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Öğe Determination of optimum blast furnace slag ash and hemp fiber ratio in cement mortars(Elsevier Science Inc, 2023) Filazi, Ahmet; Tortuk, Songul; Pul, MuharremThis study aims to investigate the effect of incorporating hemp fibers into cement mortars to enhance their mechanical properties. Additionally, the study examines the use of blast furnace slag (YFC) as a substitute for cement to reduce costs. The findings demonstrate that adding 1%, 2%, and 4% hemp fibers to cement mortars yields the best results in terms of density, water absorption, compressive strength, bending strength, compressive strength after bending, and flexural strength. In conclusion, the study reveals that incorporating hemp fibers enhances the workability of YFC-blended mixtures while reducing the spreading diameter as the hemp fiber content increases. Additionally, an increase in YFC substitution leads to a decrease in compressive strength; however, the addition of 1% hemp fiber to the Y15 mixture results in a approximately 12% increase in compressive strength, indicating improved matrix strength and reduced crack formation. Moreover, the study shows that the flexural strength increases with the addition of hemp fibers, with the highest flexural strength observed in the mixture containing 4% hemp fiber and 10% YFC substitution. The results highlight that the combination of YFC and hemp fibers can produce strong, durable, and environmentally friendly composite materials. These materials offer a lower environmental impact and cost-effectiveness compared to traditional construction materials.Öğe Developing Geopolymer Composites with Structural Damage ControlPotenti al: Uti lizati on of Blast Furnace Slag, Calcined Clay, and MWCNT(Springer Science and Business Media Deutschland GmbH, 2024) Filazi, Ahmet; Yılmazel, Rüstem; Pul, MuharremAn experimental investigation was carried out to develop geopolymer composites with the potential to self-control structural damage. In this study, blast furnace slag, calcined clay and multi-walled carbon nanotubes (MWCNTs) were substituted into the geopolymer matrix. Firstly, reference samples with 5%, 10% and 15% calcined clay substitution were formed in the experiments. It was observed that geopolymer composites with 10% calcined clay substitution gave the best results. Secondly, MWCNTs were substituted at 0.25%, 0.5%, 1.0% and 1.5% to geopolymer concrete samples with 10% calcined clay substitution. The effect of increasing MWCNT amount on the electrical properties of geopolymer concrete was investigated. SEM/EDS, XRD analyses, microstructure and phase investigations were also carried out. 1% MWCNT substitution added to the sample prepared with 10% calcined clay substitution was found to give the best result compared to other addition ratios. This experimental study is very important for the design of durable and long-lasting structures in the field of structural engineering. The study is also necessary for structural damage control of geopolymer composites. This study aimed to make new geopolymer composite structures more durable and to provide good electrical conductivity. Thus, it shows that it can shed light on further research. © The Author(s), under exclusive licence to Shiraz University 2024.Öğe Effect of Borax Pentahydrate Substitution on Soundproofing and Mechanical Properties of Cement Mortar(Kırıkkale Üniversitesi, 2022) Filazi, Ahmet; Pul, MuharremOur country is very rich in terms of boron mine. It has been observed that there are few studies on the use of borax pentahydrate in concrete. In this study, the properties of cement mortars produced by substituting borax pentahydrate in cement at 5, 10, 15, 20 and 25% by weight were investigated. For this purpose, some mechanical and physical experiments were carried out to examine the sound transmission velocity, flexural and compressive strength properties of cement mortars. As a result of the tests and experiments, it was observed that the use of borax pentahydrate decreased the flexural and compressive strength values in cement mortars. It was determined that the highest flexural strength, compressive strength and ultrasonic sound velocity transmission among borax pentahydrate substituted cement mortars were obtained from 5% borax pentahydrate substituted mortars.Öğe EFFECT OF GRAPHITE POWDER ADDITIVES ON MECHANICAL PROPERTIES AND ELECTRICAL CONDUCTIVITY IN BLAST FURNACE SLAG-BASED ALKALI-ACTIVATED MORTARS(2023) Filazi, Ahmet; Yılmazel, Rüstem; Pul, MuharremIn this study, the effect of graphite powder additive on mechanical properties and electrical conductivity of alkali-activated mortar samples produced using blast furnace slag was investigated. In the preparation of the mortar samples, graphite powder in (?75) micron size was substituted at a rate of 0%-0.5-1%, 2% and 4% by weight of the binder. Sodium hydroxide and sodium silicate were used as activators in the mortar samples produced with Blast Furnace slag, and the samples were thermal cured at 110?C for 24 hours. Workability, unit weight, electrical conductivity, tendencies and compressive strength of all mortar samples that completed the curing period were determined. In addition, experiments were carried out to determine the water absorption and void ratios of the samples that gave the best results in the cementitious system activated with alkalis. The results obtained showed that the workability of the graphite powder was improved at 1% reinforcement rate in the mortar samples activated with alkalis, and it had a negative effect at the rates above 1%. It was understood that 1% graphite powder additive contributed positively to flexural and compressive strengths, while 4% graphite powder additive contributed provided the highest electrical conductivity.Öğe Enhancement on mechanical and durability performances of binary cementitious systems by optimizing particle size distribution of fly ash(SPRINGERNATURE, 2020) Filazi, Ahmet; Demir, Ilhami; Sevim, OzerFly ash is a well-known supplementary cementitious material that is the by-product of coal-fired thermal power plants. The contribution of fly ash to the enhancement of the mechanical and durability properties of cementitious materials has been documented in concrete technology for many years. In this study, to allow superior mechanical and durability properties, fly ash-based mixtures have been produced after optimization of particle size distribution (PSD) of Class F and Class C fly ash according to the formula of Fuller-Thompson. Different distribution modulus values ranging from 0.3 to 0.6 were used to achieve ideal PSD in accordance with the Fuller-Thompson equation. 30% of F- and C-class fly ash by weight of cement were used to replace with cement in cementitious composites by optimizing PSD with help of air jet sieve. The recommended optimization technique improved the 7-, 28- and 90-day compressive and flexural strength results of mortars. Compressive and flexural strength tests and rapid chloride permeability test of cement-based systems incorporating fly ash up to 15% replacement ratio with optimized PSD at 90-days exhibited better results than those of plain samples owing to the filler effect.Öğe Influence of freeze-thaw cycling on properties of cementitious systems doped with fly ash having optimized particle size distribution(Springernature, 2022) Demir, Ilhami; Filazi, Ahmet; Sevim, Ozer; Simsek, OsmanIn this study, the particle size distribution (PSD) of class F and C fly ash (FA) was optimized using theory of the Fuller-Thompson. After defining the optimal size distribution, the distribution modulus (q) of 0.4 yields the best mechanical property results. The freeze-thaw up to 300 cycles on mechanical and permeability properties of 90-day cementitious composites incorporating optimized class F and C fly ash (5, 10, 15, 20, 25, and 30% by weight of cement) were investigated. Optimized FA has improved the mechanical and permeability properties of cementitious composites under freeze-thaw cycling by ensuring a better filler effect. The cementitious composite mortars with 20% optimized class C fly ash and class F fly ash replacement yielded high compactness and better mechanical properties than the control cementitious composite mortars without any fly ash replacement after 90 days. Finding the best particle size distribution of FA providing high compactness will save cement, reduce the carbon dioxide (CO2) emission that pollutes the environment in cement production, and contribute to the economy and environment.Öğe Influence of freeze–thaw cycling on properties of cementitious systems doped with fly ash having optimized particle size distribution(Springer Science and Business Media Deutschland GmbH, 2022) Demir, İlhami; Filazi, Ahmet; Sevim, Ozer; Simsek, OsmanIn this study, the particle size distribution (PSD) of class F and C fly ash (FA) was optimized using theory of the Fuller-Thompson. After defining the optimal size distribution, the distribution modulus (q) of 0.4 yields the best mechanical property results. The freeze–thaw up to 300 cycles on mechanical and permeability properties of 90-day cementitious composites incorporating optimized class F and C fly ash (5, 10, 15, 20, 25, and 30% by weight of cement) were investigated. Optimized FA has improved the mechanical and permeability properties of cementitious composites under freeze–thaw cycling by ensuring a better filler effect. The cementitious composite mortars with 20% optimized class C fly ash and class F fly ash replacement yielded high compactness and better mechanical properties than the control cementitious composite mortars without any fly ash replacement after 90 days. Finding the best particle size distribution of FA providing high compactness will save cement, reduce the carbon dioxide (CO2) emission that pollutes the environment in cement production, and contribute to the economy and environment. © 2022, Wroclaw University of Science and Technology.Öğe Investigation of Electrical Conductivity in Cement Mortars with Waste Iron Chips(Kırıkkale Üniversitesi, 2023) Filazi, Ahmet; Yilmazel, Rustem; Pul, MuharremIn this study, the electrical conductivity of cement mortars formed by additive waste iron chip was investigated. Mixtures with fixed water/cement (0.5) ratios and different ratios of iron chip were prepared. Cement mortars were prepared by adding 0%, 1%, 2%, 4%, 8% and 16% by weight of cement in the mixtures and waste iron chip in the range of 0.5 mm to 4 mm in size. Firstly, the flow test was applied to the cement mortars cured in normal water for 7 and 28 days and their flexure and compressive strengths were determined. Then, the electrical conductivity test was applied to the cement mortar samples. As a result, it was observed that the flow diameter values increased as the average length increased from 0.5 mm to 2 mm in 1% and 2% additive of waste iron chip. It was determined that 1% waste iron chip was higher at 4.54% compressive strength compared to the reference sample. As the amount of added waste iron chip increased, the electrical resistivity value in the samples decreased and the electrical conductivity value increased along with it. At the same time, it was determined that the added iron chip size also increased the electrical conductivity.Öğe Investigation of Electrical Conductivity in Cement Mortars with Waste Iron Chips(2023) Yılmazel, Rustem; Filazi, Ahmet; Pul, MuharremIn this study, the electrical conductivity of cement mortars formed by additive waste iron chip was investigated. Mixtures with fixed water/cement (0.5) ratios and different ratios of iron chip were prepared. Cement mortars were prepared by adding 0%, 1%, 2%, 4%, 8% and 16% by weight of cement in the mixtures and waste iron chip in the range of 0.5 mm to 4 mm in size. Firstly, the flow test was applied to the cement mortars cured in normal water for 7 and 28 days and their flexure and compressive strengths were determined. Then, the electrical conductivity test was applied to the cement mortar samples. As a result, it was observed that the flow diameter values increased as the average length increased from 0.5 mm to 2 mm in 1% and 2% additive of waste iron chip. It was determined that 1% waste iron chip was higher at 4.54% compressive strength compared to the reference sample. As the amount of added waste iron chip increased, the electrical resistivity value in the samples decreased and the electrical conductivity value increased along with it. At the same time, it was determined that the added iron chip size also increased the electrical conductivity.Öğe Investigation of the Effect of Ulexite Additive on the Mechanical Strength and Thermal Conductivity of Cement Mortar(2024) Filazi, Ahmet; Pul, Muharrem; Pehlivanlı, Zühtü Onur; Uzun, İbrahimIn this study, the effect of ulexite substitution in cement mortar and its physical and mechanical properties on cement mortar properties were investigated. First of all, the pozzolanic activity of the ulexite material was determined. Then, cement mortars with ulexite additives at different rates (0.5%, 1%, 2%, 4%); Specific gravity, specific surface, setting start and end times, consistency and expansion tests, as well as 7 and 28 days flexural and compressive strength of the mortar samples were determined and compared with the control sample. As a result of the study, with the increase of the ulexite substitution ratio, the set start and set expiration times were extended, and all of the ulexite-substituted cement mortars provided the lowest mechanical strength required in related standard. It was observed that the cement mortars with 0.5%, 1%, 2% ulexite substituted cement mortars exceeded the reference sample and the best replacement rate was in the mortars with 0.5% replacement. However, depending on the increase in the ulexite substitution ratio, a decrease in mechanical strength was detected among themselves. According to the results obtained from the thermal conductivity tests, the thermal conductivity values of the cement mortars decreased with the ulexite substitution. Depending on the ulexite substitution rate, the thermal conductivity value decreased by approximately 50%. The lowest thermal conductivity value was measured in the test sample with 4% ulexite substitute.Öğe Synergistic effects of Bacillus subtilis and PET fiber additions on the mechanical properties of Alkali-Activated composite mortars(Elsevier, 2024) Filazi, AhmetThis study investigates the impact of Bacillus subtilis and PET fiber additions on the mechanical properties of alkali-activated composite mortars (AACMs). Blast furnace slag (BFS) is used as the primary binder, activated by sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Controlled curing conditions at 20( degrees )C and 100 % relative humidity for 28 days were maintained. Comprehensive tests, including compressive strength, flexural strength, and scanning electron microscopy (SEM) analyses, were conducted. Results showed that AACMs incorporating Bacillus subtilis exhibited a 25 % increase in compressive strength and a 20 % increase in flexural strength compared to control samples. The addition of PET fibers further improved these properties by 10 % and 8 %, respectively. These findings highlight the potential of bio-enhanced alkali-activated materials in sustainable construction.Öğe Tane boyutu optimize edilmiş en yüksek dolgu faktörüne göre F ve C sınıfı uçucu küllerin çimento harçlarına etkisi(Kırıkkale Üniversitesi, 2020) Filazi, Ahmet; Demir, İlhamiGünümüzde yapı malzemelerinin teknik özelliklerinin gelişmesiyle, betonun çevresel etkilerini azaltma çabaları hız kazanmıştır. Doğal kaynakların miktarı azaldıkça çevre kirliliği sorununu gidermek ve enerji maliyetini azaltmak için endüstriyel atık kullanımı günden güne artmaktadır. Betonun çimentoya bağlı çevresel etkilerini azaltmak için kullanılabilecek ekonomik metotlardan biri, çimento içerisine puzolanik malzemelerin ikamesidir. Bu noktada çimento bazlı etkiyi azaltmak için beton agregalarında uygulanan gradasyon sistemine benzer bir şekilde uçucu kül gibi filler malzemelerin en yüksek dolgu faktörünün elde edilebilmesi için uçucu kül gradasyonu önemli bir konudur. Beton karışımında kullanılacak agreganın granülometrisinin ayarlanması, üretilecek beton karışımındaki boşluk oranını ve çimento oranını minimize edecektir. Agregalarda bu durum önemsenmesine rağmen, çimento ve uçucu kül gibi filler malzemelerde gradasyon göz ardı edilmektedir. Bu tez çalışmasında, tane dağılımı optimize edilmiş en yüksek dolgu faktörüne göre F ve C sınıfı uçucu küllerin çimento harçlarına etkisi incelenmiştir. İyi bir gradasyon, yüksek kompasite oluşturacak ve uçucu kül ikameli çimentonun hidratasyonu sonucu oluşan ürünlerin çimento harcı içerisindeki boşluklarını minimize edecektir. Bu tez kapsamında literatürdeki katkılı çimento karışımları dikkate alınarak, bu karışımlar içerisindeki granüler malzemeler tane boyutu dağılımlarına bağlı olarak, Fuller-Thompson bağıntısı ile optimize edilerek daha sıkı bir yapı oluşturuldu. Vakumlu elek ile elenen uçucu küllerin uygun tane boyut dağılımı oluşturuldu ve oluşturulan bu tane boyut dağılımı çimento yerine ikame edilerek en yüksek dolgu faktörü belirlendi. Sonraki aşamada ise tane dağılımı optimize edilmiş uçucu küllerin, çimento içerisine ikame edilmesi ile çimento harçlarının mekanik dayanımları ve durabilite etkisi incelendi. Bu çalışmada, Fuller-Thompson bağıntısında önerilen denkleme göre uçucu külün etkinliğini daha iyi anlayabilmek için %20 ikame oranında F ve C sınıfı için tane dağılımları optimize edilmiştir. Fuller-Thompson bağıntısına göre tane dağılımı optimize edilmiş uçucu kül ikameli çimento harçlarının 7, 28 ve 90 günlük çimento harcı basınç ve eğilme dayanım değerleri sonucunda, tane dağılımı katsayısı n=0.4 olarak elde edilmiştir. Tane boyut dağılımı yapılan uçucu kül ikameli çimento harçlarında sülfata karşı dayanıklılık, hızlı klor iyonu geçirimliliği, donma-çözülme, ultrases geçiş hızı, civalı porozimetre (MIP) özelliklerine bakılmıştır. n=0.4 tane dağılım katsayısı ile uçucu küllere tane dağılımı optimizasyonu yaparak yüksek hacimli uçucu kül kullanımı artırılmıştır. Tane dağılımı optimize edilmeyen, 90 günlük uçucu küllerin basınç dayanımları incelendiğinde F sınıfı uçucu kül ikamesinin %5, %10 oranlarında referans numuneyi yakaladığını, C sınıfı uçucu küllerin ise %15 ikamede referans numuneyi geçtiğini görmekteyiz. Tane dağılımı optimizasyonunun sayesinde optimizasyonu yapılmayan uçucu küllere göre, optimizasyon işlemi yapılarak %10 uçucu kül ikame yerine, F sınıfı uçucu küllerde %30 kadar, C sınıfı uçucu küllerde ise %20 ikameye kadar uçucu kül kullanarak basınç dayanımlarının aynı sonuçlar verdiği görülmüştür. Sonuç olarak, tane dağılımı optimize edilen uçucu küller, daha yüksek hacim oluşturarak boşlukları minimize etmiştir. Bu sayede eğilme ve basınç dayanımlarının yanı sıra, durabilite özelliklerini geliştirdiği açıkça görülmektedir. Bir atık olan uçucu kül kullanımının optimizasyon ile birlikte daha fazla kullanılacağı sonucu ortaya çıkmıştır. Bunun en önemli faydası çimento kullanımı azalacak ve ekonomik bir beton elde edilmiş olacaktır. Ayrıca, çevreyi kirleten karbondioksit (CO2) miktarındaki artış, çimentonun daha az kullanılmasıyla azalacaktır. En önemlisi doğal kaynakların korunması ve ülke ekonomisine büyük oranlarda katkılar sağlaması olacaktır.Öğe The Effect of SiC and MgO Ceramic Reinforcements on the Mechanical Behavior and Electrical Properties of the Composite Structure in Al7075/SiC/MgO Hybrid Composites(Kırıkkale Üniversitesi, 2023) Erten, Mustafa Yasin; Yilmazel, Rustem; Filazi, Ahmet; Pul, MuharremIn this study, certain technical properties of new generation aluminum-based composites, obtained by combining the Al7075 alloy widely used in the industrial field with two different ceramics, were investigated. For this purpose, SiC and MgO ceramics in particle form were reinforced into the Al7075 matrix material using powder metallurgy technique and composite structures were produced in three different reinforcement ratios. Measurements to determine electrical resistance and conductivity and bending and compression strength tests were performed on the obtained composite structures. The density and porosity amounts of the composite structures were also determined, and their microstructures were examined with a digital microscope. With the increase of SiC/MgO amount in the aluminum composite structure, the electrical resistance increased, and the conductivity value decreased. With the effect of SiC/MgO reinforcing materials, the density value of the composite structures decreased while the amount of porosity increased. The hardness values increased due to the effect of SiC and MgO ceramics in the structure. The bending and compression strength values initially increased and then started to decrease with the increase of reinforcement ratios. It has been determined that the formation of porosity in the composite structure negatively affects the mechanical behavior. The second important factor was evaluated to be the amount and shape of ceramic-based reinforcement particles in the structure. Due to the effect of SiC, which has very high electrical resistance, and MgO, which has dielectric properties, the electrical conductivity values of the composite structures decreased. The increase in electrical resistance and the decrease in electrical conductivity were directly proportional to the amount of ceramic-based reinforcement particles in the composite structure.Öğe The Effect of SiC and MgO Ceramic Reinforcements on the Mechanical Behavior and Electrical Properties of the Composite Structure in Al7075/SiC/MgO Hybrid Composites(2023) Erten, Mustafa Yasin; Yılmazel, Rustem; Filazi, Ahmet; Pul, MuharremIn this study, certain technical properties of new generation aluminum-based composites, obtained by combining the Al7075 alloy widely used in the industrial field with two different ceramics, were investigated. For this purpose, SiC and MgO ceramics in particle form were reinforced into the Al7075 matrix material using powder metallurgy technique and composite structures were produced in three different reinforcement ratios. Measurements to determine electrical resistance and conductivity and bending and compression strength tests were performed on the obtained composite structures. The density and porosity amounts of the composite structures were also determined, and their microstructures were examined with a digital microscope. With the increase of SiC/MgO amount in the aluminum composite structure, the electrical resistance increased, and the conductivity value decreased. With the effect of SiC/MgO reinforcing materials, the density value of the composite structures decreased while the amount of porosity increased. The hardness values increased due to the effect of SiC and MgO ceramics in the structure. The bending and compression strength values initially increased and then started to decrease with the increase of reinforcement ratios. It has been determined that the formation of porosity in the composite structure negatively affects the mechanical behavior. The second important factor was evaluated to be the amount and shape of ceramic-based reinforcement particles in the structure. Due to the effect of SiC, which has very high electrical resistance, and MgO, which has dielectric properties, the electrical conductivity values of the composite structures decreased. The increase in electrical resistance and the decrease in electrical conductivity were directly proportional to the amount of ceramic-based reinforcement particles in the composite structure.Öğe The Effects of Calcite-Producing Bacteria on the Engineering Properties of Alkali-Activated Composite Mortars(Springer Science and Business Media Deutschland GmbH, 2024) Filazi, AhmetThis study aims to explore the impact of calcium carbonate-producing bacteria on the engineering properties of alkali-activated composite mortars (AACMs). This study conducted an investigation on the mechanical properties, water absorption, rapid chloride ion permeability, ultrasonic pulse velocity, and mercury porosimetry of AACMs with varying cell concentrations of microbial Bacillus subtilis (BS) per milliliter (103, 105, and 107 cells/ml). Regarding the beneficial effects of improvement agents on concrete behavior, the effect of microbial-induced carbonate precipitation (MICP) in AACMs, which is an environmentally friendly solution for engineering properties, was investigated. AACMs with three different cell concentrations of Bacillus subtilis (103, 105, and 107 cells/ml) were investigated. Among these, the sample featuring 105 cells/ml exhibited the most favorable flexural and compressive strength. 7 and 28 days flexural strengths of 105 cells/ml added AACMs samples were 8.16 and 23.80%, while their compressive strengths were 17.70 and 22.65%, respectively. A decrease of approximately 12.27% was observed in water absorption in 28-day AACMs samples, and a decrease of 24.70% was observed in rapid chloride ion permeability. It was seen in the study that BS bacteria species caused a noticeable improvement in the performance of AACMs. © The Author(s), under exclusive licence to Shiraz University 2024.Öğe The Effects of Silicon Carbide Usage on Strength, Electrical Conductivity, and Durability in Cement Composites(Springer Science and Business Media B.V., 2024) Filazi, Ahmet; Şenses, Ahmet Mustafa; Aydin, TunaThis study investigates the effect of silicon carbide (SiC) powder on cement pastes. SiC was added in various percentages by weight of cement (1%, 2%, 4%, 8%, 12%, and 16%). The spread diameter, mechanical strength, chloride permeability, capillary water absorption, and electrical conductivity of each mixture were determined, and microstructural analyses (SEM and EDX) were conducted. The results indicate that SiC decreases the spread diameter of the mortar while increasing its mechanical strength and electrical conductivity. Specifically, 2% and 4% SiC additions resulted in the highest strength improvements. Chloride permeability tests showed that the resistance of concrete to chloride ions improved over time, with permeability levels significantly decreasing. Microstructural analyses revealed that SiC influences the formation of C-S–H and C-H structures in the cement matrix, enhancing mechanical strength and overall durability. This study highlights the potential of SiC to improve the mechanical properties and electrical conductivity of cement in the industry, suggesting avenues for future research to explore different SiC concentrations and application methods in greater detail. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
