Examining the Binding Mechanism of Chloride Ions in Sea Sand Mortar

摘要

The adsorption and binding mechanisms of chloride ion in sea sand mortars were investigated through measuring the water-soluble chloride ion content in this paper. In addition, the microstructure of Friedel's salt were characterized by three approaches: X-ray diffraction (XRD), thermal analysis method (TG/DTA) and scanning electron microscopy (SEM). The results show that water soluble chloride ion concentration in the sea sand mortar is closely related to the extraction temperature. The water soluble chloride ion concentration increases with the extraction temperature increasing. When extraction temperature is 65°C, the concentration of water soluble chloride ion is about the double of mortars at 15°C. Physically bound chloride ion in fly ash mortar shows low dissolution in lower temperatures. In the sea sand mortar, the endothermic peak of Friedel's salt does not appear on the TG/DTA curve, while the existence of Friedel's salt was determined by SEM and XRD picture. This is probably owing to the small amount of instable Friedel's salt content in the sea sand mortar.