Superplastyfikator BG97 40 is an aqueous solution of sodium salt of formaldehyde naphthalene sulfonic acid (NSF) polycondensates. The brown coloured product contains 40% of dry substance and is characterized by a very low content of free sulphates and chlorides, which allows its use as an admixture to concrete. It shows very good miscibility with other lignosulphonates plasticizers or melamine-formaldehyde condensates.
Superplastyfikator BG97 40 is a polyelectrolyte belonging to the dispersant group, used mainly in the construction industry as a base for liquefying and plasticizing admixtures. It belongs to the group of surfactants and as such consists of a hydrophobic organic chain and a hydrophilic sulfone group. Superplastyfikator BG97 40, 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).
The operation of the superplasticizer is mainly based on the principle of electrostatic repulsion. 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). The consequence is an increase in the fluidity of the concrete mix facilitating its pumpability. At the same time, the separation of cement grains from each other over considerable distances extends the time of formation of cement hydration products, which delays the start and end time of setting of the concrete mix.
The possibility of reducing the water / cement ratio (and thus reducing the consumption of batched water by up to 25%) without compromising the consistency of the mix leads to a reduction in the porosity of hardened concrete, which translates directly into a significant increase in the late strength of concrete (up to 30% compared to the mix without the addition of a superplasticizer) . It also improves the tightness of the concrete element, i.e. its resistance to aggressive substances and frost, as well as resistance to abrasion, as well as the adhesion of new concrete to old. Early strengths also increase, so the demoulding of the concrete element is accelerated. If the w / c ratio remains unchanged, and at the same time we reduce the amount of used water, we can reduce the amount of cement used, which, in addition to economic benefits, leads to a decrease in the heat of hydration emitted and reduction of shrinkage arising during the setting of concrete.
Due to the very low chloride concentration, the product does not contribute to corrosion of steel reinforcements in concrete structures. It does not introduce large amounts of air into the concrete mix, which can potentially lead to deterioration of frost resistance. In addition, it allows concrete to be made at an air temperature of up to -5 ° C without inhibiting cement hydration.
The use of even small amounts of Superplastyfikator BG97 40 (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. It is mainly recommended for the production of ready-mixed concrete, precast concrete and cement mortars.