A transportable concrete mixing plant is provided and includes a frame, a mixing drum for mixing concrete, a conveying system having at least one rail for moving a pre-measured quantity of premix concrete to the mixing drum, and a supply hopper for directing the pre-measured premix concrete into the mixing drum. The rail forms a support track that is traversed by the supply hopper, which travels from a dispensing position near the mixing drum to a loading position spaced from the mixing drum. Optionally, a concrete pump dispenses flowable concrete received from the mixing drum and pumps it to a remote location, such as a work site.

A construction site mixing machine for mixing mixing materials contains a mixing container for a mixing material, a mixing tool displacement device, by which a mixing tool is displaceable between a mixing tool use position and a mixing tool non-use position. The mixing tool displacement device has a telescoping device or is formed by such a telescoping device. The mixing tool is displaceable by the telescoping device between the mixing tool use position and the mixing tool non-use position. According to an alternative concept, a control unit is configured to drive the mixing container by the mixing container drive unit in the opposite direction to the mixing tool which is drivable in rotation by the mixing tool drive unit and/or that the control unit has a timer function by which the operating time of the mixing tool drive unit and/or the mixing container drive unit is settable.