Product Data Sheet
Show all documents

Sika® Sigunit® L-53 MY

Alkali Free Liquid Shotcrete Accelerator For Wet or Dry Shotcrete Process

Sika® Sigunit® L-53 MY is a high performance, liquid, alkali-free shotcrete accelerator.

Sika® Sigunit® L-53 MY provides the following benefits:
  • Alkali free (non-caustic) and classified as non-toxic product
  • Fast to very fast setting of shotcrete mixes according to dosage used
  • No strength loss of the accelerated concrete if used correctly
  • No additional contamination of mountain and ground water due to washed out alkalis
  • Large reduction in rebound as long as the spraying is performed according to the state of the art
  • Improves bond of shotcrete to rock and concrete, making overhead spray easier
  • Free of chlorides, no danger to steel reinforcement and steel fibers
Product Data Sheet
Show all documents

Usage

Sika® Sigunit® L-53 MY is suitable set accelerator for dry–process as well as for wet process shotcreting. The main fields of applications are:
  • Securing of rock in tunnel and mine construction (preliminary support)
  • Rock and slope stabilization
  • Dewatering work by dry process
  • High quality shotcrete for permanent support by shotcrete
 

Advantages

Sika® Sigunit® L-53 MY provides the following benefits:
  • Alkali free (non-caustic) and classified as non-toxic product
  • Fast to very fast setting of shotcrete mixes according to dosage used
  • No strength loss of the accelerated concrete if used correctly
  • No additional contamination of mountain and ground water due to washed out alkalis
  • Large reduction in rebound as long as the spraying is performed according to the state of the art
  • Improves bond of shotcrete to rock and concrete, making overhead spray easier
  • Free of chlorides, no danger to steel reinforcement and steel fibers

Packaging

1 000 L drum

Colour

White milky to grey milky liquid.

Product Details

Product Information

Shelf Life

3 months from date of production If stored properly in undamaged, original, sealed packaging.

Storage Conditions

Store in a cool, dry place. Protected from direct sunlight.

Density

1.41 ± 0.05 kg/l (at temperature 25 °C)

pH-Value

~3.0–4.0

Application

Application Information

DISPENSING

Sika® Sigunit® L-53 MY is added to the shotcrete mix using suitable liquid dosing unit such as Aliva AL 403.4 (24–240 lt/h) or AL 403.5 (30–700 lt/h).

The parameters for determining a suitable dozing unit are the cement content, spraying out-put and the accelerator dosage.
Consumption

Recommended Dosage

Accelerator dosage depends on many factors and should be adjusted to suit site conditions, including changes in the cement, aggregates and mix designs or when additives (flyash and/or GGBS) are added.
Accelerator dosage should not be fixed permanently!

 

The dosage of the accelerator would vary according to the scope of work. Typically, if the reduction of the rebound (without early strength) is required the dosage would be 2–4 %. If early strength is required, dosage would be 4–8 %. It would depend as well as on the type of application, vertical (benches) spraying or over-head spraying.

The performance of the accelerator is associated with the type of cement, age of cement, content of cement per cubic meter, quality of the cement, water-cement ratio, temperature of the concrete, substrate condition, etc.

As a guideline, the recommended dosages are as follows (subject to confirmation by conducting site trials):

Process

Requirement

Dosage

Dry

Rebound reduction or vertical application

~3 % by weight of cement/binder

Dry

Early Strength or overhead application

4–6 % by weight of cement/binder

Wet

Rebound reduction or vertical application

4–6 % by weight of cement/binder

Wet

Early Strength or overhead application

6–8 % by weight of cement/binder

Concrete temperature should not be lower than 15 °C (especially for thick layers application). Lower concrete temperatures require higher dosages.
Application steps

APPLICATION INSTRUCTIONS

The accelerator shall be added and mixed with the other concrete components as follows:

Dry Process

Sika® Sigunit® L-53 MY is supplied from the liquid dosing unit to the mixing tube assembly by means of water under pressure (2–3 bars more than the conveying pressure). The mixing tube assembly being located ~2.5 meters behind the nozzle or at the nozzle directly.

Wet Process

Sika® Sigunit® L-53 MY is supplied from the liquid dosing unit to the mixing tube assembly by means of pressurised air (2–3 bars more than the conveying pressure). The mixing tube assembly being located ~2.5 meters behind the nozzle or at the nozzle directly.

Documents