Pirohov D. Mechanochemical activation of mixed cement and its effect on the quality of building composites for various purposes

The object of research is building mortars and concretes on mixed mechanically activated Portland cement. The studies were carried out using the methods of planning of experiments and experimental-statistical modeling. Special attention was paid to determining the effective viscosity of cement-containing compositions, the amount of chemically bound water, the normal density and setting time of cement dough, the kinetics of exothermic heating of hardening cement stone, the strength of mortar and concrete, as well as its wear resistance. To solve the above tasks, a rotary countercurrent mill was designed and manufactured, and a viscometer based on Stokes' law was produced. Theoretically substantiated and experimentally proven validity of the proposed concept of reducing the material intensity of concrete products through mechanochemical activation of mixed cement binder on the strength of mortar and concrete, as well as the effect on its wear resistance. The novelty of the work consists in the fact that to study the effect of mechanochemical activation was used rotary counterflow mill, the optimal activation period of mixed Portland cement was established, which provides the achievement of maximum compressive strength of mortar and concrete and contributes to the achievement of minimum wear resistance of concrete. The results of the research are used in the Odessa State Academy of Civil Engineering and Architecture in the educational process in the training of Masters of specialty 192 “Construction and civil engineering” as well as on the production base of Small Private Enterprise “SAS” (Odessa) carried out production of 10 m3 of concrete mix on mixed activated binder strength, which at 28-day age, was 55 MPa. The results of research are recommended to use in monolithic construction as well as in road pavement construction.