Method for testing effects of sand quality on plasticizing additives in mineral binder compositions

A method for characterizing sands with regard to adsorption of plasticizing additives, comprising the steps of:

• a) providing an aqueous mixture of the plasticizing additive with a defined concentration of the plasticizing additive;
• b) determination of a characteristic of the aqueous mixture whereby the characteristic is related to the proportion of the plasticizing additive in the aqueous mixture;
• c) contacting a sample of sand to be analyzed with the aqueous mixture or a sample thereof, so that the sand sample is completely immersed in the aqueous mixture or the sample thereof;
• d) taking a sample of supernatant liquid from the mixture of step c);
• e) determination of the same characteristic as in step b) of the sample of supernatant liquid;
• f) comparing the characteristic of the aqueous mixture or the sample thereof obtained in step b) with the characteristic of the sample of supernatant liquid of step e) in order to decide whether the characteristics differ from each other by more than a predefined threshold or not.