采石场副产物对水泥稳定铁尾矿砂路面基层材料性能的影响OA

Applying quarry by-product(QBP)to cement-stabilized iron tailings pavement base material for roads can improve the problems such as insufficient strength and shrinkage cracking of the base material caused by the fine particles of iron tailings sand,thereby achieving large-scale resource utilization of iron tailings.This paper systematically studied the effects of QBP content and the fine particle plasticity index(particle size d<0.075 mm)on the mechanical properties,volume stability,and durability of cement-stabilized iron tailings.The shrinkage strain was regulated by an expansion agent,and the mechanism of QBP was revealed through microscopic analysis.The results show that when the QBP content is 40%(mass fraction),compared with the unmodified group,the 7 d unconfined compressive strength increases by 48.37%,the shrinkage strain decreases by 42.50%,and the frost resistance coefficient and water stability coefficient increase by 15.22%and 13.83%,respectively.Increasing the fine particle plasticity index improves the mechanical and durability properties of cement-stabilized iron tailings,but it also increases the risk of shrinkage cracking.After adding expansion agent,the shrinkage strain decreases by 48.69%compared with the unadulterated group,and is almost equivalent to the shrinkage strain of cement-stabilized crushed stone of the same strength grade.Microscopic analysis shows that QBP can optimize the packing structure of the cement-stabilized iron tailings mixture,improve the density and reduce the porosity,thereby improving the road performance.