Product Data Sheet Show all documents

Sika ViscoFlow®-21 AU

WORKABILITY-ENHANCING ADMIXTURE

Sika ViscoFlow®-21 AU is a workability-enhancing admixture for use in various concrete applications (slump-keeper).

Sika ViscoFlow®-21 AU is a unique concrete admixture used to improve the workability and slump retention
of fresh concrete. Sika ViscoFlow®-21 AU uses innovative polycarboxylate polymer technology, which can be
used in various concrete applications whenever extended slump retention and concrete plasticity without
set time delay is required.  
Use of Sika ViscoFlow®-21 AU delivers the following benefits to a concrete producer:
  • Extended slump retention without excessive retardation.
  • No need for concrete re-tempering.
  • Better ability to optimize concrete mix designs resulting in cost savings.
  • Ability to adjust slump retention to match transport time and temperature.
  • No deleterious effect on concrete shrinkage.
  • Enhanced early and final strength.
  • Reduced rejection rates due to issues related to concrete re-tempering.
Product Data Sheet Show all documents

Usage

Sika ViscoFlow®-21 AU can be used in conventional, high slump or Self-Compacting Concrete, in precast/prestressed or ready mix applications, or in any application where extended concrete plasticity without excessive retardation is required. Sika ViscoFlow®-21 AU does not extend slump life through slowing down the hydration process of cement. Besides the slump-retaining effect Sika ViscoFlow®-21 AU also offers a minimal water reducing effect, resulting in a lower dosage rate for the primary water reducer in the concrete mix. Sika ViscoFlow®-21 AU can be used as a stand-alone admixture or in combination with other Sika concrete admixtures.

Advantages

Sika ViscoFlow®-21 AU is a unique concrete admixture used to improve the workability and slump retention
of fresh concrete. Sika ViscoFlow®-21 AU uses innovative polycarboxylate polymer technology, which can be
used in various concrete applications whenever extended slump retention and concrete plasticity without
set time delay is required.  
Use of Sika ViscoFlow®-21 AU delivers the following benefits to a concrete producer:
  • Extended slump retention without excessive retardation.
  • No need for concrete re-tempering.
  • Better ability to optimize concrete mix designs resulting in cost savings.
  • Ability to adjust slump retention to match transport time and temperature.
  • No deleterious effect on concrete shrinkage.
  • Enhanced early and final strength.
  • Reduced rejection rates due to issues related to concrete re-tempering.

Packaging

Bulk deliveries
1000 litre IBC

Colour

Colourless clear liquid

Product Details

Sustainability / Certifications / Approvals

CERTIFICATES AND TEST REPORTS

Sika ViscoFlow®-21 AU meets the requirements of AS1478.1-2000 for Special Purpose Admixture Type (SN).
Product Information

Composition

Aqueous solution of selected modified polycarboxylates

Shelf life

Stored at temperatures between 5°C and 35°C in unopened original containers protected from direct sunlight, shelf life is 12 months.

Storage conditions

Store at temperature between 5°C and 35°C, protected from the direct sunlight and frost.

Density

1.05 kg/l

Application

Application Information

Dispensing

For maximum efficiency, add Sika ViscoFlow®-21 AU directly to freshly mixed concrete in the concrete mixer after all batching water and water reducing admixture has been added.

Sika ViscoFlow®-21 AU may also be dispensed into freshly mixed concrete in the agitator truck, at the concrete plant or at the job site.

To optimize the slump retaining effect, Sika recommends that the combined materials should be mixed for 80-100 revolutions either in the concrete mixer or in the agitator truck.

Compatibility

Sika ViscoFlow®-21 AU can be used in conjunction with all the Sika Concrete admixtures with the exclusion of Sikament NN.
All admixtures must be added separately.
Consumption

Recommended dosage

Sika ViscoFlow®-21 AU recommended dosage is 200 ml to 1000 ml per 100kg of total cementitious material.
Optimum dosage should be determined by site trials.

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