Abstract: The present invention relates to a chloride penetration resistant nano-hybrid concrete chemical admixture comprising layered double hydroxide and polyurethane copolymer. More specifically, nano-hybrid concrete chemical admixture obtained by combining the two compounds at a nano-scale, the layered double hydroxide which exhibits resistance to chloride penetration, and polyurethane copolymer which entails an excellent water reducing ability, durability and workability. In addition, the inorganic/organic hybrid material described herein exhibits high water reducing ability, improved resistance to chloride penetration, and thus can be used as chloride penetration resistant concrete chemical admixture for marine concretes.

Abstract: Disclosed are a polymer for ultra-high strength concrete admixture and a method for preparing the same, more specifically, a polymer for ultra-high strength concrete admixture prepared by polymerizing two or more copolymers based on unsaturated organic monomers having urethane derivatives, and and a method for preparing the same. Also, the concrete admixture comprising the polymer exhibits high water-reducing ability, thus improving workability and strength of the concrete composition. In addition, the concrete admixture exhibits defoaming capability, thus enabling easy control of air amount of the concrete composition without using any defoaming agent.