Truck mixers come in two forms. Each type has a mixing drum with helical paddles inside which turn and lift the concrete onto itself. The drum is mounted on an inclined axis.

The rear discharge type has a drum on the buyer’s choice of truck chassis. The front discharge type is more cost effective because it cuts down on labor costs. The driver can control the discharge chute without leaving the cab.

For truck mixing the drum is permitted to hold 63% of its total volume. In central mixing the drum is allowed to hold up to 80% of its total volume.