MIXING AGENT FOR SUPERSTIFF-CONSISTENCY CONCRETE AND PRODUCTION OF SUPERSTIFF-CONSISTENCY CONCRETE USING THE SAME

PURPOSE:To provide a mixing agent for superstiff-consistency concrete which is used for an instantaneously demoldable concrete product, rolled-compression concrete pavement(RCCP) and rolled-compression dam construction (RCD) and to provide a method for superstiff-consistency concrete with the mixing agent used therefor. CONSTITUTION:Condensate having >=20,000 weight average molecular weight is obtained by separating the condensate of aromatic sulfonic acid with formaldehyde by a polymer separation membrane. The objective mixing agent for superstiff-consistency concrete is constituted of this condensate as a main component. Unit water quantity is reduced even for superstiff-consistency concrete whose slump becomes 0cm by using the agent of this invention. The secular change in compaction properties is made small. Moreover, strong wet penetration action is held for a long time. Therefore, the agent of this invention is effectively used as the one for instantaneously demoldable concrete pursuing high-degree compaction properties and for rolled-compression concrete necessitating maintenance of compaction properties.