Epoksi Emdirilmiş Karbon Lifi Sargılı Çelik Donatıların Aderans Dayanımı

Çelik donatıların korozyon sorunu ile FRP donatıların düşük elastisite modülü ve gevrek gerilme-şekil değiştirme davranışlarına karşı geliştirilen çelik-FRP kompozit donatıların beton yapı elemanlarında kullanımlarının araştırılması çok sınırlı kalmıştır. Özellikle de yapı elemanlarının sünekliğini, enerji sönümleme ve taşıma kapasitesini önemli oranda etkileyen donatı-beton aderansı konusunda daha fazla araştırma yapılması gereklidir. Çünkü çelik-FRP kompozit donatılar, sertliği ve sünekliği birbirlerinden çok farklı iki malzemeden üretildiği için malzemenin kendi içindeki uyumu bu donatıların aderans davranışlarını etkilemektedir. Bu kapsamda, bu çalışmada, epoksi emdirilmiş karbon lifinin çelik donatı üzerine filaman sarım tekniğiyle 30 derece sarılmasıyla üretilen ve yüzeyine herhangi bir deformasyon işlemi uygulaması yapılmamış kompozit donatıların beton ile aralarındaki aderans dayanımları çekip çıkarma deneyleriyle araştırılmıştır. Elde edilen bulgular literatürdeki salt çelik donatıların, salt karbon FRP donatıların ve çelik-bazalt, çelik-karbon, çelik-cam FRP donatıların aderans dayanımları ile karşılaştırılmıştır. Çalışma sonucunda karbon FRP sargılı çelik kompozit donatıların yüzeyinde herhangi bir deformasyon işlemi olmamasına rağmen ortalama bir aderans dayanımına ve düz, kumlanmış, demet ve örgülü yüzey özelliğine sahip donatılardan da daha iyi bir aderans dayanımına sahip olduğu gözlemlenmiştir.

Anahtar Kelimeler:

Karbon lifi, karbon lifi takviyeli çelik donatı, hibrit donatı, kompozit, çekip çıkarma deneyi, FRP donatı, CTP, Aderans dayanımı

Bond Strength of Epoxy Impregnated Carbon Fiber Wrapped Steel Reinforcement

The investigation of the use of steel-FRP composite reinforcements developed against the corrosion problem of steel reinforcements and the low elasticity modulus and brittle stress-strain behavior of FRP reinforcements in concrete structural members has been very limited. More research is needed especially bond strength between reinforcement and concrete which significantly affects the ductility, energy absorption and carrying capacity of structural members. Because steel-FRP composite reinforcements are produced from two materials whose hardness and ductility are very different from each other, so the compatibility of the material within itself affects the bond behavior of these reinforcements. In this context, in this study, the bond strengths of composite reinforcements produced by wrapping epoxy impregnated carbon fiber on steel reinforcement with filament winding technique at 30 degrees and without any deformation process on the surface were investigated by pullout tests. The findings obtained were compared with the bond strength of steel reinforcements, carbon FRP reinforcements and steel-basalt, steel-carbon, steel-glass FRP reinforcements in the literature. As a result of the study has been observed carbon FRP wrapped steel composite reinforcements although there is no deformation on the surface have an average bond strength and better bond strength than reinforcements with smooth, sand-coated, strand and braided surface features.

Keywords:

Carbon fibre, Carbon fibre reinforced steel bar, hybrid rebar, composite, pull-out test, FRP reinforcement bar, GFRP, bond strength,

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ACI 440.1R-15, Guide for the Design and Construction of Structural Concrete Reinforced with Fiber-Reinforced Polymer (FRP)Bars. (2015). American Concrete Institute (ACI).
ACI 440R-07, Report on Fiber-Reinforced Polymer (FRP) Reinforcement for Concrete Structures. (2007). American Concrete Institute (ACI).
Basaran, B., & Donmez, E. T. (2020). Investigation of Bond Strength Between GFRP Wrapped Steel Reinforcement and Concrete with Pullout Test. Hittite Journal of Science & Engineering, 7(4), 321–327. https://doi.org/10.17350/HJSE19030000201
Basaran, B., & Kalkan, I. (2020). Investigation on variables affecting bond strength between FRP reinforcing bar and concrete by modified hinged beam tests. Composite Structures, 242(March), 112185. https://doi.org/10.1016/j.compstruct.2020.112185
Cheung, M. M. S., & Tsang, T. K. C. (2010). Behaviour of Concrete Beams Reinforced with Hybrid FRP Composite Rebar. Advances in Structural Engineering, 13(1), 81–93. https://doi.org/10.1260/1369-4332.13.1.81
Design Manual No.3 Reinforcing Concrete Structures with Fibre Reinforced Polymers. (2007). ISIS Canada Research Network.
EN 12390-2:2009, Testing hardened concrete-Part 2: Making and curing specimens for strength tests. (2009). European Committee For Standardization.
EN 12390-3:2009, Testing hardened concrete-Part 3: Compressive strength of test specimens. (2009). European Committee For Standardization.
Hamad, R. J. A., Megat Johari, M. A., & Haddad, R. H. (2017). Mechanical properties and bond characteristics of different fiber reinforced polymer rebars at elevated temperatures. Construction and Building Materials, 142, 521–535. https://doi.org/10.1016/j.conbuildmat.2017.03.113
Ju, M., Park, G., Lee, S., & Park, C. (2017). Bond performance of GFRP and deformed steel hybrid bar with sand coating to concrete. Journal of Reinforced Plastics and Composites, 36(6), 464–475. https://doi.org/10.1177/0731684416684209
Lin, X., & Zhang, Y. X. (2013). Bond–slip behaviour of FRP-reinforced concrete beams. Construction and Building Materials, 44, 110–117. https://doi.org/10.1016/j.conbuildmat.2013.03.023
Ma, G., Huang, Y., Aslani, F., & Kim, T. (2019). Tensile and bonding behaviours of hybridized BFRP–steel bars as concrete reinforcement. Construction and Building Materials, 201, 62–71. https://doi.org/10.1016/j.conbuildmat.2018.12.196
Okelo, R., & Yuan, R. L. (2005). Bond Strength of Fiber Reinforced Polymer Rebars in Normal Strength Concrete. Journal of Composites for Construction, 9(3), 203–213. https://doi.org/10.1061/(ASCE)1090-0268(2005)9:3(203)
Park, J.-S., Lim, A.-R., Kim, J., & Lee, J.-Y. (2016). Bond performance of fiber reinforced polymer rebars in different casting positions. Polymer Composites, 37(7), 2098–2108. https://doi.org/10.1002/pc.23388
Seo, D.-W., Park, K.-T., You, Y.-J., & Lee, S.-Y. (2016). Experimental Investigation for Tensile Performance of GFRP-Steel Hybridized Rebar. Advances in Materials Science and Engineering, 2016, 1–12. https://doi.org/10.1155/2016/9401427
Soric, Z., Kisicek, T., & Galic, J. (2010). Deflections of concrete beams reinforced with FRP bars. Materials and Structures, 43(S1), 73–90. https://doi.org/10.1617/s11527-010-9600-1
TS 802, Beton Karışım Tasarımı Hesap Esasları. (2016). Türk Standartları Enstitüsü.
Wang, L., Shen, N., Zhang, M., Fu, F., & Qian, K. (2020). Bond performance of Steel-CFRP bar reinforced coral concrete beams. Construction and Building Materials, 245, 118456. https://doi.org/10.1016/j.conbuildmat.2020.118456
Wei, W., Liu, F., Xiong, Z., Lu, Z., & Li, L. (2019). Bond performance between fibre-reinforced polymer bars and concrete under pull-out tests. Construction and Building Materials, 227, 116803. https://doi.org/10.1016/j.conbuildmat.2019.116803
Wilson, A. F., Tsiatas, G., Taggart, D. G., Nair, A. U., & Kim, T. J. (2003). Investigation of CFRP Reinforced Concrete Interfacial Load Transfer. Proceedings of the TRB 2003 Annual Meeting.
Wisnom, M. R. (2016). Mechanisms to create high performance pseudo-ductile composites. IOP Conference Series: Materials Science and Engineering, 139(1). https://doi.org/10.1088/1757-899X/139/1/012010
Wu, G., Sun, Z. Y., Wu, Z. S., & Luo, Y. B. (2012). Mechanical Properties of Steel-FRP Composite Bars (SFCBs) and Performance of SFCB Reinforced Concrete Structures. Advances in Structural Engineering, 15(4), 625–635. https://doi.org/10.1260/1369-4332.15.4.625
Yan, F., Lin, Z., & Yang, M. (2016). Bond mechanism and bond strength of GFRP bars to concrete: A review. Composites Part B: Engineering, 98, 56–69. https://doi.org/10.1016/j.compositesb.2016.04.068