New Trends in the Development of Chemical Admixtures in Japan

• DOI: 10.3151/jact.4.211
• Publication Date: 2007-01-26T15:07:56Z
• Authors: Etsuo Sakai; Atsumu Ishida; Akira Ohta
• Keywords: Superplasticizer; Alite; Aluminate; Ettringite; Portlandite

This paper describes the history and new trends in development of chemical admixtures Japan. PC (polycarboxylic acid)-based agents are main products superplasticizer market. A low-stickiness type PC-based has been developed based on conventional superplasticizer. The flowing speed concrete with low stickiness is faster than that By addition a viscosity agent consisting mix anionic cationic surface active agents, three dimensional reticulation structures formed fresh cement paste can be increased segregation prevented. hydration sludge water controlled by set-retarder, specific area does not increase while large amount unreacted alite remains water. Recycling at ready mixed plants possible without adversely influencing properties when set-retarder containing gluconate salt used. slurry powder calcium aluminate accelerator (CA) calciumsulfoaluminate (CSA) for shotcrete have developed. In case CA, final setting time mortar accelerated increasing dosage. adding CSA, both initial times shortened dosages.