Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2023Scopus SJRQ2/r/bayburt/12824
  Effect of elevated temperature on radiation shielding properties of cement and geopolymer mortars including barite aggregate and colemanite powder

  Kök, S.; Türetken, M.S.; Öksüzer, N.; Gökçe, H.S.

  This study aims to investigate the radiation shielding efficiency of cement and geopolymer-based mortars after exposure to elevated temperatures which may happen during the activation process of nuclear reactors. To contribute to the shielding properties, these binders were modified with the substitution of colemanite powder (5 and 10%), and barite aggregate was used to be an alternative to silica sand, as well. The produced specimens were exposed to 300 and 500 °C. While the colemanite powder resulted in significant retardation of setting time up to 183% for cement-based series, a set accelerator effect reaching 67% was found in the geopolymer series. Unlike expectation, the losses in mechanical and shielding properties have become more pronounced in geopolymer mortars at the applied temperatures. In particular, a significant increase reaching 28% in compressive strength of cement series was found after 300 °C exposure. It was noted that cement series with reaching a linear attenuation coefficient of 0.162 cm−1 presented more effective shielding against gamma rays when compared to that (0.134 cm−1) of geopolymers. To moderate thermal neutrons, geopolymer series reaching a linear attenuation factor of 2.799 cm−1, were found to be a more promising alternative according to cement series reaching 2.140 cm−1.

  AtıfScopus30·WoS27

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• Derleme MakaleAçık Erişim2021Scopus SJRQ1/r/bayburt/10769
  A review on developments of environmentally friendly geopolymer technology

  Krishna, R. S.; Mishra, Jyotirmoy; Zribi, Marwa; Adeniyi, Funmilayo; Saha, Suman; Baklouti, Samir; Shaikh, Faiz Uddin Ahmed; Gökçe, H. S.

  This study aims to present an overview of the progress of geopolymer composites with regards to the latest developments on its constituents (binders, activators, and aggregates) and manufacturing techniques. Some ecological, economic, and industrial limitations of the traditional aluminosilicate binders yield to the pursuit of alternative ones over the period. Some of these latest binders e.g. ferrochrome ash, mine tailings, rice husk ash, red mud, have been highlighted in this paper. Current advances on replacement of natural fine and coarse aggregates such as mine tailings (iron ore tailings), recycled/lightweight aggregates for geopolymer preparation have been reviewed from the past literature. The paper also focuses on developments regarding the new class of green alkaline and acidic activators, which is traditionally considered to be the binding agent in the preparation of geopolymer composites. Different geopolymer production methods have been briefly discussed to study their effectiveness in achieving a strong and durable composite. This paper may serve to encourage further experimental research works for achieving more sustainable, cost-effective geopolymer composites with enhanced mechanical properties.

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  AtıfScopus89·WoS77·OpenAlex88

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