Chloride Binding Behaviors of Alkali Activated Materials

Chloride-induced corrosion remains to be a significant challenge for the durability of reinforced concrete structures. This chapter reviews the various factors affecting chloride transport in Alkali-Activated Materials (AAMs), including pore structure, chloride binding capacity, activator types, and curing conditions. AAMs possess a more refined pore structure, which can limit chloride permeability, but the chloride binding mechanisms differ from ordinary Portland cement (OPC) due to the absence of phases like Friedel's salt. The impacts of admixtures, such as micro- and nano-silica, and layered double hydroxides (LDHs) on improving chloride resistance in AAMs are considered. Testing methodologies, including electrochemical techniques, are evaluated to assess chloride-induced corrosion and the long-term performance of AAMs in aggressive environments. This chapter also emphasizes the importance of optimizing AAM formulations to improve resistance to chloride induced corrosion and promote their broader adoption in sustainable construction.