Rocrete S, according to PN-EN 934-2 norm, is defined as a liquefying/plasticizing admixture, i.e. enabling the reduction of the content of added batched water in a concrete mix without affecting its consistency (reducing the water-cement ratio) or increasing the fluidity of the mix without changing the amount of batched water (maintaining a constant water-cement ratio).
Rocrete S is a surfactant composed of a hydrophobic organic chain and a hydrophilic inorganic sulfone group. After adsorbing on cement grains, it forms a layer of identical charges (sulfone groups) on them, which, when pushed together, breaks up the cement agglomerates and releases the trapped water (electrostatic repulsion mechanism). This leads to an increase in the fluidity of the concrete mix, making it easier to be pumped. In addition, due to the separation of cement grains from each other, the formation time of its hydration products increases, i.e. the setting time of the concrete mix is delayed.
By using Rocrete S, you can reduce the amount of batched water by up to 25% without changing the consistency of the mix (the water/cement ratio decreases). The concrete thus obtained has a late strength increased by up to 30% (compared to concrete produced without the use of Rocrete S) and is more airtight. Concrete tightness translates into an increase in its resistance to aggressive substances and frost, abrasion resistance and improvement of the adhesion of a new layer of concrete to the old one. Early strengths also increase, so demoulding of concrete elements can be faster.
By maintaining a constant water/cement ratio and using a small addition of Rocrete S, you can reduce the amount of cement used in the concrete mix. The fluidity of the concrete mix is maintained, and in addition to the economic benefits of lowering production costs, the amount of heat released during hydration is also reduced, reducing the shrinkage that occurs during the setting of the concrete.
The product is characterized by a low concentration of chloride, which does not contribute to the corrosion of steel reinforcements in concrete structures. Rocrete S does not introduce large amounts of air into the concrete mix, which can potentially lead to deterioration of frost resistance, and also allows the concrete mix to be made at an air temperature of up to -5 ° C without inhibiting cement hydration.
The use of even small amounts of Rocrete S (dosage from 0.5% to 3% per mass of cement) allows you to produce cheap and environmentally friendly concrete, which at the same time is characterized by very good strength and rheological properties (liquefaction of the mixture). It is mainly recommended for the production of ready-mixed concrete, precast concrete and cement mortars.