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Keywords

Ordinary CFRP bars, prestressed CFRP bars, steel stands, fatigue and corrosion resistance, bonded beam, prestressing concrete beam, harped and straight strands

Document Type

Research Paper

Abstract

This research seeks to improve the performance behavior of reinforced concrete (RC) beams by examining their load-deflection diagrams using ordinary and prestressed carbon fiber-reinforced polymer (CFRP) bars in place of standard steel reinforcement instead. Using CFRP bars as prestressed tendons to replace the bottom steel rebars, eight 1800-mm long RC beams with a 200 mm×300 mm cross-section were evaluated and split into three groups, evaluating critical loading phases (i.e., cracked, ultimate, and mid-span deflection). Relative to the reference beam, beams reinforced with CFRP had far higher load-carrying capacities and ductility. One beam, reinforced with regular CFRP bars, exhibited a mid-span deflection of 21.2 mm and an ultimate load of 157.2 kN, resulting in a cracked load of 57.7 kN. Another beam using regular CFRP bars also demonstrated improved performance with a mid-span deflection of 21.2 mm, an ultimate load of 160.6 kN, with a cracking load of 57.5 kN. Prestressed CFRP bars led to a significant decrease in mid-span deflection (7.3 mm), a rise in the ultimate load (254.2 kN), and a cracking load of 137.6 kN. Furthermore, the use of two different prestressed CFRP bars showed notable improvements. CFRP bars with these enhancements were employed instead of steel reinforcement in the tension zone, thereby greatly increasing the beam strength with respect to the bonding materials (cement grout and epoxy resin). Thus, using regular and prestressed CFRP bars in traditional steel reinforcement may significantly improve the load-carrying capacity and ductility, producing more robust reinforced concrete buildings.

References

S. Y. Park, A. E. Naaman, Shear behavior of concrete beams prestressed with FRP tendons, PCI J., 44 (1999) 74-85. https://doi.org/10.15554/pcij.01011999.74.85 C. J. Burgoyne, Should FRP be bonded to concrete?, ACI Spec. Publ., 138 (1992) 367-367. https://doi.org/10.14359/4266 A. Maissen, CAM De Smet, Comparison of concrete beams prestressed with carbon fibre reinforced plastic and steel strands, Non-Metallic Reinforcement for Concrete Structures: Proceedings of the Second International RILEM Symposium, London. 29, 1995, 430-439. https://books.google.iq/books?id=dUVZDwAAQBAJ&lpg= Chester P. Siess, Mete A. Sozen and Warwaruk, J. Investigation of prestressed reinforced concrete for highway bridges, part III, strength and behavior in flexure of prestressed concrete beams. Illinois University. Engineering Experiment Station. Bulletin; 1962. J. M. Lees, C. Burgoyne, Experimental study of influence of bond on flexural behavior of concrete beams pretensioned with aramid fiber reinforced plastics, ACI Struct. J., 96 (1999) 377-385. A. Belarbi, M. Reda, P. Poudel, H. Tahsiri, M. Dawood1, and B. Gencturk, Prestressing concrete with CFRP composites for sustainability and corrosion-free applications, MATEC Web of Conf., 149 , 2018, 01010. http://dx.doi.org/10.1051/matecconf/201814901010 A. A. Abdelrahman, G. Tadros, S.H. Rizkalla‏, Test model for first canadian smart highway bridge, ACI Struct. J., 92 (1995) 451-458. S. Heo, S. Shin, C. Lee, Flexural behavior of concrete beams internally prestressed with unbonded carbon-fiber-reinforced polymer tendons, J. Compos. Constr., 17 (2013) 167-175. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000306 T. Kakizawa, S. Ohno, T. Yonezawa, Flexural behavior and energy absorption of carbon FRP reinforced concrete beams, Spec. Publ., 138 (1993) 585-598. https://doi.org/10.14359/3940 Mertol H. C., S, Rizkalla P. Scott, Lees J. M. , El-Hacha R, Durability and fatigue behavior of high-strength concrete beams prestressed with CFRP bars, SP245-1, Case Histories and Use of FRP for Prestressing Applications; ACI. Spec. Publ., Detroit, MI, USA:1-20, 2006. A. A. Abdelrahman, S. H. Hizkalla, Serviceability of concrete beams prestressed by carbon, ACI Struct. J., 94 (1997) 447-454, https://www.researchgate.net P. X. Zou, Flexural behavior and deformability of fiber reinforced polymer prestressed concrete beams,J.Compos.Constr., 7 (2003) 275-284. https://doi.org/10.1061/(ASCE)1090-0268(2003)7:4(275) Jeong S. M. Evaluation of ductility in prestressed concrete beams using fiber-reinforced plastic tendons: University of Michigan, 1994.https://proquest.com/openview/64880c828593a1989f1da034e50d3698/ Abdelrahman, A. A. Serviceability of concrete beams prestressed by fiber-reinforced plastic tendons. A Dissertation of Docror of Philosophy Structural Engineering Division Department of Civil and Geological Engineering University of Manitoba Winnipeg, 1996. L. P. Forth, A. W. Beeby, Study of composite behavior of reinforcement and concrete in tension, ACI Structural J., 111 (2014) 397-406. https://doi.org/10.14359/51686564 Y. M. Saeed, F. N. Rad, Experimental investigation of CFRP prestressed concrete beams, Special Publication, 331 (2019) 101-121. https://doi.org/10.14359/51715596 ACI Committee 318-19 (2019). Building Code Requirement for Reinforced Concrete. American Concrete Institute. R. El-Hacha, Prestressing concrete structures with frp tendons (ACI 440.4 R-04), Proceedings Structures Congress: Metropolis and Beyond, 2005,1-8. https://doi.org/10.1061/40753(171)1

Highlights

·  The study uses an experimental method to investigate the flexural performance of CFRP prestressed beams. ·  CFRP bar beams perform better than steel beams, with higher cracking and ultimate load ratios. ·  All tested beams, especially those with CFRP bars, show reduced mid-span deflection, indicating better stability. ·  CFRP-reinforced beams exhibit higher ductility than steel, showing robustness and deformation capability.

DOI

10.30684/etj.2024.148865.1734

First Page

1314

Last Page

1326

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