粉煤灰改良铁尾矿砂用于路基填料力学性能试验研究

金属矿山 ›› 2025, Vol. 55 ›› Issue (8): 306-314.

粉煤灰改良铁尾矿砂用于路基填料力学性能试验研究

张　昊¹ 　邸国庆¹ 　汤劲松^1,2 　冯万达¹ 　娄国充^1,2

1. 石家庄铁道大学土木工程学院,河北石家庄 050043; 2. 道路与铁道工程安全保障省部共建教育部重点实验室,河北石家庄 050043

出版日期:2025-09-15 发布日期:2025-09-16
通讯作者: 汤劲松(1970—),男,教授,博士,硕士研究生导师。
作者简介:张　昊(1998—),男,硕士研究生。
基金资助:
河北省重点研发计划项目(编号:19274207D)。

Experimental Study on Mechanical Properties of Fly Ash Modified Iron Tailings Sand for Subgrade Filling

ZHANG Hao ¹ 　 DI Guoqing ¹ 　 TANG Jinsong ^1,2　 FENG Wanda ¹ 　 LOU Guochong ^1,2

1. School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China; 2. Key Laboratory of Roads and Railway Engineering Safety Control Ministry of Education,Shijiazhuang 050043,China

Online:2025-09-15 Published:2025-09-16

摘要/Abstract

摘要： 为优化铁尾矿砂力学性能,使其强度与刚度得以提升,采用外掺粉煤灰并加以养护的方法对其进行改良。通过常规三轴压缩试验,研究不同粉煤灰掺量以及养护龄期对试样的偏应力与变形模量的宏观提升效果,通过扫描电镜试验观察不同掺量的粉煤灰改良铁尾矿砂试样的细观结构,通过 X 射线衍射试验观察养护前后试样的成分组成,进而分析这些现象对力学性质影响的细观内在机理。研究结果表明:随着粉煤灰掺量增加,试样破坏时的偏差应力与变形模量呈现先增大后减小的趋势,当粉煤灰掺量为 25%时效果最优;随着粉煤灰掺量增加,试样的黏聚力显著增加,而内摩擦角逐步减少;通过细观试验可知,粉煤灰可有效填充铁尾矿砂颗粒之间的孔隙,使试样更加密实,而且试样内部的粉煤灰遇水反应后可生成无定形凝胶、水化硅酸钙凝胶和碳酸钙等物质;并且在试样经过养护后,可使得试样的力学性能得到提升。综合考虑粉煤灰改良铁尾矿砂的性能提升效果,采用掺入 25%粉煤灰改良并进行养护效果最佳。

关键词: 铁尾矿砂　力学性能　粉煤灰　扫描电镜试验　 X 射线衍射试验

Abstract: To optimize the mechanical properties of iron tailings sand and enhance its deviatoric stress and deformation modulus,the approach of external addition of fly ash along with curing was employed for improvement. Through conventional triaxial compression tests,the enhancement effects of different fly ash dosages and curing ages on the shear strength and deformation modulus of the specimens were investigated. The influences of fly ash dosage on the microstructure of the specimens and the effects of curing age on the composition variations of the specimens were explored via scanning electron microscopetests and X-ray diffraction tests. The intrinsic mechanisms of these changes on the mechanical properties were analyzed. The results indicate that as the fly ash dosage increases,the deviatoric stress and deformation modulus of the specimens initially increase and subsequently decrease,reaching the maximum when the fly ash dosage is 25%. As the fly ash dosage rises,the cohesion of the specimens significantly increases,while the internal friction angle gradually reduces. Through microscopic tests,it is evident that fly ash can effectively fill the pores between iron tailings sand particles,making the specimens more compact. Moreover,the fly ash within the specimens reacts with water to generate amorphous gels,hydrated calcium silicate gel and calcium carbonate after reacting with water. And after the sample is cured,the mechanical properties of the sample can be improved. Comprehensively considering the performance improvement effect of fly ash modified iron tailings sand,25% fly ash is used to improve and maintain the best effect.

Key words: iron tailing sands,mechanical properties,fly ash,scanning electron microscope test,X-ray diffraction test

中图分类号:

TU411

张　昊　邸国庆　汤劲松, 　冯万达　娄国充, . 粉煤灰改良铁尾矿砂用于路基填料力学性能试验研究[J]. 金属矿山, 2025, 55(8): 306-314.

ZHANG Hao 　 DI Guoqing 　 TANG Jinsong , 　 FENG Wanda 　 LOU Guochong , . Experimental Study on Mechanical Properties of Fly Ash Modified Iron Tailings Sand for Subgrade Filling[J]. Metal Mine, 2025, 55(8): 306-314.

扫码分享