A Look Into Portland Cement Types & Production Features

The post on portland cement manufacturing features is prepared in cooperation with Telling, the architectural company widely using hydraulic lime, lime mortar and concrete materials in its projects.

Plasticized portland is the product of pulverizing portland cement clinker with gypsum dihydrate (3-5%) and with addition of about 0.25% of yeast mash sulfide or other plasticizing additives at a grinding stage. These additives are adsorbed on the surface of the cement particles, improve wetting of cement with water and preventing their interaction. The additives reduce the friction between the grains of cement in concrete mixtures Рand between grains of filler, thereby increasing their mobility, which can reduce the consumption of cement in the concrete by 5-10%.

Hydrophobic Portland cement is the product of pulverizing portland cement clinker with gypsum dihydrate (3-5%) and with the addition of 0.1-0.2% of hydrophobic additives – oil soap, synthetic fatty acids, etc., during grinding. Synthetic fatty acids, their salts and other particles are adsorbed on the surface of the grains of cement, to form thinnest water repellent films, reducing wettability. As a result, the hydrophobic cements can stay a long time in air with high humidity without losing its qualities.

While stirring concrete the integrity of hydrophobic film is disrupted, after which the cement reacts with water easily. The remaining additives in the concrete improve its quality, such as increasing the frost resistance, resistance to aggressive environments, etc.

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