11, Apr 2022
Naphthalene Sulfonate Formaldehyde (SNF) as Super Plasticizier
Naphthalene Sulfonate Formaldehyde (SNF) polycondensate is a linear polymer, while Polycarboxylate Ether (PCE) has comb copolymers with an adsorbing backbone and nonadsorbing side chains. Both of them are known to adsorb on cement particles or agglomerates, thus dispersing both cement particles/agglomerates and increasing flowability.
It has a powerful dispersing action on a concrete. The use of SNF Usual is based on its ability to reduces the water/cement ratio, to form flowing concrete and consequently increases the strength of the hardened material.
SNF disperses cement particles and reduces attractive interparticle forces, such as van der Waals forces, by electrostatic repulsion, while PCE acts through both electrostatic repulsion and steric hindrance between nonadsorbing side chains .
SNF seems to be more robust in Self-Consolidating Concrete (SCC). To fulfill other rheological properties, such as high stability, low segregation, Viscosity Enhancing Admixtures (VEA) or Viscosity Modification Agents (VMA) are also commonly added in SCC.
Superplast Usual has to be disolved first (if it was in powder form). Ready to be used liquid is added into a concrete and a mortar in the amount 0.3 – 0.8 % of dry substance from cement mass.