Fosroc Structuro 402
A carboxylic-ether (PCE) based high-range water-reducing superplasticiser engineered for high-performance, high-workability and durable concrete.
What is it?
A next-generation polycarboxylic-ether (PCE) superplasticiser from Fosroc that strongly reduces water demand while retaining workability, used to produce high-strength and/or highly flowable concrete.
Where is it used?
Ready-mix and site-batched structural concrete across India — high-rise, infrastructure, precast and high-durability works in Delhi NCR and pan-India projects.
Why use it?
It delivers high water reduction at low dosage, giving higher early and ultimate strength, lower permeability and improved durability without sacrificing flow.
How is it applied?
Dispensed as a liquid admixture into the concrete mixing water at the batching plant or mixer, dosed by trial against the target water-cement ratio and slump/flow.
About Fosroc Structuro 402
Fosroc Structuro 402 is a high-performance superplasticising (high-range water-reducing) admixture from the Fosroc Structuro range. Unlike conventional sulphonated naphthalene or melamine superplasticisers, Structuro 402 is built on a unique carboxylic-ether polymer with long lateral chains — the polymer family commonly known as polycarboxylate ether or PCE. When the admixture is added to the mixing water, these lateral chains attach to the cement grains and create a steric (physical spacing) effect in addition to electrostatic repulsion. The cement particles are pushed apart and kept dispersed, which frees up the water that would otherwise be trapped between flocculated grains. The practical result is that the same concrete can be produced either with much less water at the same workability, or with much higher workability at the same water content. Because the mechanism is steric rather than purely charge-based, Structuro 402 holds workability for longer than older-technology plasticisers and gives consistent, repeatable concrete properties around the recommended dosage. For an authorised distributor like Space Arc Engineering serving Delhi NCR and pan-India ready-mix and project sites, this consistency is the key value: a strong, low-dosage PCE lets producers lock in a low water-cement ratio for strength and durability while still placing and finishing the concrete easily. Structuro 402 is positioned for high-performance concrete and high-workability concrete rather than for routine, low-grade mixes where a basic plasticiser would be more economical. Always confirm the exact graded specification, dosage window and approvals against the current Fosroc India Technical Data Sheet for your formulation, as Fosroc issues country-specific datasheets.
The technical insight
The performance of Structuro 402 comes from the architecture of the polycarboxylate-ether molecule: a charged backbone that anchors onto the cement surface plus long, neutral side (lateral) chains that project outward. Sulphonated naphthalene plasticisers disperse cement mainly by electrostatic repulsion, which decays as cement hydrates and surface charge changes — that is why naphthalene-based mixes lose slump quickly. The PCE side chains in Structuro 402 add steric hindrance: a physical brush layer that keeps grains separated regardless of charge, so dispersion is more efficient (higher water reduction per unit dose) and longer-lasting (better workability retention). A lower water-cement ratio at a given workability is the lever that improves nearly every hardened property — and Fosroc lists exactly these gains for Structuro 402: higher early and ultimate compressive strength, higher flexural strength, higher modulus of elasticity (E-modulus), better bond to reinforcing and prestressing steel, lower permeability, improved carbonation resistance, reduced shrinkage and creep, and greater overall durability. In Indian conditions — high ambient temperatures during summer pours, long ready-mix haul distances in metros like Delhi NCR, and aggressive sulphate/chloride exposure in coastal and effluent environments — the combination of low w/c, low permeability and retained workability is precisely what a durable, pumpable, high-grade concrete needs.
Where it is used
- High-performance and high-strength structural concrete (M40 and above) for columns, cores, transfer slabs and high-rise construction
- High-workability and pumpable concrete for tall buildings and congested, heavily reinforced sections
- Precast and prestressed concrete elements requiring high early strength for faster demoulding and stressing
- Durable, low-permeability concrete for water-retaining structures, basements and marine/coastal exposure
- Ready-mix concrete requiring extended workability retention over long haul and placement times
- Infrastructure concrete (bridges, flyovers, metro, industrial) where strength, durability and finish all matter
Key advantages
- High water reduction at low dosage, enabling low water-cement ratios for strength and durability
- Strong, consistent superplasticising effect giving repeatable concrete properties around the recommended dose
- Increased early AND ultimate compressive strength, plus higher flexural strength and E-modulus
- Improved durability: lower permeability, better carbonation resistance, reduced shrinkage and creep
- Better workability retention than naphthalene/melamine plasticisers, aiding long hauls and hot-weather pours
- Improved adhesion to reinforcing and prestressing steel for better composite performance
- Chloride-free PCE chemistry, suitable for reinforced and prestressed concrete
Limitations & considerations
- It is an admixture, not a standalone product — final performance depends on mix design, cement source, aggregates and water
- PCE admixtures are dosage-sensitive: overdosing can cause bleeding, segregation, retardation or excessive flow, so trial mixes are essential
- Sensitive to changes in cement/SCM chemistry, fines and water content; consistency of constituent materials matters
- Generally a premium-cost admixture, best justified for high-grade/high-durability concrete rather than low-grade mixes
- Compatibility with other admixtures (retarders, air-entrainers, other plasticisers) must be checked before site use
- Exact graded specification, dosage range and standards approvals must be confirmed against the current Fosroc India TDS for the supplied formulation
Selection & best practice
Always establish dosage by laboratory and field trial mixes using the actual project cement, SCMs, aggregates and water rather than copying a generic figure — PCE response is mix-specific. Add Structuro 402 to the pre-batched mixing water (or as directed in the current TDS), never onto dry cement, and avoid combining it with incompatible admixtures until compatibility is confirmed. Target the lowest water-cement ratio that achieves the required slump/flow to capture the strength and durability benefit, and monitor for over-dosing signs (bleeding, segregation, set delay). For hot-weather and long-haul ready-mix in Delhi NCR, validate workability retention to the actual placement time. Keep containers sealed, store away from direct sun and frost, and verify the batch is within shelf life before use. For project specifications, dosage approvals and current graded data, refer to the Fosroc India Technical Data Sheet and consult Space Arc Engineering’s technical team.
Specifications
| Product type | High-range water-reducing superplasticiser admixture |
| Chemical basis | Carboxylic-ether polymer with long lateral chains (polycarboxylate ether / PCE) |
| Primary function | Water reduction with workability retention for high-performance / high-workability concrete |
| Chloride content | Chloride-free / nil added chloride (PCE chemistry; confirm value on current TDS) |
| Compressive strength effect | Increased early and ultimate compressive strength |
| Flexural strength / E-modulus | Increased flexural strength; higher modulus of elasticity |
| Permeability | Reduced (improves durability and carbonation resistance) |
| Shrinkage / creep | Reduced |
| Typical standards reference (PCE superplasticisers) | EN 934-2 / ASTM C494 high-range water reducer (Type F/G) class — verify exact approvals on the current Fosroc India TDS |
| Specific gravity, dosage range, packaging & shelf life | Per current Fosroc India Technical Data Sheet — confirm before specifying (not stated on the public product page) |
Industry use cases
High-rise & commercial construction
Producing pumpable M40-plus concrete for columns, cores and transfer slabs where a low w/c is needed for strength but the mix must still flow into congested reinforcement.
Precast & prestressed yards
Achieving high early strength for faster demoulding and tendon stressing, improving mould turnaround and steel bond in precast elements.
Infrastructure (bridges, metro, flyovers)
High-durability, low-permeability structural concrete that resists carbonation and aggressive exposure while remaining workable over long placement cycles.
Water-retaining & below-grade structures
Low-permeability concrete for tanks, reservoirs, basements and retaining walls where reduced shrinkage and tightness limit cracking and leakage.
Ready-mix (RMC) supply, Delhi NCR & pan-India
Maintaining workability over long haul distances and hot-weather pours, with consistent batch-to-batch performance around the design dosage.
Frequently asked questions
What exactly is Fosroc Structuro 402?
How is Structuro 402 different from a conventional superplasticiser?
What concrete benefits does Structuro 402 give?
What is the correct dosage of Structuro 402?
Is Structuro 402 suitable for reinforced and prestressed concrete?
Where can I buy Fosroc Structuro 402 in India?
How should Structuro 402 be stored and handled?
How we position Fosroc Structuro 402
Within the Fosroc admixture portfolio, Structuro 402 sits in the premium PCE (polycarboxylate-ether) Structuro superplasticiser range, alongside variants such as Structuro 200, Structuro 520 and the Structuro W-series (e.g. W415, W425, W440, W450) — these differ mainly in water-reduction strength, workability-retention profile and target application (general high-performance vs. self-compacting/hyperplasticised concrete). For more conventional, economical superplasticising on standard-grade concrete, Fosroc’s own naphthalene-based Conplast SP430 / Auramix family is the usual reference point, whereas Structuro 402 is chosen when high strength, high durability or sustained workability justify PCE technology. Against competitor PCE superplasticisers, Structuro 402 is comparable in class to Sika ViscoCrete, MBS (MC-Bauchemie) MUST/Powerflow PCE admixtures, and CICO/STP and Dr. Fixit (Pidilite) high-range water reducers; selection between them typically comes down to local technical support, mix-specific trial performance, compatibility with the project’s cement/SCM source, and commercial terms. Space Arc Engineering positions Structuro 402 for clients who need a strong, consistent, durability-focused PCE and provides the trial-mix and specification support to deploy it correctly. Final product selection and dosage should always be validated against the current Fosroc India Technical Data Sheet.
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