Hydration mechanism analysis of alkali-activated fly ash and portland cement system

Sodium sulphhate and quick lime were added into fly ash and portland cement blend system which the ratio of fly ash was 50% to excite the early activity of fly ash,the early strength of the blend cement system was studied,and the misrostructure of hardened pastes was analyzed by R-ray diffraction and scanning electron microscope.The result shows that the early strength of cement paste is greatly increased,and more calcium silicate hydrate and ettringite form in the cement paste but hydrated sulphoaluminate is not existent.The hard shells of fly ash are destroyed,the polymerization degree of silicon-oxygen and aluminum-oxygen is reduced,and the potential activity of fly ash can be enhanced.