Title: Fluidity Change of Cement Paste with Superplasticizer by K2SO4 and KF

Author(s): Kazuki Matsuzawa, Daiki Atarashi, Masahiro Miyauchi, and Etsuo Sakai

Publication: Symposium Paper

Volume: 302

Issue:

Appears on pages(s): 425-436

Keywords: polycarboxylate based superplasticizer; cement paste; fluidity; sulphate ion; fluoride ion; adsorption of superplasticizer

DOI: 10.14359/51688114

Date: 6/1/2015

Abstract:
The calcination temperature in cement manufacturing can be reduced by the addition of sulphate and fluoride containing compounds and it is possible that sulphate and fluoride ions elute to the suspension after calcination. This paper describes the influence of sulphate and fluoride ions on the action of polycarboxylate based superplasticizer in cement paste. When the amount of K2SO4 or KF was increased, the viscosity of the cement paste with superplasticizer increased. The amount of adsorbed superplasticizer was decreased by K2SO4 addition but increased by KF addition. The fluidity with polycarboxylate based superplasticizer containing more functional groups was less affected by K2SO4 addition. In contrast to the case of K2SO4 addition, the increase in the degree of viscosity by KF addition was not dependent on the amount of functional groups. The specific surface area increased with K2SO4 or KF addition.