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- MakaleYalnız künye2026Scopus SJRQ1Mechanical and durability properties of sustainable alkali-activated mortars with ceramic insulator waste and andesite powder as partial substitutes for GBFS
Cemalgil, Selim; Yön, Merve Şahin; Dener, Murat; Karataş, Mehmet
This study explores the use of andesite powder (AP) and ceramic waste powder (CWP), derived from discarded electrical insulators, as supplementary precursors to ground granulated blast furnace slag (GBFS) in alkali-activated self-compacting mortars. The originality of the work lies in the combined utilization of these regionally sourced aluminosilicate wastes in binary and ternary binder systems, aiming to reduce GBFS dependency while ensuring adequate mechanical and durability performance. AP and CWP were used to replace GBFS at up to 50%, and the mixtures were evaluated for flowability, mechanical strength, density, porosity, water absorption, and capillary sorptivity. Durability was assessed through freeze–thaw cycling and high temperature exposure, and microstructural characteristics were examined using scanning electron microscope analysis. Results showed that while partial substitution with AP or CWP reduced compressive strength compared to the GBFS control, the incorporation of CWP in ternary systems partially compensated for the strength losses associated with AP. High temperature resistance improved markedly with increased CWP content; at 900°C, the 50% CWP mixture retained 44% of its original compressive strength, in contrast to 8% for the control. Although all mixtures containing waste exhibited reduced freeze–thaw resistance, mortars containing CWP exhibited superior performance compared to those with only AP. These findings highlight the potential of CWP, particularly in ternary systems, for developing sustainable alkali-activated mortars.
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İncele - MakaleAçık Erişim2024Scopus SJRQ2The Behavior of Ceramic Fiber Geopolymer Concrete under the Effect of High Temperature
Dalğıç, Aras; Yılmazer Polat, Berivan
Geopolymer concrete (GC), also known as green concrete, contains slag, silica fume, and fly ash as binders. The absence of cement in concrete is critical to protect the world from the environmental impacts of cement production. In addition, exposure to high temperatures is a critical parameter that causes loss of strength in concrete. In this study, Geopolymer concrete samples were prepared with 10 different samples containing different proportions of slag, silica fume, and porous ash and subjected to various physical, mechanical, and optical tests. The sample (GS90) with optimum workability and compressive strength, which also showed high performance in water absorption, freeze-thaw, and UPV tests, was used in high-temperature tests. Portland cement concrete (PCC) was used as a control sample. This study investigated the effect of high temperatures on the physical and mechanical properties of fiber-free GCs containing 2%, 5%, and 10% by volume of ceramic fibers. Therefore, fiber-reinforced, fiber-free, and PCC specimens were subjected to high-temperature tests at 100, 300, 600, and 900 °C. As a result of the observation of crack growth, color changes, and compressive strength parameters in the samples subjected to high-temperature tests, the thermal resistance of the 10% ceramic fiber geopolymer concrete sample was 2.5% higher than other samples. There is no study in the literature that examines the behavior of ceramic fiber-reinforced geopolymer concrete at high temperatures. This research revealed an important finding by proving that ceramic fiber reinforcement increases the compressive strength of geopolymer concretes at a remarkable rate after high-temperature impact.
AtıfScopus8WoS10OpenAlex8İncele - Yüksek Lisans TeziAçık Erişim2022Flubendiamide etken maddeli yeni nesil insektisitin farklı sıcaklıklarda Gammarus pulex'teki nörotoksik etkisinin belirlenmesi
Hilal Söylemez
Bu çalışmada, yeni nesil Flubendiamide etken maddeli insektisitin hedef dışı sucul bir organizma olan Gammarus pulex (L., 1758)'teki nörotoksitesinin sıcaklıkla değişiminin belirlenmesi amaçlanmıştır. Öncelikle G. pulex organizmalarının belirlenen (16, 18 ve 20 °C) sıcaklıklardaki flubendiamide etken maddeli insektisite olan akut toksisite değerlerinden 96 saat süredeki LC50 değerleri probit analizi ile belirlenmiştir. Flubendiamide etken maddeli insektisitin 16, 18 ve 20 °C sıcaklıktaki LC50 değerleri sırasıyla 256,83 ± 19,59 µgL-1, 169,38 ± 34,17 µgL-1 ve 155,84 ± 17,22 µgL-1 olarak belirlenmiştir. Test organizmasının artan sıcaklıkla flubendiamide etken maddeli pestisite olan akut toksisite hassasiyeti de artmıştır. Her bir sıcaklıklığa ait flubendiamide pestisitinin G. pulex'teki LC50 değerlerinin ortalamasının 1/20, 1/10 ve 1/5 oranında sublethal konsantrasyonlar belirlenmiştir. G. pulex organizmaları belirlenen söz konusu sublethal konsatrasyonlara 96 saat süreyle maruz bırakılmıştır. Kontrol grubu dahil 10 grupta her sıcaklık için asetilkolinesteraz (AChE) enzim aktivitelerindeki değişimler ELISA kitleri kullanılarak belirlenmiştir. Elde edilen bulgulara göre, tüm gruplarda konsantrasyon arttıkça AChE enzin aktivitesinin inhibe edildiği tespit edilmiştir (p˂0,05). Aynı sıcaklıktaki 24 ve 96. Saatler arasındaki maruziyet süresi istatistiksel açıdan önemsiz olduğu belirlenmiştir (p˃0,05). Sıcaklık artışına bağlı olarak flubendiamide etken maddeli pestisitin test organizması üzerinde AChE enzim aktiviteisini inhibe değerinin arttığı tespit edilmiştir. Flubendiamide insektisitine karşı farklı sıcaklıklarda G. pulex' te AChE enzim aktivitelerinde meydana gelen değişikliklere bakıldığında yararlı biyobelirteç olarak kullanılabileceği kanaatine varılmıştır.
- MakaleAçık Erişim2022Scopus SJRQ1High-temperature and abrasion resistance of self-compacting mortars incorporating binary and ternary blends of silica fume and slag
Yön, Merve Şahin; Arslan, Furkan; Karatas, Mehmet; Benli, Ahmet
Researchers from all over the world have recently developed an interest in the utilization of waste materials in the concrete industry. Using silica fume (SF) and ground granulated blast furnace slag (S) to manufacture self-compacting mortars (SCMs) could be a step toward sustainable waste management and produce the unique fresh qualities needed for SCMs. This research evaluates the abrasion and high-temperature resistance of SF and S based SCMs. A total of 14 mixtures were designed by partially replacing SF and S with Portland cement (PC) including control, binary and ternary mixtures. Binary mixtures were obtained by replacing cement by SF and S at replacement rates of 5, 10, 15 and 20 % and 10, 20, 30 % by weight respectively. Ternary mixtures were determined at the rates of 5, 10, 15 and 20 % SF and 10 and 20 % S respectively. The flexural strength and compressive strength of SF and S based binary and ternary water curing SCMs samples were determined at the age of 7, 28 and 90 days at room conditions. SCMs specimens were exposed to high temperatures after 90-day water curing. Water absorption, apparent porosity, sorptivity and abrasion resistance of 28-day water cured SCMs samples was also determined. The fresh and rheological properties of SCMs was evaluated by conducting mini-slump flow and viscosity tests. Cost analysis of the SCMs were also performed. The experimental results exhibited that the flowability of SCMs mixes containing SF was reduced with the increasing rate of SF compared to control while the workability of S incorporated SCMs mixes increased with the increase of S in comparison to control mixtures. Late- age of compressive strength above 70 MPa was achieved for 20 % SF incorporated binary mixture and 15 %SF and 10 % S incorporated ternary mixture. The ternary mixture with 15 % SF and 10 % S also exhibited the best abrasion resistance and the lowest sorptivity. Overall, it can be concluded from the mechanical characteristics and abrasion resistance that ternary combination of S with SF content of especially above 10 % and can be used to manufacture self-compacting mortar with a smaller carbon footprint.
AtıfScopus60WoS56OpenAlex62İncele