Investigation into the effect of calcium on the existence form of geopolymerized gel product of fly ash based geopolymers
By Xianhui Zhao, Chunyuan Liu, L. Zuo, Li Wang, Qin Zhu, Mengke Wang. Cement & Concrete Composites, 2019
212 citations recorded by the source corpus.
Abstract Fly ash-based geopolymer, regarded as a eco-friendly cementitious material instead of ordinary Portland cement, has been rapidly developed and applied in practical engineering practice. Previous researches demonstrated that calcium component produces distinct effect on the formation of polymer gel products, and therefore influencing the macroscopic mechanical behaviors and microstructure of geopolymers. However, the influence mechanism of calcium component on the formation of gels product is still not clear. In this study, different content of Ca(OH)2 were adopted to prepare calcium containing geopolymers. The compressive strength and hydrochloric-acid attack tests were conducted to evaluate the effect of calcium content on the macro-performances. Then, scanning electron microscopy-energy spectrum test (SEM-EDS) was carried out to accesses the morphology and elemental components of the prepared composites. Thereafter, the microstructure of gels product was probed through Fourier transform infrared (FTIR) spectroscopy and 29Si nuclear magnetic resonance (NMR) spectroscopy. The critical value of elemental ratio (Na + K + Ca)/Al to characterize the gel product was specified. Two kinds of fly ash and two alkali-activated solutions were adopted to verify the results. The geopolymerization products will be calcium-containing geopolymer gels (C,N-A-S-H) when (Na + K + Ca)/Al≤0.95, while be coexist form of C-S-H and N-A-S-H gels when (Na + K + Ca)/Al>0.95. The results provide experimental basis and references for the application of calcium-containing solid wastes in geopolymer materials.
Subfields: Civil and Structural Engineering, Materials Chemistry
View Paper: https://www.semanticscholar.org/paper/a94faf1899215ca86026328b12cc2409bb6b3e70
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Civil and Structural Engineering
In Materials Chemistry
Citations in the corpus
- Effects of slag substitution on physical and mechanical properties of fly ash-based alkali activated binders (AABs) (2019, background): “30 Ca and high-Ca binders respectively are different, as it has been reported in the literature, but the behaviour of blended systems is still under investigation [56, 57].”