The current use of sprayed concrete
Due to its flexibility, rapid application and cost effectiveness, sprayed concrete is widely used in building constructions, public works, building pits, tunneling etc., that is, throughout the entire building industry. It is largely used as part of the excavation support of slopes, trenches, building pits, tunnels and other underground structures in different sectors (e.g. railways, roads, hydropower, mining etc.) and under diverse ground conditions, as well as in the rehabilitation of old underground structures. Further use of sprayed concrete can be found in canal lining, the construction of sea walls and refractory walls, fire and corrosion protection, plastering and stabilizing brick walls etc.
Figure 1-8: Application of sprayed concrete underneath pipe roof umbrella to construct a tunnel lining
Today, the most relevant areas of use of sprayed concrete are tunneling, mining and concrete rehabilitation. In the tunneling and mining sectors, sprayed concrete has been used both as initial excavation support (mostly seen as temporary tunnel lining) as well as for permanent tunnel lining. Sprayed concrete has become indispensable in the modern design approach for the concrete lining of tunnels, which treats the sprayed concrete lining as a permanent structure, e.g. single shell lining (SSL) and composite shell lining (CSL). The latter includes a sprayapplied waterproofing membrane.