Conplast A657 is a setting accelerating additive, based on selected inorganic materials. It is supplied as a colourless, slightly yellowish solution that disperses immediately in water.

Conplast A657 acts as a catalyst for the initial hydration reactions of cements, especially at low temperatures, accelerating setting.

Uses

• Concreting at low temperatures in civil engineering and building works.
• Concretes requiring high initial strengths.

Advantages

• Helps to overcome concrete setting delays in cold conditions.
• Avoids concrete degradation due to freezing
• Rapid development of early strength
• Chloride-free, safe to use in reinforced concrete

Standards

Conplast A657 complies with UNE-EN 934-2:2010 Table 6 as a setting accelerator.

Typical dosage

The optimum dosage of Conplast A657 to achieve specific requirements should be determined by testing, using the materials and conditions that will be used in practice.

A starting point for such trials is to use a dosage rate of 0.5 to 3.0 litres per 100 kg of cementitious material, including ash, slag or microsilica.

Properties

The following results were obtained at a temperature of 20°C:

• Appearance: yellowish liquid.
• Density: 1,320 ± 0,02 kg/litre
• pH: 6,0 ± 1,0
• Water-soluble chloride content (CI-): ≤ 0,10%.
• Alkali content (Na2O equivalent): max. 5 mass %.
• Primary function: Accelerate setting of concrete.
• Secondary function: rapid development of initial strength

Mode of application

Mix design

Once the appropriate dosage has been selected, care must be taken to ensure the consistency of the materials used and the mixing and distribution processes.

The use of Conplast A657 does not exempt the precautions and measures that must be taken for the correct execution of concreting at low temperatures. The temperature of the fresh concrete must be higher than 5ºC and a minimum quantity of cement must be used according to the standard.

Compatibility

Conplast A657 is compatible with other Fosroc Euco concrete admixtures. If more than one admixture is used, they must be added to the concrete separately and not mixed together before being added. The resulting properties of concrete containing more than one admixture must be checked by prior testing.

Conplast A657 is suitable for use with all cements complying with RC-08.

Dosing system

The correct quantity of Conplast A657 should be measured by means of a suitable dosing system. Contact Fosroc Euco's Technical Department for advice on the appropriate dosing equipment and its installation.

Effects of overdosage

An overdosage of twice the quantity of Conplast A657 will result in an increase in the setting speed. In addition a faster loss of workability may be experienced.

Curing

The final characteristics of any structural concrete will depend on good curing practice. It is therefore very important to use a Fosroc Euco Concure curing membrane, water spray or wet burlap.

Clean-up and disposal

Spills of Conplast A657 should be absorbed with sand or earth and transferred to suitable containers. Product residues should be flushed away with a large amount of water.

Disposal of the product and packaging is the responsibility of the end user and should be carried out in accordance with existing local legislation.

Storage

Conplast A657 has a storage life of 12 months if kept in a dry place in its original, sealed containers at a temperature between 2ºC and 40ºC.

Freezing point: Below -15ºC.

Precautions

Safety and Hygiene

Conplast A657 is alkaline and irritant and should not be ingested or in contact with skin and eyes. Wear protective gloves and goggles. Splashes on the skin should be washed off with water. In case of contact with eyes, flush with plenty of water and seek medical advice. If swallowed, seek immediate medical attention. Do not induce vomiting.

For further information, please refer to the Material Safety Data Sheet.

Fire

Conplast A657 is water based and non-flammable.