Definition
Shotcrete is a form of spray-applied concrete where wet-mix concrete or mortar is pumped through a hose and pneumatically projected onto a surface at high velocity for repair, strengthening, or new construction.
Explanation
In the wet-mix process, all ingredients including water are mixed before pumping to the nozzle. Compressed air is then used to propel the material onto the substrate. This method allows dense compaction, strong adhesion, and efficient application on vertical and overhead surfaces.
Shotcrete is widely used for structural repairs to bridges, tunnels, retaining walls, car parks, basements, and marine structures. It is also common in concrete jacketing and section enlargement where additional structural capacity is required.
Successful application depends on thorough substrate preparation, removal of defective concrete, reinforcement cleaning, and correct curing after placement. Skilled nozzle operation is critical to minimise rebound and ensure consistent material quality.
Why It Matters
Shotcrete provides a fast and effective method for large-scale structural repair where conventional formwork is impractical. It supports durable reinstatement and helps restore strength, cover, and long-term service life.