About MC-Bauchemie MC-Crete 120

MC-Crete 120 is MC-Bauchemie’s answer to one of the most common problems on an Indian site: concrete that stiffens faster than the crew can place and finish it. When the ambient temperature climbs into the high thirties or forties, cement hydration accelerates, slump loss speeds up, and a truck that took ninety minutes to reach the pour can arrive with concrete that is already going off. This liquid admixture slows that clock down. Built on hydroxylated carboxylic acid and lignosulfonate chemistry, it interferes with the early hydration of the C3A and C3S phases in cement, pushing back both initial and final set by a controllable window of two to six hours depending on dosage and mix.

The value of that extra time shows up wherever a pour is too big or too far to finish in one go. In mass concrete, raft foundations and deep sections, retardation keeps successive layers plastic long enough to knit together, so you avoid the cold joints that become leak paths and weak planes later. For ready-mix suppliers running long hauls through Delhi NCR traffic, it protects workability over the journey. And because it is chloride-free, it is cleared for reinforced and prestressed concrete where chloride-bearing retarders would risk corrosion. Crucially, the retardation is temporary: early-age strength recovers as hydration resumes, and by 28 days the effect on compressive strength is negligible.

The technical insight

Cement sets because C3A and C3S react with water almost immediately, forming the hydration products that stiffen the paste. MC-Crete 120 works by adsorbing onto the surfaces of these reacting cement grains. The hydroxylated carboxylic acid component forms a temporary barrier film around each particle that slows the ingress of water, while the lignosulfonate fraction disperses the grains and contributes mild water reduction. The net effect is that the induction period, the dormant window before rapid stiffening begins, is stretched out. Because the admixture only delays hydration rather than stopping it, the reaction restarts once the retarding film breaks down, and the concrete then develops strength normally. This is why a mix might show a 10 to 20% drop in one-day strength but catch up completely by 28 days. Dosage is the control lever: at the low end of the 0.1 to 0.5% range you get a couple of hours, and at the top end, or in cooler conditions, retardation can extend well beyond that, which is exactly why trial mixes matter before a large pour.

Where it is used

• Hot-weather concreting where ambient temperatures sit between 35 and 45 degrees Celsius
• Ready-mix concrete on long-transit routes of 60 to 90 minutes or more through city traffic
• Large raft and mat foundations poured in continuous layers
• Mass concrete elements such as dam blocks, thick rafts and heavy transfer slabs
• Deep caisson and bored-pile concreting where placement takes time
• Slipform operations that need a consistent, extended working window
• Combination with PCE superplasticisers for high-workability, retarded flowing concrete
• Sequential layer pours where cold-joint prevention is critical

Key advantages

• Adjustable retardation from 2 to 6 hours by simply varying dosage within the recommended range
• Keeps concrete workable through hot-weather placement and long ready-mix hauls
• Prevents cold joints in large and deep pours by keeping successive layers plastic
• Chloride-free, so it is safe for reinforced and prestressed concrete
• No penalty on 28-day compressive strength at recommended dosage
• Compatible with PCE-based superplasticisers for combined flow and retardation
• Conforms to IS 9103 Type B and EN 934-2 Type B for specification compliance
• Available in 25-litre and 200-litre drums and 1000-litre IBCs to suit site or plant scale

Limitations & considerations

• Overdosing can extend retardation far beyond intent, delaying finishing, formwork stripping and the construction programme
• One-day strength typically drops 10 to 20%, so early formwork removal or early load application must be planned around it
• Retardation is temperature-sensitive: in cooler conditions the same dosage delays set considerably longer
• Not a water-reducer or plasticiser in its own right, so a separate superplasticiser is needed where high workability or water reduction is the goal
• Performance and true set times must be confirmed by trial mixes with the project’s actual cement and aggregates before a critical pour

Selection & best practice

Specifications

Industry use cases

How we position MC-Bauchemie MC-Crete 120

MC-Crete 120 is the retarder in MC-Bauchemie’s admixture line and pairs naturally with their PCE superplasticisers where a project needs both high flow and extended working time, giving you a single-source, standard-compliant retarded-flowing concrete system. Where a specification is written around Fosroc, the equivalent is Conplast R, a water-reducing and retarding admixture to IS 9103 and ASTM C494 Type B and D. Space Arc supplies both families, so we can match whichever brand your consultant or client has approved. If your real problem is slump retention rather than set delay, look at a mid-range PCE water-reducer instead of a retarder; and if you are fighting heat on a mass pour, pair MC-Crete 120 with our curing compounds and temperature-control materials for the full hot-weather concreting package.

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