Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2023Scopus SJRQ4/r/munzur/1629
  The influence of microwave curing on the strength of silica fume-added fly ash-based geopolymer mortars

  Yilmazer Polat, Berivan

  Geopolymer concretes a substitute for traditional Portland cement as a more environmentally sustainable alternative. In addition, one of the most significant advantages of geopolymer concrete is the high setting speed that can be achieved with thermal curing, that is, the short curing period. Research on geopolymer concrete has focused on curing, where curing is usually done with conventional ovens. Microwave curing initiates heat generation at the molecular level, which results in a minimal heat increase on the surface of the specimens compared to traditional thermal curing methods. In addition, it provides internal, rapid, and homogeneous heating and rapid strength development. This study is based on research that examined the effect of microwave cure on the compressive strength of silica füme-modified geopolymer mortar. In the study, sodium silicate and sodium hydroxide were used for activation, and first of all, fly ash substituted geopolymer mortar specimens were subjected to conventional thermal curing in an oven. On the other hand, the mortar specimens with the same composition were subjected to short-duration (10 minutes) microwave curing at power levels of between 200-600 W. When the results were compared regarding compressive strength, void and per-cent water absorption, UPV, and SEM-internal structure examination, it was revealed that microwave curing could be used faster than the conventional oven curing method in silica füme-added fly ash-based geopolymer mortars. This research can be considered an essential step for further optimizing and popularising geopolymer concrete and microwave curing and proposes a method that should be considered in the future development of more sustainable construction materials.

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  AtıfScopus7·OpenAlex7·TR Dizin4

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• MakaleAçık Erişim2022/r/munzur/2907
  Characterization of carbon fiber reinforced conductive mortars filled with recycled ferrochrome slag aggregates

  Doğan, Fatih; Dehghanpour, Heydar; Subaşi, Serkan; Maraşli, Muhammed

  Recently, it has been known that carbon fiber, a conductive fiber, is used in different mixture designs and the development of electrically conductive cementitious materials. Howev-er, the evaluation of ferrochrome slag as a recycled aggregate in the mixture of these special concretes has still not been investigated. In this study, electrically conductive mortars were produced using 100% recycled ferrochrome slag aggregate with a particle size of less than 1 mm as filling material and using carbon fiber in 4 different ratios, 0%, 0.5%, 0.75%, and 1%. To investigate the electrical conductivity properties, the resistivity values of the samples were measured at five different times within 2–180 days. In addition, 28-day compressive strength, flexural strength, dynamic resonance, ultrasonic pulse velocity, Leeb hardness, scanning elec-tron microscope, and X-Ray Diffraction tests were performed on all samples. The results were compared with the literature, proving that ferrochrome slag could be used as a reasonable aggregate in conductive mortars. The age effect was minimal in CF-added mixtures. With the addition of 1% CF, the resistivity values decreased approximately 40 times compared to the ref-erence. Moreover, SEM analyses of the CF-0.75 sample showed that the CFs adhered to form a conductive network between the components in the ferrochrome-filled compact structure.

  AtıfScopus10·TR Dizin5

  İncele
• MakaleAçık Erişim2022/r/munzur/2429
  Effects of single-walled carbon nanotubes and steel fiber on recycled ferrochrome filled electrical conductive mortars

  Dehghanpour, Heydar; Doğan, Fatih; Subaşi, Serkan; Maraşli, Muhammed

  The production of electrically conductive concrete was introduced years ago among construction materials, generally for anti-icing. The present study investigates the electrical, mechani-cal, dynamic, and microstructural properties of recycled ferrochrome filled cementitious mortars containing single-walled carbon nanotubes (SWCNTs) and steel fiber. Within the scope of the study, a total of 5 different mixtures were obtained. 7, 14, and 28-day non-destructive and 28-day compressive and bending tests of cementitious conductive mortars obtained from five different mixtures were performed. The two-point uniaxial method was used to determine the electrical conductivity properties of the samples. The damping ratio of the samples was obtained by performing dynamic resonance tests. Ultrasound pulse velocity (UPV) and Leeb hardness tests were performed as other non-destructive testing methods. Microstructure analysis at the interfaces of conductive concrete samples was characterized by scanning elec-tron microscopy (SEM), EDS (Energy-Dispersive X-ray Spectroscopy), and X-ray diffraction (XRD). The results showed a logical agreement when comparing their mechanical, physical, and dynamic properties. When SWCNT is used with steel fiber, the conductive mortar samples exhibited good conductivity, while their compressive and bending strengths turned below.

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  AtıfScopus11·OpenAlex13

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