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Öğe Assessment of concrete compressive strength by image processing technique(Elsevier Sci Ltd, 2012) Başyiğit, Celalettin; Çomak, Bekir; Kılınçarslan, Şemsettin; Uncu, İsmail SerkanThe aim of this study is to assess the compressive strength values of different concrete classes by using the image processing technique. For this purpose, seven different water/cement ratios were obtained using the different series of concrete. Physical and mechanical tests were conducted on the obtained specimens. In addition, analyses were carried out by using image processing techniques. Correlations between compressive strength values of the obtained concrete specimens and the results obtained at the end of image processing were sought. A good correlation (R-2 = 0.9847) between the aggregate volume was observed by means of image processing, and the aggregate volume, theoretically assigned during mixture design. Regression analyses were done using image processing and non-destructive test results. For the comparison the performance of the regression techniques R-2, RMSE, SSE and MAPE were evaluated for each analysis. It is further considered that the image processing technique that was used in this study can be an auxiliary tool to destructive and non-destructive testing methods. (C) 2012 Elsevier Ltd. All rights reserved.Öğe Beton Kabuğu Fiziksel Özelliklerinden Yararlanılarak Bulanık Mantık İle Basınç Dayanımının Belirlenmesi(Sedat ÇETİN, 2010) Subaşı, Serkan; Şahin, İbrahim; Çomak, BekirBu araştırmanın amacı, farklı yüzey yoğunluklarına sahip betonlarda beton kabuğu fiziksel özelliklerinden yararlanılarak beton basınç dayanımını belirleyen bulanık mantık modeli oluşturmaktır. Çalışma kapsamında hazırlanan C25 beton karışımı farklı yüzey özelliklerine sahip 3 adet kalıp içerisine dökülmüştür. Çam, plywood ve geçirgen astarlı olmak üzere farklı su emme kapasitelerine sahip kalıplar ile beton kabuğunda değişik yoğunluklara sahip betonların elde edilmesi sağlanmıştır. Kalıplar içerisindeki betonlar 28 gün boyunca sulanmak suretiyle kür edilmiştir. Kalıp sökümünden sonra beton bloğundan 18 adet karot örnek alınmıştır. 9 adet karot örneği beton yüzeyinden itibaren 5 cm derinliğinde kesilerek beton kabuğu numuneleri hazırlanmıştır. Diğer 9 adet karot örnek ise basınç dayanımı deneyine tabi tutulmuştur. Beton kabuğu numuneleri üzerinde yoğunluk, boşluk yüzdesi, ultrases geçiş hızı deneyleri gerçekleştirilmiştir. Elde edilen deney sonuçları kullanılarak basınç dayanımını tahmin eden bulanık model oluşturulmuştur. Oluşturulan bulanık modelde girdi olarak yoğunluk, boşluk yüzdesi ve Ultrases geçiş hızı değerleri, çıktı olarak ise basınç dayanımı değerleri kullanılmıştır. Sonuç olarak, farklı beton kabuğu fiziksel özelliklerine sahip betonların basınç dayanımını % 2,8 yanılma olasılığı ile tahmin eden bulanık mantık modeli oluşturulmuştur. Bulanık mantık yöntemi ile beton kabuğu fiziksel özelliklerinden yararlanılarak basınç dayanımının tahmin edilebildiği görülmüştür. Anahtar Kelimeler: Beton kabuğu, Basınç dayanımı, Bulanık mantık, fiziksel özellikler.Öğe Betonun Dinamik Elastisite Modülü Değerleri Üzerinde Soğuk Derz Etkisinin Araştırılması(2019) Çomak, Bekir; Ölmez, Özkan; Emiroğlu, MehmetTahribatsız test metotları, yapıların yerinde (inşaat sahasında) ve taşıyıcı elemanlara hasar vermeksizinmuayenesine olanak tanımaktadır. Betonun durabilite performansı ve dinamik yükler altındaki davranışıhakkında bilgi veren dinamik elastisite modülü değeri, tahribatsız yöntemler ile hızlı bir biçimde tespitedilebilmektedir. Beton üretimi esnasında sahada sıkça rastlanılan sorunlardan biri de soğuk derz olayıdır. Buçalışmada, farklı döküm zamanları kullanılarak yapay olarak oluşturulmuş soğuk derze sahip numunelerindinamik elastisite modüllerindeki değişim tahribatsız yöntemler kullanılarak ele alınmıştır. Bu kapsamdaReferans (serbest döküm), 30o, 45ove 90oderz yüzeyine sahip kiriş numuneler üzerinde farklı döküm sürelerinde(-30, 0, +30, +120, +240, +480, +1140. dakikalarda) numuneler üretilmiştir. Üretimi yapılan kiriş numunelerüzerinde 28 gün kür süresi ardından rezonans frekansı test metodu kullanılarak dinamik elastisite modülüdeğerleri hesaplanmıştır.Öğe Characterization of cement-based spacers for high performance concretes(Elsevier, 2022) Çomak, Bekir; Aykanat, Batuhan; Aydın, Sait; Emiroğlu, MehmetDue to the increasing trend towards high-performance concretes in recent years, cement-based spacers are becoming increasingly important instead of plastic-made ones in buildings. Cement-based concrete spacers with high resistance and durability have been produced, and their performance has been assessed in this study. Fly ash and blast furnace slag have been preferred as aggregate in this study due to their positive contributions to mechanical characteristics and to provide an environmental-friendly production. Seven different mixtures, including the reference mixture, were prepared. Flow diameter and density tests were applied on the freshly prepared mixtures, while unit weight, porosity, compressive strength, and loading tests were performed on the hardened samples. In conclusion, produced concrete spacers have met the requirements of standards, and the best performance in terms of compressive strength has been obtained by using a binary combination of fly ash and blast furnace slag.Öğe DETERMINATION OF COLOR HOMOGENEITY BY IMAGE PROCESSING IN CEMENT BASED MORTARS(Serban Solacolu Foundation, 2021) Çomak, Bekir; Bideci, Alper; Aykanat, Batuhan; Bideci, Özlem ŞallıWith the development of computer technologies in recent years, the usage of image processing techniques in different areas have significantly increased. Image processing is the computer study for altering the measured or saved digital image data in a manner to fit for a purpose in an electronical media. In this study, by adding red iron oxide pigment (RIOP) into cement mortars in 2%, 4%, 6% and 8% ratios, physical and mechanical characteristics of the mortars were analysed, and color homogenization of them were determined by image processing method. On the manufactured samples, consistency, density, water absorption, porosity, compressive strength, flexural strength tests and image processing analysis by open source coded ImageJ programme were performed. Also, SEM-EDS analyses were performed in order to determine the inner structure characteristics of the samples. As a result of this study, changes in physical and mechanical characteristics of the mortars have been observed in different ratios. When it is desired to obtain a red colored mortar, it is determined by image processing analysis that 6% of red iron oxide pigment (RIOP) addition to the mortar mixture would give the optimum result.Öğe Determination of homogeneity index of cementitious composites produced with eps beads by image processing techniques(Techno-Press, 2022) Çomak, Bekir; Aykanat, Batuhan; Bideci, Özlem Şallı; Bideci, AlperWith the improvements in computer technologies, utilization of image processing techniques has increased in many areas (such as medicine, defence industry, other industries etc.) Many different image processing techniques are used for surface analysis, detection of manufacturing defects, and determination of physical and mechanical characteristics of composite materials. In this study, cementitious composites were obtained by addition of Grounded Granulated Blast-Furnace Slag (GGBFS), Styrene Butadiene polymer (SBR), and Grounded Granulated Blast-Furnace Slag and Styrene Butadiene polymer together (GGBFS+SBR). Expanded Polystyrene (EPS) beads were added to these cementitious composites in different ratios (20%, 40% and 60%). The mechanical and physical characteristics of the composites were determined, and homogeneity indexes of the composites were determined by image processing techniques to determine EPS distribution forms in them. Physical and mechanical characteristics of the produced samples were obtained by applying consistency, density, water absorption, compressive strength (7 and 28 days), flexural strength (7 and 28 days) and tensile splitting strength (7 and 28 days) tests on them. Also, visual examination by using digital microscope, and image analysis by using image processing techniques with open source coded ImageJ program were performed. As a result of the study, it is determined that GGBFS and SBR addition strengthens the adhesion sites formed as it increases the adhesion power of the mixture and helps to get rid of the segregation problem caused by EPS. As a result of the image processing analysis it is demonstrated that GGBFS and SBR addition has positive contribution on homogeneity index. Copyright © 2022 Techno-Press, Ltd.Öğe Determination of Type and Quality of Hazelnut using Image Processing Techniques(Ieee, 2015) Bayrakdar, Sümeyye; Çomak, Bekir; Başol, Derya; Yücedağ, İbrahimHazelnut (Corylus avellana L.) comes number two after almond in the ranking of hard shelled fruits that is cultivated commonly in the world. According to the FAO (Food and Agriculture Organization) statistics, Turkey covers approximately 70% of the world hazelnut production, and 82% of the hazelnut exportation. These statistics indicate that Turkey is the first largest hazelnut producer and exporter in the world. Quality and automation have a great importance in the agricultural industry that put our country forward as world-wide leader. In the quality control systems, classification studies with image processing methods have accelerated in recent years. In this study, it is aimed that determination of type and quality of shelled hazelnuts with image processing by using size and shape characteristics of hazelnuts. As a result of studies on a variety of hazelnuts, it was reached 84% accuracy rate for grouping of shelled hazelnut according to the type and commercial definitions. The quality of hazelnuts also was acquired without error. Inshell Hazelnut Standard (TS 3074) that is published by the Turkish Standards Institute (TSE) is based for shelled hazelnuts.Öğe Effects of hemp fibers on characteristics of cement based mortar(Elsevier Sci Ltd, 2018) Çomak, Bekir; Bideci, Alper; Bideci, Özlem SallıIn recent years, using addition of fibers with plant origin in concretes has increased significantly. They not only enhance the mechanical characteristics of cement mortars, but also they are renewable, easy to access and cheap and this makes the use of plant fibers more widespread. Hemp fiber is a plant, which is planted in many places of the world and obtained in large amounts, is environmentally friendly and also used in manufacturing of composite materials. In this study, hemp fiber reinforced cement mortars with different ratios (0%, 1%, 2%, 3%) and different lengths (6 mm, 12 mm and 18 mm) were manufactured. Density, water absorption, compressive strength, flexural strength, compressive strength after flexural tensile and splitting tensile strength tests were performed on manufactured samples. Also, in order to determine the inner structural characteristics of samples, SEM analysis was conducted. As a result of the study, it was determined that cement mortars reinforced with 2-3% amount and 12 mm length of natural hemp fiber give the optimum results. (C) 2018 Elsevier Ltd. All rights reserved.Öğe Effects of use of alkaline mixing waters on engineering properties of cement mortars(Taylor & Francis Ltd, 2018) Çomak, BekirIn this study, the effect of pH level of mixing water on physical, mechanical and microstructure properties of cementitious mixtures was examined. In order to adjust the pH level of mixing water, various ratios of NaOH were added to ultra-pure water. Therefore, in total, six different mixing waters were obtained including the reference mixing water, pH10, pH11, pH12, pH13 and pH14. Mortar samples were produced using the obtained mixing waters with CEM I 42.5R Portland cement, then physical and mechanical properties of the cement mortars were determined on the 7th, 14th, 28th and 90th days. In addition, microstructure properties of the cement mortar specimens were determined after the 28days curing period. Porosity measurements by mercury intrusion porosimetry were also examined after the 28days cure periods. At the end of study, it was determined that the alkaline mixing waters (up to pH13) have positive effects on the compressive strength and workability of the cement mortars. The best result was obtained with pH12 mixing waters.Öğe Engineering Characteristics of Geopolymer Mortars Manufactured with Ground Granulated Blast Furnace Slag(2018) Çomak, BekirGeopolymers are obtained by various methods in different alkalineenvironments by changing compositions and crystal structures of pozzolans, whichhave Al and Si oxide compounds in their structures and carry little or no hydrauliccharacteristics. In this study, mechanical and physical characteristics ofgeopolymer mortars manufactured with ground granulated blast furnace slag(GGBFS) and activated with sodium silicate (water glass) were determined andalso their SEM-EDS analyses were performed. As a result of the study, it wasdetermined that geopolymers prepared with GGBFS can also be used in the areaswhere blast furnace slag cement would be used.Öğe Environmental life cycle assessment of rockwool filled aluminum sandwich facade panels in Turkey(Elsevier, 2022) Yılmaz, Emrah; Aykanat, Batuhan; Çomak, BekirAs composite materials combine multiple outstanding characteristics together such as lightweight, high resistance and durability, their consumption in the industry has been growing rapidly. This consumption causes environmental concerns due to raw material, energy and natural resource requirements through entire life cycle of composite materials in stages such as production, transportation, usage and disposal. Thus, assessment of environmental impact of composite materials gains more importance. This study provides a comprehensive life cycle inventory (LCI) data for the production process of 50 mm, 60 mm and 80 mm thick rockwool filled aluminum sandwich (RWFAS) facade panels. Environmental impacts of RWFAS panels from cradle to gate (optional) have been calculated by SimaPro software in accordance with ISO14040 and ISO14044 standards by life cycle assessment (LCA) method. As a result of the study, it was found that the most important environmental impacts have been caused by the production stage, and most of these impacts have been due to the use of aluminum sheet in the production process. When all panels were compared, it was determined that 80 mm thick RWFAS panel had the highest values in all environmental impact categories when compared with other sandwich panels.Öğe Evaluation of pH Value by Using Image Processing(Polish Acad Sciences Inst Physics, 2017) Beycioğlu, Ahmet; Çomak, Bekir; Akçaabat, DilaraIn this study strong HCl acid was titrated with a strong base of NaOH. Increasing pH values were observed during such titration. Depending on the existence of indicator in the solution, the equivalence point was determined when the color of the solution had turned into pink. After finding the equivalence point, images were taken after every addition of base to the acid solution. These images were evaluated using red, green and blue values of the pixels, through an image processing program. After analyzing the image results, it was found that the percentage of red values had increased with the increasing pH value. As a result, the image processing techniques can be used as an alternative approach to find pH values of titrated solutions.Öğe Flexural Behavior of a Novel Textile-Reinforced Polymer Concrete(Mdpi, 2022) Murcia, Daniel Heras; Çomak, Bekir; Soliman, Eslam; Reda Taha, Mahmoud M.Textile reinforced concrete (TRC) has gained attention from the construction industry due to its light weight, high tensile strength, design flexibility, corrosion resistance, and remarkably long service life. Some structural applications that utilize TRC components include precast panels, structural repair, waterproofing elements, and facades. TRC is produced by incorporating textile fabrics into thin cementitious concrete panels. Premature debonding between the textile fabric and concrete due to improper cementitious matrix impregnation of the fibers was identified as a failure-governing mechanism. To overcome this performance limitation, in this study, a novel type of TRC is proposed by replacing the cement binder with a polymer resin to produce textile reinforced polymer concrete (TRPC). The new TRPC is created using a fine-graded aggregate, methyl methacrylate polymer resin, and basalt fiber textile fabric. Four different specimen configurations were manufactured by embedding 0, 1, 2, and 3 textile layers in concrete. Flexural performance was analyzed and compared with reference TRC specimens with similar compressive strength and reinforcement configurations. Furthermore, the crack pattern intensity was determined using an image processing technique to quantify the ductility of TRPC compared with conventional TRC. The new TRPC improved the moment capacity compared with TRC by 51%, 58%, 59%, and 158%, the deflection at peak load by 858%, 857%, 3264%, and 3803%, and the toughness by 1909%, 3844%, 2781%, and 4355% for 0, 1, 2, and 3 textile layers, respectively. TRPC showed significantly improved flexural capacity, superior ductility, and substantial plasticity compared with TRC.Öğe Flexural behavior of polymer-based textile-reinforced concrete using basalt fibers(Crc Press-Balkema, 2019) Çomak, Bekir; Soliman, Eslam; Chennareddy, Rahulreddy; Taha, Mahmoud RedaTextile reinforced concrete (TRC) is a class of cementitous composites that entails several advantages compared to traditional reinforced concrete such as lightweight, high tensile strength, design flexibility, and potentially corrosion free. As a result, TRC is suggested in a variety of structural applications including facades, protection panels, bridges, and waterproofing systems. A typical TRC element consists of multiple fiber fabrics embedded in thin cementitous concrete plate. Previous research reported a high potential for debonding between the fiber fabrics and the surrounding cementitous matrix due to poor impregnation and relatively high voids content. Recently, a new class of TRC is introduced by replacing the cementitious matrix by a polymer matrix to overcome the debonding problem. In this paper, textile-reinforced polymer concrete (TRPC) is produced using basalt fiber textile mesh and fine-grained Methyl Methacrylate (MMA) polymer concrete. Four different specimen configurations were produced by incorporating 0, 1, 2, and 3 textile layers in polymer concrete. Three-point bending test was carried out to examine the flexural performance of the TRPC specimens and the flexural strength of the different configurations was compared. In addition, the crack pattern intensity was determined via image processing technique to assess the ductility of TRPC. Comparison between different TRPC configurations reveals that increasing the number of fabric layers significantly improves the flexural behavior of TRPC.Öğe A New Approach to Compressive Strength Assessment of Concrete: Image Processing Technique(Amer Inst Physics, 2012) Başyiğit, Celalettin; Çomak, Bekir; Kılınçarslan, ŞemsettinIn this study, the compressive strength levels of different concrete classes were estimated using an image processing technique. A series of different concretes were prepared by applying different water/cement ratios. The percentages of cement matrix, aggregate, and air void were calculated by processing the images obtained from the surfaces of hardened concretes. The relation between the parameters that were calculated via image processing and the compressive strengths of the concretes produced were examined. By this means, the compressive strength levels of concretes were estimated one by one via the developed image processing software and ImageJ. It was found that the compressive strength levels of concretes can be estimated with a high level of correlation by using the values obtained via the image processing technique. The developed software can be used to estimate the compressive strength levels of concretes. In addition, in considering concrete age, cure conditions, and relative humidity, the method used in this study can be used together with destructive and non-destructive test methods.Öğe Sodyum Tripolifosfat (Na5P3O10)'ın Çimento Harçlarının Mühendislik Özelliklerine Etkisi(2017) Beycioğlu, Ahmet; Akçaabat, Dilara; Aydın, Abdülkerim; Gültekin, Adil; Yılmaz, Eda; Çomak, BekirSodyum tripolifosfat; gıda sektörü ve deterjan üretiminde pH değerini artırmak için kullanılan inorganik bir tuz olup; ayrıca dispersiyon ajanı, stabilizatör ve su yumuşatıcı olarak da kullanılmaktadır. Bu çalışmada, sodyum tripolifosfat çözeltisini karışım suyu olarak içeren çimento pastalarının ve çimento harçlarının mühendislik özellikleri araştırılmıştır. Deneysel çalışmada, bir tanesi distile su içeren iki tür çimento pastası ve çimento harcı karışımı hazırlanmıştır. İkinci karışımda, sodyum tripolifosfat distile suyun %3' ü kadar kullanılmıştır. Sonuç olarak, sodyum tripolifosfatın karışım suyunda kullanılması çimento pastalarının priz başlangıç ve priz bitiş sürelerini, çimento harçlarının yayılma çapı ile 7 ve 28 günlük basınç dayanımını arttırmıştır. Ayrıca sodyum tripolifosfat çözeltisi ile üretilen çimento pastasının SEM görüntüsü incelendiğinde, tripolifosfat'ın hidratasyon ürünleri olan CH ve CSH oluşumlarına olumsuz bir etkisinin bulunmadığı görülmüştür
