www.chinatrucks.com:  When rotating in tank body mixing direction, the accurate helical vanes of Youngman Cement Mixer Truck--JNP5250GJB move the concrete towards the end seal direction. When the concrete reaches the end seal, the vanes drive the concrete to roll towards front cone direction to form the large-recirculation mixing.

Youngman Cement Mixer Truck JNP5250GJB-- Unique 3D Mixing Function of Blacksmith

When rotating in the tank body mixing direction, the force applied onto the concrete by the vanes drives the concrete to move towards the end seal direction. Under the application of acting force and counter acting force, the concrete forms the pressure onto the vanes. As the vanes are formed as streamline curved surfaces, the concrete will move along the streamline curved surfaces of the vanes. Under the guide of the vane edges, the concrete forms the rolling before the vanes and gets mixed continuously along the helical curves of the vanes. 

The accurately positioned bottom vanes disperse the pressure of concrete towards the end seal and drive the concrete to form the mixing in circumferentially rotating manner.