Tens of thousands of tons of silica-fume shotcrete have been used in Western Canada in the past few years. It has been used for tunnel lining, rock slope stabilization, and structural rehabilitation. Why is it so popular? For several reasons: Running water or rising tides do not wash out freshly applied silica-fume shotcrete. Compared to plain shotcrete, much thicker layers can be applied in one pass. The material adheres better in wet areas and creates less rebound. The compressive strength of hardened shotcrete is increased and its permeability is reduced, both of which make the material more durable.