Isolating the effects of thixotropy in geopolymer pastes

Allison S. Brandvold, Ghassan K. Al-Chaar, Waltraud M. Kriven

Research output: Contribution to journalArticlepeer-review

Abstract

The rheological properties of potassium-based geopolymers were investigated through a series of experiments intended to isolate the influence of shear rate, recovery time, and shear ramping on thixotropy for a greater understanding of geopolymer thixotropic properties within the context of the geopolymer setting reaction. It is shown that for thixotropic disruption to occur a critical shear rate of 100 s−1 must be reached or surpassed, full thixotropic restructuring occurs at around 90–100 min of total undisturbed rest time, and that reaching a state of full thixotropic disturbance heavily depends on subjected processing parameters. In addition, a consistent crossover between the storage and loss modulus within 1–3 min of oscillation during cyclical oscillatory measurements greatly indicates the repeatability and reversibility of thixotropy in geopolymers and the potential for tailorable viscosity. Overall, it is found that geopolymer pastes exhibit strong evidence of thixotropy, which is favorable for additive manufacturing, and that allotted rest time before shear and shear rate greatly influence the overall rheological properties.

Original languageEnglish (US)
Pages (from-to)2797-2807
Number of pages11
JournalJournal of the American Ceramic Society
Volume106
Issue number5
DOIs
StatePublished - May 2023
Externally publishedYes

Keywords

  • aluminosilicates
  • geopolymers
  • rheology/rheometry
  • viscosity

ASJC Scopus subject areas

  • Ceramics and Composites
  • Materials Chemistry

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