摘要
为有效改善黄土的不良工程性质,选择工业副产品木质素作为改良剂,对黄土工程性能进行改善,以满足工程对土体承载能力的要求。通过配置不同配比的木质素改良黄土,测试了改良黄土的相对质量密度、界限含水率、最大干密度-最优含水率和无侧限抗压强度,研究了素土和改良黄土的工程性质,探讨了木质素用于改良黄土的可行性。并结合物理力学特性测试结果,基于扫描电镜试验和X射线衍射试验,从细观结构和矿物成分方面分析了木质素改良黄土的加固机理。结果表明:与素压实黄土相比,木质素改良黄土的相对质量密度明显降低,液限、塑限和塑性指数均减小,最大干密度增大,最优含水率有所下降。木质素掺量和养护龄期对改良黄土工程性质有显著影响,养护龄期28 d、木质素掺量2%时,改良黄土抗压强度最大,相较于素压实黄土强度提升32%。木质素对黄土的改良加固的机制主要包括木质素对黄土的填隙作用、胶结作用、黏土矿物强化作用、离子交换和双电层吸附作用。
To effectively improve its weak engineering properties,the industrial by-product lignin is selected to improve the strength of the loess.The specific gravity,Atterberg limit,maximum dry density-optimal moisture content,and unconfined compressive strength(UCS)of the lignin-modified loess are tested by configuring the modified loess with different lignin contents.The engineering properties of the lignin-modified and the compacted loess are studied.The feasibility of the lignin-modified loess is discussed.Based on the results of the SEM,XRD,physical and mechanical properties tests,the reinforcement mechanism of the lignin-modified loess is analyzed.The results show that compared with that of the compacted loess,the specific gravity of the lignin-modified loess is significantly reduced.The liquid limit,plastic limit and plasticity index are reduced.Moreover,the maximum dry density and the optimum moisture content decrease.The lignin content and curing age significantly affect the engineering properties of the modified loess.When the curing age is 28 days and the lignin content is equal to 2%,the UCS of the modified loess is the highest,which is 32%higher than that of the compacted loess.The reinforcement mechanism of the lignin-modified loess mainly includes the interstitial effects of the lignin on the loess,cementation,clay mineral,ion exchange and electric double-layer adsorption.
作者
王谦
王兰民
刘钊钊
钟秀梅
高中南
WANG Qian;WANG Lanmin;LIU Zhaozhao;ZHONG Xiumei;GAO Zhongnan(Key Laboratory of Loess Earthquake Engineering,CEA,Lanzhou 730000,China;State Key Laboratory of Hydraulics and Mountain River Engineering,College of Water Resource and Hydropower,Sichuan University,Chengdu 610065,China;College of Civil Engineering and Water Resources,Qinghai University,Xining 810016,China;College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2024年第S02期150-154,215,共6页
Chinese Journal of Geotechnical Engineering
基金
甘肃省地震局创新团队项目(2020TD-01-01)
国家自然科学基金项目(51778590)
中国地震局地震预测研究所基本科研业务经费项目(2023IESLZ5,2021IESLZ03)。
