东北大学学报:自然科学版 ›› 2015, Vol. 36 ›› Issue (12): 1766-1770.DOI: 10.12068/j.issn.1005-3026.2015.12.021

• 资源与土木工程 • 上一篇    下一篇

木质素改良粉土基本工程特性试验研究

张涛1, 2, 蔡国军1, 2, 刘松玉1, 2   

  1. (1. 东南大学 岩土工程研究所, 江苏 南京210096; 2. 江苏省城市地下工程与环境安全重点实验室, 江苏 南京210096)
  • 收稿日期:2014-04-22 修回日期:2014-04-22 出版日期:2015-12-15 发布日期:2015-12-07
  • 通讯作者: 张涛
  • 作者简介:张涛(1986-),男,安徽合肥人,东南大学博士研究生; 刘松玉(1963-),男,江苏靖江人,东南大学教授.
  • 基金资助:
    国家自然科学基金重点项目(41330641,41202203); 全国优秀博士学位论文作者专项资金资助项目(201353); 教育部新世纪优秀人才支持计划项目(NCET-13-0118); 中央高校基本科研业务费专项资金资助项目(2242013R30014); 江苏省杰出青年基金资助项目(BK20140027); 江苏省交通科学研究计划项目(2013Y04).

Experimental Study on Basic Engineering Properties of Silt Improved by Lignin

ZHANG Tao1, 2, CAI Guo-jun1, 2, LIU Song-yu1, 2   

  1. 1. Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, China; 2. Jiangsu Key Laboratory of Urban Underground Engineering and Environmental Safety
  • Received:2014-04-22 Revised:2014-04-22 Online:2015-12-15 Published:2015-12-07
  • Contact: CAI Guo-jun
  • About author:-
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摘要: 将工业副产品木质素应用于粉土改良.通过界限含水率、颗分、击实、无侧限抗压强度和电阻率等室内试验,对素土及掺木质素改良土的基本物理力学性质、pH值和电学特性等进行对比研究,明确改良土的基本工程特性变化规律和改良效果,并采用扫描电子显微镜(SEM)对土体微观结构变化进行对比分析,阐述了木质素与土体的相互作用机理.试验结果表明:木质素可有效改善粉土的颗粒级配,降低土体的塑性指数;改良后粉土的最大干密度增加,最佳含水率减小,同时干密度对含水率变化的敏感性增强;改良土的无侧限抗压强度优于素土,pH值低于10,龄期和含水率对强度影响显著,对pH值无明显影响;胶结物质填充孔隙并联结土颗粒,改良土微观结构更为稳定.这说明木质素可有效改善粉土的基本工程特性.

关键词: 木质素, 粉土, 物理性质, 强度特性, 电阻率

Abstract: The lignin, an industrial by-product, is utilized to improve the silt. A series of laboratory tests on moisture content, particle size distribution, compaction, unconfined compression strength and electrical resistivity are carried out to study the mechanical and physical properties of natural silt and lignin-improved silt. The pH value and electrical characteristics of improved soil are also investigated. Scanning electron microscopy (SEM) is used to analyze the variations of soils microstructure, and the stabilization mechanism of lignin-treated silt is preliminarily discussed. The results indicate that lignin can effectively improve the particle size distribution and reduce the plastic index of soil. As to improved silt, maximum dry density increases, the optimum moisture content decreases, while the change of dry density with moisture content is enhanced. The lignin-treated silt has greater strength performance than the natural silt in terms of unconfined compression strength and all the improved soils have a pH value lower than 10. Curing time and moisture content have a significant impact on unconfined compression strength, but little effect on pH value. The pores of soils are filled and particles are connected with cementing material, then a more stable soil structure was formed. It is shown that adding lignin can successfully improve the basic engineering properties of silt.

Key words: lignin, silt, physical properties, strength characteristic, electrical resistivity

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