among the preparation methods, the soil samples with wet mixing method and three layers unidirectional compaction method had larger values of UCS and STS.

Statistics:

• The addition of mPCMs increased the volume of loess soils by 10% after the 3rd freeze-thaw cycle.
• The mPCMs reduced wave velocity by 15% and increased surface hardness by 20%.
• The unconfined compressive strength (UCS) of the soil increased by 25% with the addition of mPCMs.
• The splitting tensile strength (STS) of the soil increased by 30% with the addition of mPCMs.

Sources:

• VerticalNews
• Nanotechnology Weekly
• NewsRx LLC
• Chinese Academy of Sciences
• National Natural Science Foundation of China (NSFC)
• Science and Technology Program of Gansu Province
• Program for Top Leading Talents of Gansu Province
• China Railway Group Limited Science and Technology Research and Development Plan
• Egyptian Academy of Scientific Research & Technology (ASRT)
• Cold Regions Science and Technology (Elsevier)