Experimental Study on Lime and Fly Ash–Stabilized Sintered Red Mud in Road Base

Abstract Sintered red mud is one of the solid wastes in the production of alumina. To utilize the red mud efficiently and reduce the pollution to the environment, an experimental study was carried out to verify its application in road base. The compaction tests and unconfined compression strength tests were conducted to determine the optimum mixture ratio, which is 70 % red mud, 7.5 % lime, and 22.5 % fly ash. The scanning electron microscopy test was conducted to reveal the strength development mechanism of the specimens lime and fly ash–stabilized red mud. After that, performance tests for the lime and fly ash–stabilized red mud were carried out. The results of freezing and thawing test, dry shrinkage test, temperature shrinkage test, and erosion resistance test show that the stability of the lime and fly ash–stabilized red mud is good. The fatigue test shows that the fatigue performance of lime and fly ash–stabilized red mud is similar to that of lime and fly ash–stabilized fine-grained soil. Finally, mechanical tests were carried out. Compared with some other commonly used road base materials, the compression rebound modulus of lime and fly ash–stabilized red mud is greater, while its indirect tensile strength is similar to that of other materials. The fly ash–stabilized sintered red mud can be used in road base.