Shotcrete accelerators are used for high early strength requirements.  Early setting of the shotcrete lining is critical in order to enable rapid underground development with short cycle times. Sigunit® accelerators solutions are available as liquid and powder solutions to suit challenging logistics and different operational requirements.

What are the types of accelerators?

Each situation requires specific solutions and therefore different types of accelerators. Hence, Sika provides a broad range of Sigunit® products that cover all of these requirements and specific challenges. There are alkaline- and alkali-free products, powders and liquids, as well as the instant products developed for just-in-time, on-site production.


In modern tunneling and mining, the choice of the best set accelerator for a particular project rests upon a number of key arguments:

  • Compressive Strength: when the objective is to reach the highest final strength, alkali-free accelerators are the best choice.
  • Rebound: The compressive strength development of alkali-free accelerators is moderate in the early phases of spraying which can be very advantageous as it will reduce rebound.
  • Leaching: Alkali-free set accelerators do not introduce additional alkalis into the sprayed concrete mix, which greatly reduces leaching. 
  • EHS: The alternative use of alkali-free products prevents the risk of this type of accident or injuries and eliminates the danger of polluting rebound waste with alkalis.

Products in the Sigunit®-P10 AF instant powder range are designed for the on-site production of liquid alkali-free accelerators for sprayed concrete. These Sigunit® instant powders are ideally suited for use in medium and large remote mine and tunnel construction projects and are particularly suitable for very cold or warm conditions where other liquid accelerators have a shortened shelf life due to the risk of freezing and separation.

  • High Volume Availability: Due to the long shelf life of the powder and the simple on-site production process.
  • Extended Shelf Life: Even under extreme conditions, the powder itself has a much longer shelf life than any liquid accelerator (more than three (3) years).
  • Adjustable Performance: The accelerating effect of the solution can easily be adjusted by adding more powder.