| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cement admixture for an underwater concrete, capable of providing a concrete hardly flowing out from a chink such as the chink of a molding box, and the chink such as a crack, hardly causing the separation of the materials and capable of providing a stable quality, even when the concrete is applied to the position at which the water is present, and further to provide a method for producing the underwater concrete by using the admixture. SOLUTION: This cement admixture for the underwater concrete comprises a polyvinyl alcohol and a boron compound, and the cement composition comprises the cement and the cement admixture. The method for producing the underwater concrete is characterized by adding either one component of the cement admixture to the cement, and forcibly feeding the resultant mixture, also forcibly feeding the other component by different passage, and joining both at the tip part and mixing the joined components when producing the underwater concrete. |
