Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2016/r/gumushane/13084
  Use of polyvinyl chloride (PVC) powder and granules as aggregate replacement in concrete mixtures

  Bolat, Hakan; Erkus, Pinar

  Concrete is one of the materials in which polymer wastes are utilized. Generally, these wastes are added at specific rates in scientific studies but an important problem of waste polymers is size irregularity. Even when consistent dosage rates are used, variations in polymer size can lead to variability in the physical and mechanical properties of the concrete produced. The aim of this study is to determine physical and mechanical properties of polyvinyl chloride (PVC)-containing concretes. In order to produce normal and high strength concretes, 10%, 20%, and 30% replacement ratios of PVC powder and granules by volume of aggregate are used. Slump, fresh and hardened densities, compressive strength, capillary water absorption, and abrasion were tested on all concrete types. As the PVC ratio increases, important changes are seen in all physical and mechanical concrete properties. The unit weights of the 10%, 20%, and 30% replacement PVC powder concretes are lower by ∼4%, 8%, and 13%, respectively, as compared to the reference mixtures, and the replacement PVC granule concretes are lower by ∼2%, 4%, and 7%. Compressive strength test results showed similar trends. As PVC replacement increases, the capillary water absorption decreases between 10% and 50%, and abrasion decreases between 27% and 77%.

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• MakaleAçık Erişim2016/r/gumushane/11330
  Investigation of pozzolanic activity of volcanic rocks from the northeast of the Black Sea

  Çullu, Mustafa; Bolat, Hakan; Vural, Alaaddin; Tuncer, Ertan

  Mineralogical and chemical properties, as well as the pozzolanic activities, of the volcanic rocks in the northeast of the Black Sea were examined. Physical and mechanical tests were conducted on samples collected from the study area and the feasibility of using volcanic rocks as pozzolanic admixture in the concrete industry was investigated. Mortar samples containing admixture in the ratios of 0%, 10%, 20%, 30%, 40%, and 50% were prepared by keeping fineness of pozzolanic admixtures fixed. By using these mortar samples, prismatic mortar samples of 4×4×16 cm were prepared and the samples were cured in water. Their 7-, 28-, and 90-day tensile strengths, compressive strengths, and ultrasonic pulse velocity were determined. As a result, it was determined that volcanic rocks can be used to produce blended cement by considering their specific gravity, pozzolanic activities, and compressive strengths. It was noted that increase in trass rate significantly reduced tensile and compressive strength of cement in the early stage as expected.

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• MakaleYalnız künye2015/r/gumushane/16478
  EVALUATION OF ENERGY ABSORPTION OF MACRO SYNTHETIC AND STEEL FIBER REINFORCED CONCRETES

  Bolat, Hakan; Simsek, Osman

  This study alms to determine the energy absorption of concrete slabs (60x60x10cm) using polyester, polypropylene and steel fiber reinforced (SFRC, PYFRC, PPFRC) according to EN 14488-5. Significant differences in the energy absorption were observed between the concrete slabs strengthened with different fibers. The highest gain In energy absorption was observed In SFRC. Furthermore, concrete slabs strengthened with PPFRC and PYFRC showed 23.4% and 14.8% less energy to SFRC. Although the SFRC showed the highest energy absorption under directly negative conditions, it is important to evaluate the durability issues associated with SFRC, such negative conditions.

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• MakaleYalnız künye2015/r/gumushane/15703
  Evaluation of energy absorption of macro synthetic and steel fiber reinforced concretes; [Evaluarea capacitătii de absorbţie a energiei de către betonul armat cu fibre macro sintetice şi fibre de oţel]

  Bolat, Hakan; Şìmşek, Osman

  This study aims to determine the energy absorption of concrete slabs (60×60×10cm) using polyester, polypropylene and steel fiber reinforced (SFRC, PYFRC, PPFRC) according to EN 14488-5. Significant differences in the energy absorption were observed between the concrete slabs strengthened with different fibers. The highest gain in energy absorption was observed in SFRC. Furthermore, concrete slabs strengthened with PPFRC and PYFRC showed 23.4% and 14.8% less energy to SFRC. Although the SFRC showed the highest energy absorption under directly negative conditions, it is important to evaluate the durability issues associated with SFRC, such negative conditions.

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• MakaleYalnız künye2014/r/gumushane/15630
  The effects of macro synthetic fiber reinforcement use on physical and mechanical properties of concrete

  Bolat, Hakan; Şimşek, Osman; Çullu, Mustafa; Durmuş, Gökhan; Can, Ömer

  Attempts to find a construction material having increased strength, ductility, toughness, and durability have led to interest in high performance fiber reinforced concrete. The use of such materials increases day by day. When the fibers are distributed in a homogeneous way and used in appropriate quantity inside the concrete, they reduce cracks, contribute to tensile strength, toughness, ductility and durability, and improve other mechanical properties. In this study, four types of concrete were produced: steel fiber (SFRC), polyester fiber (PYFRC), polypropylene fiber (PPFRC) reinforced concrete and a reference sample made of plain concrete (R1); these were then compared to one another. The ratio of fibers was used 4.25% of volume of concrete. The effects of the different types of fiber on hardened concrete were determined by conducting physical and mechanical experiments. Compressive strength, surface hardness, ultrasonic pulse velocity, carbonation, abrasion, capillarity and freeze-thaw resistance experiments were conducted on hardened concretes. SFRC had higher 12.4%, PYFRC 3.4% higher and PPFRC 4.3% lower compressive strength with respect to R1. PPFRC showed 8.04% higher compressive strength than R1 when it was determined by the surface hardness method. SFRC showed 5.4% higher compressive strength than R1 when we applied the ultrasonic pulse velocity method. In the abrasion experiment, the highest abrasion was found in SFRC with ∼0.5%, while the lowest was found in PPFRC at ∼0.18%. The highest and lowest amount of capillary water absorption was seen in R1 and PYFRC, respectively. In a carbonation experiment, SFRC was determined ∼130.8% higher than R1. It was concluded that the types of fiber used for reinforcement influenced the physical and mechanical properties of the concrete.

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