INFLUENCE OF MINERAL FINE SAPONITE-CONTAINING ADDITIVE ON SURFACE ACTIVITY OF PLASTICIZER

Plasticizing additives, which are surface-active substances, are widely used in the production of concrete mixtures in order to reduce the water-cement ratio and at the same time maintain the required mobility of the concrete mixture. There are various classes of such additives, the mechanism of action of which may differ, but is due to the occurrence of a common stage associated with the adsorption of plasticizer molecules on the surface of clinker minerals. During this stage, part of the water is released, which provides the plasticizing effect. The mechanism of action of a plasticizer based on an aqueous solution of surfactants is determined by its surface activity. Adding an additional component to the surfactant can change the value of the surface activity of the solution. In this regard, saponite-containing material (a waste product of the diamond mining industry), capable of exhibiting high adsorption-desorption activity in a finely dispersed state, is of particular interest. To study the effect of saponite-containing material on the properties of the plasticizing additive, highly dispersed saponite-containing powder was added to aqueous solutions of the plasticizer and the surface activity of the resulting solutions was determined. It was found that adding active highly dispersed saponite-containing powder with a specific surface of at least 1500 m2/kg to an aqueous solution of the plasticizer allows for an order of magnitude increase in the surface activity of the plasticizing additive.