sika superplasticizer admixture is used in concrete to reduce water content, which results in improved workability and strength. It is available in liquid and dry powder form.

Admixtures are an essential part of a concrete mix. They can help prepare concrete to withstand challenging construction conditions, including extreme weather and increased wear. They can also increase concrete’s durability and resistance to freeze-thaw degradation, which can result in damage to the structure.

Types of admixtures

Admixture types include air-entraining, water-reducing, retarding, accelerating and plasticisers. Many of these admixtures are combined to provide one effect such as retardation or water reduction with acceleration, which can be a convenient way to use less admixture while still meeting the required properties.

Description of a specific product

Sika ViscoCrete-6100 is a high range water reducer and superplasticizer, amber liquid, pH 3 – 7, specific gravity 1.070 – 1.100, that utilizes Sika’s ViscoCrete polycarboxylate technology. It meets the requirements of ASTM C494 Types A and F and AASHTO M-194 Types A and F for conventional precast/prestress applications, as well as Self Consolidating Concrete (SCC).

The water-reducing action of the admixture is attributed to the adsorption of the cementitious particles with the chemically active groups on the adsorbent, which break the agglomeration and release the entrapped water. This allows for the reduction of the water content and increases the density of the concrete. The admixture is highly effective when dosed at a minimal wet mixing time. The dosage ranges from 0.05 to 0.5% of the powder weight.