| 摘要 |
PROBLEM TO BE SOLVED: To obtain an improving agent which can give high fluidity with a low water-cement ratio without variance in fluidity due to production factories or lots by compounding a material which can supply a cation to a liquid phase so that the cation couples with a sulfate ion to produce a hardly soluble salt when the material is kneaded with a cement and water. SOLUTION: This fluidity improving agent consists of a material which can supply a cation to a liquid phase so that the cation couples with a sulfate ion to produce a hardly soluble salt when the material is kneaded with a cement and water. For example, a material containing quicklime or one of chlorides, nitrate, nitrites, thiosulfates or org. acid salts of Ca, Sr, Ba and Pb is added by 1 to 1000 mmol to 1 kg of a cement. The fluidity improving agent is especially effective in a system using a cement dispersant. As for the dispersant, a polycarboxylic acid dispersant is preferably used and incorporated by 0.02 to 5 wt.% calculated in terms of a solid content to the cement weight. |
