1. Active hydraulic additive for long periods.
Due to the high dispersion and chemical activity of oxides of silicon and aluminum included in the fly-ash, it is energetically interacts with portlandite released during hydration of the clinker minerals, and binds it in a slightly basic hydrosilicate and hydroalumination calcium. These tumors form a gel, which fills the pores between the particles of aggregate, filler and cement grains, reducing porosity, and deposits (stores) water for further hydration of the cement. This increases the density of concrete (mortar), improves frost resistance and water resistance, disappear efflorescence.
2. Mineral plasticizer.
Usually concrete components are presented with angular debris particles, which barely fit into tight bezpustotnye packaging. Spherical particles of fly-ash are playing the role of a “bearing”, allowing the particles of the filler and the filler is easier to glide over each other. Introduction fly-ash reduces the water requirement of concrete and mortars, increases their flexibility and workability.
3. The active ingredient pozzolanic and composite cements.
The fly-ash contains as aluminosilicate glass in the form of individual microdroplets as subspectra particles composed of a mixture of active oxides of silicon and aluminum, an analogue of metakaolin. These oxides are very active and bind “extra” portlandit at an early stage of hardening of cement. As the aluminosilicate glass, on the contrary, has a prolonged effect, tying portlandit in the later period of cement hydration. The resulting hydrosilicate and hydroalumination calcium are sources of additional gain of strength, as in the early period of hardening of cement and vintage age, and the long-term curing.
In addition, the decrease in the content of portlandite prevents ettringite (“cement Bacillus”, which considerably increases the sulphate resistance cement. High dispersion of ash allows you to add it to the cement without the need of a joint grinding.