【摘要】 为研究钢渣粉改良红层泥岩填料的力学特性和作用机理，采用重型击实、无侧限、直剪和侧限压缩等试验方法进行力学特性研究，并通过X射线衍射、红外光谱、核磁共振、激光粒度和扫描电镜等试验对微观界面结构及其作用机理进行了分析。试验结果表明，钢渣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。15%钢渣粉改良填料的抗压强度由素土的0.6 MPa提升至1.5 MPa,浸水抗压强度由湿化崩解状态逐渐提高到0.8 MPa,力学强度和湿化崩解特性均得到显著改善。进一步通过微观分析揭示了钢渣粉改良填料的作用机理，主要包括水化作用和离子交换反应。基于X射线衍射和红外光谱显示出SiO₂峰减弱、C-S-H峰增强和Al3+离子配位的振动峰增强，在强离子作用下，减小了土颗粒的双电层厚度。核磁共振和激光粒度分析发现改良填料的孔隙分布曲线明显得到优化，颗粒团聚作用增强，这有助于形成更加稳定的土体结构。通过扫描电镜观测到粒间孔隙结构和土颗粒间接触形式发生了改变，土体内部形成了排列紧密的层状堆叠或絮团状结构，提高了整体结构性。同时对颗粒分形维数进行定量化分析，较好反映了改良填料抗剪强度指标的变化规律，从而建立了改良填料抗剪强度指标与其微观结构特征之间的联系。更多还原

【Abstract】 To study the mechanical property and mechanism of steel slag powder modified red beds stuffing, the mechanical properties were studied with heavy compaction, unconfined, direct shear and confined compression tests. The microstructure and mechanism of interface were analyzed by using X-ray diffraction, infrared spectroscopy, nuclear magnetic resonance, laser particle size, and scanning electron microscopy. The result indicates that the steel slag powder has good effect on the mechanical strength and water stability of red beds stuffing. The compressive strength of modified stuffing with 15% steel slag powder increases from 0.6 MPa in plain soil to 1.5 MPa; the compressive strength of impregnated stuffing gradually increases from the state of wet disintegration to 0.8 MPa; and the mechanical strength and wet disintegration characteristics are significantly improved. Further, the mechanism of modified stuffing is revealed through microscopic analysis, including hydration and ion exchange reaction. Based on X-ray diffraction and infrared spectroscopy, it is shown that SiO₂ peak is weakened, C—S—H peak is enhanced, and Al³⁺ ion coordination vibration peak is enhanced. Under the action of strong ions, the double electric beds thickness of soil particles is reduced. NMR and laser particle size analysis show that the pore distribution curve of modified stuffing is optimized, and the particle agglomeration is enhanced. That contributes to the formation of a more stable soil structure. By using scanning electron microscopy, the pore structure and contact form among soil particles are found to change. Inside the soil, the tightly arranged layered stacking or flocculated structures are formed, which improve the overall structure. Simultaneously, the particle fractal dimension was quantitatively analyzed, which reflected the variation rule of shear strength indicators of the improved stuffing. The relation between shear strength indicator of the improved stuffing and its microstructure was established.更多还原