Layered double hydroxides (LDHs) modified cement-based materials: A systematic review

Ion erosion and carbonization in concrete are the key factors leading to the deterioration of durability. Layered double hydroxides (LDHs) are a kind of functional material with layered structures and ion exchange properties, which can capture a variety of harmful anions in concrete pore solutions. Therefore, LDHs exhibit great potential in improving the durability of concrete as new modified material. This article reviews the recent progress of LDHs. Based on the structural characteristics of LDHs, this work discusses the binding effect of LDHs on Cl-, SO42-, and CO32- in cement-based materials. We also analyze the influence of LDHs on the physical, mechanical, and hydration properties of cement-based materials and describe the modification mechanisms. Further, the improved durability of concrete and the corrosion inhibition of reinforcement by LDHs were summarized. Finally, we briefly point out some problems in the current research and development trends in the future on LDHs modified cement-based materials.