Aditivos para concreto leve | Agentes espumantes de alto desempenho para concreto celular
UM cement water reducer is a chemical admixture that decreases the amount of water used in concrete. Esta diminuição da água permite que o concreto hidrate a uma taxa menor, giving it better strength and durability.
Low-range water reducers, also known as normal water reducers or regular plasticizers, typically lower the amount of water in a mix by 5 para 10%. These water reducers are often used in everyday concrete applications such as driveways, calçadas, and basement walls.
Mid-range water reducers, also called plasticizers or intermediate plasticizers, typically lower the amount of concrete that needs to be mixed by 15 para 20%. These admixtures are often used in concrete for flatwork, such as driveways and sidewalks, because they reduce the water needed to produce a good-quality surface.
Redutores de água de alto alcance, also known to be superplasticizers or high range admixtures, are synthetic water-soluble organic compounds that decrease the amount of water in concrete by 25 para 30%. This results in a higher fluidity of the concrete, allowing it to flow better and provide more flexibility for placements.
These admixtures are usually added to the concrete mixture at a low dosage rate, although some high-range admixtures require a higher dose for optimal performance.
Most of these admixtures have no effect on the hydration of the cement, but some – like polycarboxylates – may increase air entrainment. This will vary depending on the chemistry of the admixture and its dosage rate. It is important to select the proper admixture for the application.