Product Data Sheet Show all documents

Sika® Sigunit® SA 545

(former MasterRoc® SA 545)

Alkali-free, non-caustic and non-toxic high performance powder accelerator for dry-mix sprayed concrete

Sika® Sigunit® SA 545 is a high-performance alkali-free, non-caustic and non-toxic accelerator for use in the dry-mix sprayed concrete process. It is a powder additive whose dosage can be varied to the desired setting and hardening times.

  • Overhead layer thickness of 10-15 cm in a singleapplication
  • Rapid work process
  • Good early strength development
  • Limits the decrease of final strength
  • Improves durability as compared to mixes withtraditional accelerators
  • Provides an improved working environment
  • Reduces salt content in leaching water
Product Data Sheet Show all documents

Usage

Sika® Sigunit® SA 545 is suitable for all applications where high early strength, high final strength and very thick sprayed concrete layers are required.
  • For temporary and permanent ground support in tunneling and mining
  • Slope stabilization
  • For repair works
 

Advantages

  • Overhead layer thickness of 10-15 cm in a singleapplication
  • Rapid work process
  • Good early strength development
  • Limits the decrease of final strength
  • Improves durability as compared to mixes withtraditional accelerators
  • Provides an improved working environment
  • Reduces salt content in leaching water

Packaging

Sika® Sigunit® SA 545 is supplied in 20 kg bags.

Colour

White powder

Product Details

Product Information

Shelf Life

If stored dry and in tightly closed original bags, Sika® Sigunit® SA 545 has a shelf life of 12 months.

Storage Conditions

If subjected to humidity, the product loses its effectiveness. Any lumps can simply be crushed by hand. Material which is too hard must be discarded.

Bulk Density

1030 – 1100 kg/m3

pH-Value

4 ± 1

Total Chloride Ion Content

< 0.1%

 
Technical Information

Concreting Guidance

The substrate must be clean and free from loose particles and preferably damp.
It is recommended to only use fresh cement as the age of the cement can have a negative influence on the setting characteristics of the mix.


Sika® Sigunit® SA 545 is sensitive to the type of cement. With some cements the obtained setting characteristics can be too slow. This sensitivity can be compensated by reducing the water content. We recommend the use of Portland cements (PC/HPC), which normally give faster setting than blended or sulphate resistant cement types.
In any case, it is strongly recommended to carry out preliminary tests to check the setting and the 24 hour strength characteristics of the cements planned for use in a project.
Evaluation of setting and 24 hour strength characteristics:


Initial set           Final set           24h Strength          Rating
2 min.                  6-8min.            18-20 MPa              Good
5 min.                  8-12 min.         12-15 MPa              OK

>10 min.              >15 min.           <10 MPa                poor

Concrete Mix Design

The minimum cement content with the use of Sika® Sigunit® SA 545 is 350 kg per m³. It is normally added to the mix immediately prior to use.


A combination of Sika® Sigunit® SA 545 and SikaTard HCA 10 hydration control admixture prolongs the open time of the mix.

  • Dosage: 0.4% by weight of binder of SikaTard HCA10 at ambient temperatures of >20°C.
  • At ambient temperatures between +15°C and +20°C only 0.2% by weight of binder should be used.
  • Below +15°C SikaTard HCA 10 should not be used at all.

Application

Consumption

Consumption

The consumption of Sika® Sigunit® SA 545 also depends on the water added, temperature conditions (dry mix and ambient), cement reactivity and on required layer thickness, setting time and early strength development. The consumption is normally in the range of 4 to 8% of binder weight.
Overdosing (>10%) may result in decreased final strength.

 

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