Review of methods for activation of binder and concrete mixes

Increasing the efficiency of dry construction mixtures (binders) and concrete mixes can be achieved through using of various activation methods. In addition to using of various chemical modifiers in the binder composition, the important point is the grinding of dry construction mixtures, magnetic activation of mixing water, treatment of cement mortar with electrical discharges, etc. This article is a scientific review on this important issue of building materials science. The simplest method of solid-phase activation is the grinding of binder composites. A comparison of various milling machines allowing mechanochemical activation to different degrees was made. The method of solid-phase activation is effective, but a more cost-effective method is liquid-phase activation, consisting in external energy impact on the mixing water containing the functional additive. When intensive mechanical action is carried out in a rotary pulsation apparatus, the destruction of polymolecules occurs with the formation of a large number of active groups that can promote the polymerization of organic molecules with the formation of polymer structures that are more complex than the original ones. Activation of binder and inert components of the concrete (mortar) mixture by the free-impact method and subsequent vibroactivation in the turbo mixer-vibroactivator makes it possible to save expensive binder without reducing the mechanical properties of the finished building structures and increasing their cost price, improve frost resistance, improve wear resistance. The increase in temperature and pressure, the introduction of special additives, the chemical and mechanical dispersion of individual components and mixtures thereof, etc., also lead to the activation of binders. Among the non-agent methods for activating building mixtures and their components, one of the promising ones is treatment by high-voltage electric discharges.