Patent ID: 10723661

Abstract:
The present invention is to provide an economical and efficient method of reducing drying shrinkage of a cement-based hardened body without requiring the cost and/or the labor and time. A cement-based hardened body is impregnated with a solution containing urea or a solution containing sulfate together with urea. An impregnation treatment may be by a method of coating or spraying the cement-based hardened body with the solution, or alternatively, immersing the cement-based hardened body in the solution containing both urea and sulfate for a predetermined period of time. The solution containing both urea and sulfate may be a solution prepared simply by dissolving both urea and sulfate in water. Besides, there are no particular limitations on a liquid allowing dissolution of both urea and sulfate, so long as it causes no impairment of a drying shrinkage reduction effect, and therefore, a solution having the drying shrinkage reduction effect in itself is also applicable for use of a solution containing both urea and sulfate in a state of being dissolved in such solution.