Abstract: A device enabling the separation and removal of cementitious material from a concrete mix contained within a concrete mixer is provided. The concrete mixer, usually of the mobile type mounted on a land vehicle, comprises essentially, a drum or mixing vessel, a discharge or dump outlet and means for introducing water into the drum. The instant device comprises restraining and diverting member adapted to be positioned in alignment with said outlet, pulley means, for example pivotally mounting the device on the cement mixer enabling movement of the device from a position aligned with said outlet to a position displaced from said outlet, latch means for securing the device in aligned position with said outlet, and means for moving said device to a position out of alignment with said outlet, as required for normal operation of the concrete mixer.