Fosroc Conplast MR276
A chloride-free, multi-range water-reducing plasticiser engineered to keep concrete workable, dense and strong when ambient temperatures fall.
What is it?
A water-based, multi-range water-reducing plasticiser from the Fosroc Conplast admixture range, formulated from a blend of synthetic and natural polymers and tuned for concreting in cold-climate conditions.
Where is it used?
Ready-mix and site-batched structural concrete poured in low-temperature or winter conditions reinforced, prestressed and mass concrete elements such as slabs, columns, rafts, beams and precast units.
Why use it?
It cuts mixing water for a given workability, lifting strength and reducing permeability without slowing the mix the way a conventional plasticiser would when it is cold, so productivity and durability hold up in adverse weather.
How is it applied?
Dispensed into the mixing water at roughly 0.3 to 1.0 litre per 100 kg of cementitious material through a calibrated dosing system the exact rate is fixed by site trials with the actual mix materials.
About Fosroc Conplast MR276
Fosroc Conplast MR276 is a liquid concrete admixture that belongs to the Conplast family of water-reducing plasticisers. It is described by Fosroc as a multi-range, multifunctional plasticiser produced from a blend of synthetic and natural polymers, and it is positioned specifically for concrete that has to be placed and cured in cold-climate conditions. The product is water-based and non-flammable, which simplifies storage and on-site handling, and it is chloride-free, so it can be used safely in reinforced, prestressed and mass concrete without contributing to reinforcement corrosion.
The “multi-range” label is the practical heart of the product. At low dosages it behaves like a conventional plasticiser, giving a useful slump increase or a modest water reduction. As the dosage is raised, the water-reducing effect strengthens and the admixture begins to perform more like a mid-to-high range water reducer, allowing greater water savings and tighter, stronger concrete. This single-product flexibility is convenient for contractors who want to cover a range of mix designs from one tank rather than stocking several specialist admixtures.
What sets MR276 apart from a general-purpose plasticiser is its formulation for cooler weather. Plasticisers based on lignosulphonates and similar chemistries can noticeably retard concrete when temperatures drop, pushing out setting times and slowing the early strength that a site needs to strike formwork or move on to the next pour. MR276 is engineered to keep setting-time variation minimal even at higher dosages, so the workability benefit is delivered without an unwanted retarding penalty when it is cold. For Indian projects this is most relevant to North India and hill-state winters Delhi NCR, Punjab, Haryana, Uttar Pradesh, Uttarakhand, Himachal Pradesh, Jammu & Kashmir and Ladakh and to night-time or early-morning pours where ambient and concrete temperatures are low.
Space Arc Engineering supplies Conplast MR276 as an authorised Fosroc distributor and applicator, with technical support for mix-design trials, dosage optimisation and cold-weather concreting method statements across Delhi NCR and Pan-India.
The technical insight
The key technical idea behind Conplast MR276 is decoupling water reduction from setting retardation in cold weather. A plasticiser works by dispersing cement grains so that less mixing water is needed for the same flow; the released water can instead be removed from the mix to lower the water-cement ratio. Lowering the w/c ratio is the single most powerful lever on concrete the compressive strength rises, the capillary pore network shrinks, and permeability falls, which together improve durability. The catch with many conventional plasticisers is that their dispersing chemistry also delays cement hydration, and that delay grows worse as temperature falls, because hydration is already slow when it is cold. The result on a winter site can be concrete that is workable but sets and gains strength too slowly to keep a schedule. MR276’s polymer blend is formulated to deliver the dispersion and water reduction while holding setting-time variation low even at the upper end of its dosage band, so a contractor can chase strength and density without surrendering early-age performance. Two practical consequences follow. First, dosage must be established by trial with the actual cement, aggregates and water of the job MR276 interacts with cement chemistry and supplementary materials, and the optimum rate is mix-specific. Second, overdosing is self-penalising: roughly double the maximum recommended dose can cause delayed setting and extra entrapped air, so accurate calibrated dispensing matters more than with a forgiving general-purpose product.
Where it is used
- Structural reinforced concrete columns, beams, slabs and rafts poured in winter or low-temperature conditions
- Ready-mixed concrete plants needing a single multi-range plasticiser for varied cold-weather mix designs
- Prestressed and precast concrete elements where a chloride-free admixture is mandatory
- Mass concrete pours where controlled water reduction improves density without aggressive retardation
- Night and early-morning concreting where ambient and concrete temperatures are low
- Water-retaining and durability-critical structures benefiting from reduced permeability
- High-altitude and North-Indian projects (Himachal, Uttarakhand, J&K, Ladakh) facing genuine cold-climate concreting windows
Key advantages
- Increases workability for a given water content, or allows water reduction at constant slump, improving placing and compaction
- Raises compressive and mechanical strength by enabling a lower water-cement ratio
- Reduces concrete permeability, improving durability and resistance to ingress
- Chloride-free formulation safe for reinforced, prestressed and mass concrete
- Multi-range behaviour plasticiser at low dose, stronger water reduction at high dose from a single product
- Formulated for cold climates with minimal setting-time variation, unlike many conventional plasticisers
- Water-based and non-flammable, simplifying storage and site handling
- Compatible with all common cements and with several other Fosroc admixtures when dosed separately
Limitations & considerations
- Optimum dosage is mix-specific and must be confirmed by site trials, not assumed from the datasheet range
- Overdosage (around twice the maximum recommended) can cause delayed setting and additional entrapped air
- Requires an accurate, calibrated dosing system to realise its benefits and avoid over/under dosing
- Should be added with the mixing water, not dry-batched or post-added carelessly, for proper performance
- Not an antifreeze on its own it improves cold-weather concreting behaviour but does not replace proper cold-weather protection, insulation or curing
- When combined with other admixtures, they must be added separately and not pre-mixed in the same container
- Primarily a Fosroc Euco / European-market product confirm current local pack format and regional datasheet for India-specific supply
Selection & best practice
Always establish the working dosage by trial mixes using the project’s own cement, supplementary cementitious materials, aggregates and water, starting within the 0.3 to 1.0 litre per 100 kg cementitious guideline and adjusting for the target slump and strength. Dispense MR276 into the mixing water through a calibrated dosing system never eyeball it and keep it separate from any other admixture being used, adding each independently to the mix. Avoid exceeding roughly twice the maximum trial dosage, which risks delayed set and excess air. Treat the admixture as one part of a cold-weather concreting plan: maintain concrete temperature, protect freshly placed concrete from freezing, and follow proper curing. Store the product in its original closed containers in a dry place between about 2 and 40 degrees Celsius, away from frost, and use within the stated shelf life. Confirm compatibility and the current India datasheet through Space Arc Engineering before bulk ordering.
Specifications
| Product type | Multi-range water-reducing plasticiser admixture (cold-climate) |
| Base chemistry | Blend of synthetic and natural polymers, water-based |
| Function | Water reduction / workability increase plasticiser at low dose, stronger water reducer at high dose |
| Chloride content | Chloride-free (water-soluble chloride low, per EN 934-2 limits) |
| Standards | Complies with EN 934-2 (UNE-EN 934-2) Table 2 as a water reducer/plasticiser; general requirements of EN 934-1 |
| Recommended dosage | 0.3 to 1.0 litre per 100 kg of cementitious material (trial starting range) |
| Flammability | Non-flammable, water-based |
| Suitability | Reinforced, prestressed and mass concrete suitable for all common cements |
| Addition method | Add to the mixing water via a calibrated dosing system |
| Storage temperature | Approx. 2 C to 40 C, in original closed containers, kept dry and frost-free |
| Overdose effect | ~2x max dose may cause delayed setting and extra entrapped air |
Industry use cases
Ready-Mix Concrete (RMC)
A single multi-range plasticiser that lets a batching plant cover several winter mix designs from one tank, holding workability and strength as ambient temperatures drop during early-morning dispatch.
High-Rise & Commercial Building
Reinforced columns, cores and slabs poured through North-Indian winters benefit from water reduction and low setting-time variation, protecting striking schedules and floor-cycle times.
Precast & Prestressed Yards
Chloride-free chemistry suits prestressed beams, planks and precast units where reinforcement protection is non-negotiable, while denser concrete improves finish and durability.
Infrastructure & Mass Concrete
Foundations, rafts and abutments placed in cold conditions gain controlled water reduction and reduced permeability without aggressive retardation.
Hill-State & High-Altitude Projects
Projects in Himachal Pradesh, Uttarakhand, J&K and Ladakh, where genuine cold-climate concreting windows are common, use MR276 to keep concrete placeable and gaining strength.
Frequently asked questions
What is Fosroc Conplast MR276 used for?
What is the recommended dosage of Conplast MR276?
Is Conplast MR276 chloride-free and safe for reinforced concrete?
How is MR276 different from a normal plasticiser like Conplast P211?
Can Conplast MR276 be used with other Fosroc admixtures?
Does MR276 act as an antifreeze for concrete?
How we position Fosroc Conplast MR276
Within the Fosroc Conplast admixture range, MR276 sits in the water-reducing plasticiser tier alongside general-purpose products such as Conplast P211 and the multi-range MR260/MR285, but it is differentiated by its cold-climate formulation. Where a project needs higher early strength or large water reduction at normal temperatures, the Conplast SP superplasticiser line (for example the chloride-free SP430) is usually the better fit, while MR276 is the smarter choice when the controlling problem is low ambient temperature rather than peak strength. For genuinely freezing conditions it is often paired with a separate cold-weather accelerating/antifreeze admixture rather than asked to do that job alone. Against competitors, contractors in India will reasonably compare it with Sika (Plastiment / Sikament plasticiser ranges), MBS/Master Builders Solutions (MasterPozzolith and the MasterPolyheed mid-range water reducers), Dr. Fixit/Pidilite admixtures, and STP. Most of these vendors offer water-reducing plasticisers with broadly similar EN 934-2 compliance the practical decision usually turns on verified local technical support, mix-trial backing and consistent supply. As an authorised Fosroc distributor and applicator, Space Arc Engineering positions MR276 for cold-weather and winter pours where keeping concrete workable, dense and on-schedule matters, backed by hands-on dosage trials and method-statement support across Delhi NCR and Pan-India.
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