Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2026/r/gumushane/16536
  Formulation of mechanical properties of hybrid fiber alkali-activated concretes by data analysis

  Aksut, Yavuz Selim; Yetgín, Sukru

  In this study, ground blast furnace slag (GBFS) and waste volcanic rock dust (RD) produced in a natural stone processing plant were used as binders. The binders were activated with Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3) to produce two types of concrete: alkali-activated concrete without fibers (AAC) and alkali-activated concrete with fibers (FAAC). In the production of concrete, steel and polyester fibers were used separately and hybrid at 0.25%, 0.50%, 0.75% and 1.0% by volume and a total of 117 15x15x15 cm cube specimens were produced. The mechanical properties of the specimens were evaluated by concrete surface hardness, ultrasonic pulse velocity and concrete compressive strength tests at 3, 7 and 28 days. The results obtained using non-destructive test methods were matched with concrete compressive strength values using various empirical formulas. Calculated concrete compressive strength values and actual concrete compressive strength values were compared using data analysis method. As a result, it was observed that there was a very significant correlation between the experimental compressive strength and the combined method in which 7-day surface hardness and ultrasound transmission rate were used together to calculate the compressive strength.

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  AtıfWoS1

  İncele
• MakaleYalnız künye2025Scopus SJRQ1/r/gumushane/16739
  Modeling the Compressive Strength of Fiber-Reinforced Alkali-Activated Concrete Using Non-Destructive Methods in Short Curing Periods

  Aksüt, Yavuz Selim; Çullu, Mustafa; Yetgin, Sukru

  The indirect assessment of concrete compressive strength using non-destructive techniques, including the Schmidt rebound hammer and ultrasonic pulse velocity methods, is crucial for evaluating and tracking the strength of structural concrete used in construction and rehabilitation projects. However, studies focusing on alkali-activated concrete (AAC) remain insufficient. This study investigates the mechanical properties of fiber-reinforced alkali-activated concretes (FAACs) produced with short curing times, addressing this gap in the literature. Ground blast furnace slag (GBFS) was used as the binder, and waste volcanic rock dust (RD), produced in a natural stone processing plant, served as a fine filler. These materials were activated with sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) to produce alkali-activated concrete, both without fibers (AAC) and with fibers (FAAC). Steel fiber (SF) and polyester fiber (PYF) were used separately and in hybrid forms at 0.25%; 0.50%; 0.75%, and 1.0% volume fractions, resulting in a total of 117 cubic specimens (15x15x15 cm). The specimens' mechanical properties were evaluated using regression analyses based on data from Schmidt rebound number (RN), ultrasonic pulse velocity (UPV) non-destructive methods and uniaxial compressive strength (UCS) destructive tests. Optimized functions predicting compressive strength based on RN and UPV measurements were developed, highlighting the significant effects of fiber type, ratio, and mode of use. Additionally, multivariate prediction models were statistically developed using data from the three test methods.

  AtıfWoS2·OpenAlex1

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• MakaleAçık Erişim2025Scopus SJRQ2/r/gumushane/14352
  Optimal Ratio of Steel and Polyester Fibers on the Mechanical Behavior of Alkali-Activated Concrete Produced by Industrial Waste Minerals

  Aksüt, Yavuz Selim; Çullu, Mustafa; Yetgin, Şükrü

  Alkali Activation Concretes (AAC) have many superior properties compared to Ordinary Portland Cement Concrete (OPC). However, it shows traditional concrete behavior with its brittleness. In this case, the tensile strength and flexural strength which are weak in addition to ductility is being studied to be increased by using various artificial and natural fibers. In this context, it is inevitable to conduct multifaceted research to improve the behavior of Fiber Alkali Activated Concrete (FAAC). In this study, 13 different mixes were made using steel and polyester fibers in different proportions by volume (0%; 0.25%; 0.50%; 0.75%; 1%) separately and hybrid. The mechanical properties of cubic (150 × 150 × 150 mm), cylindirical (100 × 200 mm) and prismatic (150 × 150 × 600 mm) specimens were determined including compressive strength, modulus of elasticity and poison ratio, splitting tensile strength and flexural strength (toughness-energy absorption capacity and modulus of rupture). crack formation in concrete occurs early and a significant decrease in strength is observed due to the high flexibility and low flow resistance of polyester fibers. Steel fibers with high strength and higher yield strength were used in hybrid form to solve this problem. It was revealed that the blend ratio that contributed the most to the mechanical behavior of the specimens was the case where the fibers were used as hybrid at a ratio of 1% by volume evaluation from both the experimental results and the optimization.

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  AtıfScopus4·OpenAlex6

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• MakaleYalnız künye2025Scopus SJRQ1/r/gumushane/13973
  Durability properties of fiber-reinforced geopolymer concrete with natural and industrial waste mineral admixtures

  Aksüt, Yavuz Selim; Çullu, Mustafa; Yetgin, Şükrü

  In this study, ground granulated blast furnace slag (GGBFS) and quarry rock dust (RD), both industrial and natural mineral wastes were used as binder materials in geopolymer concrete. The influence of these mineral admixtures on the concrete’s durability under aggressive environmental conditions was investigated. Steel, polyester, and hybrid fibers were incorporated at volume fractions of 0%, 0.25%, 0.50%, 0.75%, and 1.0% to further enhance durability performance. Freeze-thaw and sulfate resistance tests were carried out to evaluate the effects of fiber type and content on the durability behavior of the geopolymer concrete. The test results showed that the mineral waste-based binder system itself offered considerable durability while the addition of fibers significantly improved resistance to freeze-thaw cycles and sulfate attacks. Among all types, the geopolymer concrete with 0.5% polyester fiber exhibited the highest resistance to freeze-thaw while hybrid fiber usage provided a balanced enhancement across both test environments.

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  AtıfScopus1·WoS1

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• MakaleAçık Erişim2024Scopus SJRQ2/r/gumushane/11956
  Performance of different fibre types in alkaline-activated concrete produced with industrial wastes: volcanic rock powder and blast furnace slag

  Aksüt, Yavuz Selim; Külekçi, Gökhan; Çullu, Mustafa; Yetgin, Şükrü

  The objective of the study is to determine the effects of different fibre types and ratios on the mechanical and physical properties of alkali-activated concrete (AAC) and to optimise important properties such as workability, unit weight, water absorption, compressive strength, modulus of elasticity and abrasion resistance of these concretes. Concrete samples were produced using steel and polyester fibres at ratios of 0.25%, 0.50%, 0.75% and 1%. The fibre ratios were varied, and various tests were conducted to determine the mechanical and physical properties of the concrete samples. The experiments clearly revealed the effects of fibre types and ratios on the performance of concrete. These results clearly demonstrate the effects of different fibre types and ratios on the mechanical and physical properties of AACs. Particularly noteworthy is the water-retaining property of polyester fibres, their effect on workability and their enhancing effect on abrasion resistance. The effects of steel fibres on compressive strength and modulus of elasticity are more pronounced, but they may present disadvantages in terms of workability and abrasion resistance. It is observed that mixed fibre usage provides a good balance in some properties. This study provides a roadmap for evaluating sustainable material options in the concrete industry and guiding future research.

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  AtıfScopus4·WoS3·OpenAlex4

  İncele
• MakaleYalnız künye2017/r/gumushane/16722
  THE USABILITY OF VOLCANIC ROCKS FROM UPPER EUPHRATES PART IN THE EASTERN ANATOLIA REGION AS CONCRETE AGGREGATE

  Aksüt, Yavuz Selim; Yetgin, Sukru

  In this study; the engineering properties of volcanic rocks obtained from four different quarries in the province of Erzincan region in the Upper Euphrates Part in the Eastern Anatolia Region were investigated. In laboratory studies, the experiments including bulk and aggregate tests (bulk and dense unit weight, specific mass, water absorption, Los Angeles test for resistance to wear, freezing resistance and uniaxial compressive strength) were conducted on 5 volcanic samples according to the standards (Turkish Standard, British Standard and ASTM) and in the second stage, grading of concrete tests (grading of the concrete aggregates, concrete preparation, slump test, specific density of concrete, uniaxial compressive strength, modulus of elasticity, splitting tensile strength, abrasion resistance and capillarity) were performed on the concrete samples with volcanic aggregates. For fresh concrete composition, water/cement ratio was selected as the main variable providing homogeneous mixing and the highest strength to the concrete samples with a specific granulometry. Cylindrical concrete samples were produced with a variety of water/cement ratios cured for 7 and 28 days in water and their compressive strengths were assessed in the light of their physical and mechanical properties. The results obtained from aggregates and concrete tests, which were performed in line with the standards showed that especially Yassitepe-Dogu (YTD) sample, one of the volcanic rocks from Erzincan region can be used as concrete aggregate. It was observed that compressive strength of the concrete samples could satisfy C25/30 strength class and upper classes. In addition, it was understood that they can be used in highways, bridges, dams, buildings etc., especially as structural concrete.

  AtıfWoS1

  İncele
• MakaleYalnız künye2011Scopus SJRQ1/r/gumushane/16575
  Abrasion Resistance of Cement Mortar with Different Pozzolanic Compositions and Matrices

  Yetgin, Sukru; Çavdar, Ahmet

  Abrasion of concrete occurs due to scraping, rubbing, skidding, or sliding of objects on its surface. The abrasion resistance of concrete is influenced by a number of factors, such as compressive strength, surfacing finish, aggregate properties, types of hardeners, and curing. The main objective of this study is to determine the effects of the pozzolanic compositions and matrix structure (or voids) on the abrasion resistance of cement mortars. In this study, the mortars produced with cement samples with seven different compositions and varied with an air-entraining agent were subjected to the abrasive effects. Several examples of mortars were evaluated using samples cured for six different periods throughout 1 year. This study is supported by thin section investigations, in addition to being subjected to the basic tests, such as compression, flexure, and abrasion. The Bohme apparatus was used during abrasion tests. To summarize the most important findings from this study, a compact cement matrix is more effective against abrasive effects than mineral additives.

  AtıfWoS13·OpenAlex18

  İncele
• MakaleYalnız künye2010Scopus SJRQ1/r/gumushane/15401
  Investigation of mechanical and mineralogical properties of mortars subjected to sulfate

  Çavdar, Ahmet; Yetgin, Şükrü

  The durability can be described as concrete's resistance to the destructive influences of a medium containing acid, sulfate and/or various chemicals and mechanical effects. The main objective of this study is investigation of mechanical and mineralogical properties of cement mortar with different pozzolanic compositions and subjected to sulfated medium. In the study, the mortars produced with cement samples having seven different compositions and varied with an air-entraining agent were subjected to the influence of sulfate. This study is supported by thin section and X-ray powder diffraction (XRPD) investigations, in addition to being subjected to the basic tests, such as compression and flexure. The most important findings obtained from the study are that the compact structure has more effective properties against sulfate effects for cement mortars than pozzolanic materials' effects and the highest pozzolanic material ratio is restricted about 25-30% by mass because this ratio is a boundary of mechanical properties.

  AtıfScopus34·WoS29·OpenAlex37

  İncele
• MakaleYalnız künye2010Scopus SJRQ1/r/gumushane/13168
  Investigation of abrasion resistance of cement mortar with different pozzolanic compositions and subjected to sulfated medium

  Çavdar, Ahmet; Yetgin, Şükrü

  The durability phenomenon for concrete, or cement mortar, has gained attention recently as one of the important mechanical properties. It can be described as concrete's resistance to the destructive influences of a medium containing acid, sulfate and/or various chemicals and mechanical effects, like abrasion. Most of the studies attempted to improve these individual properties in concrete. However, concrete can be subjected to two or more of these effects simultaneously. In this study, the mortars produced with cement samples having seven different compositions and varied with an air-entraining agent were subjected to the influence of sulfate and abrasive effects simultaneously. In this study, several examples were evaluated using samples cured for six different periods throughout one year. This study is supported by thin section and XRPD investigations, in addition to being subjected to the basic tests, such as compression, flexure and abrasion. If the most important findings obtained from the study are summarized, it is seen that a compact cement matrix is more effective against both sulfate and abrasive effects than mineral additives. The mortars subjected to coupled (sulfate and abrasive) effects show less durability if compared to ones cured in water and later abraded.

  AtıfScopus31·WoS27

  İncele
• MakaleYalnız künye2008Scopus SJRQ1/r/gumushane/14888
  The effects of the fiber contents on the mechanic properties of the adobes

  Yetgin, Şükrü; ÇAVDAR, Özlem; Çavdar, Ahmet

  In this study, compression and tensile tests were conducted for five different adobe mixtures. The important part of this study consisted of uniaxial compressive tests done with natural fiber mixtures. Thus, the results obtained from mechanical tests were presented in the form of stress-strain graphs. In addition, mechanical properties were related to the water content for workability, unit weight and fiber contents and discussions were given. The results show that as fiber content increases, compressive and tensile strengths decrease, and shrinkage rates decrease.

  AtıfScopus170·OpenAlex195

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