Experimental Study on the Influence of Dry–Wet Cycles on the Static and Dynamic Characteristics of Fiber-Modified Lime and Fly Ash-Stabilized Iron Tailings at Early Curing Age

Using fiber, lime and fly ash to modify iron tailings and apply them to a road base is an effective way to utilize iron tailings as resources. To explore the influence of fiber on lime and fly ash-stabilized iron tailings (EIT) under dry and wet cycles at an early curing age, the static and dynamic characteristics of EIT and fiber-modified lime and fly ash-stabilized iron tailings (FEIT) under dry and wet cycles were studied through an unconfined compressive strength (UCS) test, splitting test and dynamic triaxial test. The results show the following. (1) EIT and FEIT still have high UCS and splitting strength after dry–wet cycles, and the dry–wet cycles can promote the static properties of FEIT. (2) The dry–wet cycle is the main factor affecting the change in the dynamic elastic modulus of EIT and FEIT. The dynamic elastic modulus of EIT first increases and then decreases with the increase in dry–wet cycles, and the dynamic elastic modulus of FEIT first decreases and then increases with the increase in dry–wet cycles. The damping ratio of EIT and FEIT decreases with the increase in dry–wet cycles, and then tends to be stable. (3) After seven dry–wet cycles, the compressive performance, tensile performance, deformation resistance and vibration resistance of FEIT are better than those of EIT. This study can provide a reference for the resource application of iron tailings in road engineering.