Simultaneous influences of nanomaterial and fiber reinforcement on enhancing the mechanical performance of geopolymer stabilized soft clayey soils  

纳米材料与纤维增强材料对提高地聚物加固软黏性土力学性能的协同影响

作　　者：KHOSRAVI Hassan GOODARZI Amir Reza LAJEVARDI Seyed Hamid 

机构地区：[1]Department of Civil Engineering,Arak Branch,Islamic Azad University,Arak,Iran [2]Department of Civil Engineering,College of Engineering,Hamedan Branch,Islamic Azad University,Hamedan,Iran

出　　处：《Journal of Central South University》2025年第2期597-623,共27页中南大学学报(英文版)

摘　　要：This study was designed to enhance the soft clayey soil treatment effects using an innovative mechanochemically activated geopolymer(GP)through the optimized inclusion of nano-metakaolin(NM)and polypropylene fiber.The study also investigated the possible improvements in the binding ability of GP stabilization under different curing regimes.To this end,binders including lime alone,LG(slag-based geopolymer),LGNM(nano-modified LG with NM)and LGNMF(LGNM/fiber)mixture were separately added to soft soil samples.The fabricated composites were then subjected to a set of macro and micro level tests.The results indicated that,adding LG binary with a 20%NM replacement can lead to a significant increase(by nearly 21 times)in soil strength and a remarkable decline(about 70%)in the compression index.In fact,NM can play a great role in accelerating the rate of hydration reactions and forming a densely packed fabric,which staggeringly improve the soil hydromechanical attributes.It was also observed that raising the curing temperature will effectively augment the polymerization kinetics,leading to a substantial increase(~2 times)in the soil solidification process.However,the stabilized composites containing NM may reveal a brittle nature under more intense stress.Such a potential drawback seems to be resolved by the integration of fibers within the matrix.LGNM combined with fiber would boost(≥10 times)the energy absorption capacity of the soil,notably enhancing its residual strength.Overall,LGNMF may not only feature a broader range of benefits(inc.economic,technical,environmental)compared to traditional binders but also promote the ductility of the GP materials.本研究旨在通过优化纳米级偏高岭土(NM)和聚丙烯纤维的掺入量,采用创新的机械化学活化法合成(GP)来增强软黏土的处理效果。此外,本研究还探讨了在不同养护条件下地聚物稳定化作用对黏结力的改善情况。为此,分别向软土样品中添加了仅含石灰的黏结剂、基于矿渣的地聚物(LG)、纳米改性矿渣地聚物(LGNM)以及LGNM/纤维混合物(LGNMF)等黏结剂。随后,对制备的复合材料进行宏观和微观测试。结果表明,添加20%NM的LG双元体系能够显著提高(约21倍)土壤强度,并显著降低(约70%)压缩指数。NM能够在加速水化反应速率和形成紧密排列的结构方面发挥重要作用,从而显著改善土壤的流体力学性能。此外,提高固化温度能够有效地加快聚合物反应速率,从而显著加快土壤固化过程(约2倍)。然而,含有NM的稳定复合材料在更强应力作用下可能会表现出脆性特征。这种潜在的缺陷可以通过在基质中融入纤维而得到解决。LGNM与纤维结合能够显著提高(≥10倍)土壤的能量吸收能力,显著增强其残余强度。总体而言,与传统黏结剂相比,LGNM-FM可能不仅具有更广泛的应用(包括经济、技术、环境方面),而且还能提高GP材料的延展性。

关 键 词：soft clayey soil LIME slag-based geopolymer nano-metakaolin(NM) fiber enhanced nanomodification 

分 类 号：TU411[建筑科学—岩土工程]