赤泥复合固化剂固化粉土路用性能及其机理  

Road Performance of Red Mud Composite Solidification Agent for Solidified Silt and Its Mechanism

作　　者：吴伟军 张鲲鹏 张宁[2] 丁北斗[2] 王佳辉 WU Weijun;ZHANG Kunpeng;ZHANG Ning;DING Beidou;WANG Jiahui(Shanghai Road and Bridge(Group)Co.Ltd.,Shanghai 200433,China;Jiangsu Key Laboratory of Disaster Impact and Intelligent Prevention in Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]上海公路桥梁(集团)有限公司,上海200433 [2]中国矿业大学土木工程灾变与智能防控省高校重点实验室,江苏徐州221116

出　　处：《建筑材料学报》2025年第3期227-235,共9页Journal of Building Materials

基　　金：“十四五”国家重点研发计划项目(2023YFC2907301)。

摘　　要：利用工业废弃物赤泥、电石渣和脱硫石膏组成的赤泥复合固化剂对低液限粉土进行固化,探究了固化粉土的力学性能(无侧限抗压强度和劈裂强度)和耐久性(水稳定性和干湿循环),并采用扫描电镜(SEM)和X射线衍射仪(XRD)分析赤泥复合固化剂的固化机理.结果表明:固化粉土的无侧限抗压强度和劈裂强度随着赤泥复合固化剂掺量的增加和养护龄期的延长而提高;当赤泥复合固化剂掺量由8%增至24%且养护龄期由7 d延至28 d时,固化粉土的水稳系数由69.5%提高到82.4%;干湿循环12次后,固化粉土的强度损失率为35.14%.赤泥复合固化剂掺入粉土中发生水化反应,生成具有胶凝作用的水化硅酸钙(C-S-H)和水化铝酸钙(C-A-H)凝胶,同时C-A-H与CaSO_(4)生成钙矾石(AFt)晶体;C-S-H和C-A-H包裹并填充着土颗粒,AFt晶体穿插在土颗粒间,使其成为一个整体,有效提高了固化粉土的路用性能.Red mud composite stabilizers,composed of industrial wastes such as red mud,carbide slag,and desulfurized gypsum,were used to solidify low liquid limit silt.The changes in mechanical properties(unconfined compressive strength and splitting strength)and durability(water stability and dry-wet cycle)of the solidified silt were explored.Additionally,scanning electron microscopy(SEM)and X-ray diffraction(XRD)were employed to analyze the solidification mechanism of red mud composite solidification agent.The results show that the unconfined compressive strength and splitting strength of solidified silt increase with both the increasing content of the stabilizer and the extension of curing age.When the content of red mud composite solidification agent is increased from 8%to 24%and the age of maintenance is extended from 7 d to 28 d.The water stability coefficient improves from 69.5%to 82.4%.After 12 dry-wet cycles,the strength loss rate of stabilized silt reaches 35.14%.When the red mud composite stabilizer is incorporated into the silt,hydration reactions occur,forming gelatinous calcium silicate hydrate(C-S-H)and calcium aluminate hydrate(C-A-H)gels.Simultaneously,C-A-H reacts with CaSO_(4) to produce ettringite(AFt)crystals.The C-S-H and C-A-H gels encapsulate and fill the soil particles,while the AFt crystals interpenetrate the soil particles,integrating them into a whole and effectively enhancing the road performance of solidified silt.

关 键 词：赤泥 低液限粉土 路用性能 固化机理 

分 类 号：U416.1[交通运输工程—道路与铁道工程]