A three-dimensional printing system for reinforced concrete and a nozzle therefor. The system employs an extruder for extruding unreinforced concrete and a concrete reinforcement feeder is for feeding one or more elongate reinforcement members. The nozzle has an outlet and is operatively connected to the extruder and the concrete reinforcement feeder to receive the unreinforced concrete from the extruder and to receive the one or more elongate reinforcement members from the concrete reinforcement feeder. The nozzle combines the unreinforced concrete from the extruder and the one or more elongate reinforcement members from the concrete reinforcement feeder into a reinforced concrete extrusion and imparts the reinforced concrete extrusion through the outlet.