Sürdürülebilir Kalkınma Amaçları

• 2

Yazarlar

• Gökçe, H. Suleyman(1)
• Gökçe, H.S.(1)
• Hatungimana, Daniel(1)
• Hosseinnezhad, Hojjat(1)
• Pourghadri Sefidehkhan, H.(1)
• Ramyar, Kambiz(1)
• Üzüm, Onur(1)
• Şimşek, O.(1)

• MakaleYalnız künye2022Scopus SJRQ1/r/bayburt/13076
  Performance of fly ash-blended Portland cement concrete developed by using fine or coarse recycled concrete aggregate

  Şimşek, O.; Pourghadri Sefidehkhan, H.; Gökçe, H.S.

  The recycling of concrete and industrial wastes in the production of new concrete structures has increased its share due to the growing environmental concerns of the world. In this study, the use of recycled concrete aggregate at various replacement amounts (0–100 %) was investigated to be fine or coarse aggregate sources instead of crushed natural aggregate to understand better its effects on the dimensional stability and durability aspects of fly ash-blended Portland cement concrete. In the presence of recycled concrete aggregate, fly ash was very important for eliminating possible mechanical losses of concrete at 90 days. The use of coarse recycled concrete aggregate resulted in better compressive strength values of concrete exposed to with and without wetting–drying and freezing-thawing cycles when compared to fine ones. While the free drying shrinkage of concrete increased at significant amounts (68 and 79 %) for fine and coarse recycled concrete aggregate, the restrained drying shrinkage crack widths were reduced up to by 13.5 %. In conclusion, it should be noted that the amount and size of recycled concrete aggregate need to be designed by considering the residual quality and dimensional stability of concrete, which exposes weathering actions in place.

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  AtıfScopus57·WoS50·OpenAlex54

  İncele
• MakaleAçık Erişim2020/r/bayburt/14311
  Optimising High Lime Fly Ash Content By Means of Silica Fume Incorporation to Control Alkali-Silica Reaction And Drying Shrinkage of Mortars

  Gökçe, H. Suleyman; Hosseinnezhad, Hojjat; Üzüm, Onur; Hatungimana, Daniel; Ramyar, Kambiz

  In this study, the effect of binary and ternary cementitious systems composed of portland cement, high-lime fly ash and silica fume on the compressive strength, alkali-silica reaction (ASTM C 1567) and drying shrinkage of mortar mixtures was researched. For this purpose, binary and ternary binders were prepared with partial replacement of cement with either fly ash (15wt% and 30wt%) or silica fume (5wt%) or both mineral admixtures (15wt+%5wt% and 30wt%+5wt%). An alkali reactive basalt aggregate was used in this study. It was found that partial replacement of cement with high-lime fly ash reduced the strength of mortar mixtures even up to 28-days. Besides, addition of 5% silica fume had not a significant effect on the early strength of fly ash-bearing mixtures. However, silica fume inclusion improved the 28-day strength of mixtures. In terms of alkali-silica reaction (ASR), the fly ash with lower lime content reduced the 14-day expansion more than that of fly ash with higher lime content. The opposite results were the case in 28-day ASR expansions. The ASR expansions of the fly ash-bearing mixtures were significantly reduced by the introduction of the additional 5% silica fume to these mixtures. However, silica fume incorporation remarkably increased the drying shrinkage values of the mixtures. Finally, fly ash with higher lime content was found to be more satisfactory in terms of compressive strength, alkali-silica reaction and drying shrinkage in the ternary binder system.

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  AtıfOpenAlex1

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