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Öğe Effect of water curing temperature on compressive strength development and water absorption capacity of mortar mixtures(Yıldız Teknik Üniversitesi, 2020) Aghabaglou, Ali Mardanı; Özen, Süleyman; Altun, Muhammet Gökhan; Faqırı, Zia AhmadIn this study, the effect of different curing temperature processes on the 1, 3, 7 and 28-day compressive strength and 28-day water absorption ratios of mortar mixtures were investigated. All mortar mixtures were prepared according to ASTM C109. The water/cement ratio, sand/binder ratio and flow values of mortar mixture were kept constant as 0.485, 2.75 and 25±2 cm, respectively. Polycarboxylate ether-based high range water reducing admixture was used for providing desired flow value. All mortar mixtures were cured at fresh state in a curing room under the same conditions (Temperature of 20?C and Relative humanity (RH) of 95%) during 24 hours from casting. Then, specimens were subjected to 6 different water-curing conditions. According to test results, the 3-day compressive strength of mixtures cured in water having a temperature of 40ºC was higher than that of mixtures cured at 20ºC in water. At early ages, the high curing temperature negatively affected the 7 and 28-day compressive strength of mixtures. Specimens cured in water at 20ºC and 40ºC had the highest and lowest 28-day compressive strengths, respectively. Different curing conditions had no significant effect on the 28-day water absorption ratios of mortar mixtures.Öğe Effects of Shrinkage Reducing Admixture and Polypropylene Fiber Utilization on Some Fresh State, Mechanical and Durability Properties of Khorasan Mortar(Taylor and Francis Ltd., 2024) İsafça-Kaya, Tuğçe; Karakuzu, Kemal; Özen, Süleyman; Mardani, Ali; Do?angün, AdemThis study aimed to improve the mechanical and durability properties of Khorasan mortar, a type of lime-based mortar, using polypropylene shrinkage reducing admixture (SRA) and fiber. In addition to the control mixture without fiber and chemical admixture, three series of mixtures were prepared. The first series contains 0.4–0.6-0.8% polypropylene fiber by total volume; the second series contains SRA at the 0.05–0.1-0.15% by binder weight; the third series consists of mixtures containing both fiber and the SRA. Within the scope of the study, some fresh state, mechanical and durability properties were determined. The results show that utilization of fiber and SRA reduced the length change depending on drying-shrinkage and mass loss due to abrasion compared to the control mixture. In addition, the 90-day flexural and compressive strength values for all mixtures were lower than the 28-day results. It was determined that the decrease in strength values is less than the control mixture with the utilization of fiber and SRA because of the degradation in drying-shrinkage. © 2022 Taylor & Francis.Öğe GRAFEN OKSİT İLE YÜZEY İYİLEŞTİRME YAPILMIŞ JÜT LİFLERİN HARÇ KARIŞIMLARIN MEKANİK ÖZELLİKLERİ VE KURUMA BÜZÜLME DAVRANIŞINA ETKİSİ(2024) Özen, SüleymanÇimentolu sistemlerin mekanik özelliklerini iyileştirebilmek ve süneklik kazandırmak amacı ile genellikle karışımlara lif ilave edilmektedir. Doğal liflerin üretim maliyetinin daha düşük olması, daha az karbon emisyonu ve fosil yakıt tüketimi, biyolojik olarak parçalanabilirlik, daha düşük yoğunluk ve imalat kolaylığı gibi çevresel etkilerinin daha az olması nedeniyle tercih edilmektedir. Diğer yandan, grafen türevi malzemelerin, lif-matris mekanik ve arayüz özelliklerini iyileştirici bir etki gösterdiği kanıtlanmıştır. Bu çalışma kapsamında, grafen-oksit (GO) ile yüzey iyileştirme işlemine tabi tutulan jüt liflerinin harç karışımlarının işlenebilirliğine, basınç dayanımı, eğilme dayanımı, su emme ve kuruma-büzülme performanslarına etkisi araştırılmıştır. Deneysel çalışma kapsamında lif içermeyen kontrol karışımına ilaveten, 0,5 ve 1 cm uzunluğuna sahip GO kaplamalı ve kaplamasız jüt lifler toplam hacmin %0,1, 0,3 ve 0,5 oranlarında karışıma ilave edilerek farklı lifli harç karışımları hazırlanmıştır. Deney sonuçlarına göre lif içeren karışımlarda su azaltıcı katkı ihtiyacı artmıştır. Karışımlara 0,5 cm ve %0,1 lif ilave edilmesi basınç ve eğilme dayanımlarını artırmıştır. GO kaplama yapılması kaplamasız liflere kıyasla dayanımların bir miktar artmasını sağlamıştır. Su emme oranları basınç dayanımı ile ters orantı göstermiştir. Lif ilave edilmesi kuruma-büzülme miktarlarını düşürmüştür. GO kaplama yapılan lifler bu durumda olumlu yönde daha etkili olmuştur. Ancak GO kaplı lif içeriklerinin %0,1’den fazla olması kuruma-büzülmelerin artmasına neden olmuştur.Öğe Mineral katkı kullanımının hava sürükleyici katkılı çimentolu harçların taze ve sertleşmiş hal özeliklerine etkisi(Pamukkale Üniversitesi, 2020) Güleryüz, Ece; Özen, Süleyman; Mardanı-aghabaglou, AliBu çalışmada, silis dumanı ve uçucu kül kullanımının hava sürükleyici katkılı tekli, ikili ve üçlü çimentolu sistemleri içeren harç karışımlarının taze ve bazı sertleşmiş hal özelliklerine etkisi karşılaştırmalı olarak incelenmiştir. Bu kapsamda tek tip CEM I 42.5R tipi çimento, tek tip polikarboksilat esaslı su azaltıcı katkı, tek tip hava sürükleyici katkı, silis dumanı ve uçucu kül kullanarak farklı kombinasyonlara sahip harç karışımları hazırlanmıştır. Mineral katkı içermeyen kontrol karışımına ilaveten, üç seri daha harç karışımı hazırlanmıştır. Birinci ve ikinci seride uçucu kül ve silis dumanı sırasıyla, %30 ve %10 oranında çimento ile yer değiştirmiştir. Üçüncü seride ise, çimento ağırlığının %30 ve %10’u oranında, hem uçucu kül hem de silis dumanı kullanılmıştır. Çalışmada tüm harç karışımlarında su/çimento oranı, kum/bağlayıcı oranı ve yayılma değerleri sırasıyla, 0.485, 2.75, 270±20 mm olarak sabit tutulmuştur. Harç karışımlarının zamana bağlı yayılma değerleri, 90 günlük su emme değerleri, 3, 7, 28 ve 90 günlük basınç dayanımları ve 0, 50, 100, 150, 200 donma-çözülme çevrimi sonrası basınç dayanım değerleri elde edilmiştir. Deney sonuçlarına göre, hava sürükleyici katkılı çimento harçlarında mineral katkı kullanımı karışımların taze hal özelliklerini olumlu yönde etkilemiştir. Mineral katkı içeren karışımlar erken yaşlarda kontrol karışımına kıyasla daha düşük dayanım gösterirken, 90 günün sonunda kontrol karışımından daha yüksek basınç dayanım değerlerine sahip olmuşlardır. Mineral katkı kullanımı ile harç karışımlarının 90 günlük su emme değerleri, kontrol karışımına kıyasla daha düşük olmuştur. Donma-çözülme çevrimleri bakımından en başarılı karışımın hem uçucu kül hem de silis dumanı içeren, üçlü bağlayıcı sisteme sahip olan K-UK-SD-HSK karışımı olduğu tespit edilmiştir.Öğe OBSERVED STRUCTURAL DAMAGES AFTER THE FEBRUARY 6, 2023, KAHRAMANMARAS EARTHQUAKES IN TURKEY(International Association for Earthquake Engineering, 2024) Sezgin, Sedef Kocakaplan; Sakcalı, Gökhan Barış; Özen, Süleyman; Bayhan, Beyhan; Ça?lar, NaciTwo damaging earthquakes occurred in Kahramanmaras on 06.02.2022 with magnitudes of Mw=7.7 and Mw=7.6, respectively, causing loss of lives and economic losses. Field investigation conducted in provinces and districts of Kahramanmaras, Hatay, Gaziantep, Adiyaman, Malatya, Kilis, Adana, Diyarbakir, Osmaniye and Sanliurfa. Technical examinations and observations were conducted by the faculty members of Bursa Technical University of Earthquake Engineering Application and Research Centre. Damages as well as cause of failures in reinforced concrete, masonry, and historical structures were reported in this paper. Damages due to material properties, errors during the design and construction process stated in detail. Further, application suitability of the structures according to the current and old seismic specifications was investigated. Lessons learned and recommendations were provided to prevent failures in possible future earthquakes. © 2024, International Association for Earthquake Engineering. All rights reserved.Öğe The Effect of Sulfonate and Phosphate Anionic Monomers of Water Reducing Admixtures on Fresh State and Mechanical Properties of Self Compacting Concrete(Bursa Uludağ Üniversitesi, 2022) Altun, Muhammet Gökhan; Özen, Süleyman; Karakuzu, Kemal; Mardani, AliIn this study, the effect of anionic monomer content of polycarboxylate-ether based water reducing admixture on various fresh and hardened state properties of self-compacting concrete (SCC)mixtures was investigated. For this purpose, in addition to the control admixture whose anionic monomer is 100% carboxylate, 5 different water reducing admixtures were synthesized by replacing the anionic monomer of the control admixture with 10% and 30% sulfonate and phosphate. According to the results, the substitution of the water reducing admixture anionic monomer with sulfonate increases the admixture requirement of the mixtures; had a positive effect on time-dependent flowing performances. In the case of phosphate substitution, the admixture requirement of the mixtures decreased, while the time-dependent flowing performance was adversely affected. The best performance among all mixtures was obtained with 10% sulfonate substituted admixture. The anionic monomer change did not cause any significant changes in the compressive strength, water absorption rates, ultrasonic pulse velocity (UPV) and dynamic elasticity modules of the SCC mixtures.Öğe Başlıksız(Higher Education Press, 2020) Özen, Süleyman; Altun, Muhammet Gokhan; Mardani-Aghabaglou, Ali; Ramyar, KambizDespite the large variations in the behaviors of water-reducing admixtures upon changes in their structures, most previous reports on the cement-admixture compatibility did not provide sufficient information on the structure of the admixture. Hence, the evaluation and generalization of the reports on the cement-admixture compatibility are challenging. In this study, three different polycarboxylate-ether-based water-reducing admixtures with the same free nonionic content, anionic/nonionic molar ratio, and main chain length and different side chain lengths were produced. The compatibility of these admixtures with a CEM I 42.5 R-type cement was investigated. In addition, an analysis of variance was performed on the experiment results to evaluate the contributions of the admixture type, admixture/cement ratio, and elapsing time to the Marsh funnel flow time, mini-slump, slump flow, and compressive strength. The water-reducing admixtures having long or short side chains reduced the initial flow characteristics of the cementitious systems. However, the admixture having the shortest side chain was better with regard to flow retention. The side chain length of the admixture did not have significant effects on the compressive strength and water absorption capacity of the mortar mixtures and mini-slump performances of the cement paste mixtures. Regarding the behaviors of the admixtures in the cementitious systems, an optimal admixture side chain molecular weight is proposed.Öğe Başlıksız(Taylor & Francis Ltd, 2021) Özen, Süleyman; Altun, Muhammet Gokhan; Mardani-Aghabaglou, Ali; Unlu, Ayda; Ramyar, KambizIn this study, the effects of anionic monomer functional group type of the water-reducing admixture (WRA) on the fresh properties and compressive strength of self-compacting concrete (SCC) mixtures were investigated. Nine types of polycarboxylate ether-based high-range WRAs with the same main chains but different anionic monomers linked to the main chain were synthesized and used in different dosages to provide the desired slump-flow value in SSC mixtures. For this motivation, in addition to the control admixture consisted of 100% carboxylate functional group, 5, 10, 20 and 30% of carboxylate functional group was replaced by either phosphate or sulfonate group. Test results revealed that the admixtures containing sulfonate and phosphate anionic monomer improved the fresh properties of SCC mixtures compared to those of the control admixture. However, anionic monomer exchange in the structure of the WRA did not significantly affect the compressive strength and water absorption capacity of the SCC mixtures.Öğe Başlıksız(Pamukkale Univ, 2020) Guleryuz, Ece; Özen, Süleyman; Mardani-Aghabaglou, AliIn this study, the effect of silica fume and fly ash on the fresh and some hardened state properties of mortar mixtures containing plain, binary and ternary cementitious systems and air entraining admixture (AEA) were investigated comparatively. Within this regard, different mortar admixture combinations were prepared by using a CEM I 42.5R type cement, a type of polycarboxylate-ether based water reducing admixture, air entraining admixture, silica fume and fly ash. In addition to the control mixture containing no mineral admixture, three series of mortar mixtures were prepared. In the first and second series, silica fume and fly ash were replaced by 30% and 10% of cement, respectively. In the third series, both silica fume and fly ash were used as 30% and 10% of cement weight Within all mortar mixtures, water/cement ratio, sand/binder ratio and flow values were kept constant as 0.485, 2.75, 270 +/- 20 mm, respectively. Time-dependent flow values, 90-day water absorption values, 3, 7, 28 and 90-day compressive strengths and compressive strengths values after 0, 50, 100, 150, 200 freeze-thaw cycle of mortar mixtures were measured. According to the results, the use of mineral additives in cement mortars containing air-entraining admixture had a positively effect on the fresh state properties of the mixtures. While mixtures containing mineral admixture exhibited lower strengths at early ages compared to the control mixture, they had higher compressive strength values than the control mixture at the end of 90 days. The 90-day water absorption values of the mortar mixtures were observed to be less with the use of mineral admixture compared to that of control mixtures. In terms of freeze-thaw cycles, the most successful mixture was determined to be K-UK-SD-HSK mixture having ternary cementitious system and containing both fly ash and silica fume.Öğe Başlıksız(Elsevier Sci Ltd, 2020) Altun, Muhammet Gokhan; Özen, Süleyman; Mardani-Aghabaglou, AliIn this study, the effect of side chain length, molecular weights changes and adsorption amount of polycarboxylate ether-based high range water reducing admixtures having constant main chain length, free non-ionic amount and anionic/non-ionic ratio on fresh properties, early and advanced age compressive strength, water absorption capacity and ultrasonic pulse velocity value of self-compacting concretes (SCC) were investigated. FTIR (Fourier transform infrared) and GPC (Gel Permeation Chromatography) analyzes were carried out to characterize admixtures. According to the test results, all SCC mixtures produced within the scope of the study provided EFNARC criteria. If the admixture side chain length is higher or shorter than a certain value, the admixture requirement is increased for providing the desired target slump-flow value in SCC mixtures. This negative effect is thought to be due to the weakness of the steric hindrance effect for admixture with short side chain, the low adsorption amount and interlacing risk of side chains for admixture with the long side chain. On the other hand, the increase in the side chain length of the admixtures had a positive effect on the time-dependent fresh state performance of the mixtures. This positive effect is thought to be due to the low adsorption amount of the admixture, the increase in the side chain length and the increase of the non-adsorbed free polymer content in the mixture. While side chain length change of the water reducing admixture affected the 1 and 2-day compressive strength values of SCC mixtures, the 3, 7 and 28-day compressive strengths and the 28-day water absorption, ultrasound and dynamic elasticity modulus values did not significantly affect. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Başlıksız(Yildiz Technical Univ, 2020) Mardani Aghabaglou, Ali; Özen, Süleyman; Altun, Muhammet Gokhan; Faqiri, Zia AhmadIn this study, the effect of different curing temperature processes on the 1, 3, 7 and 28-day compressive strength and 28-day water absorption ratios of mortar mixtures were investigated. All mortar mixtures were prepared according to ASTM C109. The water/cement ratio, sand/binder ratio and flow values of mortar mixture were kept constant as 0.485, 2.75 and 25 +/- 2 cm, respectively. Polycarboxylate ether-based high range water reducing admixture was used for providing desired flow value. All mortar mixtures were cured at fresh state in a curing room under the same conditions (Temperature of 20 degrees C and Relative humanity (RH) of 95%) during 24 hours from casting. Then, specimens were subjected to 6 different water-curing conditions. According to test results, the 3-day compressive strength of mixtures cured in water having a temperature of 40 degrees C was higher than that of mixtures cured at 20 degrees C in water. At early ages, the high curing temperature negatively affected the 7 and 28-day compressive strength of mixtures. Specimens cured in water at 20 degrees C and 40 degrees C had the highest and lowest 28-day compressive strengths, respectively. Different curing conditions had no significant effect on the 28-day water absorption ratios of mortar mixtures.Öğe Başlıksız(Elsevier Sci Ltd, 2020) Özen, Süleyman; Altun, Muhammet Gokhan; Mardani-Aghabaglou, AliIn this study, the effect of polycarboxylate ether-based water reducing admixture (WRA) main chain length on fresh state properties, compressive strength, ultrasonic pulse velocity (UPV) and water absorption capacity of self-compacting concrete (SCC) mixtures were investigated. Within this aim, three polycarboxylate ether-based high range WRAs with stabilized polyethylene oxide side chain molecular weight, free non-ionic content and constant anionic/non-ionic ratios, but different main chain length were synthesized. FTIR (Fourier transform infrared) and GPC (Gel Permeation Chromatography) analyzes were carried out to characterize admixtures. According to test results, the admixture requirement for reaching targeted main chain length in SCC increased and adsorption of admixture decreased in case the admixture main chain length is higher and lower than a certain value. However, time-dependent flow performance of the mixtures improved with the increase of admixture main chain length and a reverse situation was observed when the length was decreased. Similar behaviors were also observed in V funnel flow, L box and U box passing tests. While the admixture main chain length change affected early age strength, it showed no effect on the strengths of later ages. No considerable differences were observed in the 28-day water absorption, UPV and dynamic modulus of elasticity values of the mixtures with the change of admixture main chain length. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Başlıksız(Ernst & Sohn, 2021) Özen, Süleyman; Altun, Muhammet Gokhan; Mardani-Aghabaglou, Ali; Ramyar, KambizIn this study, the effect of both main and side chain length changes of the admixtures on some properties of cementitious systems were investigated. Three different polycarboxylate-ether-based water-reducing admixtures (WRA) having constant molecular weights and different main and side chain lengths were synthesized. Single type of raw material and carboxylate functional group were used in all WRAs. The molecular weights, free nonionic contents, and anionic/nonionic ratios of the admixtures were kept constant. Test results showed that degree of fluidity was observed in cement paste and mortar mixtures in case the admixture main and side chain length is more or less than a critical value. This negative effect is thought to be due to the weakening of the adsorption ability by the chain length change of the admixtures, the being tendency of polymers to intertwine and the adsorbing of admixture on several cement particles simultaneous. Admixtures having excessive long or short main chain and side chain improved the time-dependent slump-flow retention of the mortar mixtures. The admixtures with short main and side chains had insufficient adsorption ability and the admixture with excessive long main and side chains had the interlacing risk of polymers. In both cases, time-dependent behavior improved because the amount of free admixture in solution increased. The change in the chain lengths of the WRAs affected the 1-day compressive strength of the mortar mixtures.Öğe Başlıksız(Pontificia Univ Catolica Chile, Escuela Construccion Civil, 2020) Mardani-Aghabaglou, Ali; Özen, Süleyman; Altun, Muhammet GokhanAs it is well known, the curing method directly affects many properties of cementitious composites. In previous studies, the effect of different curing conditions on the properties of the cementitious systems has been generally investigated in the period after first 24 hours after casting. However, there are not many studies in the literature related to the effects of curing conditions on the specimens kept in mold during 24 hours after casting. In this study, strength development, ultrasonic pulse velocity (UPV) and water absorption capacity of mortar specimens subjected to steam-curing at different temperatures during keeping in mold for the first 24 hours after production were compared. In this regard, all mortar specimens were exposed to curing in a steam-curing cabin at 95% constant relative humidity (RH) under 5 different temperatures such as 20, 35, 50, 65 and 80 degrees C for the first 24 hours after the specimens were placed into the molds. Afterwards, the specimens were removed from the molds and cured in water conformed to the standard until the testing day. In this context, the water-cement ratio, sand- binder and slump-flow value of all mortar mixtures were kept constant as 0.485, 2.75, 25 +/- 2 cm, respectively. As a result, the application of steam-curing at high temperature for the first 24 hours positively affected the 1-day compressive strength and UPV values of the mixtures, while the 3,7 and 28-day compressive strength, UPV values and the 28-day water absorption capacity of mixtures were adversely affected.Öğe Başlıksız(ICE Publishing, 2022) Özen, Süleyman; Altun M.G.; Mardani-Aghabaglou A.; Ramyar K.In this study, the effect of main chain and side chain length of polycarboxylate-ether based high range water reducing admixture (WRA) on the fresh properties, compressive strength and water absorption of cementitious systems containing 0, 15, 30 and 45 wt.% fly ash was investigated. For this purpose, 3 WRAs with same molecular weight but different chain lengths were produced. According to test results, flowability of paste and mortars was negatively affected when the length of the main chain and side chains of the admixture was longer or shorter than a certain value. This adverse effect is thought to be arisen from the weakening of the adsorption of admixture with increase of its chain lengths. However, when the main chain and side chain lengths of the admixture were shorter or longer than a certain value, the time-dependent flow properties of the mortar mixtures improved. The main chain and side chain lengths of the WRAs had not a significant effect on the compressive strength and water absorption capacity of the mortar mixtures. However, irrespective of the admixture characteristics, with the increase of fly ash substitution the flow and time-dependent flow properties of the mixtures were negatively affected but their water absorption decreased.Öğe Başlıksız(2020) Yiğit, Berna; Salihoğlu, Güray; Mardanı-Aghabaglou, Ali; Salihoğlu, Nezih; Özen, SüleymanBursa ili kentsel atıksu arıtma tesislerinde oluşan arıtma çamurları, 2017 yılından itibaren Bursa Su ve Kanalizasyon İdaresi’ne bağlı 400 ton/gün kapasiteli bir akışkan yataklı yakma tesisinde yakılarak bertaraf edilmektedir. Yakma sürecinin sonunda her ay bertaraf edilmeyi bekleyen ortalama 615 ton kül oluşmaktadır. Bu çalışmanın amacı çamur yakma sürecinin sonunda oluşan atık çamur küllerinin yapı malzemesi olarak geri kazanılıp kazanılamayacağını araştırmaktır. Bu amaçla çamur küllerine stabilizasyon/solidifikasyon (S/S) ve jeopolimerizasyon teknolojileri uygulanmıştır. Bağlayıcı malzeme olarak Portland çimentosu, termik santral uçucu külü ve mermer çamuru kullanılmıştır. S/S örnekleri su, jeopolimer örnekleri 8MNaOH ve NaSilNaOH çözeltileriyle aktive edilmiştir. Hazırlanan pasta örnekleri 28 günlük hava kürü sonunda basınç dayanımı ve ağır metal sızma testlerine tabi tutulmuştur. Çamur külü kullanılarak hazırlanan S/S örneklerinde 21,8 MPa, jeopolimer örneklerinde ise 50,0 MPa düzeylerine ulaşan basınç dayanım değerleri elde edilmiştir. Atık çamur külü içeren bazı örneklerin basınç dayanım düzeylerinin, atık içermeyen kontrol örneklerinin basınç dayanım düzeylerinden yüksek olması dikkat çekmiştir. Sızma testi sonucunda çamur külüyle hazırlanan örneklerin tehlike sınır değerlerinin oldukça altında kaldığı görülmüştür. Gerek sızma testi gerekse basınç dayanım testi sonuçları, çamur küllerinin, yapı malzemesi olarak değerlendirilmesi gereken bir potansiyel vadettiğini göstermektedir.Öğe Başlıksız(2020) Mardanı-Aghabaglou, Ali; Bayqra, Sultan Husein; Özen, Süleyman; Altun, Muhammet Gökhan; Faqırı, Zia Ahmad; Ramyar, KambizGeleneksel betonlara oranla hızlı üretimi, düşük maliyeti ve dayanıklılığının iyi olması silindirle sıkıştırılmış betonların (SSB) son zamanlarda dünyada yaygın olarak tercih edilmesine neden olmuştur. Söz konusu SSB, fabrikalar, petrol istasyonları, hava limanları, çeşitli endüstriyel zeminler, yollar ve barajlar gibi birçok alanda kullanılmaktadır. Normal betona kıyasla çok farklı üretim tekniğine sahip SSB’lerin karışım oranları çeşitli tasarım yöntemlerine göre belirlenmekte ve en çok tercih edilen yöntem olarak maksimum yoğunluk yöntemi dikkat çekmektedir. Bu çalışmada, SSB’lerin tasarım yöntemlerinden genel olarak bahsedilerek, maksimum yoğunluk yöntemi detaylı olarak açıklanmıştır. Ayrıca maksimum yoğunluk yöntemi ile tasarlanan SSB’ler ile ilgili çalışmalar özetlenerek bundan sonra yapılacak araştırmalar için önerilerde bulunulmuştur.Öğe Başlıksız(Elsevier, 2021) Durgun, Muhammed Yasin; Özen, Süleyman; Karakuzu, Kemal; Kobya, Veysel; Bayqra, Sultan Husein; Mardani-Aghabaglou, AliIn this study, the effect of polypropylene (PP) fiber utilization ratio on the fresh and some hardened properties of mortar mixtures containing colemanite waste (CW), which mainly contains B2O3, SiO2 and CaO, containing mortar mixtures were investigated. The 17 mortar mixtures were prepared by replacing 0, 1, 3, 5, and 7 wt% of cement with CW and by adding 0, 0.5, 0.75, and 1% by volume of PP fibers to the control mixture. In all mixtures, water/binder ratio, sand/binder ratio and slump-flow values were kept constant as 0.485, 2.75 and 220 +/- 20 mm, respectively. Water reducing admixture requirement of each mixture was determined to provide the target slump-flow range in mortar mixtures. There was a change in the amount of admixture according to the amount of CW and fiber content in the mixture. The 28 and 56-day water absorption capacity, compressive strength and high temperature resistance of mortar mixtures were determined. Strength reduction of specimens exposed to 300 degrees C and 600 degrees C were compared. In addition, thermal and scanning electron microscopy (SEM) analyses were performed on the specimens. According to the test results, with the increase in the amount CW and PP fiber in the mixtures, the admixture demand to provide target flow value and the 28-day water absorption capacity of the mixtures increased, while the 28-day compressive strengths decreased. However, while there was no significant change in the 56-day water absorption capacity and compressive strength values of the specimens containing CW, the water absorption capacity increased and the compressive strength decreased upon the presence of fiber in the matrix. The specimens containing both of CW and PP fiber showed better performance in terms of high-temperature resistance.Öğe Başlıksız(Taylor and Francis Ltd., 2021) İsafça T.; Karakuzu K.; Özen, Süleyman; Doğangün A.; Mardani-Aghabaglou A.Historical buildings are an important piece of our cultural heritage. It is important that the materials used in the preservation, repair and reinforcement applications of these structures should be compatible with the existing structure. In many of the historical buildings in Turkey, it was reported use of the Khorasan mortar as the masonry mortar and plaster. Khorasan mortar contains slaked lime as a binder, river sand, and clayey materials as aggregate, which are fired at high temperature. It was emphasized that this mortar is an essential building material widely used in the construction and repair of historical buildings from past to present. In this study, the effects of binder, aggregate, chemical admixture, organic admixture, and fiber properties on the mechanical and durability performance of Khorasan mortar and lime-based mortar mixtures were investigated. For this purpose, a comprehensive literature research was carried out on this subject. In addition, the positive and negative effects of these materials on the mortar mixture were emphasized.Öğe Başlıksız(American Society of Civil Engineers (ASCE), 2021) Altun, M.G.; Özen, Süleyman; Mardani-Aghabaglou, A.In this study, the effect was investigated of side chain length changes of polycarboxylate-ether-based high-range water-reducing (HRWR) admixture on fresh properties, compressive strength, and water adsorption capacity of cementitious systems. For this aim, three HRWR admixtures having same raw materials, anionic/nonionic group ratio, free nonionic group content, and main chain length but different side chain length and molecular weight were synthesized. The effect was investigated of the mentioned admixtures on the properties of mixtures containing 0%, 15%, 30%, and 45% of fly ash. According to the test results, regardless of fly ash utilization ratio, the flowability of the mixtures was positively affected with the increase of the water-reducing admixture side chain length to a certain value. However, utilization of admixtures having the longer side chain length than a certain value adversely affected the flow properties of the mixtures. It is thought that this situation is due to the reduction of the admixture efficiency (steric effect) by increasing the possibility of intertwining of polymers of admixture having higher side chain length. The admixture with 2,400 g/mol of side chain molecular weight (length) showed the best performance in terms of fresh properties. The change of HRWR admixture properties had no significant effect on the strength and water adsorption capacity of the mixtures. Moreover, regardless of HRWR admixture properties, the time-dependent flowability of the mixtures was adversely affected and the water adsorption capacity was decreased with the utilization of fly ash. This effect was more pronounced with increasing replacement ratio of fly ash. © 2021 American Society of Civil Engineers.
