About Fosroc Concure AB

Fosroc Concure AB is an acrylic emulsion curing compound used to control the loss of mix water from freshly placed concrete and cementitious renders. In the first hours after placing, concrete is at its most vulnerable: high ambient temperatures, low humidity and wind – everyday conditions across Delhi NCR, Rajasthan, Gujarat and most of the Indian plains – drive surface water out of the slab faster than it can bleed up. That premature drying starves the surface cement of the water it needs to hydrate, leaving a weak, dusty, permeable skin prone to plastic and drying shrinkage cracks. Concure AB addresses this by forming a continuous film over the surface the moment it is applied, acting as a temporary membrane that keeps water inside the concrete where it belongs.

The product is a single-component liquid that is simply sprayed (or, where necessary, brushed or rollered) onto the concrete. There is no mixing, no batching and no need to return to the slab with water – a decisive advantage over traditional wet curing using hessian, ponding or repeated sprinkling, all of which demand continuous labour, large volumes of clean water and constant supervision for seven days or more. On a busy Indian site, that translates into real savings on water, manpower and programme time, and a far more consistent result than hand-curing can deliver.

Concure AB complies with ASTM C309 Type 1 Class B, the international standard for liquid membrane-forming curing compounds. A distinguishing feature of the AB grade is that it is compatible with after-trades: because it is acrylic and over-paintable, subsequent finishes such as paints, renders and screeds can bond to the treated surface, and the film itself acts as a primer for many of these systems. This makes it especially suited to building work where the cured slab or wall will later be finished, rather than only to bare industrial floors. For situations demanding a white reflective version or higher moisture-retention efficiency, Fosroc offers Concure AB White (ASTM C309 Type 2 Class A) and the high-efficiency Concure 90; Space Arc Engineering can advise on the correct grade for a given specification.

The technical insight

The performance of any curing compound comes down to how effectively its dried film resists water vapour transmission, and that is exactly what ASTM C309 classifies. Concure AB is certified to Type 1 (clear/translucent, no reflective requirement) Class B, meaning the film is tested to limit water loss from a curing concrete specimen below the standard’s threshold – the practical proof that the membrane works. Chemically, Concure AB is an acrylic emulsion: acrylic polymer dispersed in water. On application the water phase evaporates and the acrylic particles coalesce into a coherent, continuous film that is non-penetrating (it sits on the surface rather than soaking in) yet adherent enough to act as a primer for later coatings. The acrylic chemistry is what gives the AB grade its over-paintability and after-trade compatibility – solvent-based wax or chlorinated-rubber curing compounds form effective barriers but can interfere with the adhesion of subsequent finishes, whereas the acrylic film of Concure AB is designed to receive them. Timing is the critical control variable: the compound must go on after surface bleed water has dispersed but before the surface dries, so that the film seals a still-moist slab. Applied too early it floats on bleed water; applied too late, the surface has already lost the water the membrane was meant to retain.

Where it is used

• Curing of freshly placed structural concrete – slabs, beams, columns, rafts and walls – in building and infrastructure works
• Curing of large-area concrete pavements, hardstandings, roads and external paving where wet curing is impractical
• Curing of newly demoulded concrete elements immediately after striking formwork
• Curing of cement renders and plastered surfaces, interior and exterior
• Concrete work that will receive after-trades such as paints, renders or screeds, where the cured surface must remain bondable
• Precast and site-cast elements where consistent, labour-light curing is required across a large surface

Key advantages

• Improves curing by enhancing cement hydration, producing more durable, denser concrete
• Controls moisture loss to give a harder-wearing, less permeable, dust-free surface
• Minimises plastic and drying shrinkage and the surface cracking that follows
• Compatible with many after-trades and over-paintable – acts as a primer for subsequent finishes
• Single-component, no mixing; spray application is fast and reduces labour costs versus wet curing
• Eliminates the large water volumes and continuous supervision needed for ponding or hessian curing
• Suitable for both interior and exterior application, and can be applied to fresh or newly hardened concrete
• Non-flammable, water-based emulsion with a 12-month shelf life in unopened containers

Limitations & considerations

• Type 1 Class B grade – for higher-efficiency curing membranes Fosroc specifies Concure 90, and for a white reflective film Concure AB White (ASTM C309 Type 2 Class A)
• Timing is critical: must be applied after surface bleed water has gone but before the surface dries out
• Forms a film barrier, so it is not intended for surfaces requiring deep penetrating treatment
• The applied film must not be walked on or trafficked until fully dry, and care is needed not to break it
• Before over-coating, the cured surface must be completely free of stains, oils and other adhesion-affecting contaminants
• Surfaces (when applied to hardened concrete) must be free of stains, oils or form-coating that would prevent adhesion
• Coverage is indicative and varies with surface texture and porosity; an on-site trial is advisable
• Store between 4 C and 35 C and protect from freezing and direct heat or sunlight; do not use if evaporated, thickened or discoloured

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Concure AB

Within the Fosroc Concure range, Concure AB is the everyday acrylic emulsion option for projects that need reliable, labour-light curing on surfaces that will later be finished – its over-paintability and after-trade compatibility are its key selling point. Step up to Concure AB White (ASTM C309 Type 2 Class A) when a white reflective film is wanted in hot conditions, or to the high-efficiency Concure 90 when the specification demands greater moisture retention; Concure A, Concure WB and Concure CR cover permanent and wax-based curing variants. Against the wider Indian market, Concure AB competes with Sika Antisol and Sika Antisol E (acrylic/wax emulsion curing compounds), MYK Arment / MBS curing compounds, Dr. Fixit Pidicure and STP (Shalimar) curing membranes. Like-for-like, buyers should compare the ASTM C309 Type and Class, water-retention efficiency, over-paintability and coverage rate rather than headline price – for slabs that will be painted or rendered, an over-paintable acrylic such as Concure AB usually avoids the cost of removing a wax film before finishing. As an authorised Fosroc distributor for Delhi NCR and Pan-India, Space Arc Engineering supplies genuine Concure AB with technical support on grade selection, coverage and after-trade compatibility.

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