Chloride binding in sound and carbonated cementitious materials with various types of binder

摘要: Abstract Carbonation and chloride ingress are the main causes of reinforced concrete structures degradation. Usually, these two phenomena studied individually. Here, has been investigated on sound carbonated cementitious materials (cement pastes concrete). The supplementary (SCM) fly ash, slag metakaolin. were by exposure to accelerated conditions (1.5% CO 2 65% RH) in laboratory. Chloride binding isotherms samples assessed equilibrium method (exposure various alkaline NaCl solutions). microstructure was characterized not only usual techniques such as XRD TGA–DTA, but also 29 Si 27 Al NMR spectroscopy. results show that bind less chlorides than ones. use a combination microstructural characterization reduces number possible explanations findings. In materials, both quantity Friedel’s salts bound C–S–H decrease. first decrease can be explained lack portlandite modification aluminate phases equilibrium. second seems due (change surface charge) during carbonation process. Moreover, differences according nature amount observed.