Özet:

In this study, a mixture of fly ash (UK) and blast furnace slag (YFC) as an alumino-silicate source and NaOH and Na2SiO3 as the activators were chosen to investigate the synergistic effects of the UK and YFC on the mechanical and durability properties of geopolymer concrete. 5 different geopolymer concrete groups were produced using fly ash and blast furnace slag at the rates of 100-0, 80-20%, 70-30%, 60-40%, and 50-50% as binders. As a result of the preliminary experiments, the produced geopolymer samples were cured at 90°C for 72 hours. The compressive strengths of 3, 7, 28, and 90 days of produced samples were determined. Within the scope of durability tests, 28 day’s samples were exposed to 4 different high-temperature effects such as 200°C, 400°C, 600°C, and 800°C. The compressive strengths, capillary water absorption coefficients, weight changes, and UPV values of the samples were determined after high temperatures. As the internal structure analysis, scanning electron microscopy (SEM) analysis was performed after the high-temperature effect. As a result, with the addition of slag in the production of fly ash-based geopolymer, the mechanical and durability properties of the concrete improved and it was obtained a denser microstructure. After the effect of high temperature, among all mixtures, the highest compressive strength results belong to the mixture containing 50% slag.

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