What are Admixtures?

Admixtures are additional materials that are added to the mix constituents to improve the properties of the concrete. A  selection of admixtures and their uses are listed below:

• Superplasticisers Give a high workability concrete without the need for excess water in  the mix. Very good in applications where placing of the concrete is difficult, i.e. heavily reinforced areas etc.
• Retarders These are particularly useful for hot weather concreting as they delay the initial set  of the concrete. A normal dose will retard the concrete for 2-4 hours. Also used to produce an exposed aggregate finish on concrete surfaces.
• Accelerators Increase the rate of chemical reaction which aids the development of early strength in concrete. Particularly useful in the winter where conditions often require rapid strength in concrete in order to withstand effects of low temperatures.
• Air Entraining Agents Improve workability and durability of concrete. Cohesion os also increased which reduces the risk of segregation and bleeding.
• Expanding  Agents Used to avoid cracking and  to compensate for water loss and plastic settlement.
• Fibres Assist in crack control and increase durability.
• Waterproofers Reduce the rate at which water can penetrate into or through  concrete.
• Colour Pigments Produce decorative  coloured concrete. Available in a variety of colours.

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Allied Concrete
Telephone 0800 4 ALLIED (Dial 0800 425 543)

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Telephone: +64-3-217-1600, Fax: +64-3-217-1077
 

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