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Behavior of the Column Stubs of Telecommunication Towers Strengthened with Different Types of FRP Fabrics

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Abstract

The research investigated the behavior of reinforced concrete column stubs of telecommunication towers, which are strengthened with FRP fabrics. Six RC full-scale telecom column stubs with a square cross section and anchor bolts in the center were tested experimentally under concentric load. The experimental study is implemented to demonstrate the influence of confining FRP composite on the performance of telecom column stubs under axial loading. Parameters investigated by specimens were the influence of FRP number of layers, FRP type and FRP orientation on the axial load capacity, stiffness, ductility, and energy absorption of full-sized telecom stubs. The experimental results indicated significant enhancement in capacity and axial deformation of telecom column stubs fully wrapped with double unidirectional CFRP sheet when compared with double-wrapped heavy bidirectional GFRP light or heavy sheet. Examined specimens showed a noticeable increase in terms of strain values compared to unconfined specimens when the number of plies increased. Edges are circulated as FRP sheet ruptured due to the accumulation of confinement effect in specimens' corners. Ductility and energy absorption of column stubs wrapped with GFRP sheets were lesser than CFRP with the same plies number, even though GFRP was heavy-woven mesh sheets, not unidirectional light sheets. CFRP ductility index reached more than double the control by about 207%. It is noticed that load capacity calculations of telecom stub columns based on ECP 203–2020 and ECP 208–2015 calculations were more conservative than ACI 318–19 and ACI 440.2R-17 calculations when compared to experimental test results.

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Data Availability

All data generated or analyzed during this study are included in this published article.

Abbreviations

μ ∆ :

Ductility index

K1:

Pre-yield “initial” stiffness (kN/mm)

K 2 :

Post-yield stiffness (kN/mm)

ϕ :

Reduction factor of tied members

f cc’ :

Confined concrete peak strength

fc’:

Unconfined concrete peak strength

fy:

Yield strength of reinforcing steel

fl:

Maximum confinement pressure

Ast:

Longitudinal reinforcement area

Ag:

Gross area of concrete section

A e :

Effective area of concrete section

f cu :

Concrete compressive strength

h :

Column stub depth

ɣ f :

Reduction of FRP ult. strength

ε*fu :

Ultimate strain of the fiber

PET:

Polyethylene terephthalate

C E :

An environmental reduction factor

\({\Delta }_{@0.85 \mathrm{Pu}}\) :

Yielding deflection at 85% of failure load

\({\Delta }_{y}\) :

Yielding deflection (mm)

Py:

Yielding load (kN)

\({P}_{@0.85\mathrm{ Pu}}\) :

Load at 85% of failure (kN)

t f :

Thickness of one layer of FRP

n :

Number of FRP layers

b :

Column stub width

r c :

Radius of corners

κ a :

Confinement efficiency factor

ε fu :

FRP fiber strain

ε fe :

Effective strain of FRP

E f :

FRP modulus of elasticity

κ ε :

Factor of efficiency strain

ψ f :

FRP additional reduction factor

References

  1. A. Parvin, W. Wang, Behavior of FRP jacketed concrete columns under eccentric loading. J. Compos. Construct. ASCE 5(4), 146–152 (2001)

    Article  Google Scholar 

  2. L. Lam, J.G. Teng, Strength model for fiber-reinforced plastic- confined concrete. J. Struct. Eng. ASCEStruct. Eng. ASCE 128(5), 612–623 (2002)

    Article  Google Scholar 

  3. J. Li, M.N.S. Hadi, Behaviour of externally confined high strength concrete columns under eccentric loading. Compos. Struct.Struct. 62, 145–153 (2003)

    Article  Google Scholar 

  4. T.C. Rousakis, A.I. Karabinis, P.D. Kiousis, FRP-confined concrete members: axial compression experiments and plasticity modelling. Eng. Struct.Struct. 29, 1343–1353 (2007)

    Article  Google Scholar 

  5. J.G. Teng, L. Lam, Behavior and modelling of fiber reinforced polymer-confined concrete. J. Struct. Eng. ASCEStruct. Eng. ASCE 130(11), 1713–1723 (2004)

    Article  Google Scholar 

  6. A.D. Diego, S. Martínez, J.P. Gutiérrez, L. Echevarría, Experimental study on concrete columns confined with external FRP, ICSECT, 113 (Italy, Rome, 2019)

    Google Scholar 

  7. M.N.S. Hadi, Behavior of FRP wrapped normal strength concrete columns under eccentric loading. Compos. Struct.Struct. 72, 503–511 (2006)

    Article  Google Scholar 

  8. D. Yahiaoui, M. Saadi, T. Bouzid, Compressive behavior of concrete containing glass fibers and confined with glass FRP composites. Int. J. Concr. Struct. Mater. 16, 37 (2022)

    Article  CAS  Google Scholar 

  9. R. Kumutha, R. Yaidyanathan, M.S. Palanichamy, Behavior of reinforced concrete rectangular columns strengthened using GFRP. Cement Concr. Compos.Concr. Compos. 29(8), 609–615 (2007)

    Article  CAS  Google Scholar 

  10. L.M. Wang, Y.F. Wu, Effect of corner radius on the performance of cfrp-confined square concrete columns: test. Eng. Struct.Struct. 30, 493–505 (2008)

    Article  Google Scholar 

  11. D.Y. Wang, Z.Y. Wang, S.T. Smith, T. Yu, Size effect on axial stress-strain behavior of CFRP-confined square concrete columns. Constr. Build. Mater. 118, 116–126 (2016)

    Article  CAS  Google Scholar 

  12. J.J. Zeng, G. Lin, J.G. Teng, L.J. Li, Behavior of large-scale FRP-confined rectangular RC columns under axial compression. Eng. Struct.Struct. 174, 629–645 (2018)

    Article  Google Scholar 

  13. J.J. Zeng, D.H. Zhu, J. Liao, Y. Zhuge, Y. Bai, L. Zhang, Large-rupture-strain (LRS) FRP-confined concrete in square stub columns: effects of specimen size and assessments of existing models. Elsevier-Construct. Build. Mater. J. 326, 950–618 (2022)

    Google Scholar 

  14. M.N. Hadi, I.B.R. Widiarsa, Axial and flexural performance of square RC columns wrapped with CFRP under eccentric loading. J. Compos. Construct. 16(6), 640–649 (2012)

    Article  Google Scholar 

  15. T. Patel, S. Salla, S. Vasanwala, C. Modhera, Strengthened of a square RC columns using BFRP and GFRP: the experimental investigations. Trends Sci. 19(15), 5602 (2022)

    Article  Google Scholar 

  16. H.-X. Tin, N.-T. Thuy, S.-Y. Seo, Structural behavior of RC column confined by FRP sheet under uniaxial and biaxial load. Polymers 14, 75 (2022). https://doi.org/10.3390/polym14010075

    Article  CAS  Google Scholar 

  17. ACI (American Concrete Institute). Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures; ACI 440.2R-17; ACI: Farmington Hills, (MI, USA, 2017)

  18. N.P. Nithyapriya and R.F. Shalu and R. Anandlal, Effect of Shape Modification on the Performance of CFRP Confined Square Concrete Columns (2021). Proceedings of the International Conference on Systems, Energy & Environment (ICSEE) (2021)

  19. ECP 208–2015 Egyptian Code Egyptian Code for the use of fiber reinforced polymer (FRP) in the construction fields, Standing Committee to prepare the Egyptian, “HBRC, (Cairo-Egypt, 2015)

  20. BS EN 197–1; (British Standards Institution). Cement - Part 1 composition, specifications and conformity criteria for common cements; BSI: (London, UK, 2017)

  21. BS EN 12390–1; (British Standard Institution). Concrete - Part 1: shape dimensions and other requirements for specimens and moulds; (BSI): (London, UK, 2011)

  22. ECP 203-2020 Egyptian code of practice for design and construction of concrete structures code, Standing Committee to prepare the Egyptian, “HBRC, (Cairo, Egypt, 2020)

  23. BS 4449:2005 +A3; (British Standard Institution). Steel- Part 1: Steel for The Reinforcement Of Concrete. Weldable Reinforcing Steel, Bar, Coil, And Decoiled Products Specifications. (BSI): (London, UK, 2016)

  24. A. Manoj, D. Sathyan, Strengthening of concrete square column using FRP composites. in Journal of Physics: Conference Series (Vol. 2070, No. 1, 2021). IOP Publishing p. 012206

  25. A. Karabinis, T. Rousakis, G. Manolitsi, 3D finite-element analysis of substandard RC columns strengthened by fiber-reinforced polymer sheets. J Compos Struct (2008). https://doi.org/10.1061/(ASCE)1090-0268(2008)12:5(531),531-540

    Article  Google Scholar 

  26. B. Csuka, L.P. Kollár, Analysis of FRP confined columns under eccentric loading. J Compos Struct 94(3), 1106–1116 (2012)

    Article  Google Scholar 

  27. T.M. Pham, M.N. Hadi, Strain estimation of CFRP-confined concrete columns using energy approach. J Compos Construct 17(6), 04013001 (2013)

    Article  Google Scholar 

  28. A. Saljoughian, D. Mostofinejad, Axial-flexural interaction in square RC columns confined by intermittent CFRP wraps. Compos. Part B Eng.Eng 89, 85–95 (2016)

    Article  CAS  Google Scholar 

  29. M.N.S. Hadi, A. Al-Tikrite, Behavior of fiber-reinforced RC columns under different loading conditions. Construct Build Mater 156, 293–306 (2017)

    Article  CAS  Google Scholar 

  30. ACI (American Concrete Institute)., Building code requirements for structural concrete; ACI 318–19; ACI: Farmington hills (MI, USA, 2019)

    Google Scholar 

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Acknowledgements

The authors are greatly thankful to the technical staff of the reinforced concrete laboratory at the House and Building Research Center in Egypt.

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Authors and Affiliations

  1. Civil Engineering Department, Faculty of Engineering at Mataria, Helwan University, Cairo, 11718, Egypt

    Mostafa Shaban Mahmoud Mohamed, Nagi F. Hanna & Nehal M. Ayash

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  1. Mostafa Shaban Mahmoud Mohamed
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  2. Nagi F. Hanna
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  3. Nehal M. Ayash
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MS interpreted results, drew graphs, and wrote the paper. NM edited the manuscript. All authors read and approved the final manuscript.

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Correspondence to Mostafa Shaban Mahmoud Mohamed.

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Mohamed, M.S.M., Hanna, N.F. & Ayash, N.M. Behavior of the Column Stubs of Telecommunication Towers Strengthened with Different Types of FRP Fabrics. J. Inst. Eng. India Ser. A 105, 25–35 (2024). https://doi.org/10.1007/s40030-023-00768-z

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