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Öğe Application of waste ceramic powder as a cement replacement in reinforced concrete beams toward sustainable usage in construction(Elsevier, 2023) Aksoylu, Ceyhun; Oztilic, Yasin Onuralp; Bahrami, Alireza; Yildizel, Sadik Alper; Hakeem, Ibrahim Y.; Ozdoner, Nebi; Basaran, BogachanThe main purpose of this study was to investigate the flexural behavior of reinforced concrete beams (RCBs) containing waste ceramic powder (CP) as partial replacement of cement. For this purpose, flexural tests were carried out using various amounts of mixing ratios. By determining the amount of CP utilized in the optimum ratios, it was aimed both to make predictions for design engineers and to show its beneficial effect on the environment by recycling the waste material. For this purpose, twelve specimens were produced and verified to monitor the flexural behavior. The longitudinal reinforcements percentage (0.77%, 1.21%, and 1.74%) and CP percentage (0%, 10%, 20%, and 30%) were chosen as the parameters. CP could be effectively used up to 10% of cement as a replacement material. Increasing the CP percentage by more than 10% could considerably reduce the load-carrying capacity, ductility, and stiffness of RCBs, specifically when the longitudinal reinforcements percentage was high. In other words, as CP increased from 0% to 30%, the load-carrying capacity decreased between 0.4% and 27.5% compared with RCBs with the longitudinal tension reinforcements of 2 phi 8 without CP. However, reductions of 5.5-39.8% and 2.15-39.5% in the load-carrying capacity occurred respectively compared with RCBs with the longitudinal tension reinforcements of 2 phi 10 and 2 phi 12 without CP. The achieved longitudinal reinforcements percentage was close to the balanced ratio, while more than 10% CP cannot be used without any precautions for mixtures.Öğe Crashworthiness performance of filament wound GFRP composite pipes depending on winding angle and number of layers(Elsevier, 2024) Hakeem, Ibrahim Y.; Ozkilic, Yasin Onuralp; Bahrami, Alireza; Aksoylu, Ceyhun; Madenci, Emrah; Asyraf, Muhammad Rizal Muhammad; Beskopylny, Alexey N.The main goal of this study is to enhance the crashworthiness performance of tubular composites to absorb more energy by optimizing the winding angle of their fibers. The crashworthiness performance of glass fiber-reinforced polymer composite pipes manufactured using the filament winding is investigated in detail. The effects of the winding angle of the fibers and thickness of the tube wall on the energy absorption were examined through quasi-static compression tests. The composite pipes were produced with 1200 tex E-glass fibers and Epikote 828 resin as the matrix material. The winding angles of +/- 30 degrees, +/- 45 degrees, +/- 55 degrees, +/- 75 degrees, and +/- 90 degrees were evaluated, and the number of the winding layers, ranged from 1 to 3, was also assessed. Quasi-static axial compressive loading was applied to 15 specimens using a hydraulic actuator. The results revealed that the one-layer specimens experienced buckling damage at low load levels, while an increase in the number of the layers led to higher load-carrying capacity and different types of damages. Furthermore, as the number of the layers increased, the load-carrying capacity and energy absorption of the specimens significantly improved. Progressive failure was observed in the specimens [+/- 90] for all the layers' configurations, with the specimen [+/- 90]3, having three layers, exhibiting the highest performance in terms of the load-carrying capacity and energy absorption. The failure modes indicated a combination of the fibers' separation, buckling, diagonal shear failure, and crushing in the upper and lower heads.Öğe Effect of thermal cycles on the engineering properties and durability of sustainable fibrous high-strength concrete(Frontiers Media Sa, 2023) Hakeem, Ibrahim Y.; Hosen, Akter; Alyami, Mana; Qaidi, Shaker; Ozkilic, Yasin O.; Alhamami, Ali; Alharthai, MohammadIn this research, the effect of heat-cool cycles (HCCs) on high-strength concrete (HSC) containing steel fibres (SFs), polypropylene fibres (PPFs), and date palm fibres (DPFs), which were named fibrous high-strength concrete (FHSC), was studied. To produce FHSC, three doses of 0.2, 0.6, and 1 percent of each fibre were used. All samples were tested after 28 days of normal water curing and 270 days of exposure to HCCs (continuing the authors' project and research published at 28 and 180 days). This entails heating for 2 days at 60 C in the oven and cooling for another 2 days at room temperature for 270 days. The experiment's findings revealed that fibre reinforcement in concrete enhances its strength and durability. By incorporating the three types of fibres into high-strength concrete, with and without HCCs, the modulus of rupture was significantly increased. In both conditions, including with or without the implementation of HCCs, incorporating the three fibre types into the HSC showed a significant increase in toughness. As a result, natural date palm fibres can produce sustainable FHSC that can withstand harsh environmental conditions. Moreover, compared to the previous study conducted by the authors at 180 days, there is a slight severity in both the pattern of decrease and increase of the studied characteristics at 270 days caused by the effect of thermal cycles and fibres.Öğe Effects of glass fiber on recycled fly ash and basalt powder based geopolymer concrete(Elsevier, 2023) Celik, Ali Ihsan; Ozkilic, Yasin Onuralp; Bahrami, Alireza; Hakeem, Ibrahim Y.This experimental study encompasses a comprehensive exploration of multiple parameters aiming to enhance the strength, workability, setting time, and environmental attributes of geopolymer concrete (GPC). A pivotal solution lies in substituting fly ash with waste basalt powder, not only reducing binder costs but also ameliorating the overall ecological footprint. A secondary signif-icant factor entails the integration of trimmed glass fibers. Throughout the experimentation process, the predominant GPC binder and fly ash underwent substitution with basalt powder at the proportions of 25%, 50%, and 75%. The mixtures were augmented with glass fibers of 3 mm, 6 mm, and 12 mm lengths, introduced at the ratios of 0.5%, 1%, 2%, and 3%. Then, the acquired samples were subjected to a 24-h curing regimen in an 85 degrees C oven. Subsequently, after a 7-day period of exposure to external conditions post-incubation, these samples were tested for both the compressive and flexural strengths. Samples incorporating a basalt ratio of 50% exhibited the highest capacities, contrasting with reduced capacities when the basalt ratio was elevated to 75%. Conversely, samples utilizing a sodium hydroxide (NaOH) molarity (M) of 12 demonstrated su-perior performance. Impressively, the compressive strength exceeding 40 MPa was achieved with the amalgamation of M 12 and 50% basalt additive. However, the workability experienced a notable reduction at the fiber ratios of 2% and 3%. The molarity concentrations did not impede the slump, workability, or setting time. A consistent setting time of 6 h was attained, and the desired workability was obtained without the need for a superplasticizer. For achieving the optimal triad of the workability, setting time, and strength, while maximizing the environmental advantages of GPC, the recommendation is to incorporate a distinct combination comprising 1-2% glass fibers (with 12 mm length), M 12, and 50% basalt powder into the mixture formulation.Öğe Mechanical performance of geopolymer concrete with micro silica fume and waste steel lathe scraps(Elsevier, 2023) Celik, Ali Ihsan; Ozkilic, Yasin Onuralp; Bahrami, Alireza; Hakeem, Ibrahim Y.Environmental studies for solutions are among the most important agendas of the scientific world. Most of the new studies are taking into account environmental effects. However, it is interesting for the scientific world to find solutions for accumulated environmental problems, to reduce harmful production, and to turn wastes that cause environmental pollution into useful products. In addition to incorporating fly ash, a recognized environmentally friendly and sustainable ma-terial, geopolymer concrete, utilizes micro silica fume (micro silica) as a binding agent. Furthermore, waste lathe scraps are introduced to enhance and safeguard the concrete's me-chanical properties. During the preparation phase, significant enhancements have been identified in the workability and setting time of concrete. A total of 16 test samples were prepared in this study. Micro silica of 0%, 5%, 10%, and 20%, and lathe scraps of 0%, 1%, 2%, and 3% were examined. Experimental findings revealed that incorporating 5% micro silica resulted in notable improvements in the compressive, flexural, and splitting tensile strengths, with the increases of 14.4%, 7.45%, and 6.18%, respectively. However, higher additions of 10% and 20% were found to decrease these strengths. In contrast, the inclusion of 1% lathe scraps led to considerable in-creases in the compressive, flexural, and splitting tensile strengths by 11.4%, 6.35%, and 8.23%, respectively. However, the addition of 2% and 3% lathe scraps resulted in the reduced capacity. The findings demonstrated that combining 5% micro silica with 1% lathe scraps provided the highest strength, with the improvements of 25.7%, 14.4%, and 12% in the compressive, flexural, and splitting tensile strengths, respectively. Considering the enhancements in the workability, setting time, and strengths observed in all the tests, the recommended optimal geopolymer mixture is 5% micro silica together with 1% lathe scraps.Öğe Optimum usage of waste marble powder to reduce use of cement toward eco-friendly concrete(Elsevier, 2023) Ozkilic, Yasin Onuralp; Zeybek, Ozer; Bahrami, Alireza; Celik, Ali Ihsan; Mydin, Md Azree Othuman; Karalar, Memduh; Hakeem, Ibrahim Y.In this study, waste marble powder (WMP) was used to replace cement of concrete in specific amounts. To accomplish this aim, WMP was replaced at 10%, 20%, 30%, and 40% of the cement weight, and a reference concrete sample without WMP (REF) was created to compare the compressive strength, splitting tensile strength, and flexural strength. The replacement of WMP at 10%, 20%, 30%, and 40% of the cement weight resulted in 5.7%, 21.7%, 38.1%, and 43.6% decreases in the compressive strength compared with REF. Furthermore, the splitting tensile strength results commonly followed the same trend as the compressive strength. However, WMP at 10%, 20%, 30%, and 40% led to 5.3%, 8.6%, 19.4%, and 26.7% decreases in the flexural strength compared with REF. In addition, three different calculations, ranging from simple to complex, were proposed to compute me-chanical resistances of concrete with WMP. These proposed calculations for practical ap-plications were validated using values from the literature and the implications obtained from the current research. While the simple calculations were based on the strength of REF and the WMP percentages, the complex calculations were dependent on the design of the concrete mixture, age of the samples, and the WMP percentages. For the complex calcu-lations, the ANN approach was used with the help of the coefficient of determination (R2) for the K-fold cross validation method. All the proposed methods provided high accurate estimation to predict the properties of concrete with WMP. Based on the studies, utilizing 10% WMP as the replacement of cement is recommended to obtain the optimum benefits considering both mechanical and environmental aspects. Moreover, scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analyses were then conducted to observe the interaction of WMP in concrete. According to the SEM analyses, some pores were detected and the interfacial transition zone was observed in the reaction zone. On the other hand, based on the EDX analyses, the presence of WMP in concrete was manifested by the presence of high levels of calcium.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Öğe A potential review on the influence of nanomaterials on the mechanical properties of high strength concrete(Techno-Press, 2023) Jagadesh, P.; Prabhu, T. Karthik; Charai, Moutassim; Hakeem, Ibrahim Y.; Madenci, Emrah; Ozkilic, Yasin OnuralpIn the current scenario, conventional concrete faces a substantial challenge in the modern era of the construction industry. Today's structures are massive, featuring innovative designs and strict time constraints. Conventional concrete does not provide the required compressive strength, tensile strength, flexural strength, toughness, and cracking resistance. As a result, most of engineers and professionals prefer to use ultra-high-performance concrete (UHPC), based on its wide advantages. Several advantages like mechanical and durability properties of UHPC provides dominant properties than the traditional concrete. Mix proportions of UHPC consists of higher powder content which provides maximum hydration and pozzolanic reaction, thereby contributing to the enhancement of the UHPC properties. Apart from that the nanomaterials provides the filler behavior, which will further improve the density. Enhanced density and mechanical properties lead to improved durability properties against water absorption and other typical chemicals. Nanomaterials are the most adopted materials for various applications, ranging in size from 0.1 nanometers to 100 nanometers. This article explores the effects of nanomaterial application in UHPC as a replacement for cementitious material or as an additive in the UHPC mix. The physical and durability properties modifications and improvements of UHPC, as well as negative effects, limitations, and shortcomings, are also analyzed.Öğe A potential review on the influence of nanomaterials on the mechanical properties of high strength concrete(Techno-Press, 2023) Jagadesh, P.; Prabhu, T. Karthik; Charai, Moutassim; Hakeem, Ibrahim Y.; Madenci, Emrah; Ozkilic, Yasin OnuralpIn the current scenario, conventional concrete faces a substantial challenge in the modern era of the construction industry. Today's structures are massive, featuring innovative designs and strict time constraints. Conventional concrete does not provide the required compressive strength, tensile strength, flexural strength, toughness, and cracking resistance. As a result, most of engineers and professionals prefer to use ultra-high-performance concrete (UHPC), based on its wide advantages. Several advantages like mechanical and durability properties of UHPC provides dominant properties than the traditional concrete. Mix proportions of UHPC consists of higher powder content which provides maximum hydration and pozzolanic reaction, thereby contributing to the enhancement of the UHPC properties. Apart from that the nanomaterials provides the filler behavior, which will further improve the density. Enhanced density and mechanical properties lead to improved durability properties against water absorption and other typical chemicals. Nanomaterials are the most adopted materials for various applications, ranging in size from 0.1 nanometers to 100 nanometers. This article explores the effects of nanomaterial application in UHPC as a replacement for cementitious material or as an additive in the UHPC mix. The physical and durability properties modifications and improvements of UHPC, as well as negative effects, limitations, and shortcomings, are also analyzed.Öğe Pressure Optimization in Pneumatic Interfaces Using a Single-Bay Seven-Story Infilled Reinforced Concrete Frame: Experimental and Numerical Investigation(Mdpi, 2023) George, Prem Kumar; Varatharajan, Thirumurugan; Srinivasan, Satyanarayanan Kachabeswara; Hakeem, Ibrahim Y.; Ozkilic, Yasin OnuralpReinforced concrete infilled frames have been studied over the years along with the infilled openings. To resist the lateral loads that are applied on the frames, stress is transferred from the reinforced concrete (RC) to infill, which leads to brittle collapse. The conventional interface medium, which was considered by researchers and recent studies, was prepared by changing the interface materials between the RC frame and infill panels to different elastic materials. This study focuses on optimizing the interface pressure using a butyl rubber tube, which reduces the stress distribution to the infill panel from the RC frame. A 50% window opening was adopted in this study, which is the optimized size from previous research. The optimization patterns followed linear and nonlinear patterns, such as the same pressures in all stories and varying pressures in all stories. The third story had a 8 PSI pattern and the other stories had a 2 PSI pattern; all stories with 8 PSI patterns achieved the least displacement when compared to other variations. A monotonic static analysis was performed for both the experimental and analytical study. The boundary conditions were pinned, and coupling interfaces were made for the master and slave surfaces. The pressure conditions were applied in various linear and nonlinear patterns to optimize the pressure. A comparative study was performed on the displacement, stiffness, and drift ratio for the critical position of the interface pressure in both the analytical and experimental studies. The difference was approximately 0.53% in the analytical study and 0.37% in the experimental work. The optimization was performed using both an experimental model and an analytical model, which had an error percentage of 0.61%.Öğe Shear and Bending Performances of Reinforced Concrete Beams with Different Sizes of Circular Openings(Mdpi, 2023) Ozkilic, Yasin Onuralp; Aksoylu, Ceyhun; Hakeem, Ibrahim Y.; Ozdoner, Nebi; Kalkan, Ilker; Karalar, Memduh; Stel'makh, Sergey A.The present study pertains to the effects of transverse opening diameters and shear reinforcement ratios on the shear and flexural behavior of RC beams with two web openings across different spans, i.e., a single opening in each half-span. Within the scope of the study, a total of 12 RC beams with five different opening diameter-to-beam depth ratios (0, 0.20, 0.27, 0.33, 0.40, and 0.47) and two shear reinforcement ratios were tested to failure under four-point bending. The load capacities, ductilities, rigidities and energy dissipation capacities in the elastic and plastic ranges of beam behavior were compared. Furthermore, the load capacities of the beams were compared to the existing analytical shear strength formulations in the literature. The test results indicated that whether an RC beam with openings has adequate or inadequate amounts of shear reinforcement, the frame-type shear failure becomes much more pronounced with increasing opening diameter. The reductions in the load capacity and modulus of toughness with increasing opening diameter are more considerable in the presence of inadequate amounts of shear reinforcement, while the beam ductility is less affected in shear-deficient RC beams with openings as compared to the ones with adequate shear reinforcement.Öğe Use of waste steel fibers from CNC scraps in shear-deficient reinforced concrete beams(Techno-Press, 2023) Kalkan, Ilker; Ozkilic, Yasin Onuralp; Aksoylu, Ceyhun; Mydin, Md Azree Othuman; Martins, Carlos Humberto; Hakeem, Ibrahim Y.; Isik, ErcanThe present paper summarizes the results of an experimental program on the influence of using waste lathe scraps in the concrete mixture on the shear behavior of RC beams with different amounts of shear reinforcement. Three different volumetric ratios (1, 2 and %3) for the scraps and three different stirrup spacings (160, 200 and 270 mm) were adopted in the tests. The shear span-to-depth ratios of the beams were 2.67 and the stirrup spacing exceeded the maximum spacing limit in the building codes to unfold the contribution of lathe scraps to the shear resistances of shear-deficient beams, subject to shear-dominated failure (shear-tension). The experiments depicted that the lathe scraps have a pronounced contribution to the shear strength and load-deflection behavior of RC beams with widely-spaced stirrups. Namely, with the addition of 1%, 2% and 3% waste lathe scraps, the load-bearing capacity escalated by 9.1%, 21.8% and 32.8%, respectively, compared to the reference beam. On the other hand, the contribution of the lathe scraps to the load capacity decreases with decreasing stirrup spacing, since the closely-spaced stirrups bear the shear stresses and render the contribution of the scraps to shear resistance insignificant. The load capacity, deformation ductility index (DDI) and modulus of toughness (MOT) values of the beams were shown to increase with the volumetric fraction of scraps if the stirrups are spaced at about two times the beam depth. For the specimens with a stirrup spacing of about the beam depth, the scraps were found to have no considerable contribution to the load capacity and the deformation capacity beyond the ultimate load. In other words, for lathe scrap contents of 1-3%, the DDI values increased by 5-23% and the MOT values by 63.5-165% with respect to the reference beam with a stirrup spacing of 270 mm. The influence of the lathe scraps to the DDI and MOT values were rather limited and even sometimes negative for the stirrup spacing values of 160 and 200 mm.Öğe Use of waste steel fibers from CNC scraps in shear-deficient reinforced concrete beams(Techno-Press, 2023) Kalkan, Ilker; Ozkilic, Yasin Onuralp; Aksoylu, Ceyhun; Mydin, Md Azree Othuman; Martins, Carlos Humberto; Hakeem, Ibrahim Y.; Isik, ErcanThe present paper summarizes the results of an experimental program on the influence of using waste lathe scraps in the concrete mixture on the shear behavior of RC beams with different amounts of shear reinforcement. Three different volumetric ratios (1, 2 and %3) for the scraps and three different stirrup spacings (160, 200 and 270 mm) were adopted in the tests. The shear span-to-depth ratios of the beams were 2.67 and the stirrup spacing exceeded the maximum spacing limit in the building codes to unfold the contribution of lathe scraps to the shear resistances of shear-deficient beams, subject to shear-dominated failure (shear-tension). The experiments depicted that the lathe scraps have a pronounced contribution to the shear strength and load-deflection behavior of RC beams with widely-spaced stirrups. Namely, with the addition of 1%, 2% and 3% waste lathe scraps, the load-bearing capacity escalated by 9.1%, 21.8% and 32.8%, respectively, compared to the reference beam. On the other hand, the contribution of the lathe scraps to the load capacity decreases with decreasing stirrup spacing, since the closely-spaced stirrups bear the shear stresses and render the contribution of the scraps to shear resistance insignificant. The load capacity, deformation ductility index (DDI) and modulus of toughness (MOT) values of the beams were shown to increase with the volumetric fraction of scraps if the stirrups are spaced at about two times the beam depth. For the specimens with a stirrup spacing of about the beam depth, the scraps were found to have no considerable contribution to the load capacity and the deformation capacity beyond the ultimate load. In other words, for lathe scrap contents of 1-3%, the DDI values increased by 5-23% and the MOT values by 63.5-165% with respect to the reference beam with a stirrup spacing of 270 mm. The influence of the lathe scraps to the DDI and MOT values were rather limited and even sometimes negative for the stirrup spacing values of 160 and 200 mm.
