| 土性对工程泥浆固化强度影响规律及微观机理 |
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| 引用本文：卞夏,叶迎春,刘凯,李晓昭,樊朱益,郭光泽,张伟.2024.土性对工程泥浆固化强度影响规律及微观机理[J].地球学报,45(1):123-130. |
| DOI：10.3975/cagsb.2023.030601 |
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| 基金项目:国家自然科学基金项目(编号: 52178328);中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金课题(编号: SKLGDUEK2114) |
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| 中文摘要:本文开展了一系列不同液限高分子吸水树脂固化工程泥浆无侧限抗压强度试验, 探讨了泥浆土液限对固化效率的影响规律, 对比研究了掺入高岭土对泥浆固化强度的改进程度, 最后基于XRD和SEM试验揭示了液限和高岭土对固化泥浆强度影响的微观机理。结果表明: 随着泥浆土液限的增大, 固化泥浆土强度逐渐降低, 固化效率随着泥浆土液限增大显著衰减, 当液限增加10%, 固化泥浆土强度qu平均减少48.2%。然而高岭土的掺入则显著提升了固化泥浆土的强度, 并且强度增长率随着龄期逐渐增大, 对于龄期为90天时, 增加40%高岭土能够提升固化泥浆土强度qu 1.17倍。微观结构试验表明泥浆土液限变化对水化产物产量的影响较小, 固化泥浆土强度随泥浆土液限减小主要是由于固化泥浆土孔隙随着泥浆土液限增大而增多, 使得微观结构松散从而导致强度降低。高岭土的掺入则显著提升了固化泥浆土的水化产物产量, 增强了固化泥浆土胶结强度, 从而提升了固化泥浆土强度。因此, 在实际工程中, 一方面可以通过调配泥浆土液限来提高固化效率; 另一方面可以通过掺入高岭土或者一些高岭土基废弃物(如高岭土尾矿)来提高固化强度, 实现“以废制废”绿色环保的理念。 |
| 中文关键词:高分子吸水树脂 液限 高岭土 微观机理 无侧限抗压强度 |
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| The Influence of Soil Properties on the Stabilization Strength of Engineering Slurry and Its Micro-mechanism |
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| Abstract:A series of unconfined compressive strength tests were carried out on engineering slurries stabilized with super-absorbent polymer at different liquid limits. The influence of the liquid limit of slurry on the stabilization efficiency is discussed. Furthermore, the impact of kaolin clay on the stabilization efficiency at the same liquid limit was compared. Finally, based on XRD and SEM microscopic observations, the micro-mechanism of the influence of liquid limit and kaolin on the strength improvement was revealed. The results showed that when the liquid limit of the slurry increased, the unconfined compressive strength (qu) of stabilized soil gradually decreased, i.e., the solidification efficiency significantly decreased with the increase in slurry liquid limit. When the liquid limit increased by 10%, qu decreased by 48.2% on average. In contrast, qu of stabilized soil significantly increased by adding kaolin clay. This effect on the strength enhancement was greatly enhanced with increased curing times. By adding 40% kaolin clay at 90 days of curing, qu increased by 1.17 times. The microscopic test results demonstrated that the change of liquid limit had little effect on the magnitude of hydration product. The main reason for qu decreasing with liquid limit was that the micropores of stabilized soil increased with increased liquid limit, resulting in a loose fabric with increased slurry liquid limit. In contrast, the amount of hydration products significantly increased for stabilized soil after adding kaolin clay, leading to the enhancement of the cementation structure of the stabilized soil, eventually resulting in improvement of its strength. These behaviors suggested that for the utilization of engineering slurry in actual projects, the adjustment of liquid limit of slurry onsite can be used to improve the stabilization efficiency. Meanwhile, kaolin-based wastes (such as kaolin tailings) can be added as an additional binder to improve stabilization efficiency, thereby contributing to a green and environmentally sustainable strategy. |
| keywords:super-absorbent polymer liquid limit kaolin clay microscopic mechanism unconfined compressive strength |
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