Shotcrete

Definition

Shotcrete is the name used to refer to wet concrete that is pneumatically projected onto a prepared surface at high velocity through a nozzle. Applications for shotcrete in engineering geology tend to be cut slopes that are marginally stable or that will tend to degrade with time by sloughing, slaking, or raveling. The surface on which the shotcrete will be applied needs to be prepared with drainage for positive relief of hydrostatic pressures and reinforcing steel bars or mesh, if needed. Steel fibers may be added to the shotcrete mix for reinforcement in lieu of applying reinforcing steel bars or mesh.

The wet concrete mix design must meet certain specifications and be deliverable at high velocity through a nozzle (Morgan and Totten 2008). Cementing materials are Portland cement plus optional fly ash and silica fume additives. Water must meet drinking water standards. Mineral aggregates must be normal weight and meet the durability and alkali reactivity requirements for...