Abstract: The invention relates to a system for extruding cementitious material beads for a robot used for the additive manufacturing of architectural structures, comprising: a head for depositing beads of cementitious material, referred to as printhead (30), comprising an inlet mouth (31) and an outlet nozzle (34) configured to form beads of cementitious material; a feed circuit (20) for said printhead (30), comprising a reservoir (10) for storing cementitious material, a feed conduit (21) connecting said storage reservoir (10) to said printhead (30), and a booster pump (22) for said feed conduit (21), characterized in that it further comprises a sensor (33) for sensing the pressure rate of the cementitious material flowing in said printhead (30), and suitable for transmitting pressure/flow rate measurements to said booster pump (22), and in that the booster pump (22) is configured to control the boosting of the feed conduit (21) on the basis of the measurements transmitted by the sensor (33).