Fosroc Auracast 220A
Polycarboxylate (PCE) accelerating superplasticiser engineered for precast concrete, SCC and fast mould turnaround — chloride-free, EN 934-2 compliant, with high early strength.
What is it?
A ready-to-use, water-based polycarboxylate ether (PCE) admixture that combines high-range water reduction with cement-hydration acceleration in a single product. It is an amber liquid (SG 1.085) dosed at the batching plant, classified under EN 934-2 Tables 3.1 and 3.2 as a high-range water-reducing / superplasticising admixture.
Where is it used?
Primarily precast and prestressed yards, paver and block plants, and any plant producing Self-Compacting Concrete (SCC) or high-strength, low water/cement concrete where steel reinforcement is present and chloride-free admixtures are mandatory.
Why use it?
It lets producers cut water (>12% vs reference) for higher strength while accelerating early strength gain, so moulds and beds can be stripped and re-cycled faster — directly improving daily output without sacrificing surface finish or cohesion.
How is it applied?
Added at the batching plant via a calibrated dispenser, ideally with the latter part of the mixing water, at 0.4 to 1.6 litres per 100 kg of cementitious content. Optimum dosage is fixed by site trial mixes; it is never pre-mixed with other admixtures.
About Fosroc Auracast 220A
Fosroc Auracast 220A sits in the Auracast family — Fosroc’s purpose-built admixture range for the precast and manufactured-concrete sector. Unlike a general-purpose plasticiser, it is built around a tailored blend of polycarboxylate (PCE) polymers whose comb-shaped molecules disperse cement grains far more efficiently than older naphthalene or melamine sulphonate chemistries. The practical result for an Indian precast producer is concrete that flows freely at a much lower water content, holds that flow long enough to place and finish, and then sets and gains strength quickly so the bed or mould can be turned around the same shift. What distinguishes 220A from a standard superplasticiser is that the accelerating function is engineered into the molecule rather than bolted on as a separate calcium-based accelerator. The product is specifically tuned to deliver high early AND high late-age strength, which matters when a yard needs to lift, demould or transfer prestress early but cannot compromise the 28-day characteristic strength the consultant has specified. It is supplied ready to dose at the batching plant and is described by Fosroc as robust and relatively insensitive to aggregate grading and moisture fluctuations — a real advantage on Indian sites where sand quality and aggregate moisture vary batch to batch. For Space Arc’s clients across Delhi NCR and Pan-India, 220A is the answer when the brief is high-output precast, SCC, or low-W/C high-strength concrete with embedded steel.
The technical insight
The performance comes from PCE steric hindrance rather than simple electrostatic repulsion. Each polymer has a charged backbone that anchors onto the cement particle and long side chains that physically hold neighbouring grains apart, keeping the paste fluid at very low free-water levels. Because less water is needed for a given workability, the water/cement ratio drops, capillary porosity falls and both strength and durability rise. The accelerating behaviour is delivered through components drawn from EN 934-1 Annex A.2 (thiocyanates) — which is also why the corrosion-behaviour clause is satisfied without introducing chlorides; the product is chloride-free (chloride ion content <0.1% by mass) and safe around reinforcement and prestressing strand. Verified properties: amber liquid; pH 5 ±1; specific gravity 1.085 @ 20°C; alkali content <2.0% by mass. It works across a wide consistence band, from S3 slump classes up to SF3 flow classes, which is why the same product can serve both conventional high-workability precast and fully self-compacting mixes. Water reduction exceeds 12% versus the reference mix per EN 934-2, with consistence increase >120 mm from initial slump (or >160 mm from initial flow) and retained workability at 30 minutes — all independently within the EN 934-2 T3.1/3.2 declared performance. Overdosing beyond 1.6 L/100 kg can promote bleeding and segregation, so dispenser calibration and trial-mix discipline are non-negotiable.
Where it is used
- Producing high-workability flowing concrete for precast structural and architectural elements
- Self-Compacting Concrete (SCC) for congested or heavily reinforced sections with no bleeding or segregation
- High-strength, low water/cement-ratio concrete for prestressed beams, planks and hollow-core slabs
- Precast paving blocks, kerbs and manufactured concrete products needing fast demoulding
- Wet-cast architectural and façade panels where a high-quality, blemish-free surface finish is required
- Precast yards running ground-granulated blast-furnace slag (GGBS), PFA / fly-ash or micro-silica blended cements
- High daily-output bed casting where rapid early strength enables same-shift mould or bed turnaround
Key advantages
- Single product gives both high-range water reduction and acceleration — improving early AND late-age compressive strength
- Chloride-free (<0.1% Cl- by mass), so safe for reinforced and prestressed concrete with embedded steel
- Faster mould and bed turnaround increases plant throughput without extra accelerator dosing
- Produces cohesive, low-viscosity SCC with reduced bleeding and segregation risk
- Robust, consistent performance across different cement sources, GGBS/PFA/micro-silica blends and varying aggregate moisture
- Wide working window from S3 slump to SF3 flow classes — one product covers conventional and self-compacting mixes
- Improved surface finish on demoulded units, reducing patching and rework
- Water-based, non-flammable and EN 934-2 T3.1/3.2 compliant for specification and QA records
Limitations & considerations
- Engineered for precast / manufactured concrete and SCC — not the default choice for general site-batched RMC, where Auramix or Conplast PCE grades may suit better
- Overdosing above 1.6 L/100 kg cementitious can cause segregation and excessive bleeding; requires a calibrated dispenser and trial-mix verification
- Optimum dosage must be established by trial mixes with actual site materials — published 0.4-1.6 L/100 kg is a starting range, not a fixed recipe
- Must never be pre-mixed with other admixtures before addition to the concrete
- PCE superplasticisers can be sensitive to clay-bearing or poorly graded sand; aggregate cleanliness still matters
- Shelf life of 12 months is conditional on storage between 2°C and 50°C; if frozen, the product must be fully thawed and thoroughly re-agitated before use
- Being a specialist precast admixture, it commands a premium over conventional sulphonated naphthalene (SNF) plasticisers
Selection & best practice
Always begin with laboratory or plant trial mixes using the exact cement, GGBS/PFA, sand and aggregate the yard will run, and dial the dosage within the 0.4-1.6 L/100 kg cementitious band to hit the target slump/flow and demoulding strength. Add Auracast 220A with the latter part of the mixing water through a calibrated dispenser — never neat onto dry cement and never pre-blended with other admixtures. For SCC, validate slump-flow, T500 and segregation resistance before production casting. Keep drums sealed and stored between 2°C and 50°C, rotate stock within the 12-month shelf life, and re-agitate any product that has been chilled or frozen. Hold the EN 934-2 DoP and batch certificates with your QA records for consultant approval.
Specifications
| Product type | Polycarboxylate (PCE) accelerating high-range water-reducing / superplasticising admixture |
| Chemical base | Combination of polycarboxylate polymers |
| Appearance | Amber liquid |
| pH | 5 ± 1 |
| Specific gravity | 1.085 @ 20°C |
| Chloride ion content | <0.1% by mass (chloride-free) |
| Alkali content | <2.0% by mass |
| Typical dosage | 0.4 to 1.6 litres per 100 kg of cementitious content |
| Water reduction | >12% compared with reference mix (EN 934-2) |
| Consistence increase | >120 mm from initial slump, or >160 mm from initial flow |
| Consistence retention | At 30 min > reference mix at initial |
| Workability range | Slump class S3 up to flow class SF3 |
| Standard compliance | EN 934-2: Tables 3.1 and 3.2 (high-range water-reducing / superplasticising) |
| Corrosion behaviour | Components only from EN 934-1:2008 Annex A.2 (thiocyanates) |
| Cement compatibility | All Portland cements and replacements — GGBS, PFA, micro-silica |
| Packaging | 20 litre drums or bulk supply |
| Shelf life | 12 months minimum, stored 2°C to 50°C |
| Fire / flammability | Water-based, non-flammable |
Industry use cases
Precast & Prestressed Concrete
Beams, hollow-core slabs, planks and columns where early demoulding or prestress transfer is needed alongside high 28-day strength — 220A’s accelerating PCE chemistry enables same-shift bed turnaround.
Manufactured Concrete Products
Paving blocks, kerbs, drainage units and compound walls in high-volume yards needing rapid mould cycling and a clean demoulded finish.
Infrastructure & Metro
Precast segmental tunnel linings, U-girders and parapets for metro and elevated-corridor projects, where chloride-free admixtures are mandatory around dense reinforcement and post-tensioning.
Architectural & Façade Panels
Wet-cast cladding and GFRC-style panels where SCC delivers a blemish-free, fair-faced finish without vibration in congested moulds.
High-Rise & Commercial Construction
Factory-produced high-strength precast elements for fast-track Delhi NCR and metro-city projects, reducing site labour and cycle time.
Water-Retaining & Durable Structures
Low W/C, low-permeability precast for tanks, channels and sleepers where durability and reinforcement protection are critical.
Frequently asked questions
Is Fosroc Auracast 220A chloride-free and safe for reinforced concrete?
What is the recommended dosage of Auracast 220A?
How is Auracast 220A different from a normal superplasticiser like Conplast SP430?
Can it be used to make Self-Compacting Concrete (SCC)?
Which cements and additions is it compatible with?
What pack sizes and shelf life apply, and how should it be stored?
How we position Fosroc Auracast 220A
Within Fosroc’s own range, Auracast 220A is the accelerating, high-early-strength member of the precast-focused Auracast family — sitting alongside grades such as Auracast 100 and Auracast 270M, and complementing site/RMC superplasticisers like Conplast SP430 and the Auramix range used for ready-mix concrete. Specify 220A when the job is genuinely precast, SCC, or low-W/C high-strength with a fast demoulding requirement; for general structural RMC a Conplast or Auramix PCE grade is usually the more economical fit, and Space Arc can advise on the right Fosroc product for each pour. Against the wider market, 220A competes with PCE precast/SCC superplasticisers such as Sika ViscoCrete grades, Master Builders Solutions (MBS) MasterGlenium, and PCE admixtures from STP and BASF-lineage suppliers; Dr. Fixit (Pidilite) is strong in waterproofing and repair but is less dominant in high-performance precast admixtures. Where 220A earns its place is the combination of built-in acceleration, robust performance across variable Indian cements and aggregates, EN 934-2 documentation for consultant sign-off, and Fosroc’s nationwide technical-support network. As an authorised Fosroc distributor and applicator serving Delhi NCR and Pan-India, Space Arc Engineering supplies Auracast 220A with trial-mix support, dispenser guidance and the full Auracast/Conplast/Auramix admixture portfolio so producers can match the admixture precisely to the mix design and output target.
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