矿渣微粉改良红层填料的力学特性及其机理分析  

Strength,Microstructure and Mechanism Analysis of Red Mudstone Improved by Steel Slag

作　　者：余云燕[1] 高远 杜乾中 牛浩莹 YU Yunyan;GAO Yuan;DU Qianzhong;NIU Haoying(Scholl of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;School of Chemistry and Chemical Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]兰州交通大学化学化工学院,兰州730070

出　　处：《兰州交通大学学报》2024年第4期1-9,共9页Journal of Lanzhou Jiaotong University

基　　金：甘肃省科技计划项目资助(21YF5GA050);甘肃省教育厅产业支撑计划项目资助(2021CYZC-28);甘肃省教育厅优秀研究生“创新之星”项目(2023CXZX-601);甘肃省交通运输厅科技研发项目资助(2021-12);甘肃省基础研究创新群体(145RJIA332,21JR7RA347)。

摘　　要：为研究矿渣微粉改良红层填料的力学特性及其作用机理,通过无侧限抗压强度、直剪等试验,对不同矿渣微粉掺量下的红层填料进行了强度特性分析,并采用X衍射、热重分析、红外光谱、激光粒度、核磁共振和扫描电镜等微观分析方法,围绕矿渣微粉改良土体的作用机理进行了研究。试验结果表明,矿渣微粉对红层填料的力学强度和水稳定性具有较好的改良作用,改良填料的无侧限抗压强度由0.76 MPa逐渐增大至3.10 MPa;黏聚力与内摩擦角也得到了显著提高。通过红外光谱、激光粒度和核磁共振分析发现,改良填料颗粒间Al^(3+)阳离子配位的振动峰增强,降低了黏土矿物的双电层厚度,土颗粒团聚性显著增强,孔隙分布得到优化;通过X射线衍射和热重分析证明了水化产物的生成过程;扫描电镜观测到改良填料的具体作用机理:主要为填充效应和胶凝效应,其胶凝效应包括水化作用和离子交换作用。对微观扫描图的定量化分析进一步表明土体结构复杂程度增大,颗粒粗糙程度及骨架性增强。In order to study the mechanical properties and mechanism of red layer filler modified by slag powder, the strength characteristics of red layer filler under different slag powder content were analyzed through unconfined compressive strengthand direct shear tests, and microscopic analysis methods such as X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, laser particle size, nuclear magnetic resonance and scanning electron microscopy were used.The mechanism of soil improvement by slag powder is studied.The experimental results show that the slag powder can improve the mechanical strength and water stability of the red layer filler, and the unconfined compressive strength of the modified filler increases from 0.76 MPa to 3.10 MPa.The cohesion and internal friction Angle are also significantly improved.By infrared spectroscopy, laser particle size and nuclear magnetic resonance analysis, it is found that the vibration peak of Al^(3+) cationic coordination between the modified packing particles is enhanced, the thickness of the double electric layer of clay minerals is reduced, the agglomeration of soil particles is significantly enhanced, and the pore distribution is optimized.The formation process of hydration products was proved by X-ray diffraction and thermogravimetric analysis.The specific action mechanism of the modified filler was observed by scanning electron microscopy: The primary effects are the filling effect and the cementing effect, with the cementing effect including hydration and ion exchange.Quantitative analysis of micrographs further indicates an increase in the complexity of the soil structure, as well as enhanced particle roughness and skeletal framework.

关 键 词：改良红层填料 矿渣微粉 力学特性 微观分析 作用机理 

分 类 号：U416.1[交通运输工程—道路与铁道工程]