What are admixtures used for?
Admixtures are chemicals which can be added to concrete to modify its properties. Available in liquid or mineral form, admixtures can be added before or during mixing to alter the state and performance of concrete. The use of admixtures can change the properties of fresh or hardened concrete, improving its durability, workability and strength. However, the result that admixtures achieve can depend on the cement brand and mixing proportions.
Why are admixtures used in concrete?
Admixtures are often used in concrete to meet challenging construction requirements. Whether the concrete is exposed to extreme climates or subjected to increased wear, admixtures can be used to prepare concrete to better withstand many conditions. Doing so will help reduce the overall cost of construction, as without admixtures, concrete exposed to severe conditions will likely need regular maintenance.
What are the different types of admixtures?
There are five main types of admixtures available, each classified by their function. These are air-entraining, water-reducing, retarding, accelerating, and plasticisers.
Accelerating admixtures reduce the setting time of concrete. These are recommended for use in cold conditions and will enable the concrete to withstand damage from freezing. If you’re on the lookout for an effective accelerating admixture, take a look at Sika Accelerator.
Water-reducing admixtures help to decrease the amount of water that’s required to mix concrete. This means concrete needs less water to reach its required level of workability and strength.
Air-entraining agents increase concrete’s durability and resistance to freeze-thaw degradation, by producing air bubbles in the concrete mixture. For an air-entraining admixture solution, take a look at Sika Air.
Retarding admixtures are used to delay the setting of the concrete. These are often used for long journeys or hot climates, to avoid the concrete setting too quickly.
Plasticisers or superplasticisers reduce the water content in concrete to increase its strength. This also helps to reduce the likelihood of separation or bleeding. For a liquid plasticiser admixture, find out more about Sika Mix Plus.
What is the best admixture for concrete?
Which admixture you choose for your concrete will depend on the properties you require for your construction project. However, the best brand for admixture products is Sika.
Sika have been producing high-quality concrete products for over 100 years. They believe that concrete should no longer be made up of cementitious materials, aggregates and water. Instead, concrete requires the addition of admixtures to reach its full potential. That’s why Sika provides a wide range of concrete admixtures to suit a variety of construction needs. To reinforce the strength of your concrete we’d recommend SikaCim No Crack Concrete Admixture or to reduce the porosity of your concrete take a look at Sika Proof Liquid Waterproofer.