This work presents a laboratorial study based on previous researches about geopolymeric binders. The study is aimed at the knowledge of the effect of admixtures in the workability of this type of binders.
In this study, an investigation related to the rheological behavior of alkali-activated pastes is described.
Those pastes were prepared by mixing land mining waste from Panasqueira with an alkaline solution and adding some commercial chemical admixtures used in the Portland cement concrete fabrication, like polycarboxylates (latest generation) and naphthalene based.
The paste rheological data were determined by rotational viscometer measurements as well as by the use of the flow table test. Results indicate that chemicals admixtures used do not work the same in the Portland cement systems than alkali-activated systems although there were slight improvements in the workability of the pastes.
In order to improve the workability of this type of pastes was also tested the effect of temperature in the mixing process. Increasing temperature decreased the viscosity of alkaline solution but didn’t improve the workability of the paste.
Master Dissertation in Civil Engineering-Construction of Luís Filipe da Costa Vaz, 2011.