System for extruding cementitious material beads for an architectural structure additive manufacturing robot

A robot used for the additive manufacturing of architectural structures, comprising:

• a positioning system, such as an articulated arm, controlled by a control unit, characterized, the positioning system comprising a system for extruding cementitious material comprising:
• a head for dispensing strands of cementitious material, referred to as a print head, comprising a mouth for the inlet of cementitious material and an outlet nozzle designed to form strands of cementitious material,
• a circuit for feeding cementitious material to said print head, comprising a cementitious material storage tank, a cementitious material feed pipe connecting said storage tank and said print head, and a pump for filling said feed pipe with cementitious material from said storage tank,
• a sensor for detecting the pressure/flow rate of said cementitious material flowing in said print head between the mouth and outlet of said print head, which sensor is suitable for transmitting pressure/flow rate measurements to said filling pump, said filling pump being designed to control the filling of the feed pipe on the basis of said measurements transmitted by said sensor, characterized in that said dispensing head further comprises:
• a mixing chamber which is arranged upstream of said outlet nozzle and into which an admixing device leads which is suitable for injecting admixtures that modify the characteristics of the cementitious material before ejection of said strands of cementitious material through said outlet nozzle, said admixing device comprising at least one admixing needle which leads into said mixing chamber in an admixing direction which forms an angle of between 0 and 90° with said longitudinal direction and is connected to an admixture barrel so as to be able to inject said admixtures from said admixture barrel into said mixing chamber in said admixing direction,
• a dynamic mixer designed to be able to mix said cementitious material and admixtures provided by said admixing device in said mixing chamber, said dynamic mixer comprising at least one shaft extending into the mixing chamber in a direction referred to as the longitudinal direction, and carrying radial fingers distributed along the shaft, and a motor designed to be able to rotate an eccentric-screw metering pump designed to be able to convey the cementitious material from said inlet mouth of said print head to said mixing chamber said shaft so as to be able to provide a homogeneous mixture of the cementitious material and the admixtures,
• an eccentric-screw metering pump designed to be able to convey the cementitious material from said inlet mouth of said print head to said mixing chamber.