工业副产品木质素改良路基粉土的微观机制研究

发布时间：2018-04-06 06:30

  本文选题：工业副产品　切入点：粉土　出处：《岩土力学》2016年06期

【摘要】：为揭示工业副产品木质素与土体间的相互作用机制,将木质素应用于路基粉土改良,通过对木质素及其改良土进行无侧限抗压强度、pH值、微观结构、化学元素、矿物成分和官能团等试验分析,研究不同掺量下木质素改良土的力学性能和pH值变化,对比分析改良前后粉土的微观结构变化,并基于化学分析结果探讨木质素的分子结构及与土体间的相互作用,提出木质素改良土体的机制。试验结果表明,改良土强度随木质素掺量增加而增加,掺量超过一定范围时,土体强度降低,木质素改良粉土的最优掺量为12%,且龄期对土体强度有着重要影响;强度与pH值基本呈线性相关关系;改良土微观结构更为致密、稳定,胶结物质将土颗粒相互联结,且未生成新的矿物;木质素通过水解、离子交换、质子化和静电引力等作用,导致双电层厚度减小,带正电荷的木质素高分子聚合物联结土颗粒并填充孔隙,改良土工程性质得以改善。提出的木质素改良土体机制可为工业副产品木质素的工程应用提供理论参考。
[Abstract]:In order to reveal the interaction mechanism between lignin and soil by industrial by-product, lignin was applied to the improvement of subgrade silt. The unconfined compressive strength, pH value, microstructure and chemical elements of lignin and its modified soil were studied.The changes of mechanical properties and pH value of lignin modified soil were studied by means of mineral composition and functional groups, and the microstructure of silt before and after the improvement was compared and analyzed.Based on the results of chemical analysis, the molecular structure of lignin and the interaction between lignin and soil are discussed, and the mechanism of lignin improving soil is put forward.The results show that the strength of the improved soil increases with the increase of lignin content. When the content exceeds a certain range, the soil strength decreases, the optimum content of lignin modified silt is 12, and the age has an important effect on the soil strength.The microstructure of the improved soil is denser and more stable, and the cemented material connects the soil particles with each other, and no new minerals are formed. The lignin is treated by hydrolysis, ion exchange, protonation and electrostatic force, etc.As a result, the thickness of the double electric layer decreases, and the positively charged lignin polymer binds the soil particles and fills the pores, thus improving the engineering properties of the improved soil.The improved soil mechanism proposed by lignin can provide a theoretical reference for the engineering application of industrial by-product lignin.
【作者单位】： 东南大学岩土工程研究所;东南大学江苏省城市地下工程与环境安全重点实验室;江苏省交通规划设计院股份有限公司;
【基金】：江苏省杰出青年基金资助项目(No.BK20140027) 中央高校基本科研业务费(No.2242016K41062) 江苏省交通科学研究计划项目(No.2013Y04)~~
【分类号】：U414
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本文编号：1718402