Karma lifli betonların tokluk açısından değerlendirilmesi

Year 2016, Volume: 7 Issue: 3, 365 - 376, 01.12.2016

Fehmi Çivici Engin Güngör

Abstract

Günümüzde farklı lifleri bir arada kullanarak elde ettiğimiz karma lifli beton ile betonun değişik özelliklerini
iyileştirebilmekteyiz. Bu mükemmel malzeme konusundaki deneyimlerimiz her geçen gün artarak istenilen
özellikte, amaca uygun ürünler elde edilmektedir. Yapılan çalışmalar neticesinde betonun gevreklik
özelliğinden kurtarıp sünek bir malzeme haline getirmenin bir yolu da liflerin kullanılmasıdır.
Bu çalışmada 11 farklı beton numune üretimi gerçekleştirilmiştir. Karışımlarda çelik lif miktarı, 20 kg/m3,
40 kg/m3 ve polipropilen lif miktarı ise 600 g/m3 alınmıştır. Karma lifli beton karışımlarında ise çelik lif 20
kg/m3, polipropilen lif ise 500 g/m3 miktarında karışıma eklenmiştir. Üretilen 150x150x550 mm lik kiriş ve
150 mm lik küp numuneler eğilme ve basınç deneylerine tabi tutulmuştur. Aynı su/çimento oranına sahip
numunelerin eğilme deneyleri aracılığıyla yük-sehim diyagramları oluşturulmuştur. Her bir numune için
kayıt altına alınan kırılma davranışına bağlı olarak numunelerin enerji yutma kapasiteleri yük-sehim
diyagramları aracılığıyla ölçülmüştür. En iyi performansın karma lifli beton numunelerden elde edilmesi,
Ülkemizin deprem kuşağında bulunması gerçeğine bağlı olarak depreme karşı sünek elemanlar üretmenin
önemini bir kez daha vurgulamaktadır

Keywords

hibrit lif, çelik lif, propilen lif, tokluk, eğilme

Evaluation of toughness of the hybrid fiber concrete

Abstract

It is known for its concrete brittleness feature a
popular building material. The ductility of the
structure of the delivery system, however, the
concept is becoming important. The studies result
in a concrete way to make a ductile material
rescued from the brittleness feature is the use of
fiber. The fibers used; steel, synthetic and naturebased
materials. Our experience in this perfect
material fit for purpose in every day products rose
desired properties are obtained. By using
different fibers together to obtain hybrid fiber
concrete. Hybrid fiber concrete; Instead of a
single fiber type and size is more than one type
and size of a new cement -based composite
material is contained in the mixture with the fiber.
It intended to control the size of the cracks under
load with hybrid fiber concrete.
In this study 11 different types of concrete samples
were produced. The amount of steel fibers in the
mixture is 20 kg/m3 and 40 kg/m3
, the amount of
polypropylene fiber is 600 g/m3
. In the mixedfiber
concrete amount of steel fiber 20 kg/m3 and
polypropylene fiber 500 g/m3 are considered. The
specimens were tested under bending and
compression. All experiments were carried out in
the Balıkesir University's faculty of engineering
and architecture building labs. Produced
150x150x550 mm beam samples and 150 mm
cube samples are subjected to compressive and
flexural tests. The same water/cement ratio
concrete sample tests through bending loaddeflection
diagrams are created. The energy
absorbing capacity depending on the fracture
behavior of the received record for each sample
was measured. One of the aims of the work load
energy absorption capacity of different types of
samples depends on the deflection diagram to
compare. The load deflection diagrams have been
normalized to the same sample group. Plain
concrete specimens are broken in a brittle
whereas fiber concrete specimens showed a
ductile behavior. Different test methods and
specifications to determine their level of
toughness of fiber concrete is available. In this
study, toughness values were calculated
according to the method given in TS 10515.
Toughness index were found to be among the
calculated values given in the specification.
These values are given in the table 2. Depending
on the experimental setup, the load -deflection
curves were plotted to 8 mm deflection.
Toughness values of all samples were compared.
Toughness of fiber and hybrid fiber samples
showed a significant increase. The best results
were obtained from the behavior of the hybridfiber
concrete samples, producing ductile element
for our country in the earthquake zone, the
importance of the earthquake behavior
emphasizes once again.

Keywords

hybrid fiber, steel fiber, polypropylene fiber, toughness, flexure.