Abstract: Iron mineral tailings have special physical and hydraulic properties, it can be used for subgrade filling after soil improvement treatment. In order to study the effect of subgrade moisture condition variation on the strength of cement modified iron mineral tailings, the comparative analyses of strength reduction and moisture stability by the unconfined compressive strength and California bearing ratio tests under the immersion conditions. The results show that the cement improved iron mineral tailings have good moisture stability, when the cement content is in the range of 6%~8%, the reduction rate of the saturated strength is less than 15%, and the California bearing ratio value is greater than 100%. The evaluation results can provide reference for the improvement treatment and performance evaluation of iron mineral tailings for the pavement engineering projects.

Key words: Iron Mineral Tailings, Pavement Engineering, Cement Improvement, Strength Reduction, California Bearing Ratio