This study investigated the influence of the different forms of silica fume on the plastic and hardened porperties of wet-mix shotcrete. The silica fume forms studied were: uncompacted silica fume; compacted low density silica fume; compacted high density silica fume. This study demonstrated significant improvements in the adhesive and cohesive properties and thickness of build-up before sloughing on vertical and overhead surfaces for all forms of silica fume, when compared to a conventional portland cement wet-mix shotcrete. Various other physical properties of the shotcretes were evaluated. This study demonstrated that while there are some differences in the relative performance of shotcretes made with the 3 different forms of silica fume, all 3 forms can be used to produce high quality wet-mix shotcrete.