ABSTRACT

The adverse effects of the long term application of electrochemical chloride extraction on binding capacity of hydrated cement products are inneg-ligible. In this study, the influences of electrochemical chloride extraction in the microstructural properties of hydrated cement products of cement pastes were investigated in paste specimens by using a modified migration cell that was conducted with the applied current density of 4.5 A/m2 and synthesized pore solutions used as electrolytes for 8 weeks. Three types of cement pastes were used with the water/binder ratio of 0.4; that were ordinary Portland cement, fly ash cement and blast furnace slag cement pastes. Chloride source was supplied by adding 1.5% sodium chloride. After extraction, the acid-soluble chloride content significantly reduced. Portlandite content increased proportionally with the time of extraction in ordinary Portland cement and fly ash cement pastes Furthermore, the alteration and decomposition of C-S-H were inevitable with different rates.