Use of calcium aluminum-layered double hydroxide to control chloride ion penetration of cement-based materials

Layered double hydroxide (LDH) has been successfully used for various purposes including anion exchange applications. In this work, calcium aluminum-layered double hydroxide (Ca-Al LDH) was utilized to immobilize the migration of chloride ion into cement-based materials. Among various types of LDH, Ca-Al LDH was chosen because it is the most similar form of LDH that can be found in cement-based materials. According to the results, it was found that synthesized Ca-Al LDH that showed chloride ion binding can be used for concrete up to 10% by replacement of Portland cement. The 10% replacement of Ca-Al LDH did not significantly affected 28-day compressive strength, but reduced the chloride ion penetration by both ASTM C 1202 and NT-BUILD 492 methods.