Construction material and/or slurry pump for conveying construction material and/or slurry, and method for operating same

The invention relates to a method for operating a construction material and/or slurry pump (1) for conveying construction material and/or slurry (DS), the construction material and/or slurry pump (1) having: at least one conveying cylinder (2a, 2b), the conveying cylinder (2a, 2b) being designed to receive and discharge construction material and/or slurry (DS); and at least one conveying piston (3a, 3b), the conveying piston (3a, 3b) being movably arranged in the conveying cylinder (2a, 2b) for sucking the building material and/or slurry (DS) into the conveying cylinder (2a, 2b) and for extruding the sucked building material and/or slurry (DS) out of the conveying cylinder (2a, 2b), and wherein the method comprises the following steps: conveying the building material and/or slurry (DS) by means of a movement of the conveying piston (3a, 3b) for drawing in and extruding the building material and/or slurry (DS), detecting at least one position variable (PGa, PGb) during the movement, the position variable (PGa,