Title: Interaction between Cements and Superplasticizers

Author(s): H. Lombois-Burger, L. Guillot, and C. Haehnel

Publication: Symposium Paper

Volume: 239

Issue:

Appears on pages(s): 357-374

Keywords: adsorption; aqueous phase; cement; interaction; incompatibility; PEO side chains; polycarboxylate; rheology; sulphates; superplasticizer

DOI: 10.14359/18390

Date: 10/1/2006

Abstract:
The interaction between CEM I type cements and PolyCarboxylates with PolyEthyleneOxide side chains superplasticizers was examined to clarify the origin of incompatibility problems. Particular care was devoted to the possible role of a competition between sulphates and superplasticizer in these issues. Both laboratory and industrial cements were examined so as to analyze the influence of set regulator amount and/or nature, and of alkali level. The study mainly focused on the ionic composition of the aqueous solution, the consumption isotherms of the superplasticizers and the rheology of cement grouts. The results showed a major influence of the alkali sulphates of the clinker: the higher the latter, the higher the concentration of sulphates in the aqueous solution and the lower the superplasticizer consumption. The yield stress was correlated to superplasticizer consumption: it decreased when the consumption increased. On the other hand, the amount and nature of the set regulator appeared to induce a second order effect on the aqueous phase composition and on the superplasticizer consumption.