The most critical point in terms of time and material efficiency in shotcrete projection is to prevent the shotcrete from bouncing as much as possible when it hits the surface. Experimental studies in recent years show that the tendency of shotcrete to adhere to the surface is directly proportional to its kinetic energy, that is, the speed of the particle at the moment before it touches the surface. Another factor is the spraying angle of the nozzle, which is the angle between vertical outer edges of wet concrete when it exits the nozzle tip. Since the velocity distribution in wet shotcrete is almost homogeneous in a projected area, the velocity plays a much more important role than the angle. In dry shotcrete applications, the angle should be considered as well. This is because the speed of each particle change vertically.
Once wet concrete comes out of the nozzle, it keeps its acceleration. The speed of concrete when it travels one meter is higher than the speed at half a meter distance. Therefore, shotcrete spraying distance has been determined as between 1-2m optimally. The aerodynamic structure of the nozzle tip, the air inlet and outlet openings significantly affect the particle velocity. As SLMG, we design nozzle body and polyethylene nozzle tip that we for different working environments. SLMG nozzles fulfill the particle acceleration task and the ability to hold to the surface at the highest level. Therefore, the nozzles used in shotcrete machines should be carefully selected and used. Any randomly selected piece might cause unnecessary material waste and time loss. Sometimes mistakes such as cutting the nozzle tip for more convenient use in construction sites cause a very sharp decrease in performance. One must use shotcrete pump with suitable parts considering the working environment beforehand. In such technical applications for different shotcrete uses, you can always consult our technical service and get detailed information about suitable nozzles.