3.3 Primary Shotcrete protection

•The primary stabilisation of the tunnel excavation is achieved by shotcrete.

•The shotcrete stabilises the excavated rock surface by filling the cracks produced in the rocks

•Primary shotcrete consists of M40A10 grade concrete. The shotcrete is sprayed throughout the excavation with the help of a computer operated machine called MYCO POTENZA.

•Along with shotcrete, an accelerator admixture is pumped so as to harden the shotcrete concrete immediately.

•If accelerator is not used, the shotcrete may not stick to the excavated surface.

•The accelerator commonly used is Sodium Silicate.

•The quantity of accelerator is kept 7% of the volume of shotcrete.

MYCO potenza for Shotcreting