Sika® Sigunit®-2770 AFL

Aluminium salts

4 months from date of production if stored in original, unopened, undamaged and sealed containers

• Protected from direct sunlight and frost and kept at temperatures between +5°C and +35°C.
• After prolonged storage the performance of Sigunit®-2770 AFL should be tested and the material should always be stirred up before using.
• Containers have to be cleaned before refilling. Containers must always be stored firmly closed.

1.37 kg/l

~ 3.0

48.0 +/- 3.0%

≤ 0.1%

≤ 1.0%

• Aggregate grading for pumped concrete: Usual mix with 8 mm max. aggregate size.
• The suitability of the proposed mix design must first be tested in field trials before commencement of the project.
• Concrete consistency (dependent on spraying equipment used): Flow table spread size ≥ 45 cm; w/c ratio ≤ 0.48
• The use of an appropriate superplasticiser (such as Sika® ViscoCrete® / SikaTard®) is essential.
• Temperature of fresh concrete: > +15°C

The following Sika® products are generally used for the basic shotcrete mix:

• Sika® ViscoCrete
• Sika® ViscoFlow
• SikaTard®-930
• SikaFume®

Dosage of Sigunit®-2770 AFL is by peristaltic pump such as the Sika® Aliva-403 pump. Optimized mixing with the concrete mix is also essential.

• If thicker layers of shotcrete are to be applied, ensure that the temperature of the basic concrete is not lower than +15°C. Lower temperatures require higher dosage of accelerator.
• The substrate must be clean, free of loose stones and free of water under hydrostatic pressure.
• The accelerator’s effect depends on the cement content, the age and type of cement, on the substrate and the shotcrete temperature as well as on the layer thickness and spraying process, quality of equipment and application technique. The w/c ratio of the basic concrete mix in the wet spraying process, and the quantity of gauging water in the dry spraying process are also parameters influencing the acceleration effect of Sigunit®-2770 AFL.
• When using sulphate resistant cements strength development can be slower. Sigunit®-2770 AFL is not compatible with alkaline shotcrete accelerators. Before using Sigunit®-2770 AFL the accelerator hoses must be cleaned thoroughly. The use of Sigunit®-2770 AFL requires technically correct dosing and conveying / spraying technology. Metal parts of the pump that come into direct contact with Sigunit®-2770 AFL must be made of stainless steel.
• Contact your local Sika company for any additional technical support required.

The correct dosage must be determined by preliminary testing. For layer thicknesses of up to 10 cm in one pass, dosage is between 4% and 8% of weight of binder.