Performance of Fly ash Based Geopolymer Mortars in Sulphate Solution
TLDR
In this paper, the performance of fly ash based geopolymer mortar specimens in Magnesium Sulphate solution was evaluated in terms of visual appearance, variation of pH of solution, change in weight and change in compressive strength over the exposure period.Abstract:
An experimental investigation was conducted to study the performance of fly ash based geopolymer mortar specimens in Magnesium Sulphate solution. Specimens were manufactured from low calcium fly ash by activation with a mixture of Sodium Hydroxide and Sodium Silicate solution and cured thermally. 10% by weight Magnesium Sulphate solution was used to soak the specimen up to 24 weeks. Performance of the specimens was evaluated in terms of visual appearance, variation of pH of solution, change in weight, and change in compressive strength over the exposure period. White deposits occurred on the surface of specimen which was initially soft but later converted to hard crystals. pH of solution increased noticeably during the initial weeks which indicate migration of alkalis from mortar specimens. At the end of 24 weeks samples experienced very little weight gain and recorded a loss of compressive strength by up to 56%.read more
Citations
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References
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TL;DR: In this article, the degradation of geopolymer materials using a class F fly ash (FA) and alkaline activators when exposed to 5% solutions of acetic and sulfuric acids was studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).
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TL;DR: In this paper, the authors investigated the durability of geopolymer materials manufactured using class F fly ash and alkaline activators when exposed to a sulfate environment and found that the most significant deterioration was observed in the sodium sulfate solution and it appeared to be connected to migration of alkalies into solution.
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