ACI CERTIFIED NOZZLEMAN
An ACI-certified Shotcrete Nozzleman is an individual who has demonstrated knowledge of the wet-mix shotcrete process and holds an active ACI Certification. The nozzleman is responsible for applying the shotcrete and for bringing it to required line and grade in a workmanlike manner. The nozzleman’s duties include coordinating the application with the foreman, finisher or rodman, and pump/ gun operator. Before the shotcrete is installed, the nozzleman should ensure all areas to receive shotcrete are clean, sound, and free of loose material, and that anchors, reinforcement, and ground wires are properly placed and spaced. In the dry process, the nozzleman controls the water content for hydration and ensures that the operating air pressure is uniform and will provide high velocity at impact for good consolidation. In the wet process, the nozzleman controls the air that increases or decreases the velocity to ensure proper placement, including proper encasement of the reinforcement. The nozzleman provides leadership and direction for the shotcrete crew, which aids in the task of shooting high-quality shotcrete.
The finisher rods or cuts the freshly placed shotcrete surface, bringing it to line and grade before final finishing. The finisher also locates and removes sand pockets, sags, and sloughs, and guides the nozzleman to low spots that require filling with additional shotcrete. Before the shotcrete takes the final set, the finisher brooms and prepares the surface for final application.
The wireman sets elevations and thicknesses for the shotcrete placement, which may include the top and face of the wall. Grades set by the wiremen are the lines the nozzleman and finishers will follow. The wireman may use many devices for setting grades, such as piano wire, fiber glass metal rods, and plastic pipe.