An auger mixer for mixing a concrete mix includes an elongated mixer housing having a mixing chamber for mixing the concrete mix therein. A mixing auger is rotatably mounted within the mixing chamber. A bearing assembly mounts one end of the auger shaft to the mixer housing. A seal assembly comprising a stationary seal remains stationary relative to the mixer housing and a rotating seal rotates with the auger. The stationary seal and the rotating seal contact one another to create a seal preventing the concrete mix from exiting the mixing chamber and moving toward the bearing assembly.