Wet sprayed concrete means delivery (handling) of a ready-mixed sprayed concrete consisting of aggregate, cement, water and sprayed concrete admixtures in a workable mix. For spraying, the wet sprayed concrete is mixed with air and shotcrete accelerators and then applied. The wet sprayed concrete can be processed by the dense-flow or the thin-flow method. Dense-flow sprayed concrete is the latest high-performance process.


Wet sprayed concrete is always used when high set concrete quality is specified and high output is required. This process is by far the most popular in mechanical tunneling. Ultimately the choice of process is also determined by the contractor’s preferences! The main applications of the wet sprayed concrete process are:

  • sprayed concrete works with high output capacity
  • substantially improved working conditions in the spraying area
  • higher durability due to controlled mixing water quantity

The advantages of the wet spraying process cover many different areas. Wet sprayed concrete is the more modern and efficient method.

  • increased spraying output, up to 25 m3/h in some cases
  • rebound level reduced by a factor of two to four
  • substantially improved working conditions due to less dust generation
  • reduced wear costs on the spraying equipment
  • low air requirement during spraying
  • higher quality installed sprayed concrete (constant water content)