Effect of Chloride Ion on Free Nitrite Ion in Cement

Abstract

This was an experiment in which chloride was externally permeated into cement paste. The influence of on the content and distribution of free-form in the cement paste was researched using the chemical quantitative analysis method. The action mechanism was investigated by the micro-means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the physical competitive adsorption of with on C-S-H and the chemical substitution of to NO2-AFm caused more free-form in the cement paste. In the cement paste with chloride salt erosion, the concentration in the erosion surface was the lowest, and the concentration reached the highest value at 10mm from the erosion surface. The concentration decreased gradually with the depth from the erosion surface.