Rheology and agglomerate structure of fresh geopolymer pastes with different Ms ratio of waterglass

Abstract

This paper investigates the effect of Ms ratio of waterglass on the early age properties of the fresh geopolymer pastes, especially rheology properties. Rheology properties (fluid, yield stress, and plastic viscosity), agglomerate structure, and electrostatic repulsion (zeta potential) of geopolymer fresh pastes are measured in this paper. Morphologi G3 microscope is quantitative investigation on the agglomerate structure distribution and geometrical property of geopolymer fresh suspensions. Results show that Ms and content of waterglass has significantly influence on the agglomerate structure and rheology properties through the structure of waterglass and charge characteristic of geopolymer pastes. Structure of waterglass and electrostatic repulsion play important role in the agglomerate structure of geopolymer pastes in the early age. In the low Ms of waterglass, chain and ring structure of waterglass (Ms = 1.5) could reduce the inter-particles junction resulting to the formation of unstable chain agglomerate structure, which has low HS circularity and high elongation of structure. And High value of zeta and ring/sphere structure of waterglass would increases the dispersion of agglomerate structure and rheology of geopolymer pastes.