Effect of carbonation in high chloride-binding capacity mortars subjected to a marine environment at early ages

This paper presents an experimental research on the effect of carbonation on the chloride penetration in mortars exhibiting a refined porous network and high chloride-binding capacity. The research was focused on the use of metakaolin combined with nanosilica, evaluating the influence of the surface area of the nanoadditions. It was observed that the addition of nanosilica reduces the binding capacity of metakaolin, this reduction was influenced by the type of nanosilica. The analysis of the carbonated samples following carbonation periods of three and six months allowed observing that the free chloride content as well as the bound chloride content are diminished with carbonation. Thence, it can be concluded that the carbonation process hinders the chloride penetration, which can lead to a reduction with time in the chloride concentration of samples.