Effect of ionic soil stabilizer on the properties of lime and fly ash stabilized iron tailings as pavement base

Abstract

The large use of iron tailings is in urgent need given its huge emissions and pollution to environment. This paper sought to utilize a large quantity of iron tailings with fly ash and lime to prepare road base materials, and use ionic soil stabilizer (ISS) to improve its pavement performance. Different dosage ISS content of was added to the lime-fly ash stabilized iron tailing materials to improve the mechanical strength, frost resistance properties and decrease the dry shrinkage. The results show that the UCS of the specimen with 0.67 % ISS represents enhancement of 195.5 % compared to the control sample at 7 d. After undergoing 15 freeze-thaw cycles, the residual UCS ratio remains at 76.6 %, whereas the control sample exhibits signs of failure. Additionally, the dry shrinkage strain at 30 d was 66.3 % lower than that of the control sample without ISS. The mechanisms underlie that the adsorbed ISS onto iron tailings can reduce the repulsion between total fine particles by lowering the general zeta potential, thus decreasing the porosity of the road base materials. Besides, the ISS can hinder the phase transformation from ettringite (AFt) to monosulfoaluminate (AFm) and its hydrophobic groups can prevent the infiltration and migration of water. The findings reveal that ISS significantly enhances the pavement performance of the stabilized iron tailings, thereby presenting a novel approach for the incorporation of iron tailings in road construction endeavors.