摘要 |
An underwater concreting cement composition comprising a base prepared by adding (a) 0.2 to 2.0 parts by weight of hydroxyethylcellulose and (b) 0.01 to 0.2 part by weight of high-molecular weight polyethylene oxide and/or 0.2 to 4.0 parts by weight of calcium formate. The hydroxyethylcellulose preferably has the molar number of ethylene oxide substituted per glucose unit of 1.5 to 4.0 and a viscosity at 25 DEG C. in a 1% aqueous solution of 1,000 to 7,000 cP. The high-molecular weight polyethylene oxide preferably has an average molecular weight of 60,000 to 6,000,000. Calcium formate is added to accelerate the setting. This underwater concreting cement composition can be directly placed under water or in a watery place. Moreover, this composition is free from bleeding and can be pumped. |