Fosroc Auracast 550HE
A new-generation polycarboxylate superplasticiser engineered for the precast and pre-stressed concrete industry, combining high water reduction, low viscosity and built-in hydration acceleration for faster mould turnaround.
What is it?
A high-range water-reducing (superplasticising) concrete admixture based on new-generation polycarboxylate ether (PCE) polymers blended with hydration accelerators, giving high workability plus early strength gain in a single dose.
Where is it used?
Precast and pre-stressed concrete factories, self-compacting concrete (SCC) production, high-strength/low water-cement ratio mixes, and any plant chasing faster mould turnaround and demoulding cycles.
Why use it?
It delivers more than 12% water reduction, low-viscosity flowable concrete, and accelerated early strength so elements can be demoulded and de-tensioned sooner, lifting plant throughput without sacrificing late-age strength or finish.
How is it applied?
Dosed at the batching plant at 0.5 to 1.6 litres per 100 kg of cementitious content, added with the latter part of the mixing water via a calibrated dispenser; never premixed with other admixtures.
About Fosroc Auracast 550HE
Fosroc Auracast 550 HE sits at the high-performance end of Fosroc’s Auracast superplasticiser range and is built specifically around the economics of a precast yard. It is a unique combination of new-generation polycarboxylate ether (PCE) polymers and hydration accelerators that together give excellent cement dispersion, low plastic viscosity and accelerated early strength development. In a precast or pre-stressed plant, the bottleneck is rarely the 28-day strength of the concrete; it is how quickly a mould or bed can be cleared and re-used. Auracast 550 HE attacks exactly that problem by combining the water reduction of a modern superplasticiser with an in-built acceleration of the hydration reaction, so transfer strength is reached sooner and the casting cycle tightens. For Indian precast operators, segmental bridge yards, sleeper plants, pre-stressed plank and hollow-core lines, and SCC producers, that translates directly into more units off a fixed asset base each day. The product is chloride-free, making it suitable for reinforced and pre-stressed elements where embedded steel must be protected. It is supplied ready-to-use as an amber liquid and is added at the batching plant, requiring no on-site mixing or dilution. Because Space Arc Engineering is an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India, the material is available with genuine batch documentation, technical back-up and trial-mix support so a plant can validate dosage against its own cements and aggregates before committing to production.
The technical insight
The defining characteristic of Auracast 550 HE is that it is a dual-function admixture, not simply a water reducer. The polycarboxylate backbone works by steric hindrance: long side-chains graft onto cement particles and physically push them apart, releasing trapped water and de-flocculating the paste. This gives the >12% water reduction and the low-viscosity, self-levelling rheology that makes it ideal for self-compacting concrete with no bleeding or segregation. Layered onto this is a hydration-accelerating component that drives faster early strength gain rather than the strength retardation often seen when high superplasticiser doses are pushed. The result is a mix that is highly flowable at low water-cement ratio yet still reaches transfer/demoulding strength quickly. Per the EN 934-2 declaration, the product meets Table 3.1 and 3.2 requirements for high-range water-reducing/superplasticising admixtures, with increase of consistence greater than 120 mm from initial slump (or greater than 160 mm from initial flow) and consistence retention at 30 minutes exceeding the reference mix. Fosroc also highlights robustness: the formulation is less sensitive to aggregate and moisture fluctuations and to changes in cement source and type, which matters in India where cement chemistry varies between OPC, PPC, PSC and blended binders. It is compatible with GGBS, PFA, limestone filler and micro silica, so it suits low-clinker, lower-carbon mix designs. Critically, optimum dosage must be established by trial mixes using the actual site materials, because PCE response is mix-specific.
Where it is used
- Precast concrete elements requiring high workability for easy mould filling around dense reinforcement
- Pre-stressed concrete (railway sleepers, beams, planks, hollow-core slabs) needing rapid transfer strength
- Self-compacting concrete (SCC) production with no bleeding or segregation
- High-strength, low water-cement ratio structural concrete
- Segmental and bridge-girder precast yards chasing faster mould turnaround
- Architectural and visual precast where improved surface finish is required
- Plants running blended cements (GGBS, PFA, micro silica) needing a robust, source-tolerant admixture
Key advantages
- High water reduction (>12% vs reference mix) at a high range, enabling low W/C high-strength concrete
- Built-in hydration acceleration for superb early strength and faster demoulding/de-tensioning
- Low plastic viscosity producing easily placed, self-compacting flow
- Reduced workability loss and good consistence retention at 30 minutes
- Reduced risk of bleeding and segregation, even in SCC
- Robust, consistent performance across different cement sources, types and moisture conditions
- Chloride-free, so safe for reinforced and pre-stressed concrete with embedded steel
- Improved surface finish and faster mould turnaround, raising plant productivity
- Water-based and non-flammable; ready for direct addition at the batching plant
Limitations & considerations
- Optimum dosage is mix-specific and must be confirmed by trial mixes with actual site materials; values cannot simply be copied between plants
- Overdosing above 1.6 L/100 kg can promote segregation and excessive bleeding and may actually impair high early strength performance
- Engineered for precast/pre-stressed and SCC; it is not the most economical choice for routine general-purpose ready-mix where a mid-range Auramix product may suffice
- Must never be premixed with other admixtures before addition to the concrete
- Requires accurate dispensing equipment; manual or uncalibrated dosing risks variability
- Performance and shelf life depend on storage between 2 C and 50 C; frozen product needs full thawing and thorough agitation before use
- As a high-cement-efficiency PCE, mix designs running very low water content need careful control to avoid loss of cohesion
Selection & best practice
Always establish the working dose through laboratory and plant trial mixes using your actual cement, supplementary cementitious materials and aggregates, starting near the lower end of the 0.5-1.6 L/100 kg range and increasing only as needed for target flow and transfer strength. Add Auracast 550 HE with the latter part of the mixing water through a calibrated, dedicated dispenser, never premixed with other admixtures. Validate transfer/demoulding strength on trial cubes before locking in the casting cycle, and recheck dosage whenever the cement source, blend or aggregate moisture changes. Store sealed containers between 2 C and 50 C, use within the 12-month shelf life, and thoroughly agitate any product that has thawed after freezing before dosing.
Specifications
| Product type | High-range water-reducing / superplasticising admixture (polycarboxylate PCE based) with hydration accelerator |
| Appearance | Amber liquid |
| Specific gravity | 1.07 +/- 0.02 |
| pH | 5 +/- 1 |
| Chloride content | <= 0.1% by mass (chloride-free) |
| Alkali content | <= 2.0% by mass |
| Typical dosage | 0.5 to 1.6 litres per 100 kg of cementitious content |
| Water reduction | > 12% compared with reference mix |
| Increase of consistence | > 120 mm from initial slump or > 160 mm from initial flow |
| Standard compliance | EN 934-2: Table 3.1 and 3.2 (high range water reducing / superplasticising); DoP UK9-175, 0086-CPR-473151 |
| Cement compatibility | All Portland cements plus GGBS, PFA, limestone filler, micro silica and other SCMs |
| Fire / safety | Water-based and non-flammable |
| Packaging | 1000 L IBCs and 200 L / 20 L drums |
| Shelf life | Minimum 12 months stored at 2 C to 50 C |
Industry use cases
Precast manufacturing
Producing high-workability concrete that fills moulds easily around congested reinforcement, reducing labour and compaction effort while improving surface finish on visual precast units.
Railways / pre-stressed
Casting pre-stressed sleepers, beams and planks where rapid early strength allows earlier de-tensioning and faster bed turnaround on high-volume production lines.
Infrastructure / bridges
Segmental and girder precast yards using low W/C, high-strength concrete that demoulds quickly to keep moulds and casting beds in continuous rotation.
Ready-mix SCC
Producing self-compacting concrete for heavily reinforced or architectural pours with no bleeding or segregation and reliable consistence retention.
Low-carbon concrete
Enabling blended-cement mixes with GGBS, PFA or micro silica to remain highly workable at low water content, supporting durability and reduced clinker factor.
Frequently asked questions
What type of admixture is Fosroc Auracast 550 HE?
What is the recommended dosage?
Is Auracast 550 HE suitable for pre-stressed and reinforced concrete?
Which standards does it comply with?
How is it supplied and stored?
How does it differ from a standard Auramix superplasticiser?
How we position Fosroc Auracast 550HE
Within Fosroc’s portfolio, Auracast 550 HE is the high-early-strength specialist of the precast-focused Auracast PCE family, sitting alongside related grades such as Auracast 550 SM and Auracast 550 XP, and the broader Auracast 50, 100, 200, 270M and 405 superplasticisers. Where a project is general-purpose ready-mix rather than precast, Fosroc’s Auramix range (for example Auramix 500) or Conplast water reducers are usually the more economical fit; Auracast 550 HE earns its place specifically where rapid demoulding, pre-stress transfer and SCC quality are the priorities. Against the wider Indian market, credible PCE alternatives in the same high-early-strength precast niche include Sika’s ViscoCrete range, BASF/Master Builders Solutions MasterGlenium admixtures, and offerings from Dr. Fixit (Pidilite) and STP. Buyers typically benchmark these on trial-mix performance with their own cements, transfer-strength timing and total cost per cubic metre rather than headline price. As an authorised Fosroc distributor and applicator serving Delhi NCR and Pan-India, Space Arc Engineering supplies genuine Auracast 550 HE with batch traceability and provides trial-mix and dosing support so plants can validate the product against their existing mix designs before scaling to production.
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