Effects of activator properties and GGBFS/FA ratio on the structural build-up and rheology of AAC

By Xiaodi Dai, S. Aydın, M. Yardımcı, Karel Lesage, G. de Schutter. 2020

147 citations recorded by the source corpus.

Abstract The effects of ground granulated blast furnace slag/fly ash (GGBFS/FA) ratio, mass ratio of SiO2 to Na2O (Ms) of activator solution and sodium silicate dosage on structural build-up, flow properties and setting characteristics of alkali-activated cement (AAC) mixtures were investigated. The solid-like behavior becomes more dominant with increasing GGBFS/FA ratio. Ms value had significant effect on the structural build-up. Significantly higher initial storage modulus with a low increasing rate was observed for the Ms values lower than 0.8. However, for higher Ms values, a sudden increase in storage modulus was observed after negligible initial structuration. An increase in sodium silicate dosage caused a considerable delay in the abrupt increase in the structural formation. It was observed that flow curves of AAC fit the Herschel-Bulkley model with shear-thickening behavior. ICP-OES tests revealed the lower release of aluminum and calcium into the pore solution of GGBFS/FA mixtures with low Ms values.

Subfields: Building and Construction, Civil and Structural Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/bdc207b415d3644402dd6e8ca1bdf1fef76c5ed6