Standard Transit Concrete Mixers are in essence trucks, which transport concrete from the plant to job or construction site. At the plant the truck is either filled with dry materials (or aggregates), which go into making concrete and are mixed together during transport or the truck is loaded with Ready Mixed concrete. With the latter process, the aggregates are mixed at the plant, and then loaded onto the truck. The Transit Concrete Mixers function is to maintain the concrete's liquid state, through turning of the drum, to the point of delivery at the construction site.

Transit Concrete Mixers have a drum mixer in which the concrete materials are mixed. Blades attached to the inside of the movable drum do the mixing. The blades are of two helixes rotating in a clockwise and a counter-clockwise direction. Their main purpose is to mix and lift the concrete as the drum rotates. In each rotation, the lifted concrete drops back into the mixer at the bottom of the drum and the cycle starts again. The counter-clockwise rotation causes the material to be lifted by the blades towards the discharge end of the drum. The concrete is then discharged onto chutes to guide the concrete to where it is required at the construction site. If the concrete mixer cannot get close enough to the site, the concrete may be discharged into a concrete pump, which is able to pump the concrete to a precise location.

Transit Concrete Mixers are either trucks with rear discharge drums or trucks with front discharge drums. The disadvantage of rear discharge trucks is that it is the responsibility of the driver to guide the truck back and fourth to ensure the chute is in the exact position where concrete is to be placed. The more modern Standard Transit Mixers have front discharge drums and the cabs are fitted with controls to allow the driver to move the chute in all directions as required.

A Self-Loading Concrete Truck Mixer is designed to work as a ready-mix concrete delivery vehicle and can handle all types of concrete deliveries, from large pour volume jobs to small volumes as requested by the DIY market. It can even work on-the-job as an on-site concrete batching plant.

Self-loading concrete trucks can be fitted with electronic weigh-batching equipment, which shows the exact weight of raw materials going into the concrete mixer drum roller and the exact amount of concrete that is discharged. This offers a big cost saving to the construction industry and concrete suppliers as it allows the operator to split loads of any quantity thus reducing wastage and it enables multiple deliveries. A further advantage is that it can re-load with raw materials from any builder merchant, as it has its own self-loading equipment and on-board water system.