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Öğe A comparative investigation of eco-friendly fly ash-based geopolymer mortar produced by using electrical and heat curing: Mechanical properties, energy consumption and cost(Elsevier Sci Ltd, 2024) Urunveren, Husamettin; Beycioglu, Ahmet; Resulogullari, Emriye Cinar; Disken, Nihal BayramogluThis study investigates the eco-friendly fly ash-based geopolymer mortar (GM) production using electrical curing (EC) and heat curing. Within the scope of the study, GM produced using the EC method was compared with GM produced using the heat curing (HC) method in terms of mechanical properties, energy consumption, and cost. The study consists of a preliminary experiment to determine the parameters to be used, mortar experiments using the limited parameters defined in preliminary experiments, and an energy consumption and cost analysis. In the preliminary experiments, different mix designs produced according to different MS modulus and Na 2 O concentrations were studied to decide an applicable range for temperatures of HC and an applicable range for voltages of EC. In the second stage, EC and HC were compared according to temperature changes in GMs, current changes in GMs, and compressive strength (CS). As a final stage, an energy consumption and cost analysis were performed to compare two curing methods according to the updated dollar-based unit prices for electricity per kWh for industrial uses in various countries in February 2024. Results showed that the MS modulus should be at least 1.2 and the Na 2 O concentration should be 10 % on average to obtain a workable mortar. The compressive strength of all mortars with any MS modulus increased up to 100 degrees C and then decreased HC applied samples. Stress values of 20, 25, 30, and 35 volts are applicable and the highest compressive strength values could be obtained with 25 volts, and 6 h of application is sufficient at 25 volts EC. MS module is a key parameter in current and temperature change. In EC application, 30 volts is the threshold value, and when an electrical voltage above 30 volts is applied, the mortar 's internal temperature suddenly reaches the peak value and the desired compressive strength results cannot be achieved. According to the cost analysis, it is seen that the HC electricity cost is 6.78 times more than the EC cost. A comprehensive efficiency calculation is strongly recommended for future studies. It has also been concluded that geopolymers could gain strength at much lower voltage values, so they have the potential to consume less electrical energy in comparison to conventional concrete.Öğe A Review on the Physical Parameters Affecting the Bond Behavior of FRP Bars Embedded in Concrete(Mdpi, 2022) Basaran, Bogachan; Kalkan, Ilker; Beycioglu, Ahmet; Kasprzyk, IzabelaThe present study is a detailed literal survey on the bond behavior of FRP (Fiber Reinforced Polymer) reinforcing bars embedded in concrete. There is an urgent need for the accurate assessment of the parameters affecting the FRP-concrete bond and quantification of these effects. A significant majority of the previous studies could not derive precise and comprehensive conclusions on the effects of each of these parameters. The present study aimed at listing all of the physical parameters affecting the concrete-FRP bond, presenting the effects of each of these parameters based on the common opinions of the previous researchers and giving reasonable justifications on these effects. The studies on each of the parameters are presented in detailed tables. Among all listed parameters, the surface texture was established to have the most pronounced effect on the FRP-concrete bond strength. The bond strength values of the bars with coarse sand-coating exceeded the respective values of the fine sand-coated ones. However, increasing the concrete strength was found to result in a greater improvement in bond behavior of fine sand-coated bars due to the penetration of concrete particles into the fine sand-coating layer. The effects of fiber type, bar diameter and concrete compressive strength on the bar bond strength was shown to primarily originate from the relative slip of fibers inside the resin of the bar, also known as the shear lag effect.Öğe Assessment of glass fiber-reinforced polyester pipe powder in soil improvement(Higher Education Press, 2021) Bagriacik, Baki; Beycioglu, Ahmet; Topolinski, Szymon; Akmaz, Emre; Sert, Sedat; Guner, Esra DenizThis study investigates the use of glass fiber-reinforced polyester (GRP) pipe powder (PP) for improving the bearing capacity of sandy soils. After a series of direct share tests, the optimum PP addition for improving the bearing capacity of soils was found to be 12%. Then, using the optimum PP addition, the bearing capacity of the soil was estimated through a series of loading tests on a shallow foundation model placed in a test box. The bearing capacity of sandy soil was improved by up to 30.7%. The ratio of the depth of the PP-reinforced soil to the diameter of the foundation model (H/D) of 1.25 could sufficiently strengthen sandy soil when the optimum PP ratio was used. Microstructural analyses showed that the increase in the bearing capacity can be attributed to the chopped fibers in the PP and their multiaxial distribution in the soil. Besides improving the engineering properties of soils, using PP as an additive in soils would reduce the accumulation of the industrial waste, thus providing a twofold benefit.Öğe Assessment of pipe powder in soil improvement applications: an optimization by response surface methodology(Springer Heidelberg, 2020) Bagriacik, Baki; Yildirim, Zeynel Baran; Guner, Esra Deniz; Beycioglu, AhmetExperimental design methods have become very popular approaches in engineering studies thanks to providing some advantages to reduce time period of experiments. In this study, shear strength characteristics of sandy soils were investigated by using central composite design (CCD) approach which is one of the response surface methods. Shear box test results performed at different time intervals were used to design CCD. In model application, the effect of time period under constant load (TPUL) and pipe powder (PP) content (8-12-16%) were used as independent factors to observe shear strength characteristics. Regression equations, variance analysis results, and factor interactions of response variables were used as statistical parameters to analyze CCD performance. Experimental results showed that TPUL is a significant parameter. CCD analysis also determined the importance of TPUL and suggested 14 days as the best time period. CCD results also showed that the optimum PP content can be selected as 12%.Öğe Evaluation and Multi-Objective Optimization of Lightweight Mortars Parameters at Elevated Temperature via Box-Behnken Optimization Approach(Mdpi, 2021) Kaya, Mehmet; Yildirim, Zeynel Baran; Koksal, Fuat; Beycioglu, Ahmet; Kasprzyk, IzabelaIn this research, the mechanical properties of lightweight mortars containing different percentages of additional powder materials has been investigated using response surface methodology (RSM). Box-Behnken design, one of the RSM techniques, was used to study the effects of silica fume content (5, 10, and 15%), vermiculite/cement (V/C) ratio (4, 6, and 8), and temperature (300, 600, and 900 degrees C) on the ultrasonic pulse velocity (UPV), bending strength, and compressive strength of lightweight mortars. Design expert statistical software was accustomed to determining and evaluating the mix-design of materials in mortar mixtures and temperature effect on mortars. After preliminary experimental research of the relationships between independent and response variables, regression models were built. During the selection of the model parameters, F value, p-value, and R-2 values of the statistical models were taken into account by using the backward elimination technique. The results showed a high correlation between the variables and responses. Multi-objective optimization results showed that the critical temperatures for different levels of silica fume (5-10-15%) were obtained as 371.6 degrees C, 306.3 degrees C, and 436 degrees C, respectively, when the V/C ratio kept constant as 4. According to the results obtained at high desirability levels, it is found that the UPS values varied in the range of 2480-2737 m/s, flexural strength of 3.13-3.81 MPa, and compressive strength of 9.9-11.5 MPa at these critical temperatures. As a result of this research, RSM is highly recommended to evaluate mechanical properties where concrete includes some additional powder materials and was exposed to high temperature.Öğe Experimental Research of the Structure Condition Using Geodetic Methods and Crackmeter(Mdpi, 2022) Sztubecki, Jacek; Topolinski, Szymon; Mrowczynska, Maria; Bagriacik, Baki; Beycioglu, AhmetThe article presents an approach to monitoring the structure's condition with two measurement methods: the SHM-X crackmeter and the classic geodetic method of determining displacements, supplemented with additional information on the condition of the external environment obtained from thermal images. The study aimed to propose an approach combining geodetic and non-geodetic methods of assessing the condition of a structure and its effectiveness in practical application. The research facility is a public utility building of the Bydgoszcz University of Technology with a reinforced concrete structure. Objects of this type require periodic tests of their constancy. Interpreting the test results and identifying possible dangerous states that may indicate the risk of a construction failure is extremely important. The results presented in the article are an extension of the previous ones, in which several factors that could have a destructive effect on the structure were excluded. Observation of the object showed that only the reinforced construction plate is deformed. The only factor influencing the change in structure geometry is thermal changes. As part of the tests in places where cracks were noticed, the SHM-X crackmeter was used to measure the cracks' opening. In the geodetic research, measurements of the measurement and control network displacement were carried out, in which the TDRA6000 laser station measurement technology was used. The control points were also placed in places where the width of the cracks was directly observed. The proposed approach, with the applied calculation scheme and supplementing the information with the temperature measurement with thermal images, showed the submillimeter accuracy of the determined 3D displacements of the controlled points. Additionally, the parallel application of these methods gives a complete picture of changes in the structure elements, in which signs of destruction appear under the influence of stress.Öğe Exploring the effect of basalt fibers on maximum deviator stress and failure deformation of silty soils using ANN, SVM and FL supported by experimental data(Elsevier Sci Ltd, 2022) Ndepete, Cyrille Prosper; Sert, Sedat; Beycioglu, Ahmet; Katanalp, Burak Yigit; Eren, Ezgi; Bagriacik, Baki; Topolinski, SyzmonBecause the experimental trials in civil engineering field are difficult and time-consuming, the application of artificial intelligence (AI) techniques is attracting considerable attention, with their use enabling successful results to be more easily obtained. In this study, we investigated the effect of fiber size, fiber amount, water content, and cell pressure on maximum deviator stress (MDS) and failure deformation (FD) of basalt fiber (BF) -reinforced, unsaturated silty soils using three AI techniques: the artificial neural network (ANN), support vector machine (SVM), and fuzzy logic (FL). The numerical analyses and experiments were conducted using varying amounts (1, 1.5, and 2%) and lengths (6, 12, and 24 mm) of BF, and a total of 180 samples were prepared for the detailed investigation. In order to compare model performances, R-2 and MAPE goodness-of-fit metrics were used. The experimental results revealed that the addition of BF generally increased the MDS of the soils, which corresponds to the shearing resistance. According to AI models result, FL outperformed the SVM and ANN, with a R-2 value of 0.938, especially in FD prediction. The sensitivity analysis was performed to ascertain the effect of the inputs on the MDS and FD response variables. Results revealed that fiber length and cell pressure have substantial influence in MDS estimations.Öğe Fresh Properties and Fracture Energy of Basalt and Glass Fiber-Reinforced Self-Compacting Concrete(Asce-Amer Soc Civil Engineers, 2022) Gultekin, Adil; Beycioglu, Ahmet; Arslan, Mehmet Emin; Serdar, Ahmet Hamdi; Dobiszewska, Magdalena; Ramyar, KambizIn this study, the fresh properties, fracture energy, compressive strength, and flexural strength of self-compacting concrete including glass or basalt fibers were examined, and the effect of fibers on these properties were studied comparatively. For this purpose, fibers having three different lengths (6, 12, and 24 mm) were used in two different contents (2 and 4 kg/m(3)). The workability of concrete mixtures decreased with fiber addition. The negative effect of basalt fibers on workability was greater than that of the glass fibers. The reduction in flow diameter was up to 40% and 44% as well as the reduction in L-box ratio was up to 41% and 48% in glass and basalt fiber mixtures, respectively. While the fiber addition generally reduced the compressive strength, it increased the flexural strength and fracture energy significantly. Increase in flexural strength was up to 58.6% in glass fiber and 43.5% in basalt fiber mixtures. The fracture energies of glass and basalt fiber mixtures were up to 55.1% and 30.4% higher than that of the control mixture, respectively. (C) 2021 American Society of Civil Engineers.Öğe IMPORTANCE OF TEACHING STATISTICAL OPTIMIZATION IN ENGINEERING EDUCATION: A CASE STUDY ON THE CONTRIBUTION OF A PHD STUDENT FOR A GEOTECHNICAL DESIGN(Int Council Materials Education, 2020) Bagriacik, Baki; Yildirim, Zeynel Baran; Beycioglu, Ahmet; Cetin, Suna; Guner, Esra DenizIn engineering education, the students are often guided by their advisors to take courses related to their areas of expertise. In addition to the courses related to their areas of expertise, especially in the fields of applied engineering, taking math-based statistics or artificial intelligence courses improves students' analytical thinking skills significantly. For this reason, new perspectives for teaching in engineering education are required. In this study, the importance of teaching mathematically based statistical optimization techniques in engineering education has been discussed through an experimental case study. Within the study, the disposal of Drinking Water Treatment Sludge (DWTS) through its use in sandy soil improvement was studied experimentally and it was discussed whether the sludge usage improves the engineering properties of sandy soils. Besides, the experimental process of this research was supported by a Response Surface Methodology (RSM) analysis, thanks to the knowledge of a Ph.D. student. The RSM studied by Ph.D. students aims to suggest a useful approach to decrease laboratory efforts considering the difficulties of laboratory studies. It has been observed that the results found experimentally and calculated by a Ph.D. student are very close to each other, and the approach suggested by a Ph.D. student can be a useful way to decrease laboratory experiments. It can be concluded from this applied research that statistical knowledge gives strong advantages to engineers for reducing labor efforts, gaining time and having economic advantages. As a result, teaching some statistical approaches to engineering students is very useful for their professional lives.Öğe Influence of Rock Dust Additives as Fine Aggregate Replacement on Properties of Cement Composites-A Review(Mdpi, 2022) Dobiszewska, Magdalena; Bagcal, Orlando; Beycioglu, Ahmet; Goulias, Dimitrios; Koksal, Fuat; Niedostatkiewicz, Maciej; Urunveren, HusamettinConcrete production consumes enormous amounts of fossil fuels, raw materials, and is energy intensive. Therefore, scientific research is being conducted worldwide regarding the possibility of using by-products in the production of concrete. The objective is not only to identify substitutes for cement clinker, but also to identify materials that can be used as aggregate in mortar and concrete productions. Among the potential alternative materials that can be used in cement composite production is rock dust of different geological origin. However, some adversarial effects may be encountered when using rock dust regarding the properties and durability of mortars and concrete. Therefore, comprehensive research is needed to evaluate the adequacy of rock dust use in cementitious composite production. This paper presents a comprehensive review of the scientific findings from past studies concerning the use of various geological origins of rock dust in the production of mortars and concrete. The influence of rock dust as a replacement of fine aggregates on cementitious composites was analyzed and evaluated. In this assessment and review, fresh concrete and mortar properties, i.e., workability, segregation, and bleeding, mechanical properties, and the durability of hardened concrete and mortar were considered.Öğe Load-Deflection Behavior of Over- and Under-Reinforced Concrete Beams with Hybrid FRP-Steel Reinforcements(Mdpi, 2021) Kartal, Saruhan; Kalkan, Ilker; Beycioglu, Ahmet; Dobiszewska, MagdalenaThe present study pertains to the load-deflection behavior and cracking moments of concrete beams with hybrid FRP-steel reinforcement. Under and over-reinforced hybrid beams were tested for failure along with reference beams with only steel or FRP reinforcement. The first-cracking moments of the beams were estimated analytically by using different uncracked moments of the inertia and modulus of rupture definitions. The uncracked moment of inertia definitions include the gross and uncracked transformed moments. The adopted modulus definitions are comprised of the experimental values from tests on prisms and the analytical values from the equations in different concrete codes. Furthermore, analytical methods were developed for estimating the deflections of concrete beams with hybrid FRP-steel or only FRP reinforcement. Two different types of elastic moduli, namely the secant modulus corresponding to the extreme compression fiber strain and the ACI 318M-19 modulus, were used in deflection calculations. Closer estimates were obtained by using the secant modulus, particularly in hybrid-reinforced beams. In the post-yielding region of the steel tension reinforcement, the deflection estimates were established to lay in closer proximity to the experimental curve when obtained by adding up the deflection increments instead of directly calculating the total deflections from the elastic curve equation. Accurate estimation of the cracking moment was found to be vital for the close prediction of deflections.Öğe Optimization Based on Toughness and Splitting Tensile Strength of Steel-Fiber-Reinforced Concrete Incorporating Silica Fume Using Response Surface Method(Mdpi, 2022) Koksal, Fuat; Beycioglu, Ahmet; Dobiszewska, MagdalenaThe greatest weakness of concrete as a construction material is its brittleness and low fracture energy absorption capacity until failure occurs. In order to improve concrete strength and durability, silica fume SF is introduced into the mixture, which at the same time leads to an increase in the brittleness of concrete. To improve the ductility and toughness of concrete, short steel fibers have been incorporated into concrete. Steel fibers and silica fume are jointly preferred for concrete design in order to obtain concrete with high strength and ductility. It is well-known that silica fume content and fiber properties, such as aspect ratio and volume ratio, directly affect the properties of SFRCs. The mixture design of steel-fiber-reinforced concrete (SFRC) with SF addition is a very important issue in terms of economy and performance. In this study, an experimental design was used to study the toughness and splitting tensile strength of SFRC with the response surface method (RSM). The models established by the RSM were used to optimize the design of SFRC in terms of the usage of optimal silica fume content, and optimal steel fiber volume and aspect ratio. Optimum silica fume content and fiber volume ratio values were determined using the D-optimal design method so that the steel fiber volume ratio was at the minimum and the bending toughness and splitting tensile strength were at the maximum. The amount of silica fume used as a cement replacement, aspect ratio, and volume fraction of steel fiber were chosen as independent variables in the experiment. Experimentally obtained mechanical properties of SFRC such as compression, bending, splitting, modulus of elasticity, toughness, and the toughness index were the dependent variables. A good correlation was observed between the dependent and independent variables included in the model. As a result of the optimization, optimum steel fiber volume was determined as 0.70% and silica fume content was determined as 15% for both aspect ratios.Öğe Physical Properties and Microstructure of Concrete with Waste Basalt Powder Addition(Mdpi, 2020) Dobiszewska, Magdalena; Beycioglu, AhmetThe natural aggregates are one of the main components in the production of concrete. Although deposits of natural aggregates lie on the earth's surface or at low depths and belong to common deposits, the shortage of aggregate, especially natural sand, is presently observed in many countries. In such a situation, one is looking for other materials that can be used as a substitute for natural aggregates in mortars and concrete production. This paper presents the results of an experimental investigation carried out to evaluate the potential usage of waste basalt powder in concrete production. For this purpose, the waste basalt powder, which is a by-product of the production of mineral-asphalt mixtures, was substituted with 10%, 20%, and 30% sand replacement. In the experimental program, the workability, compressive strength, water transport properties, and microstructural performances were evaluated. The results showed that the production of concretes that feature a strong internal structure with decreased water transport behavior is possible with waste basalt usage. Furthermore, when waste basalt powder is used as a partial sand replacement, the compressive strength of concretes can be increased up to 25%. According to the microstructural analyses, the presence of basalt powder in concrete mixes is beneficial for cement hydration products, and basalt powder substituted concretes have lower porosity within the interfacial transition zone.Öğe Use of GRP Pipe Waste Powder as a Filler Replacement in Hot-Mix Asphalt(Mdpi, 2020) Beycioglu, Ahmet; Kaya, Orhan; Yildirim, Zeynel Baran; Bagriacik, Baki; Dobiszewska, Magdalena; Morova, Nihat; Cetin, SunaThere is an increasing global trend to find sustainable, environmentally friendly and cost-effective materials as an alternative to limited natural raw materials. Similarly, the use of waste materials has been gaining popularity in the production of hot-mix asphalt (HMA). In this study, the sustainable use of glass-fiber-reinforced polyester (GRP) pipe waste powder (GRP-WP), gathered from the cutting and milling process of GRP pipe production, utilizing it in asphalt mixes as a filler, is evaluated based on lab testing to find out: (i) if it produces similar or better performance compared to the most conventionally available filler material (limestone) and, (ii) if so, what would be the optimum GRP-WP filler content to be used in asphalt mixes. For this reason, an experimental test matrix consisting of 45 samples with three different amounts of binder content (4%, 4.5% and 5.0%), and a 5% filler content with five different percentages of the GRP-WP content (0%, 25%, 50%, 75% and 100% replacement by weight of the filler), was prepared to figure out which sample would produce the similar Marshall stability and flow values compared to the control samples while also satisfying specification limits. It was found that the samples with 4.5% binder content, 3.75% GRP-WP and 1.25% limestone filler content produced the results both satisfying the specification requirements and providing an optimum mix design. It is believed that use of GRP-WP waste in HMA production would be a very useful way of recycling GRP-WP.Öğe Utilization of rock dust as cement replacement in cement composites: An alternative approach to sustainable mortar and concrete productions(Elsevier, 2023) Dobiszewska, Magdalena; Bagcal, Orlando; Beycioglu, Ahmet; Goulias, Dimitrios; Koksal, Fuat; Plominski, Blazej; Urunveren, HusamettinProduction of concrete is consuming significant amounts of raw materials, high level of energy, and is heavily dependent on fossil fuels. This induces significant harmful impact on the environment. Scientific research is being conducted worldwide on the possibility of using different waste by-products in the production of concrete, particularly as a substitute for cement clinker. Rock dust of different geological origin can be considered as potential alternative material that can be used in cement composites production. However, there are some conflicting findings concerning the effect of rock dusts as partial cement replacement on the physical and mechanical properties and durability of cement composites as reported in the literature. Thus, a comprehensive assessment and analysis are needed to evaluate the value of rock dust application as cement replacement in concrete production. This paper presents a comprehensive review of the findings from scientific articles concerning the use of rock dust of different geological origins in mortar and concrete productions. The effect of rock dusts as partial cement substitution on cementitious composites properties were analyzed particularly on the cement hydration, the concrete and mortar mixture properties, mechanical properties and durability. The impact of rock dust is mainly related to the filler effect i.e., due to modification of particle size distribution, heterogenious nucleation, and cement dilution. This effect is more significant when cement is substituted with a rock dust of greater fineness than cement. Partial replacement of cement with up to about 10-15% of rock powder does not deteriorate cement composite properties. However higher substitution leads to reduction of mechanical properties and cement composite durability decline.
