Concrete is made up of three ingredients: aggregates, cement and water. Thanks to the additives added to it, concrete can become more workable, impermeable and lend itself even better to the needs of construction. It can even be said that admixtures have become the fourth component of concrete.
Why add an admixture to concrete?
Admixtures are chemicals that added to concrete in low doses (less than 5% by volume) will modify its properties in the fresh or hardened state. Concrete admixture Malaysia use to be added during mixing.
Adjuvants are classified according to their effects:
- Setting retarders or accelerators.
- Plasticizers which increase the workability of fresh concrete.
- Water repellents that waterproof.
- The air coaches.
- Curing products that protect concrete during hardening.
- Grinding agents.
Use of concrete retarders
They slow down the setting by delaying the hydration of the concrete.
They are useful in hot weather to prevent concrete from hardening too quickly or when transporting concrete over long distances. When the conditions of setting up are difficult or long, they make it possible to carry out this one or to make a recovery more easily.
Use of concrete setting accelerators
They work by accelerating the hydration of the concrete. They are of two kinds: setting accelerators or hardening accelerators. Note that their use may result in lower mechanical resistance of the concrete.
Use of plasticizer for concrete
They facilitate the laying of concrete by making it more manageable. The water-decreasing plasticizers offer it better resistance.
Superplasticizers, which are synthetic polymers, have a greater action than traditional plasticizers for less product. Some are specifically designed for self-leveling (BAN) or self- leveling (BAP) concrete .
Use of water repellents for concrete
They make it possible to waterproof concrete by stopping capillary absorption. They are more suitable for use in coating plasters rather than in all concrete.
They are of two kinds: the bulk water repellent which is incorporated into the mixture when mixing concrete or the surface water repellent which is applied to hardened concrete. In the second case, the water repellent happens not to be any longer really an adjuvant. For more articles like this one, click here.