Research Progress of Mechanical and Durability Performance of Concrete with Layered Double Hydroxides

Corrosion of reinforcing steel is one of the dominant factors in the durability degradation of reinforced concrete structures, posing a long-standing challenge in practical engineering. In recent years, Layered Double Hydroxides (LDHs) have shown great potential in concrete corrosion protection and other related fields due to their excellent ion-exchange properties and structural memory effect. Existing studies had indicated that the incorporation of an appropriate amount of LDHs (<5wt%) could significantly shorten the concrete setting time (by 5%~69%), enhance compressive strength (by 10%~46%) and flexural strength (by 18.1%~62%), as well as improve durability. However, there is a lack of systematic summaries on the differentiated effects and mechanisms of various LDH systems on different cement concretes. To fully understand the unique advantages that LDHs can offer in concrete,and to clarify the ways and mechanisms through which LDHs improve concrete properties, this paper first birefly described the physical and chemical properties and preparation methods of LDHs. Secondly, it summarized the recent research progress on the application of LDHs in cement-based materials, providing a comparative review of their effects on workability, mechanical properties, and durability, while also exploring their mechanisms of action and influencing factors. Finally, it offered an outlook on the current challenges in LDHs research, including difficulties in large-scale preparation, limited studies on mechanical properties, and a lack of long-term research, aiming to provide valuable insights for the future research and application of LDHs in concrete.