磁性指数对铁尾矿水泥基材料特性的影响-《建筑科学与工程学报》

文章信息/Info

Title:: Effect of Magnetic Index on Properties of Cementbased Materials with Iron Ore Tailings

Author(s):: LI Xiao-guang, JING Shuai-shuai, MA Yu-ping; School of Civil Engineering, Changan University

Keywords:: iron ore tailing; magnetic index; mechanical property; microhardness; antichloride permeability; cement mortar; durability

摘要:: 为实现铁尾矿代替天然河砂制备水泥基材料的目标，以8种磁性指数的铁尾矿和天然河砂为骨料分别制备了水泥砂浆和混凝土试件。通过测试砂浆的力学性能、试件断面的显微硬度、孔结构参数以及混凝土的抗氯离子渗透性能，分析了磁性指数对铁尾矿水泥基材料特性的影响。试验结果表明：在相同配合比下，铁尾矿砂浆力学性能优于天然河砂砂浆；提高铁尾矿的磁性指数，砂浆力学性能呈现下降趋势，但是磁性指数为40%的铁尾矿砂浆强度仍然较高；当磁性指数为0%时，铁尾矿砂浆界面区显微硬度最高，磁性指数为40%的铁尾矿砂浆次之；磁性指数为0%和40%的铁尾矿砂浆孔隙率较低且无害孔含量更多；通过磁选分离降低铁尾矿的磁性指数，有利于增强铁尾矿混凝土的抗氯离子渗透性能，提高其耐久性。

Abstract:: A series of specimens of cement mortar and concrete were fabricated with iron ore tailings (IOT) containing eight different magnetic indexes and river sand respectively for purpose of application of IOT in cementbased materials. Mechanical properties, microhardness values of section cross, parameters of pore structure of mortars and antichloride permeability of concrete for specimens were measured to clarify effect of magnetic index on properties of cementbased materials with IOT. The test results show that mechanical property of IOT mortar is superior to that of river sand mortar and decreases with increasing of magnetic index of IOT, except mortar with 40% magnetic index still acquiring higher strength. Maximum microhardness can be measured on interface region of IOT mortar as 0% magnetic index, IOT mortar of 40% magnetic index secondly. Lower porosity and more harmless pore can be discovered in the IOT mortars with 0%, 40% magnetic indexes. Magnetic separation to IOT can generate a high antichloride permeability of concrete resulting in better long term durability.