Title:
Physicochemical Mechanism of the Action of the Naphthalene Sulfonate Based Superplasticizers on Silica Fume Concretes
Author(s):
M. Buil, P. Witier, F. de Larrard,
M. Detrez, and A. M. Paillere
Publication:
Symposium Paper
Volume:
91
Issue:
Appears on pages(s):
959-972
Keywords:
adsorption; mortars (material); naphthalene sulfonate;
plasticizers; silica; workability; zeta potential.
DOI:
10.14359/10106
Date:
2/1/1986
Abstract:
The adsorption of a naphthalene sulfonate formaldehyde (NSF) superplasticizer on the surface of a silica fume (SF) has been studied by adsorption isotherms and zeta potential measure-ments. A model is proposed for the fixation of NSF on a SF surface in the presence of cement, which can explain the high efficiency of this type of superplasticizer on the Portland cement - SF - Water system. The rheological efficiencies of several SF have been eva-luated by the determination of the water content of one fresh SF mortar composition at a constant workability. An hypothesis is suggested for explaining the higher water demands by the five silicon or ferro-silicon SF tested in this study, compared to a zirconia SF.