盐卤腐蚀环境中铝土矿超细尾砂-水泥充填材料的损伤行为  

Damage Behavior of Bauxite Superfine Tailings-Cement Filling Material in Halogen Corrosion Environment

作　　者：刘洪伟[1] 吴凯 郑宏 LIU Hongwei;WU Kai;ZHENG Hong(Henan Technical College of Construction,Department of Civil Engineering,Zhengzhou 450064,China;Institute of Resources&Environment,Henan Polytechnic University,Jiaozuo 454000,China;Northwest Branch of China Construction First Bureau Co.,Ltd.,Xi'an 710000,China)

机构地区：[1]河南建筑职业技术学院土木工程系,郑州450064 [2]河南理工大学资源环境学院,焦作454000 [3]中国建筑一局(集团)有限公司西北分公司,西安710000

出　　处：《腐蚀与防护》2024年第12期46-51,112,共7页Corrosion & Protection

基　　金：国家自然科学基金(51908198)。

摘　　要：采用盐卤腐蚀液对铝土矿超细尾砂-水泥充填材料进行了不同时间的浸泡处理,通过单轴压缩试验和计算机断层(CT)扫描,研究了材料的力学性能和微观结构的变化规律,并结合显微形貌分析其腐蚀机理。结果表明:随着腐蚀时间从0增至360 d,该充填材料的抗压强度和变形模量均逐渐下降,变化速率先慢后快,腐蚀360 d后,该充填材料的抗压强度和变形模量的降幅均超过30%;试件内部的微观裂隙在腐蚀过程中逐渐扩张,面孔隙率呈指数型增长趋势;在一定范围内增加料浆的质量分数能提高试件抗压强度,但强度提升效果随腐蚀时间的增加而逐渐减弱;试件的抗压强度与面孔隙率呈负线性相关关系,相关系数超过了0.95,说明采用CT扫描结果预测材料强度折减规律合理可行。在地下水盐卤溶液的长期腐蚀作用下,腐蚀性离子的侵入和化学作用使得水泥水化产物的微观形态发生演变,孔隙逐渐扩张,颗粒黏结程度下降,最终导致材料力学性能衰减。The superfine tailings and cement filling material of bauxite was soaked with halide corrosion solution at different time.The change rule of mechanical properties and microstructure was studied by uniaxial compression test and computed tomography(CT)scanning,and the corrosion mechanism was analyzed by microscopic morphology.The results showed that with the corrosion time increasing from 0 d to 360 d,the compressive strength and deformation modulus of the filling material decreased gradually,and the change rate was first slow and then fast.After 360 d corrosion,the compressive strength and deformation modulus of the filling material decreased by more than 30%.In the process of corrosion,the microscopic cracks in the specimen expanded gradually,and the surface porosity increased exponentially.Increasing mass fraction of slurry in a certain range could improve the compressive strength of specimen,but the enhancement effect decreased with the increase of corrosion time.There was a negative linear correlation between compressive strength and surface porosity of specimens,and the correlation coefficient was more than 0.95,indicating that it was reasonable and feasible to use CT scanning results to predict the regulation of material strength reduction.Under the long-term corrosion action of brine solution in groundwater,the invasion of corrosive ions and chemical action made the microscopic morphology of cement hydration products evolved,the pores gradually expanded,the particle bonding degree decreased,and finally led to the mechanical properties of materials attenuation.

关 键 词：铝土矿超细尾砂 水泥充填材料 盐卤腐蚀 损伤行为 

分 类 号：TD435[矿业工程—矿山机电]