Product Data Sheet Show all documents

Sika® Sigunit® SA 540

(former MasterRoc® SA 540)

Alkali-free, high performance powder accelerator for dry-mix shotcrete

Sika® Sigunit® SA 540 is a high performance alkali- free, non caustic and non toxic accelerator for the use in dry-mix shotcrete processes. It is a powder additive whose dos-age can be varied to the desired setting and hardening times.

The quick setting properties allow:
  • Overhead layer thicknesses of 100-150 mm in a single application.
  • Rapid work progress
The unique formula
  • Provides good early strength development.
  • Limits the decrease of final strength
  • Improves durability as compared to mixes with traditional accelerators
The non-caustic and nontoxic nature of the product:
  • Prevents skin burns and provides an improved working environment.
  • Reduces required handling precautions and hence improves economy.
  • Reduces salt content in leaching water.
Product Data Sheet Show all documents

Usage

Sika® Sigunit® SA 540 is suitable for all applications, where high early strength, high final strength and large thick-ness are required.
  • For temporary and permanent rock support
  • For Final lining (one pass lining)
  • For repair works
  • In tunnels
  • In mining  

Advantages

The quick setting properties allow:
  • Overhead layer thicknesses of 100-150 mm in a single application.
  • Rapid work progress
The unique formula
  • Provides good early strength development.
  • Limits the decrease of final strength
  • Improves durability as compared to mixes with traditional accelerators
The non-caustic and nontoxic nature of the product:
  • Prevents skin burns and provides an improved working environment.
  • Reduces required handling precautions and hence improves economy.
  • Reduces salt content in leaching water.

Packaging

20 kg bag

Colour

White Powder

Product Details

Product Information

Shelf Life

12 months from date of production if stored in unopened, undamaged and original sealed packaging.

Storage Conditions

Store under cover out of direct sunlight and protect from extremes of temperature. In tropical climates the product must be stored in an air-conditioned environment.

Bulk Density

500 – 700 kg/ m3

Total Chloride Ion Content

< 0.1%

Application

Consumption

Recommended Dosage

Depending on the required setting time and early strength requirements dosage of Sika® Sigunit® SA 540 will normally be in the range of 2-6% of cement weight. Over dosing, in excess of 10% will lead to lower final strengths. On site trails are recommended prior to use.

Consumption

The consumption of Sika® Sigunit® SA 540 depends on the temperature of concrete, air, substrate and reactivity of the cement being used.
Application steps

SUBSTRATE PREPARATION

The substrate must be clean and free from loose parti-cles and only lightly sprinkled.

MIXING

The minimum cement content with the use of Sika® Sigunit® SA 540 is 350 kg/m3 preferably it should be 400kg/m3. Sika® Sigunit® SA 540 is added to the mix immediately prior to use.

APPLICATION

Sensitivity to cement
Age: It is recommended to only use fresh cement since the age of the cement can have a negative influence on the setting characteristics of the mix.
Type:Sika® Sigunit® SA 540 is sensitive to the type of cement. With some cements the obtained setting characteristics can be too slow. This sensitivity can be compensated by lowering the W/C ratio. We recommend the use of OPC (Ordinary Portland Cement) or RHPC (Rapid Hardening Portland Cement) which will normally give faster setting characteristics than Blended Cements or SRC (Sulphate Resistant Cement).
In any case, it is strongly recommended to do preliminary tests to check the setting time and the 24 hour strength characteristics of the cement type used in the project.

 


Evaluation of setting and 24 hour strength characteristics:

Initial setFinal set24 h StrengthRating
2 min.6-8 min.18-20 MPaGood
5 min.8-12 min.12-15 MPaOK
>10 min.>15 min.<10 MPaPoor

Remarks: if the setting times are poor, the 24 hour strength is usually good. With a slow setting it is possible to apply 50-70mm on the vertical and 30- 50mm over-head.

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