碱激发矿渣加固淤泥的物理力学性能与机理  

Properties and Mechanism of Solidified Silty Sediment from Alkali-Activated Slag

作　　者：陈林 李彬 陈胜邦 徐仰龙 陶送林 熊海蓉 CHEN Lin;LI Bin;CHEN Sheng-bang;XU Yang-long;TAO Song-lin;XIONG Hai-rong(Qinghai First Nonferrous Geological Exploration Institute,Xining 810007,China;Key Laboratory of Geological Processes and Mineral Resources in Northern Qinghai Tibet Plateau,Xining 810000,China;Qinghai Third Nonferrous Geological Exploration Institute,Xining 810000,China;Qinghai Zhongmei Geological Engineering Co.,Ltd.,Xining 810000,China)

机构地区：[1]青海省有色第一地质勘查院,西宁810007 [2]青海省青藏高原北部地质过程与矿产资源重点实验室,西宁810000 [3]青海省有色第三地质勘查院,西宁810000 [4]青海中煤地质工程有限责任公司,西宁810000

出　　处：《科学技术与工程》2024年第2期789-796,共8页Science Technology and Engineering

基　　金：青海省青藏高原北部地质过程与矿产资源重点实验室开放课题(2019-KY-01);2021年青海省“高端创新人才”拔尖人才计划(202113)。

摘　　要：为绿色低碳处置渣土并进行资源化利用,通过碱激发高炉矿渣(ground granulated blast-furnace slag, GGBS)作为绿色固化剂固化淤泥质工程渣土进行路基填料应用,探究不同固化剂掺量对固化土的综合性能影响规律,采用X射线衍射(X-ray diffraction, XRD)、扫描电镜(scanning electron microscopy, SEM)、核磁共振(nuclear magnetic resonance, NMR)对固化效果进行微观表征,用分形理论阐述微观孔隙特征揭示碱激发GGBS固化淤泥质渣土机理。结果表明:固化剂增加了固化土液塑限,降低了塑性指数,最优含水率随固化剂掺量增加呈现先减少后增大的趋势,最大干密度与之相反。掺入固化剂提高了渣土力学性能和水稳性,10%的掺量的固化渣土,强度、加州承载比(California bearing ratio, CBR)、水稳性以及渗透性分别为2.36 MPa、210.7%、81.3%和1.36×10^(-7)cm/s,各项指标均能满足路基填筑强度要求。微观机理表明,改良土的主要水化产物为(N,C)-A-S-H以及钙矾石Aft,固化体主要孔隙数量减少,10%的掺量的固化渣土,中孔隙减少了14.7%,孔隙分布分维数由1.23减小为1.06。通过碱激发GGBS固化淤泥质工程渣土,改善了渣土的稳定性,具有较好的应用前景。For promoting a green,low-carbon way of disposition of architecture sediment and resource utilization,alkali-activated blast furnace slag(GGBS)as a green solidification agent was adopted to solidify mucky engineering waste soil for subgrade filling.The influence of different dosages of solidification agent on the comprehensive performance of solidified soil was explored.Furthermore,X-ray diffraction,scanning electron microscopy and nuclear magnetic resonance were carried out to characterize the properties of the solidification.Fractal theory was used to describe the micropore characteristics and a generalized model was established to reveal the mechanism of alkali-activated GGBS solidification of muddy muck.The results show that the liquid limit and plastic limit of the solidified soil is increased and the plasticity index is reduced owing to the curing agent.The optimum moisture content decreased first and then increased with the increase of the content of the curing agent.The maximum dry density is the opposite compared with that of the optimum moisture content.The addition of curing agent can improve the mechanical properties and water stability of slag soil.The strength,CBR,water stability,and permeability of 10%solidified slag is 2.36 MPa,210.7%,81.3%,and 1.36×10^(-7) cm/s,respectively.All indicators can satisfy the engineering application requirement.The micro-mechanism showes that the main hydration products of the improved soil are(N,C)-A-S-H and ettringite Aft.The number of main pores in the solidified soil is reduced.For the slag with 10%of calcium solidification agent,the middle pores are reduced by 14.7%,and the fractal dimension of pore distribution is reduced from 1.23 to 1.06.The solidification of muddy engineering waste soil by alkali activated GGBS has improved the stability of the waste soil and has good application prospects.

关 键 词：淤泥质工程渣土 绿色胶凝材料 固化处置 路基填料 微观机理 

分 类 号：U414[交通运输工程—道路与铁道工程]