Investigations of chloride diffusion for reinforced geopolymer mortar

Alkali activated materials/geopolmers belong to a new class of materials which is re- ceiving a lot of attention in these last years thanks to their potential use as binder alternative to ordinary Portland cement. As the efficiency of geopolymers as new building materials still needs to be assessed from the durability point of view, rein- forced geopolymers mortars based on carbon fly ash were prepared with different Na2O/SiO2 molar ratio. The corrosion behavior of steel bars was investigated for samples subjected to wet and dry cycles in 0.1 M NaCl solution and a comparison with cement based mortars was carried out. In the investigated conditions, rein- forcements in geopolymers are corroded faster than in cement matrix mainly due to a quick lowering of the pH.