Gunning in Shotcreting

Question

Explain the direction of Gunning in Shotcreting?

Answer 1

Throughout, the shotcrete construction, it aimed at gunning the full thickness in the single operation and this aids to decrease the occurrence of likely delamination and formation of planes of weakness. In addition, the nozzles must be held around 0.6m to 1.8m above the surface and normal to the receiving surface. The aim of gunning perpendicular to the receiving surface is to prevent the possible rebound and rolling resulting from the gunning at an angle deviated from the perpendicular. The rolled shotcrete forms a non-uniform surface which serves to trap the overspray and shotcrete resulting from the rebounding action. This is not desirable since the wastage of materials and the generation of the rough and uneven surface.