Title:
Setting and Hardening of Geopolymeric Cement Pastes Incorporated with Fly Ash
Author(s):
Yunsheng Zhang, Zongjin Li, Wei Sun, and Wenlai Li
Publication:
Materials Journal
Volume:
106
Issue:
5
Appears on pages(s):
405-412
Keywords:
electrical resistivity; fly ash; geopolymeric cement; hydration.
DOI:
10.14359/51663140
Date:
9/1/2009
Abstract:
In this study, a fully automated electrodeless resistivity apparatus was developed and used for continuously monitoring the changes in electrical resistivity with time of geopolymeric cement pastes with fly ash. The results showed that the incorporation of fly ash increased the geopolymerization reaction rate to some extent and ultimate electrical resistivity of geopolymeric cement pastes. Comparatively, the fly ash content had a little impact on electrical resistivity. The physicochemical process that occurred during the geopolymerization process was also analyzed on the basis of the electrical resistivity evolution curves. To aid in understanding the resistivity measurement, an environment scanning electron microscope with energy dispersive X-ray (EDX) analysis (ESEM-EDXA) was employed to observe in place the geopolymerization process at early ages. In addition, geopolymeric products were characterized by using X-ray diffraction (XRD) and infrared analysis (IR). Based on the aforementioned analysis, a describable model involving dissolution, reorientation, and polycondensation reactions was established for a better understanding of the geopolymerization reaction during the setting and hardening process of geopolymeric cement incorporated with fly ash.