About Fosroc Concure RB90

Fosroc Concure RB90 is a high-quality, resin-based concrete curing compound formulated for the single most under-managed stage of any concrete pour in India: the first few days of curing. When freshly placed concrete loses water too quickly to sun, wind and dry heat, the cement near the surface never fully hydrates. The result is the familiar set of defects every site engineer in Delhi NCR knows well, crazing, dusting, plastic shrinkage cracking and a weak, low-abrasion-resistance top layer. Concure RB90 addresses this by being sprayed onto the green concrete as a thin liquid that cures into a continuous, film-forming moisture barrier, trapping the mix water inside the slab so hydration can run to completion.

Chemically, Concure RB90 is a low-viscosity resin emulsion supplied as a single-component liquid that is ready for immediate on-site use, with no mixing of multiple parts and no induction time. It is offered in two versions: a clear (translucent) grade and a white-pigmented grade. The white-pigmented version is the workhorse for Indian conditions because the pigment makes it visually obvious which areas have been sprayed (eliminating misses and double-coats), and the white surface reflects solar radiation to reduce temperature gain in the curing slab, a genuine benefit on exposed pours through the North Indian summer.

The headline performance figure is a controlled curing efficiency of 90% measured to BS 7542, and the product is also classified to ASTM C309 (Type 1 or 2, Classes A and B) and complies with BS 8110 Part 1, clause 6.6.3(c). These are the standards a specifier or third-party consultant will look for, so the product can be written into a specification with confidence rather than relying on a vague “apply curing compound” instruction.

For Space Arc Engineering customers, Concure RB90 sits in the sweet spot for large-area flatwork: it is specifically formulated for low-cost spray application, is non-hazardous and non-flammable, can be cleaned up with water, and at 3.5 to 5.0 m2 per litre it covers a lot of ground per drum. It is best understood as a productivity and quality-assurance tool, one operator with a knapsack sprayer can cure a slab area that would otherwise need a crew laying and re-wetting hessian or building ponding bunds for a week.

The technical insight

Curing efficiency is the number that matters, and it is precisely defined. BS 7542 measures the water retained by a sealed concrete surface versus an uncovered control; a 90% efficiency means the membrane prevents 90% of the moisture loss that would otherwise occur. That retained water is what keeps the cement hydrating in the critical first 3 to 7 days, directly building the surface compressive and abrasion strength that field problems like dusting and early wear depend on. The ASTM C309 classification (Type 1 clear / Type 2 white, Classes A and B) describes the membrane chemistry and reflectance class, so Concure RB90 is interchangeable in specs written to either the British or American standard. A point Space Arc always flags to clients: Concure RB90 is a curing membrane, not a permanent sealer or aesthetic coating. The film is designed to break down under UV and trafficking over roughly 28 days, and the datasheet explicitly notes it discolours to yellow or brown under sunlight. Where a slab will later receive epoxy flooring, tiling, screed or a bonded topping, the residual membrane must be mechanically removed (high-pressure water/steam or light shot/sand blasting) before the next layer goes down, otherwise it becomes a bond-breaker. This is the single most common detailing mistake on site and the reason a chlorinated-rubber or wax compound is sometimes preferred where removal would be impractical.

Where it is used

• Industrial and warehouse ground-floor slabs where surface abrasion resistance and freedom from dusting are critical
• Suspended and on-grade car park decks and ramps
• Airport runways, taxiways, aprons and hardstanding areas
• Water-retaining structures such as concrete tanks, reservoirs, STP/ETP basins and water treatment works
• Reinforced columns, beams and walls immediately after striking formwork (applied while the concrete is still damp)
• Large external pavements, hardstandings and loading/unloading bays
• Marine and coastal concrete including piers, jetties and harbour works
• Highway and bridge-deck concrete requiring specified curing efficiency

Key advantages

• Controlled 90% curing efficiency verified to BS 7542, giving a specifiable, auditable curing performance instead of relying on labour-dependent water curing
• Better cement hydration at the surface, improving durability and abrasion resistance and reducing dusting
• Reduces plastic and drying shrinkage cracking, lowering add-on costs for crack and surface repairs
• Single-component liquid ready for immediate use, no mixing, no waiting
• Specifically formulated for low-cost, high-output spray application over large areas
• Non-hazardous and non-flammable resin; water can be used for cleaning equipment and spillages
• White-pigmented version gives a visible spray check and reflects solar heat to reduce slab temperature gain
• Saves significant water and labour versus ponding or hessian curing, a real benefit on water-scarce Indian sites
• Classified to ASTM C309 and compliant with BS 8110 Part 1, so it slots directly into international and Indian specifications

Limitations & considerations

• Not a permanent sealer or aesthetic coating; the membrane is designed to break down and should be removed after about 28 days
• Discolours to yellow, brown or darker shades under sunlight, so it is unsuitable where the bare concrete finish must stay clear
• Must be fully removed (high-pressure water/steam or light sand/shot blasting) before any bonded topping, screed, tile, paint or coating is applied, or it acts as a bond-breaker
• Must not be applied to dry surfaces or while bleed water is still present; dry substrates cause absorption, staining and difficult removal
• Single grade, single coverage role only; it does not repair, level or strengthen concrete
• Should be re-circulated only with a low-shear diaphragm pump to avoid breaking the emulsion
• Pigmented version has a shorter shelf life (6 months) than the clear version (12 months)
• Treated surfaces must not be disturbed or loaded until the concrete has gained sufficient strength

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Concure RB90

Within the Fosroc curing range, Concure RB90 is the resin-emulsion, spray-applied compound positioned for large flatwork where a verifiable 90% efficiency is wanted at low applied cost. It sits alongside Fosroc Concure WB (a wax-emulsion compound, often chosen where membrane removal is impractical and a residual film is acceptable), Concure A (an aluminised/reflective grade) and Concure 90/1315 type compounds; the right choice depends mainly on what happens to the slab next. Choose Concure RB90 when the surface will be exposed or where you have planned for mechanical removal before a bonded topping; favour a wax-based grade where no subsequent bonded finish is involved. Against competitor systems commonly seen in India, it competes directly with Sika Antisol and Antisol WB (Sika), MBS / MYK curing compounds, Dr. Fixit Pidiproof curing compounds and STP curing membranes; all occupy the same resin- or wax-emulsion curing-compound space. The honest differentiator is not radical chemistry but the explicit, audited BS 7542 / ASTM C309 standard compliance, the two-version (clear/white) flexibility, and Fosroc’s specification and on-site technical support, which Space Arc Engineering backs locally. Because curing quality directly governs the durability of every downstream Fosroc system, Concure RB90 is best specified together with related products such as Fosroc Conplast water-reducing admixtures in the mix, Nitobond bonding aids and Renderoc repair mortars for any remedial work, and Nitoflor industrial flooring or Dekguard/Nitocote protective coatings as the eventual surface treatment once the membrane is removed.

Related Concrete Repair products

View all Concrete Repair products →