<p>The device has a washing out container (17) to receive the residual concrete and separate out the coarse components such as sand or gravel. There is also a storage container (33) to which the cement-water mixture remaining in the washing out container is taken. Both the washing-out container and the storage container are fixed to a common transporting device (10) in the form of a vehicle trailer. The wheels (12) of the transporter can be vertically raised. There may be a pumping device on the transporter for feeding the mixture into the storage container.</p>
