PURPOSE: To easily remove laitance by a method wherein a mixture made of retarder and polymer that is soluble to alkali while being unsoluble to water is applied to the surface of concrete cast over a floor, and a solubilized gelled coat is formed therewith.
CONSTITUTION: Rough levelling is made after casting of floor concrete C, and a mixture, being a copolymer comprising an organic compound having saturated group and organic acid having unsaturated bonding, and made of retarder and a polymer that is insoluble to neutral or weak acid water while being soluble to alkaline water at ordinary temperature is sprayed or applied uniformly to the surface of the concrete C. The mixture is swelled by alkaline component in bleeding water (w) bleeding out of the concrete C, and solubilized afterward, forming a thin, uniform gelled coat 1a. Then, a coat 1b that is solidified with laitance contained therein is formed over the surface of the concrete C, dividing the laitance layer clearly from the concrete surface layer lying thereunder. Thereby, the laitance can be removed easily by peeling off the coat 1b.
ASAMI MASAHIRO
ASAMI TSUTOMU
AOYAMA MIKI
HAYASHI YOSHIMASA
OGAWA HARUKA
DAICEL CHEM
ABC TRADING CO