Sika ViscoFlow-6262 NS
A modified-polycarboxylate superplasticiser engineered to hold slump over long haul and pump times without piling on retarder or losing early strength.
What is it?
A ready-to-use PCE (polycarboxylate ether) superplasticiser supplied as a brown hazy liquid, designed specifically for extended workability retention in concrete.
Where is it used?
Ready-mix plants, long-haul deliveries, high-rise and pumped pours, and hot-weather concreting across Delhi NCR and pan-India projects.
Why use it?
It keeps concrete flowing and placeable for a long window without extra retardation, so mixes reach site workable and still gain early strength on schedule.
How is it applied?
Dosed at 0.2-2.0% by weight of cementitious material, added to the mixing water or into the mixer after 50-70% of the water is in, then mixed for at least 60 seconds.
About Sika ViscoFlow-6262 NS
Sika ViscoFlow-6262 NS belongs to Sika’s ViscoFlow family of slump-retaining admixtures, built around a modified polycarboxylate polymer that works differently from a conventional superplasticiser. Instead of dispersing all the cement grains at once and then losing effect as the mix stiffens, its polymers release their water-reducing action gradually over time. The practical result is concrete that stays workable and cohesive through long transit and waiting periods, which is exactly the problem ready-mix suppliers face when a truck sits in Delhi traffic or a pour runs longer than planned.
Because the retention comes from the polymer chemistry rather than from added retarder, the mix does not pay for extended workability with delayed setting or a soft first day. That distinction matters on jobs where the schedule depends on early strength for stripping, stressing or a fast pour cycle. Space Arc Engineering supplies this product to RMC plants, contractors and consultants who need dependable placeability at the far end of a haul or a pump line, backed by application support for trial dosing and mix optimisation.
The technical insight
The mechanism is time-controlled water reduction. A standard PCE adsorbs onto cement particles immediately, creating steric (physical) separation that frees trapped water and gives high initial flow, but that dispersing force fades as hydration proceeds and slump drops away. ViscoFlow-6262 NS uses a modified polycarboxylate architecture that keeps a reservoir of polymer available and lets it become active progressively as the mix ages. So fresh flow is generated continuously rather than front-loaded, and the slump curve stays flat where an ordinary superplasticiser would fall off. Critically, this is achieved without a retarding admixture in the system, which is why early strength development and setting behaviour are preserved. The same gradual-dispersion effect improves particle distribution and cohesion, reducing bleed and segregation and helping cut drying shrinkage in the hardened concrete.
Where it is used
- Ready-mix concrete requiring extended transport and delivery windows
- Pumped concrete for high-rise and long horizontal runs
- Hot-weather concreting where slump loss is accelerated
- Heavily reinforced sections needing cohesive, free-flowing placement
- Large-volume pours where the placing period is prolonged
- Concrete across a wide range of high or low water-cement ratios
- Mixes using different cements and supplementary cementitious materials
- Projects combining long haul with a demand for early strength gain
Key advantages
- Long slump-flow retention without adding a retarder to the mix
- Early strength development is preserved, protecting stripping and cycle times
- Improved cement dispersion for cohesive, free-flowing concrete
- Reduced drying shrinkage and enhanced durability of the hardened concrete
- Effective across wide water-cement ratios and ambient temperature ranges
- Compatible with all common cements and cementitious materials
- Complies with IS 9103 and ASTM C494 for admixture performance
- Water-based liquid, straightforward to dispense at the batching plant
Limitations & considerations
- Retention performance is dosage- and mix-sensitive; trials are needed to set the right rate for each mix design
- Overdosing beyond the recommended range can promote bleeding or delayed set and should be done only with consultant approval
- It is a workability-retention admixture, not an air-entrainer, accelerator or waterproofer, and does not replace those functions
- Supplied mainly in 255 kg drums or bulk, which suits plant use more than small site quantities
- Needs storage between +10C and +40C, protected from sunlight and frost, to hold its 12-month shelf life
- Performance depends on correct addition timing and adequate mixing, so batching discipline is essential
Selection & best practice
Add the admixture to the mixing water, or dose it into the mixer once 50-70% of the mixing water has been charged, and never onto dry cement. Mix for at least 60 seconds after adding to allow the polymer to disperse fully. Always establish the working dose within the 0.2-2.0% band through site trials on the actual mix, ambient temperature and haul time, since these govern how much retention you need; go above the range only with the consultant’s written approval. Keep drums sealed and stored between +10C and +40C, away from direct sunlight and frost, and consult the current safety data sheet for handling. For best results, treat the admixture as one input in a validated mix design rather than a field top-up.
Specifications
| Chemical base | Aqueous solution of modified polycarboxylate (PCE) |
| Appearance | Brown hazy liquid |
| Density | ~1.08 kg/l at 25C |
| pH | greater than or equal to 6 |
| Recommended dosage | 0.2 – 2.0% by weight of cementitious material |
| Standards | IS 9103 and ASTM C494 |
| Packaging | 255 kg drums or bulk supply |
| Storage | +10C to +40C, protected from sunlight and frost |
| Shelf life | 12 months in unopened, undamaged original packaging |
Industry use cases
Ready-Mix Concrete (RMC)
Holds slump through long urban hauls and dispatch queues so concrete arrives on site workable and pumpable rather than needing rejection or field water addition.
High-Rise Construction
Maintains flow and cohesion through tall vertical pump runs, supporting continuous placement in reinforced columns, cores and walls.
Infrastructure and Large Pours
Extends the placing window on rafts, foundations and mass pours where the operation runs for hours without allowing the leading concrete to stiffen.
Hot-Weather Regions
Counters accelerated slump loss in high ambient temperatures across northern and central India, keeping mixes placeable without over-retarding the set.
Precast and Fast-Cycle Work
Delivers extended workability while preserving early strength, so long placing times do not push out stripping or the production cycle.
Frequently asked questions
How is ViscoFlow-6262 NS different from a normal superplasticiser?
Does the long workability come from added retarder?
What dosage should we use?
How and when do we add it to the mix?
Is it approved to relevant standards?
How is it supplied and stored?
How we position Sika ViscoFlow-6262 NS
Within the Sika range, ViscoFlow-6262 NS is the slump-retention specialist; where a mix needs sharp initial water reduction and high early strength rather than a long open time, a standard Sika Sikament or SikaPlast high-range water reducer is the more direct fit, and the sister grades in the Sika ViscoFlow line offer different retention profiles for shorter or longer haul times. For clients standardised on other brands we stock, the Fosroc Auramix and Conplast admixture ranges and MC-Bauchemie’s MC-PowerFlow PCE plasticisers cover comparable ground. Space Arc can help match the right admixture to your haul time, temperature and strength requirement rather than defaulting to one product.
Fosroc Auramix 400 — Choose the Fosroc Auramix 400 when the project is specified on Fosroc admixtures or needs a PCE high-range water reducer geared to self-compacting and pumped concrete with extended workability.
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