水泥改良电解锰渣-碎石土路基填料力学性能及其微观特性的研究  

Study on the Mechanical Properties and Microstructural Characteristics of Cement-electrolytic Manganese Residue-crushed Stone Soil Subgrade Filler

作　　者：宋宇 肖懿训 王凌涛 范二龙 冯浩 毕研立 何兆益[2] SONG Yu;XIAO Yixun;WANG Lingtao;FAN Erlong;FENG Hao;BI Yanli;HE Zhaoyi(MCC Construction Engineering Group Co.,Ltd.,Chongqing 400037;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074)

机构地区：[1]中冶建工集团有限公司,重庆400037 [2]重庆交通大学土木工程学院,重庆400074

出　　处：《公路交通技术》2025年第2期9-16,共8页Technology of Highway and Transport

摘　　要：针对电解锰渣无害化处治问题,采用水泥改良电解锰渣与碎石土混合制备出水泥-电解锰渣-碎石土路基填料,研究不同水泥掺量对电解锰渣-碎石土路基填料力学性能的影响及对电解锰渣无害化处理效果。研究表明:1)5%的水泥掺量能使电解锰渣中Mn^(2+)、NH_(4)^(+)-N浓度分别下降至1.86 mg/L、3.593 mg/L,使其满足排放标准;2)使用2.5%、3.5%、4.5%的水泥掺量对电解锰渣-碎石土进行改良后,CBR值为61.7%~74.3%,满足高速公路、一级公路上路床填料要求;回弹模量为112.9 MPa~135.4 MPa,满足极重交通下路基顶面回弹模量要求;压缩系数为0.23 MPa-1~0.26 MPa-1,压缩模量为5.24 MPa~6.29 MPa,性质类似中压缩性土;粘聚力为42.61 kPa~49.09 kPa,内摩擦角为16.20°~17.05°,抗剪强度性能表现良好;3)XRD和SEM分析中,水泥-电解锰渣-碎石土内部生成了C-S-H凝胶和钙矾石(AFt),使得整体结构较改良前更加密实,强度大幅提升;4)动态淋溶试验模拟中,水泥-电解锰渣-碎石土在酸雨淋溶下,20年内Mn 2+、NH 4+-N最大浸出浓度分别为1.799 mg/L、3.466 mg/L,无二次污染风险。To address the harmless treatment of electrolytic manganese residue(EMR),a novel cement-modified EMR-gravelly soil composite material was developed for subgrade filler.This study investigated the effects of different cement dosages on the mechanical properties of the EMR-gravelly soil filler and its efficacy in neutralizing EMR contamination.Key findings include:1)5%cement dosage reduced the concentrations of Mn 2+and NH+4-N in EMR to 1.86 mg/L and 3.593 mg/L,respectively,meeting discharge standards;2)With cement dosages of 2.5%,3.5%,and 4.5%,the composite achieved a California Bearing Ratio(CBR)of 61.7%-74.3%,satisfying requirements for upper roadbed fill in highways and first-class roads.The resilient modulus reached 112.9 MPa-135.4 MPa,meeting specifications for subgrade surfaces under ultra-heavy traffic.The compression coefficient(0.23-0.26 MPa-1)and compression modulus(5.24-6.29 MPa)indicated medium compressibility,while the cohesive strength(42.61-49.09 kPa)and internal friction angle(16.20°-17.05°)demonstrated excellent shear resistance;3)XRD and SEM analyses revealed the formation of C-S-H gels and ettringite(AFt)within the cement-EMR-gravelly soil matrix,significantly densifying the structure and enhancing strength;4)Dynamic leaching tests simulating acid rain exposure over 20 years showed maximum Mn 2+and NH+4-N leaching concentrations of 1.799 mg/L and 3.466 mg/L,respectively,confirming no secondary pollution risk.

关 键 词：电解锰渣 碎石土 路基填料 力学性能 微观特性 

分 类 号：U414[交通运输工程—道路与铁道工程]