Changes in C-S-H composition during chloride exposure

Mortar samples were exposed to two NaCl solutions with different pH, to investigate the impact of leaching on total chloride profiles. One set of samples was exposed to a 3% NaCl solution. A set of twin samples was exposed to a 3% NaCl solution additionally containing KOH, to limit leaching. A clear correlation between the leaching depth and the chloride ingress depth was observed. We, therefore, investigated the changes in the C-S-H composition as a function of the depth from the exposed surface in the two sets of samples with SEM-EDS after 180 days of exposure. The results showed that the Ca/Si ratio of the C-S-H changed only in the outermost 0.3 mm. The Cl/Si ratio of the C-S-H followed the trend observed in the total chloride profiles. The adsorption of sodium and potassium on the C-S-H was also found to be depending on the leaching conditions during the exposure.      «

Mortar samples were exposed to two NaCl solutions with different pH, to investigate the impact of leaching on total chloride profiles. One set of samples was exposed to a 3% NaCl solution. A set of twin samples was exposed to a 3% NaCl solution additionally containing KOH, to limit leaching. A clear correlation between the leaching depth and the chloride ingress depth was observed. We, therefore, investigated the changes in the C-S-H composition as a function of the depth from the exposed surfac...     »