Kademeli Lif Takviyeli Kompozit Beton Kirişlerin Eğilme Davranışı

Öz

Bu çalışmada kademeli lif takviyeli kompozit kirişlerin eğilme dayanımları araştırılmıştır. Beton hacmine oranla %2 oranında lif (çelik ve makro sentetik polipropilen lif/MS) takviyeli karışımlar hazırlanmıştır. Katmanın konumuna (alt, üst ve tamamı) göre farklı özelliklerde hazırlanan 7 adet yarım ölçekli kiriş üzerinde 4 noktalı eğilme testi yapılmıştır. Deneyler sonrası numunelerde yük-deplasman davranışı, enerji yutma kapasitesi, çatlak ilerleyişi ve göçme durumları incelenmiştir. Yük taşıma kapasitelerinde referans kirişlere kıyasla, tamamı MS lif takviyeli olan kirişlerde %30, çelik lif takviyeli betonun alt katmanda olduğu kirişlerde %27 artış görülmüştür. MS lif takviyeli kirişlerde yük taşıma kapasiteleri maksimuma ulaştıktan sonra yük altında deplasman yapabilme kabiliyeti çelik lif içeren kirişlere göre daha fazla çıkmaktadır. Enerji yutma kapasiteleri incelendiğinde lif takviyeli betonun (FRC) alt katmanda olduğu kirişlerin, üst katmanda bulunan kirişlere oranla daha sünek davranış gözlenmiştir. FRC tabakasının kirişin üst kısmında olduğu durumlarda maksimum yük taşıma kapasitesine ulaşıldıktan sonra normal beton (NC) tabakasında erken göçme gözlendiğinden ani yük kayıpları gözlenmiştir. Çalışma sonucunda fiber miktarının azaltılmasının fiber kullanımının yaygın olduğu yapıların maliyetlerine olumlu yönde katkı sağlayacağı düşünülmektedir.

Anahtar Kelimeler

• Fiber takviyeli beton
• Makro sentetik polipropilen fiber
• çelik fiber
• eğilme dayanımı
• Kompozit.
• Fiber takviyeli beton, Makro sentetik polipropilen fiber, çelik fiber, eğilme dayanımı, Kompozit.

Flexural Behavior of Graded Fiber Reinforced Composite Concrete Beams

Öz

In this study, the flexural strengths of graded fiber-reinforced composite beams were investigated. Mixtures reinforced with fiber (steel and macro-synthetic polypropylene fiber/MS) at a ratio of 2% to the concrete volume were prepared. A 4-point bending test was performed on 7 half-scale beams prepared according to the position of the layer (bottom, top and whole). After the tests, load-displacement behavior, energy absorption capacity, crack propagation, and failure mechanism of the specimens were investigated. Compared to the reference beams, the load-carrying capacities increased by 30% in beams with full MS fiber reinforcement and by 27% in beams with steel fiber reinforced concrete in the substrate. After the load-carrying capacity of MS fiber-reinforced beams reaches the maximum, the ability to make displacement under load is higher than the beams containing steel fiber. When the energy absorption capacities are examined, it can be said that the beams with fiber reinforced concrete (FRC) in the bottom layer behave more ductility than the beams in the upper layer. In cases where the FRC layer is at the top of the beam, sudden load losses are observed as early failure is observed in the normal concrete (NC) layer after the maximum load-carrying capacity is reached. As a result of the study, it is thought that reducing the amount of fiber will contribute positively to the costs of structures where fiber use is common.

Anahtar Kelimeler

• Fiber reinforced concrete
• Macro synthetic polypropylene fiber
• Steel fiber
• Flexural behavior
• Composite.

Kaynakça

1. Abbass, W., Khan, M. I., & Mourad, S. (2018). Evaluation of mechanical properties of steel fiber reinforced concrete with different strengths of concrete. Construction and Building Materials, 168, 556–569. https://doi.org/10.1016/j.conbuildmat.2018.02.164
2. Altoubat, S., Yazdanbakhsh, A., & Rieder, K. A. (2009). Shear behavior of macro-synthetic fiber-reinforced concrete beams without stirrups. ACI Materials Journal, 106(4), 381–389. https://doi.org/10.14359/56659
3. ASTM C 1116. (2015). Standard Specification for Fiber-Reinforced Concrete.
4. Biolzi, L., & Cattaneo, S. (2017). Response of steel fiber reinforced high strength concrete beams: Experiments and code predictions. Cement and Concrete Composites, 77, 1–13. https://doi.org/10.1016/j.cemconcomp.2016.12.002
5. Bolat, H., Şimşek, O., Çullu, M., Durmuş, G., & Can, Ö. (2014). The effects of macro synthetic fiber reinforcement use on physical and mechanical properties of concrete. Composites Part B: Engineering, 61, 191–198. https://doi.org/10.1016/j.compositesb.2014.01.043
6. BS EN 197-1. (2011). Cement Composition, specifications and conformity criteria for common cements.
7. Buratti, N., Mazzotti, C., & Savoia, M. (2011). Post-cracking behaviour of steel and macro-synthetic fibre-reinforced concretes. Construction and Building Materials, 25(5), 2713–2722. https://doi.org/10.1016/j.conbuildmat.2010.12.022
8. Chaboki, H. R., Ghalehnovi, M., Karimipour, A., & de Brito, J. (2018). Experimental study on the flexural behaviour and ductility ratio of steel fibres coarse recycled aggregate concrete beams. Construction and Building Materials, 186, 400–422. https://doi.org/10.1016/j.conbuildmat.2018.07.132

9. Chaboki, H. R., Ghalehnovi, M., Karimipour, A., de Brito, J., & Khatibinia, M. (2019). Shear behaviour of concrete beams with recycled aggregate and steel fibres. Construction and Building Materials, 204, 809–827. https://doi.org/10.1016/j.conbuildmat.2019.01.130
10. Chiranjeevi Reddy, K., & Subramaniam, K. V. L. (2017). Analysis for multi-linear stress-crack opening cohesive relationship: Application to macro-synthetic fiber reinforced concrete. Engineering Fracture Mechanics, 169, 128–145. https://doi.org/10.1016/j.engfracmech.2016.11.015
11. de Alencar Monteiro, V. M., Lima, L. R., & de Andrade Silva, F. (2018). On the mechanical behavior of polypropylene, steel and hybrid fiber reinforced self-consolidating concrete. Construction and Building Materials, 188, 280–291. https://doi.org/10.1016/j.conbuildmat.2018.08.103
12. Ding, Y., Liu, G., Hussain, A., Pacheco-Torgal, F., & Zhang, Y. (2019). Effect of steel fiber and carbon black on the self-sensing ability of concrete cracks under bending. Construction and Building Materials, 207, 630–639. https://doi.org/10.1016/j.conbuildmat.2019.02.160
13. Hasan, M. J., Afroz, M., & Mahmud, H. M. I. (2011). An Experimental Investigation on Mechanical Behavior of Macro Synthetic Fiber Reinforced Concrete. Environmental Engineering, 11(03), 18–23.
14. Hsie, M., Tu, C., & Song, P. S. (2008). Mechanical properties of polypropylene hybrid fiber-reinforced concrete. Materials Science and Engineering A, 494(1–2), 153–157. https://doi.org/10.1016/j.msea.2008.05.037
15. Hu, B., & Wu, Y. F. (2018). Effect of shear span-to-depth ratio on shear strength components of RC beams. Engineering Structures, 168(May), 770–783. https://doi.org/10.1016/j.engstruct.2018.05.017
16. Hussein, L., & Amleh, L. (2015). Structural behavior of ultra-high performance fiber reinforced concrete-normal strength concrete or high strength concrete composite members. Construction and Building Materials, 93, 1105–1116. https://doi.org/10.1016/j.conbuildmat.2015.05.030
17. Issa, M. S., Metwally, I. M., & Elzeiny, S. M. (2011). Influence of fibers on flexural behavior and ductility of concrete beams reinforced with GFRP rebars. Engineering Structures, 33(5), 1754–1763. https://doi.org/10.1016/j.engstruct.2011.02.014
18. Kazemi, M. T., Golsorkhtabar, H., Beygi, M. H. A., & Gholamitabar, M. (2017). Fracture properties of steel fiber reinforced high strength concrete using work of fracture and size effect methods. Construction and Building Materials, 142, 482–489. https://doi.org/10.1016/j.conbuildmat.2017.03.089
19. Kazmi, S. M. S., Munir, M. J., Wu, Y. F., & Patnaikuni, I. (2018). Effect of macro-synthetic fibers on the fracture energy and mechanical behavior of recycled aggregate concrete. Construction and Building Materials, 189, 857–868. https://doi.org/10.1016/j.conbuildmat.2018.08.161
20. Kazmi, S. M. S., Munir, M. J., Wu, Y. F., Patnaikuni, I., Zhou, Y., & Xing, F. (2019). Axial stress-strain behavior of macro-synthetic fiber reinforced recycled aggregate concrete. Cement and Concrete Composites, 97(January), 341–356. https://doi.org/10.1016/j.cemconcomp.2019.01.005
21. Martinola, G., Meda, A., Plizzari, G. A., & Rinaldi, Z. (2010). Strengthening and repair of RC beams with fiber reinforced concrete. Cement and Concrete Composites, 32(9), 731–739. https://doi.org/10.1016/j.cemconcomp.2010.07.001
22. Mudadu, A., Tiberti, G., Germano, F., Plizzari, G. A., & Morbi, A. (2018). The effect of fiber orientation on the post-cracking behavior of steel fiber reinforced concrete under bending and uniaxial tensile tests. Cement and Concrete Composites, 93(July), 274–288. https://doi.org/10.1016/j.cemconcomp.2018.07.012
23. Nguyen, D. L., Thai, D. K., Nguyen, H. T. T., Nguyen, T. Q., & Le-Trung, K. (2021). Responses of composite beams with high-performance fiber-reinforced concrete. Construction and Building Materials, 270, 121814. https://doi.org/10.1016/j.conbuildmat.2020.121814
24. Oh, B. H., Kim, J. C., & Choi, Y. C. (2007). Fracture behavior of concrete members reinforced with structural synthetic fibers. Engineering Fracture Mechanics, 74(1–2), 243–257. https://doi.org/10.1016/j.engfracmech.2006.01.032
25. Pujadas, P., Blanco, A., Cavalaro, S., de la Fuente, A., & Aguado, A. (2017). The need to consider flexural post-cracking creep behavior of macro-synthetic fiber reinforced concrete. Construction and Building Materials, 149, 790–800. https://doi.org/10.1016/j.conbuildmat.2017.05.166
26. Smarzewski, P., & Barnat-Hunek, D. (2018). Property Assessment of Hybrid Fiber-Reinforced Ultra-High-Performance Concrete. International Journal of Civil Engineering, 16(6), 593–606. https://doi.org/10.1007/s40999-017-0145-3
27. Song, P. S., & Hwang, S. (2004). Mechanical properties of high-strength steel fiber-reinforced concrete. Construction and Building Materials, 18(9), 669–673. https://doi.org/10.1016/j.conbuildmat.2004.04.027
28. Sucharda, O., Pajak, M., Ponikiewski, T., & Konecny, P. (2017). Identification of mechanical and fracture properties of self-compacting concrete beams with different types of steel fibres using inverse analysis. Construction and Building Materials, 138, 263–275. https://doi.org/10.1016/j.conbuildmat.2017.01.077
29. Tong, T., Yuan, S., Wang, J., & Liu, Z. (2021). The role of bond strength in structural behaviors of UHPC-NC composite beams: Experimental investigation and finite element modeling. Composite Structures, 255(February 2020), 112914. https://doi.org/10.1016/j.compstruct.2020.112914
30. Yao, W., Li, J., & Wu, K. (2003). Mechanical properties of hybrid fiber-reinforced concrete at low fiber volume fraction. Cement and Concrete Research, 33(1), 27–30. https://doi.org/10.1016/S0008-8846(02)00913-4
31. Yin, S., Tuladhar, R., Shi, F., Combe, M., Collister, T., & Sivakugan, N. (2015). Use of macro plastic fibres in concrete: A review. Construction and Building Materials, 93, 180–188. https://doi.org/10.1016/j.conbuildmat.2015.05.105