Hu Peng, Chen Shufeng, Duan Zhao, Wang Nian-Qin, Hao Ye, Wang Xian
College of Geology and Environment, Xi'an University of Science and Technology, Xi'an, China.
Shaanxi Tiandi Geology Co., Ltd, Xi'an, China.
PLoS One. 2025 Apr 29;20(4):e0319909. doi: 10.1371/journal.pone.0319909. eCollection 2025.
Construction in northwest China is generally packed with issues linked to loess soil with poor engineering properties and day-night and seasonal freeze-thaw (FT) actions. This study explored the potential benefits of nano-MgO (NM) as an innovative solution for improving mechanical properties of loess. To this end, a series of unconfined compression test (UCT) and nuclear magnetic resonance tests (NMRT) were conducted. Results showed that the unconfined compressive strength (UCS) exhibited an a "rise-fall" trend with the addition of NM. An optimum dosage of 2% NM is expected to bring about 71.9% and 143.5% strength gain for non-FT and FT samples, respectively. Meanwhile, the FT-induced strength reduction ratio decreased from 56.3% to 38.1% with NM content from 0 to 2%. These illustrated that NM can be very effective in improving mechanical performance and alleviating freeze-thaw damage. On the other hand, deformation modulus presented similar trends with UCS, while failure strain behaved in a reverse way. Accordingly, empirical models for UCS, as well as its relationships with modulus and failure strain, were established and validated by literature data. Furthermore, nuclear magnetic resonance tests revealed that adding NM could increase the proportion of bound water with intensive interaction, yielding improved performance and durability. This investigation shows that NM represents an alternative to cement for soil stabilization, and provides scientific support for the construction design in cold regions.
中国西北地区的建设通常面临诸多与工程性质较差的黄土以及昼夜和季节性冻融作用相关的问题。本研究探索了纳米氧化镁（NM）作为改善黄土力学性能的创新解决方案的潜在益处。为此，进行了一系列无侧限抗压试验（UCT）和核磁共振试验（NMRT）。结果表明，随着NM的添加，无侧限抗压强度（UCS）呈现出“先上升后下降”的趋势。预计2%的NM最佳剂量分别可为非冻融和冻融样品带来71.9%和143.5%的强度增益。同时，随着NM含量从0增加到2%，冻融引起的强度降低率从56.3%降至38.1%。这些表明NM在改善力学性能和减轻冻融破坏方面非常有效。另一方面，变形模量与UCS呈现相似趋势，而破坏应变则相反。因此，建立了UCS的经验模型及其与模量和破坏应变的关系，并通过文献数据进行了验证。此外，核磁共振试验表明，添加NM可以增加具有强烈相互作用的结合水比例，从而提高性能和耐久性。本研究表明，NM是土壤稳定化中水泥的一种替代物，并为寒冷地区的建设设计提供了科学支持。
