Представлены результаты электрокинетических измерений в реакционной системе "портландцемент – вода – добавка". Проведено сопоставление изменений температуры, окислительно-восстановительного потенциала, концентрации ОН⁻-ионов и значений рН в системе "портландцемент – вода – добавка" в зависимости от времени гидратации. Установлены закономерности и особенности влияния каждой из исследуемых добавок на процессы гидратационного структуро- и фазообразования в портландцементном тесте в ранние сроки твердения. Исследовано микроструктуру и поверхности излома образцов цементного камня, образовавшегося при твердении цементного теста с оптимальным содержанием добавок. Отображены особенности гидратационных процессов в микроструктуре цементного камня. The paper sets out the resultant electrokinetic evaluations of “Portland-cement – water – additive” investigated system. A comparison of the temperature, redox potential, ОН⁻-ions amount and pH values changes in “Portland-cement – water – additive” system depending on the hydration time has been carried out. Influence features of additives investigated on structure and phase forming processes of hardened Portland-cement paste in early curing times were determined. A probability of directed synthesis the crystallohydrate phases required combination, the desired morphology crystal growth, and also unstable solid solutions structure stabilization along with cement stone density and strength increasing are critically dependent on effect of reaction system electrokinetic variables. The microstructure and fracture surface of cement stone specimens obtained during the cement paste with optimum additives amount curing have been investigated. The cement stone microstructure hydration processes features are shown. The mutual individual phase arrangement into the crystallohydrate splices of cement stone and its microstructure porosity were studied. It is directly correlated to the electrokinetic variables performance corresponds with the latest curing times of cement stone.