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Additives for concrete: types, dosing and compatibilities

Plasticizers, superplasticizers, retarders, accelerators, water repellents and air-entraining agents — what each one does, typical dosing based on cement weight and combinations that do work.

By Equipo técnico QuimicaSur Published on 16 de April de 2026 9 min read
Drums and containers of chemical additives for concrete

Without additives, modern concrete would not exist. However, their misuse explains a good part of the construction pathologies: cracking due to overdosage of plasticizer, delayed setting due to incompatibility between accelerator and water reducer, or loss of durability due to poorly calculated air-entraining agents.

The six families

  • Plasticizers (mid-range water reducers). Reduce mixing water by 5-12% while maintaining workability. Typical dosage: 0.3-1.2% based on cement weight.

  • Superplasticizers (high range). Reduce water by 12-30%. Self-compacting concrete, precast, high strength. Dosage: 0.5-2%.

  • Retarders. Prolong the setting time in warm climates or long transports. Dosage: 0.1-0.4%.

  • Accelerators. Speed up hardening. Useful in cold weather and for quick formwork removal. Dosage: 0.5-3% (chloride-free for reinforced concrete).

  • Mass water repellents. Reduce the capillary absorption of hardened concrete. Dosage: 0.5-2%.

  • Air-entraining agents. Generate stable microbubbles that improve resistance to freeze-thaw cycles. Dosage: 0.02-0.2%. Each 1% of air reduces strength by ~5%, calculate the final dosage carefully.

What the Quimicasur range covers

Our line of additives covers the families that concentrate the largest volume of work in concrete and mortar: water reduction, setting control, durability against moisture, and work in cold weather. For specific applications outside the catalog (civil engineering retarders, air-entraining agents for pavements in very cold climates) please consult us: we also work with third-party brands on request.

  • Plasticizer / water reducer: Adiflu 100, ideal for mortars and conventional concretes where workability is improved without increasing mixing water.

  • Superplasticizer: Adiflu C, for high strength, self-compacting and precast concretes.

  • Setting accelerator: Acelenet, chloride-free, suitable for reinforced concrete.

  • Antifreeze: Adiflu Gel, for concreting and mortars at low temperatures.

  • Mass water repellent: Hidro-masa (classified under waterproofing due to its end use), provides water repellency to the mixing water.

Compatibilities — what works

Plasticizer + retarder: yes, they are used together in summer concreting. Plasticizer + chloride accelerator: never in reinforced concrete. Polycarboxylate superplasticizer + high C3A cements: check the time loss curve of workability before purchasing at scale.

Air-entraining agent + plasticizer: compatible, but the plasticizer may carry additional air, recalibrate dosage after trials in the plant.

Rules to avoid issues

Adding dosages is not adding effects. Two additives at double the dosage do not yield double the result — they may cancel each other out or generate side effects (segregation, excessive delay, exudation). Start with the lower limit of the technical data sheet.

Always request the CE mark according to UNE-EN 934-2. Verify the compatibility test with your cement; polycarboxylates are sensitive to the C3A/SO3 ratio of the clinker.

Common mistakes on site

Add the additive to the mixing water instead of following the recommended sequence (dry mixing, water, additive). Overdose to "gain" workability without first measuring the slump. Reuse dirty water for cleaning the mixer: you alter the setting curve.

Products mentioned

Catalogue solutions for this case

View the full range

Adiflu C

Superplasticizer for mortars

Next-generation superplasticizer, plasticizing and air-entraining, substitute for lime in the preparation of mortars. Improves the workability of the mix, facilitates its placement, increases adhesion, eases demolding, and allows for a reduction in mixing water.

More information PDF disponible

Adiflu 100

Plasticizer-fluidifier for cement mortars

Water-reducing plasticizer that provides mortars with better workability, plasticity, cohesion, and an improvement in the water/cement ratio.

More information PDF disponible

Acelenet

Setting accelerator for mortars

Product created to accelerate the setting and hardening of concrete and mortar, increasing its strength even at very low temperatures. Free of corrosive substances in its composition. It is used in mass or reinforced concrete when it is necessary to shorten the setting time or maintain it at low temperatures.

More information PDF disponible

Hidro-masa

Water-repellent additive for concrete and mortars

Powerful water-repellent for mixing with mortars and concrete, achieving waterproofing of up to 99%. It also provides better plasticity and long life against carbonation and aluminosis. It does not alter transpiration (water vapor permeability).

More information PDF disponible

Adiflu Gel

Antifreeze for mortars

Protects concrete that may be exposed to cold temperatures during the hours following placement. It lowers the freezing point of water and accelerates setting, compensating for the slow development of strengths at low temperatures.

More information PDF disponible

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