Additives and admixtures are chemicals added to freshly batched concrete to improve the concrete properties for particular construction or landscaping applications. Some admixtures make the concrete set faster or slower, or make it denser, or make it stronger and more durable.
The commonly used admixtures include:
- Air-entraining agents – develops millions of tiny air bubbles in the concrete which improves workability and durability. Also reduces the risk of segregation and bleeding.
- Accelerators – increase the rate of chemical reaction which helps in the development of early strength. Very useful in winter and the colder times of the year.
- Water-reducing agents – help produce a medium slump, workable concrete, with less mixing water required.
- Superplasticisers – give a high workability and increase slump without the need for excess water in the mix (adding excess water dramatically affects concrete strengths). Very good in hard-to-place areas.
- Retarders – useful for hot conditions as they delay the initial set of the concrete.
- Fibres – provide secondary reinforcement in concrete and help prevent shrinkage cracking. We supply polypropylene, nylon, polyester, and steel fibres.
- Colour oxides – provide a vast array of colours for concrete.