Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Yener, Engin(2)
- Andiç-Çakır, Ö.(1)
- Aydin, Abdulkadir Cüneyt(1)
- Bilir, Turhan(1)
- Brostow, Witold(1)
- Canbaz Öztürk, B.(1)
- Emre Gençoğlu(1)
- Gencel, Osman(1)
- Gokce, H. Suleyman(1)
- Gökçe, H. S.(1)
- Gökçe, H.S.(1)
- Gökçe, H.Süleyman(1)
- Gül, Muhammed Said(1)
- Gül, Rüstem(1)
- Hagg Lobland, Haley E.(1)
- Hinislioğlu, Sinan(1)
- Hinislioǧlu, Sinan(1)
- Kotan, Türkay(1)
- Kurt, Murat(1)
- Nehdi, M. L.(1)
- Ramyar, K.(1)
- Simsek, Osman(1)
- Teke, Çağatay(1)
- Tekin, Ilker(1)
- Tuyan, M.(1)
- Uçurum, Metin(1)
- Yasin Durgun, Muhammed(1)
- Çam, N.F.(1)
- Özdemir, Akın(1)
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ1Optimization of surface modification parameters of fly ash with high calcium oxide (CaO) content to use as a filling material
Uçurum, Metin; Özdemir, Akın; Teke, Çağatay
Fly ash (FA) is the fine-grained waste product obtained by burning coal after being ground to specific sizes in thermal power plants, carried with flue gases, and kept in cyclones or electro-filters. Like every industrial waste, the possibilities of utilizing FA have been investigated, and it can be utilized as an additive in cement and concrete. Despite this, industrial waste, which increases daily in the world, brings many problems, especially environmental problems. For this reason, alternative usage areas of the waste in question are constantly being investigated. In this paper, FA containing approximately 50 % CaO from Afşin-Elbistan, Turkiye was processed with stearic acid in a planetary mill to be used as a filling material in industrial products, and it has a grain size of 68.10 μm on a d50 basis, a specific surface area (SSA) of 176.40 m2/g and a contact angle of 13.89. An optimization and characterization study was conducted to make the hydrophilic surface structure hydrophobic by mechanochemical surface modification. Also, surface modification parameters, such as operational speed (rpm), ball filling ratio (%), FA filling ratio (%), pulp density, stearic acid dosage (% of FA), and modification time (min.) were optimized with the D-optimal experimental design. Based on the optimum surface modification parameters, a coated fly ash (CFA) product was obtained with an active ratio of 99.70 %, a contact angle of 95.06o, a medium size (d50) size of 10.60 μm, and an SSA of 926.90 m2/g.
AtıfScopus8WoS8OpenAlex9
İncele - Yüksek Lisans TeziAçık Erişim2022Yüksek plastisiteli kil zemin stabilizasyonunda uçucu kül dane boyutunun CBR ve dayanıma etkisi
Emre Gençoğlu
Zemin stabilizasyonunu genel olarak derin ve yüzeysel stabilizasyon olmak üzere ikiye ayırmak mümkündür. Yüzeysel stabilizasyon uygulamalarından biri kimyasal stabilizasyondur. Kimyasal zemin stabilizasyonunda inceliğin etkisini incelemeyi amaçlayan bu çalışma kapsamında, yüksek plastisiteli kil bir zeminin mühendislik özellikleri uçucu kül kullanılarak iyileştirilmiştir. Uçucu kül termik santralden alındığı haliyle ve inceltilmiş (öğütülmüş) olarak zemine ayrı ayrı ilave edilmiştir. Uçucu kül zemine %5, %10, %15, %20, %25, %30 oranlarında hem ham hem de öğütülmüş olmak üzere ilave edilerek CBR ve dayanım verileri incelenmiştir. Çalışma sürecinde serbest basınç deneyleri için kür süreleri 7 ve 28 gün olarak belirlenmiştir. Kıvam limitleri, kompaksiyon, CBR ve serbest basınç dayanımı deneylerinin gerçekleştirildiği bu çalışma sonucunda uçucu külün inceltilerek zemin stabilizasyonunda kullanılmasının kompaksiyon parametrelerindeki etkisinin sınırlı olduğu, kıvam limitleri üzerinde nispeten etkin olduğu, CBR ve dayanım değerlerinde ise çok yüksek artışlar meydana getirdiği tespit edilmiştir. Bu sonuçlar ışığında yüksek plastisiteli kil bir zeminde daha ince uçucu kül katkısıyla daha yüksek CBR ve dayanım verilerine ulaşılabilecek stabilizasyon çalışmalarının yapılabileceği kanaatine varılmıştır.
- MakaleAçık Erişim2021Scopus SJRQ3Aggressive environment performance of low energy cements containing fly ash
Gokce, H. Suleyman; Simsek, Osman
In this study, compressive strength performance of boron active belite cement containing fly ash at the ratios of 0, 10, 20, and 30% (by weight of cement) is researched against aggressive environments; sea water, 5% sodium sulphate solution, and 5% ammonium nitrate solution in addition to tapping water. Alternative low energy cement i.e., Portland-composite cement was used and its results were compared with those of boron active belite cement. Early strength losses (reaching up to 40%) of the boron active belite cement with incorporation of fly ash up to 30% were found to be less pronounced than those (reaching up to 51%) of Portland-composite cement in tapping water. Although, the losses were highly compensated with the prolonged curing period (90 days), boron active belite cement and Portland-composite cement kept their losses up to 14% and 36%, respectively. Residual mechanical properties (reaching up to 67%) of boron active belite cement against aggressive environments were found almost similar to those of Portland-composite cement in presence of 30% fly ash. In conclusion, the study shows that belite cements with low fly ash contents can be a reasonable alternative for specific applications such as mass concrete, hot weather concreting especially in aggressive environments.
AtıfScopus3WoS1OpenAlex5TR Dizin1
İncele - MakaleAçık Erişim2020Scopus SJRQ1Development of Eco-Efficient Fly Ash-Based Alkali-Activated and Geopolymer Composites with Reduced Alkaline Activator Dosage
Gökçe, H. S.; Tuyan, M.; Ramyar, K.; Nehdi, M. L.
The eco-efficiency and economy of geopolymer composites largely depend on their alkaline activator dosage. In this study, the effect of applying a pre-setting pressure and variation of the aggregate-to-fly ash ratio on the alkaline solution dosage and mechanical strength of fly ash-based geopolymer composites was explored. It is shown that through control of the aggregate-to-ash ratio and application of pre-setting pressure, compressive strength could be increased by 102% and 86% for Class F fly ash-based geopolymer and alkali-activated Class C fly ash-based mixture, respectively. The total alkaline solution consumption could be reduced from 718 to 188 kg/m(3) and from 769 to 262 kg/m3 for Class F fly ash-based geopolymer and alkali-activated Class C fly ash-based mixture, respectively. The proposed method reduced the alkaline solution consumption per compressive strength (6.2 kg.m(-3).MPa-1) by up to 85% compared to that of the reference manually consolidated control geopolymer. The findings demonstrate that fly ash-based geopolymers could be made more sustainable and eco-efficient through tailored production techniques. (C) 2019 American Society of Civil Engineers.
AtıfWoS23OpenAlex30İncele - MakaleYalnız künye2020Scopus SJRQ1Natural radioactivity of barite concrete shields containing commonly used supplementary materials
Gökçe, H.S.; Canbaz Öztürk, B.; Çam, N.F.; Andiç-Çakır, Ö.
The recycling of hazardous materials within new composites has a sustainable importance as it contributes on the reduction of high radionuclide concentrations. In this study, the effect of cementitious materials i.e. viscosity modifier, silica fume and fly ash on the 226Ra, 232Th and 40K activity levels of barite concrete shields was researched by using different mixing compositions in terms of binder content, w/b ratio and the amount of supplementary cementitious materials. In comparison to cement, silica fume and fly ash used in the production of concrete shields were found to have significantly higher activity levels of 40K, as well as 226Ra, 232Th and 40K, respectively. The 226Ra, 232Th and 40K activity levels of concrete shields range between 2.2 and 20.7 Bq kg−1; 2.6 and 7.0 Bq kg−1; 51.5 and 89.3 Bq kg−1, respectively. These activity values were found similar or less than those of building materials in the world. These satisfactory results are mostly caused by the barite source which has lower radioactivity levels. The concrete mixture details used in the study caused significant variation in the natural radioactivity of barite concrete shields. The introduction of silica fume which has high 40K activity levels and fly ash with high 226Ra, 232Th and 40K activity levels compared to cement and barite aggregate, significantly increased the radiological hazard parameters, although all results were found to be below the limits recommended by international reports. In conclusion, 226Ra activity levels of the concrete shields were significantly increased (up to 8.4 times) by the variation of mix design parameters used in comparison with concrete mixtures that have the least 226Ra activity level. The 232Th and 40K activity levels were as well increased in relatively less amounts (1.7 and 0.73 times higher, respectively).
AtıfScopus22WoS20OpenAlex23İncele - MakaleAçık Erişim2019Scopus SJRQ1High temperature resistance of boron active belite cement mortars containing fly ash
Gökçe, H.Süleyman
Boron allowing stability of reactive belite phase in clinker production enhances neutron shielding capability of cement. In the study, neutron attenuation factor of boron active belite cements at various fly ash introduction was theoretically revealed by comparing with an alternative low heat cement (portland composite cement). High temperature resistance of the cements with and without fly ash introduction was determined on standard mortar prisms at elevated temperatures up to 900 °C with regard to compressive strength and flexural strength. Neutron shielding performance of boron active belite cement was found almost 25 times higher than Portland composite cement. Fly ash introduction significantly reduced the neutron attenuation factor of boron active belite cement. High temperature resistance of boron active belite cement mortar was found lower than that of Portland composite cement mortar at 700 °C at later curing time. 10% fly ash introduction improved the high temperature performance of boron active belite cement mortar exposed to 900 °C. Residual compressive strength values of the mortars containing fly ash were between 16% and 28% after exposing 900 °C.
AtıfScopus39WoS36OpenAlex39İncele - MakaleAçık Erişim2017Scopus SJRQ1Concretes with synthetic aggregates for sustainability
Tekin, Ilker; Yasin Durgun, Muhammed; Gencel, Osman; Bilir, Turhan; Brostow, Witold; Hagg Lobland, Haley E.
We have used waste marble aggregates, marble dust and fly ash from thermic power plants as fillers in concretes for replacing natural aggregates. We have used two different kinds of cements. After curing, we have determined the workability (by slump tests), air content, unit weight, Schmidt hardness, ultrasound pulse velocity, compressive strength and carbonation depth. The concretes containing waste marble at least match or exceed the workability and strength of the control concrete type. Fly ash significantly improves the workability. Utilizing waste marble aggregate at the replacement ratio of 100% along with waste marble dust, fly ash and pozzolanic cements in concrete leads to lower cost – achieving at the same time environmentally friendly production process with decreased consumption of natural resources and energy. Our work also contributes to enhancement of sustainability by finding a use for marble waste and fly ash.
AtıfScopus28WoS24OpenAlex33İncele - MakaleAçık Erişim2015Scopus SJRQ2The effect of fly ash to self-compactability of pumice aggregate lightweight concrete
Kurt, Murat; Aydin, Abdulkadir Cüneyt; Gül, Muhammed Said; Gül, Rüstem; Kotan, Türkay
This paper presents the results of an experimental study on the effects of fly ash, different water/(cement + mineral additive) ratios and pumice aggregates to some physical and mechanical properties of self-compacting lightweight aggregate concrete. In this study, pumice had been used as lightweight aggregates. Several properties of self-compacting pumice aggregate lightweight concretes like the unit weight, flow diameter, T50 time, flow diameter after an hour, V-funnel time, and L-box tests, 7, 28, 90 and 180-day compressive strength, 28-day splitting tensile strength, dry unit weight, water absorption, thermal conductivity and ultrasonic pulse velocity tests were investigated. For this purpose, 18 series of concrete samples were prepared in two groups. Pumice aggregate was used as a replacement of natural aggregate, at the levels of 0, 20, 40, 60, 80, and 100% by volume. Furthermore, a second series of 100% pumice aggregate was used for the production of self-compacting lightweight aggregate concrete with constant w/(c + m) ratios as 0.35, 0.40, and 0.45 by weight. The flow diameters, T50 times, paste volumes, 28-day compressive strengths, dry unit weights and thermal conductivities of self-compacting lightweight aggregate concrete were obtained in the range of 600–800 mm, 2–8 s, 471–572 lt/m 3, 9.2–53.26 MPa, 839–2156 kg/m 3 and 0.321–1.508 W/mk, respectively, which satisfies not only the strength requirement of semi-structural lightweight concrete but also the flowing ability requirements and thermal conductivity requirements of self-compacting lightweight aggregate concrete.
AtıfScopus30OpenAlex36İncele - MakaleAçık Erişim2011Scopus SJRQ3The effects of silica fume and fly ash on the scaling resistance and flexural strength of pavement concretes
Yener, Engin; Hinislioğlu, Sinan
The purpose of this study is to investigate the effects of Silica Fume (SF) and Fly Ash (FA) additives on the frost salt scaling resistance and flexural strength properties of pavement concrete. An attempt is also made to attain a more durable and higher strength concrete by a suitable combination of Ordinary Portland Cement (OPC), SF and FA. SF and FA are used as cement replacement in proportions of 0, 5, 10% and 0, 5, 10, 15% by weight respectively. Flexural strength is tested after 7, 28 and 91 days of the lime saturated water curing period. The experimental results indicate that using FA only decreases while SF only slightly increases 28-days flexural strength. On the other hand, using SF and FA together shows relatively more strength gain. Among all those tested, maximum 28 days flexural strength of 4.53 MPa is obtained for the mix proportions of 85% OPC + 10% FA and 5% SF. SF significantly decreases the amount of liquid absorption by capillary suction and has a significant effect on the scaling resistance. In addition, all the ternary mixtures showes better scaling resistance than the control mixture with 100% OPC.
AtıfScopus9OpenAlex25İncele - MakaleAçık Erişim2011Scopus SJRQ3The effects of silica fume and fly ash on the scaling resistance and flexural strength of pavement concretes
Yener, Engin; Hinislioǧlu, Sinan
The purpose of this study is to investigate the effects of Silica Fume (SF) and Fly Ash (FA) additives on the frost salt scaling resistance and flexural strength properties of pavement concrete. An attempt is also made to attain a more durable and higher strength concrete by a suitable combination of Ordinary Portland Cement (OPC), SF and FA. SF and FA are used as cement replacement in proportions of 0, 5, 10% and 0, 5, 10, 15% by weight respectively. Flexural strength is tested after 7, 28 and 91 days of the lime saturated water curing period. The experimental results indicate that using FA only decreases while SF only slightly increases 28-days flexural strength. On the other hand, using SF and FA together shows relatively more strength gain. Among all those tested, maximum 28 days flexural strength of 4.53 MPa is obtained for the mix proportions of 85% OPC + 10% FA and 5% SF. SF significantly decreases the amount of liquid absorption by capillary suction and has a significant effect on the scaling resistance. In addition, all the ternary mixtures showes better scaling resistance than the control mixture with 100% OPC.
AtıfScopus13WoS23İncele