COMPARATIVE STUDY OF THE EFFECT OF LIGNOSULFONATE PLASTICIZER ON RHEOLOGICAL BEHAVIOUR OF VARIOUS ALKALI ACTIVATED MATERIALS AND CEMENT PASTES

prezentace, poster

angličtina

Alkali-activated materials (AAMs) are more sustainable alternative to ordinary Portland cement binders in the construction and building industry. However, these materials come with some cons, namely poor workability along with the limited effectiveness of commercially available plasticizers are some of the main issues [1]. Therefore, this study deals with the effect of different doses of lignosulfonate (LS) plasticizer in AAMs on their rheological properties and was based on previous experiments by Kalina [2] and Bílek [3]. To prepare AAM pastes, commonly used alkaline activators with a concentration of Na+ 4 mol∙dm−3 and precursors, namely ground granulated blast furnace slag, low calcium fly-ash and metakaolin were used. The effectiveness of the LS plasticizer was also investigated in Portland cement-based pastes to compare the functionality in more known systems. The rheology was tested by rotation and oscillation measurements using a DHR-2 rheometer, where the results of the rotation measurements were analysed by the Herschel-Bulkley model, and the oscillation measurements were amplitude sweep tests with evaluation of yield point and flow point. LS showed a significant improvement on workability in pastes activated by NaOH, namely in slag pastes (Figure 1).

MARKUSÍK, D.; BÍLEK, V.

12. 9. 2024

Brno, Czech Republic

80

80

113

https://www.fch.vut.cz/chl/konference/program/bookofabstracts-pdf-p269547