Fosroc Concure S
Clear silicate-solution curing membrane and dust-proofing surface hardener for runways, roads, bridge decks and large industrial slabs.
What is it?
A clear, colourless, water-based liquid built on a silicate solution that is sprayed onto fresh and hardened concrete to retain mix water during curing while chemically reacting with free lime to harden and dust-proof the surface.
Where is it used?
Large-area concrete pours where conventional ponding or hessian curing is impractical — airport runways and aprons, highways and toll roads, bridge decks, canal linings, warehouse and factory floor slabs across Delhi NCR and Pan-India.
Why use it?
It locks in moisture for proper cement hydration, cuts plastic-shrinkage and surface cracking, and produces a harder, denser, less permeable, dust-free wearing surface — all in one fast, low-labour spray pass that leaves no peelable film to remove.
How is it applied?
Spray-applied in a uniform coat (typically around 5 m2 per litre) over the prepared concrete surface using low-pressure spray equipment; the silicate penetrates and reacts, needing no subsequent removal.
About Fosroc Concure S
Fosroc Concure S is a clear, silicate-solution-based liquid used to cure and harden concrete in a single application. Unlike the wax- and resin-emulsion compounds in the wider Concure family (which form a temporary surface film), Concure S works chemically: the soluble silicate penetrates the concrete surface and reacts with free calcium hydroxide (lime) released during hydration. This reaction both retains the moisture needed for proper curing and densifies the surface zone, producing a harder, more abrasion-resistant, dust-free finish. Because it is colourless and leaves no visible traces, it is well suited to architectural and trafficked surfaces where appearance matters.
For Indian conditions, where high ambient temperatures, low humidity and strong winds during the dry season drive rapid evaporation from fresh slabs, controlling early moisture loss is critical. Concure S is engineered to address exactly this: a sprayed coat reduces water escaping from the surface, supporting fuller cement hydration, lower permeability and a reduced tendency for plastic-shrinkage cracking. It is water-based and non-flammable, which simplifies storage, handling and site safety compared with solvent-borne curing compounds.
The product is positioned by Fosroc primarily for large-area concrete works — airport runways and taxiways, highways, bridge decks and similar civil structures — where the labour and water demand of traditional curing (ponding, wet hessian, continuous sprinkling) becomes impractical or unreliable. A spray-applied curing solution lets a small crew treat very large areas quickly, immediately after finishing, and the chemical surface-hardening benefit is a useful bonus on slabs that will see heavy traffic or forklift wear. Space Arc Engineering supplies Concure S as an authorised Fosroc distributor, with technical guidance on application rates and suitability for each project’s exposure and surface requirements.
The technical insight
The defining feature of Concure S is its chemistry: it is a silicate solution, not a film-forming emulsion. This matters for specification. ASTM C309 — the standard most Indian tenders quote for “liquid membrane-forming curing compounds” — explicitly notes that solutions of silicate salts are chemically reactive in concrete rather than membrane-forming, and therefore fall outside the intent of that standard. So Concure S should not be specified or compared as if it were an ASTM C309 / AASHTO M148 Type 1 membrane compound; that family is represented in the Fosroc range by the wax- and acrylic-emulsion products such as Concure WB and Concure A. Concure S instead behaves as a penetrating reactive silicate hardener-cum-curing aid, comparable in mechanism to lithium/sodium/potassium-silicate floor hardeners. The practical takeaway: it delivers genuine surface densification and dust-proofing that a sacrificial wax membrane cannot, but its curing efficiency is governed by penetration and reaction depth rather than by an impermeable film, so uniform coverage on a properly timed, clean surface is essential to performance.
Where it is used
- Curing and surface-hardening of airport runways, taxiways and aprons
- Highway, expressway and toll-road concrete pavements
- Bridge decks and approach slabs
- Canal linings and large hydraulic concrete surfaces
- Warehouse, factory and logistics-park floor slabs needing a dust-free wearing surface
- General large-area civil concrete where ponding or hessian curing is impractical
- Dust-proofing and densifying existing hardened concrete floors
Key advantages
- Single product cures and hardens — retains moisture for hydration while chemically densifying the surface
- Colourless and leaves no traces, so it suits visible and architectural concrete
- Produces a hard-wearing, dust-free, lower-permeability surface that resists abrasion
- Reduces plastic-shrinkage and surface cracking by controlling early moisture loss
- Water-based and non-flammable — safer to store, transport and apply than solvent-borne compounds
- Spray application covers large areas fast with minimal labour, cutting curing costs
- No film to peel or wash off, unlike wax-emulsion membrane compounds
- Eliminates the water demand and labour of ponding, wet hessian or continuous sprinkling
Limitations & considerations
- Silicate chemistry is reactive, not membrane-forming — it does NOT comply with ASTM C309 / AASHTO M148, so it cannot be substituted where a C309 Type 1 membrane is specified
- Curing efficiency depends on penetration and reaction; uniform coverage and correct timing of application are critical
- Best suited to dense, well-finished concrete — very porous or contaminated surfaces may absorb unevenly
- Provides surface hardening rather than a heavy-duty wearing topping; not a replacement for metallic or non-metallic floor hardeners in extreme-abrasion zones
- Effectiveness can be reduced if the surface dries out before application or if rain falls before the silicate has reacted
- On surfaces to receive coatings, tiling or toppings, adhesion of subsequent layers must be checked, as with any reactive silicate treatment
Selection & best practice
Apply Concure S as a uniform spray to freshly finished concrete as soon as the surface water sheen has disappeared and the surface can take foot traffic without marking, or to clean, sound hardened concrete for dust-proofing. Use clean, low-pressure spray equipment and work to an even rate of roughly 5 m2 per litre, avoiding pooling. Do not over-apply on dense surfaces, as excess unreacted silicate can leave residue. Protect the treated area from rain until the silicate has reacted, and keep traffic off until the surface is firm. In peak Indian summer, apply promptly after finishing to beat rapid evaporation, and on highly absorptive concrete consider a light pre-dampening to aid even penetration. Always confirm the current region-specific Fosroc Technical Data Sheet and trial a small area first; for slabs that must comply with an ASTM C309 membrane specification, use a Fosroc emulsion curing compound (Concure WB / Concure A) instead.
Specifications
| Product type | Spray-applied silicate-solution curing compound and surface hardener |
| Chemical basis | Aqueous silicate solution (reactive, penetrating) |
| Appearance / colour | Clear, colourless liquid; leaves no traces |
| Carrier | Water-based |
| Flammability | Non-flammable |
| Application method | Spray (low-pressure); pour/brush possible on small areas |
| Typical coverage | Approx. 5 m2 per litre (surface-dependent) |
| Primary function | Moisture retention for curing + chemical surface hardening / dust-proofing |
| Standards note | Silicate solutions are reactive, not membrane-forming — outside the scope of ASTM C309 |
| Film removal | None required — penetrating reactive treatment, no peelable film |
Industry use cases
Airports & Aviation
Curing and dust-proofing runway, taxiway and apron concrete over very large areas with a small crew, where ponding is impossible and surface durability under jet/tyre traffic is essential.
Highways & Bridges
Rapid spray curing of expressway pavements and bridge decks immediately after paving, reducing plastic-shrinkage cracking during hot, windy Indian construction seasons.
Warehousing & Logistics
Hardening and dust-proofing large factory and distribution-centre floor slabs so they resist forklift abrasion and shed less dust in clean-storage environments.
Water Infrastructure
Curing canal linings and other large hydraulic concrete surfaces where continuous wet curing of long runs is labour-intensive and water-scarce.
Industrial Civil Works
General large-pour concrete in plants and infrastructure projects needing reliable curing plus a denser, lower-permeability wearing surface in one operation.
Frequently asked questions
Is Fosroc Concure S a membrane-forming curing compound?
Does Concure S comply with ASTM C309?
What coverage should I expect from Concure S?
Can Concure S be used to dust-proof an existing concrete floor?
Is Concure S safe to store and use on site?
How does Concure S compare with Fosroc Concure WB, Sika Antisol or Dr. Fixit curing compounds?
How we position Fosroc Concure S
Within the Fosroc Concure range, Concure S is the reactive silicate option, distinct from the emulsion membrane curing compounds. If a project specification demands an ASTM C309 / AASHTO M148 film-forming membrane, the right Fosroc choices are the wax-emulsion Concure WB or acrylic Concure A; Concure S should not be substituted for them. Where the goal is curing plus permanent surface hardening and dust-proofing on dense, well-finished concrete, Concure S is the better fit, and it pairs naturally with Fosroc floor systems and Nitoflor hardeners for heavy-duty zones. Against competitors, the membrane compounds Sika Antisol-E/S, MBS/MC-Bauchemie curing aids, Dr. Fixit Pidicure and STP curing compounds are film-forming and ASTM C309-oriented, so they compete with Concure WB rather than with Concure S; on the silicate-hardener side, Concure S sits alongside products such as lithium/sodium-silicate densifiers (e.g. Sika or MC silicate hardeners). Honest guidance: specify Concure S for its dual cure-and-harden action on quality slabs, but reach for a Fosroc or competitor emulsion membrane when the tender language is explicitly C309 or when the concrete is very porous. Space Arc Engineering, as an authorised Fosroc distributor in Delhi NCR and Pan-India, can advise on the correct product for each exposure and specification.
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