Device for applying a building material

A system for applying a building material, the system comprising:

• a movement device for changing a site of application within a space;
• a first component of the building material;
• a second component of the building material;
• and
• a mixer for mixing the first component and the second component,
• wherein the mixer includes a drive module with a first coupling element and a mixing chamber module with a second coupling element,
• the drive module and the mixing chamber module are configured to be separable from one another by the coupling elements,
• the drive module and the mixing chamber module are operatively connected together by the coupling elements when the system is in an application state,
• the mixing chamber module includes a drum module and a shaft module configured to be separable from one another,
• the shaft module includes the second coupling element, a proximal closure, and an agitating shaft, the agitating shaft being operatively connected to the second coupling element,
• at least one of (i) the agitating shaft is fitted with pins on a first portion, and (ii) the agitating shaft has on a second portion a conveying element which is operatively connected to the agitating shaft and to the second coupling element, and
• the first component includes a pumpable concrete and the second component includes an accelerating admixture.