Sprayset NSA is a strength-enhancing additive based on nanotechnology. Through reactions with chemical components unfavourable to concrete, it generates a greater quantity of calcium silicate gel, improving the initial and final strength of the concrete, as well as its durability. It is supplied as a white solution that is immediately dispersed in the mixing water.

Uses

• Specially designed for any concrete requiring high early strengths at any temperature.
• Heavy precast
• Production of tunnel segments (TBM)
• Production of segments for wind towers

Advantages

• Increased early strength at all temperatures, while improving ultimate strength.
• Significant reduction of water and gas permeability.
• Reduction of the porosity of the concrete, increasing its durability.
• Greater resistance to the attacks of different chemical agents.
• Reduction of thermal curing in the manufacture of segments.
• Increased formwork performance.
• Optimisation of energy and material costs.

Typical dosage

The optimum dosage of Sprayset NSA 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 of between 1.0 to 3.0 litres per 100 kg of cementitious material, including ash, slag and microsilica.

Properties

The following results were obtained at a temperature of 20ºC:

• Appearance: White liquid
• Density: 1,100 ± 0,02 kg/litre
• pH: 10 ± 1
• Water-soluble chloride content (CI-): ≤ 0,10%.
• Alkali content (Na2O equivalent): max. 5% by mass
• Primary function: Increase resistance
• Secondary function: Improve durability

Mode of use

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 Sprayset NSA 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 above 5ºC and a minimum amount of cement must be used in accordance with the standard.

Compatibility

Sprayset NSA 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 prior to addition. The resulting properties of concrete containing more than one admixture must be checked by prior testing.

Sprayset NSA is suitable for use with all RC-08 compliant cements.

Dosing system

The correct quantity of Sprayset NSA must be measured using a suitable dosing system. Contact Fosroc Euco's Technical Department for advice on suitable dosing equipment and installation.

Effects of overdosage

An overdosage of twice the amount of Sprayset NSA 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 Concure curing membrane, water spray or wet burlap.

Clean up and disposal

Spills of Sprayset NSA 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 must be carried out in accordance with existing local legislation.

Storage

Sprayset NSA has a storage period of 12 months in a dry place in its original, closed containers at a temperature between 2 and 40ºC.

Freezing point: Below -15°C.

Precautions

Safety and hygiene

Sprayset NSA is not classified as harmful by current regulations. However, it must not be swallowed or come into contact with skin and eyes. Wear suitable 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

Sprayset NSA is water based and non-flammable.