Sprayed concrete mix… with a compressive strength of 40MPa: Material Volume Cement 540kg/m3 Natural aggregates from river, dmax= 8mm 1467kg/m3 Silica 60kg/m3 Steel fibre 60kg//m3 Additives: Pozzolith 322R 3 litre/m3 Reobuild 1000R 6 litre/m3 Water 280 litre/m3 w/c ratio 0.52 Accelerator – Sodium Aluminate Approximately 25%