Sanyo Chemical Industries, Ltd.

Takenaka Komuten Co., Ltd.

Takenaka Doboku Co., Ltd.

Soichi Kiya

Koichi Ito

Yasuhiko Yoshioka

Masaharu Sakuta

Tsunetoshi Shioya

Yoshifumi Shimoyama

Iwao Uchizaki

Tadahiro Kaya

Toshio Saito

Hiroyuki Yamakawa

A cement composition is provided which has the property of being inseparable in water, having improved strength and no effect in delaying setting time or reducing strength. It is produced at a cheaper cost by reducing the amount of a polyacrylamide compound to a considerable great extent. The polyacrylamide compound is present in an amount of 0.1 to 3% by weight based on the weight of cement, when a dialdehyde is added thereto.

Cement composition for laying underwater

A concrete composition is provided which has the property of being inseparable in water and no effect in delaying setting time or reducing strength. A polyacrylamide partial hydrolysate having a molecular weight of one million or higher and a hydrolysis degree of from 0.5 to 20% moles is present in an amount of 0.5 to 4% by weight based on the cement constituent proportion.

Water-inseparable concrete composition

Growing community of inventors

Hachioji, Japan

Soichi Kiya