Sika® Sigunit® L-1453 AF
ALKALI FREE LIQUID SHOTCRETE ACCELERATOR FOR WET OR DRY SHOTCRETE PROCESS
Sika® Sigunit® L-1453 AF is a high performance, liquid, alkali-free shotcrete accelerator.
- 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
Usage
Sika® Sigunit® L-1453 AF is suitable set accelerator for dry process as well as for wet process shotcretingThe 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-1453 AF 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
200/1000 L
Colour
Liquid / Yellowish
Product Details
Chemical base
Special inorganic substances in liquid form
Shelf life
6 months if stored properly in original unopened packaging
Storage conditions
Stored in cool and dry conditions, protected from direct sunlight
Density
1.36 – 1.46 kg/l
(At 20°C)
pH-Value
2.00 – 3.00
(At 25°C)
Concreting Guidance
Concrete temperature should not be lower than 15 deg.C (especially so for thick layers). Lower temperatures require higher dosages.
Specific Advice
Generally speaking, the accelerator will be added and mixed with the other concrete components as follows:
Dry process: Sika® Sigunit® L-1453 AF 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-1453 AF is supplied from the liquid dosing unit to the mixing tube assembly by means of air 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.
Application
DISPENSING
Sika® Sigunit® L-1453 AF is added thanks to suitable liquid dosing unit such as Aliva AL 403.4 (24-240 lt/h) or AL 403.5 (30-700 lt/h).
Suitable dosing unit type is determined according to cement content, spraying out-put and the accelerator dosage.
Restrictions
When using sulphate resistant cement, strength development may be slower
- Sika® Sigunit® L-1453 AF is not compatible with Sika® Sigunit® L-20/L-62
- Accelerator hoses must be throughly cleaned before using Sika® Sigunit® L-1453 AF
- Metal parts of the pump coming into contact with Sika® Sigunit® L-1453 AF must be stainless steel
- The set accelerating effect depends on cement content, cement age, cement type, temperature of shotcrete and substrate as well as on layer thickness and shotcreting method
A further efficiency parameter of Sika® Sigunit® L-1453 AF is the W/C ratio of the concrete mix in wet process or the quantity of water added at the nozzle in dry process
- Do not store under direct sunlight
- Sika® Sigunit® L-1453 AF is suspended solution. Stir the product well before use
Recommended Dosage
Accelerator dosage depends on many factors and actually should be adjusted as per the site conditions met.
It should not be fixed for one time at all!
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 4-6%. It would depend as well as on the type of application,
vertical (benches) spraying or over-head spraying.
The performance of the accelerator would depend on the cement type, content, age and quality, the W/C of the mix, temperature of the mix, the
substrate condition, etc.
As guide line, accelerator dosage – that need to be confirmed by site trial:
| PROCESS | REQUIREMENT | DOSAGE |
| Dry | Rebound reduction or vertical application | ~3% by weight of cement |
| Dry | Early strength or overhead application | 4-6% by weight of cement |
| Wet | Rebound reduction or vertical application | 4-5% by weight of cement |
| Wet | Early strength or overhead application | I5-6% by weight of cement |