An Experimental Investigation of CFRP Strengthening Efficiency on The Retrofitted Damaged Geopolymer Concrete Beams

Abstract

In this study, beams produced by geopolymer concrete (GC) with different properties such as compressive strengths, stirrups ratios, and shear-span to effective depth ratio (a/d) were tested up to the failure to attain the load-deflection behaviors. Then, tested damaged beams were retrofitted using Carbon Fiber Reinforced Polymer (CFRP) in both shear and flexure to examine the CFRP strengthening efficiency. A three-point flexural test was conducted on both reference and retrofitted GC beams. According to this study, applying the CFRP strengthening to damaged GC beams increased the load-carrying capacity between 4% - 72%, depending on the compressive strength, stirrups spacing, and a/d with reference to the reference GC beams. The area calculated under the load-deflection graph of the retrofitted GC beams was lower than the reference beams in all tested series. The initial stiffness in the tested retrofitted beams was generally obtained lower compared to the reference GC beams. The deflection capability of the retrofitted beams in the tested series was between 18% -80% lower than the reference beams.

Keywords

• Retrofitted beam
• Strengthening
• CFRP
• Shear Strength
• Geopolymer Concrete

References

1. [1] Malhotra, V. M., “Introduction: sustainable development and concrete technology”, Concrete International, 24(7): 1-22, (2002).
2. [2] Huntzinger, D. N., and Eatmon, T. D., “A life-cycle assessment of Portland cement manufacturing: comparing the traditional process with alternative technologies”, Journal of cleaner production,17(7): 668-675, (2009). DOI:10.1016/j.jclepro.2008.04.007
3. [3] Meyer, C., “The greening of the concrete industry”, Cement and concrete composites, 31(8): 601-605, (2009). DOI:10.1016/j.cemconcomp.2008.12.010
4. [4] Davidovits, J., “False Values on CO2 Emission for Geopolymer Cement/Concrete”, Geopolymer Institute Library, 24: 1-9, (2015). http://www.materialstoday.com/polymers-soft-materials/features/environmental-implications-of-geopolymers/
5. [5] Mahasenan, N., Smith, S., and Humphreys, K., “The Cement Industry and Global Climate Change Current and Potential Future Cement Industry CO2 Emissions”, In: Greenhouse Gas Control Technologies - 6th International Conference, 995-1000, (2003). https://linkinghub.elsevier.com/retrieve/pii/B9780080442761501574
6. [6] Shi, C., Jiménez A. F., and Palomo, A., “New cements for the 21st century: The pursuit of an alternative to Portland cement”, Cement and concrete research, 41(7): 750-763, (2011). DOI:10.1016/j.cemconres.2011.03.016
7. [7] Davidovits, J., “Soft mineralogy and geopolymers”, In: Proceedings of the Geopolymer, International Conference, the Universit´ e de Technologie, Compi` egne, France, (1988).
8. [8] Omer, S. A., Demirboga, R., and Khushefati, W. H., “Relationship between compressive strength and UPV of GGBFS based geopolymer mortars exposed to elevated temperatures”, Construction and Building Materials, 94: 189-195, (2015). DOI:10.1016/j.conbuildmat.2015.07.006

9. [9] Davidovits, J., “Geopolymers: inorganic polymeric new materials”, Journal of Thermal Analysis and Calorimetry, 37 (8), 1633–1656, (1991).
10. [10] Komnitsas, K. A., “Potential of geopolymer technology towards green buildings and sustainable cities”, Procedia Engineering, 21: 1023-1032, (2011). DOI:10.1016/j.proeng.2011.11.2108
11. [11] Tanyildizi, H., Ziada, M., Uysal, M., Güngör, N. D., and Coşkun, A., “Comparison of bacteria-based self-healing methods in metakaolin geopolymer mortars”, Case Studies in Construction Materials, 16:e00895, (2022). DOI:10.1016/j.cscm.2022.e00895
12. [12] Ziada, M., Tanyildizi, H., and Uysal, M., “Bacterial healing of geopolymer concrete exposed to combined sulfate and freeze-thaw effects”, Construction and Building Materials, 369: 130517, (2023). DOI:10.1016/j.conbuildmat.2023.130517
13. [13] Ziada, M., Erdem, S., González-Lezcano, R. A., Tammam, Y., and Unkar, I., “Influence of various fibers on the physico-mechanical properties of a sustainable geopolymer mortar-based on metakaolin and slag”, Engineering Science and Technology, an International Journal, 46: 101501, (2023). DOI:10.1016/j.jestch.2023.101501
14. [14] Ziada, M., Erdem, S., Tammam, Y., Kara, S., and Lezcano, R. A. G., “The Effect of Basalt Fiber on Mechanical, Microstructural, and High-Temperature Properties of Fly Ash-Based and Basalt Powder Waste-Filled Sustainable Geopolymer Mortar”, Sustainability, 13(22): 12610, (2021). DOI:10.3390/su132212610
15. [15] Rao, A. K., and Kumar, D. R., “Effect of various alkaline binder ratio on geopolymer concrete under ambient curing condition”, Materials Today: Proceedings, 27: 1768-1773, (2020). DOI:10.1016/j.matpr.2020.03.682
16. [16] Al Bakri Abdullah, M. M., Kamarudin, H., Abdulkareem, O. A., Ghazali, C. M. R., Rafiza, A. R., and Norazian, M. N., “Optimization of alkaline activator/fly ash ratio on the compressive strength of manufacturing fly ash-based geopolymer”, Applied Mechanics and Materials, 110-116: 734-739, (2012). DOI:10.4028/www.scientific.net/AMM.110-116.734
17. [17] Sofi, M., Van Deventer, J. S. J., Mendis, P. A., and Lukey, G. C., “Bond performance of reinforcing bars in inorganic polymer concrete (IPC)”, Journal of Materials Science, 42(9): 3107-3116, (2007). DOI:10.1007/s10853-006-0534-5
18. [18] Sarker, P. K., “Bond strength of reinforcing steel embedded in fly ash-based geopolymer concrete”, Materials and Structures, 44(5): 1021-1030, (2011). DOI:10.1617/s11527-010-9683-8
19. [19] Antonyamaladhas, M. R., Chachithanantham, S., and Ramaswamy, A., “Performance and Behaviour of Ground Granulated Blast Furnace Slag Imparted to Geopolymer Concrete Structural Elements and Analyzed with ANSYS”, Advances in Materials Science and Engineering, 2016: 1-9, (2016). DOI:10.1155/2016/7023897
20. [20] Kumaravel, S., and Thirugnanasambandam, S., “Flexural behaviour of reinforced low calcium fly ash based geopolymer concrete beam”, Global Journal of Research in Engineering, 13(8), (2013).
21. [21] Maranan, G., Manalo, A., Karunasena, K., and Benmokrane, B., “Bond Stress-Slip Behavior: Case of GFRP Bars in Geopolymer Concrete”, Journal of Materials in Civil Engineering, 27(1): 4014116, (2015). DOI:10.1061/(ASCE)MT.1943-5533.0001046
22. [22] Sumajouw, M., and Rangan, B. V., “Low-calcium fly ash-based geopolymer concrete: reinforced beams and columns, Research Report GC 3”, Curtin University of Technology, Perth, Australia, (2006).
23. [23] Kumaravel, S., Thirugnanasambandam, S., and Jeyasehar, C. A., “Flexural behaviour of low calcium fly ash based geopolymer concrete beams”, International Journal of Civil and Structural Engineering, (2013).
24. [24] Chandra Kumar, B. S., and Ramesh, K., “Analytical study on flexural behaviour of reinforced geopolymer concrete beams by ANSYS”, In IOP Conference Series: Materials Science and Engineering, 455(1), 012065, (2018). IOP Publishing. https://iopscience.iop.org/article/10.1088/1757-899X/455/1/012065/meta
25. [25] Hutagi, A., and Khadiranaikar, R. B., “Flexural behavior of reinforced geopolymer concrete beams”, In 2016 International Conference on Electrical, Electronics, and Optimization Techniques (ICEEOT) IEEE, 3463-3467, (2016). DOI: 10.1109/ICEEOT.2016.7755347
26. [26] Kumar, P. U., and Kumar, B. S. C., “Flexural behaviour of reinforced geopolymer concrete beams with GGBS and metakaoline”, International Journal of Civil Engineering and Technology, 7(6), (2016).
27. [27] Andalib, R., Hussin, M. W., Majid, M. Z. A., Azrin, M., and Ismail, H. H., “Structural performance of sustainable waste palm oil fuel ash-fly ash geo-polymer concrete beams”, Journal of Environmental Treatment Techniques, 2(3), 115-119, (2014).
28. [28] Kumaravel, S., Thirugnanasambandam, S., and Jeyasehar, C. A., “Flexural behavior of geopolymer concrete beams with GGBS”, IUP Journal of Structuring Engineering, 7(1), 45-54, (2014).
29. [29] Chang, E. H., “Shear and bond behaviour of reinforced fly ash-based geopolymer concrete beams”, Doctoral dissertation, Curtin University, (2009).
30. [30] Madheswaran, C. K., and Philip, P., “Experimental and Analytical Investigations on Flexural Behaviour of Retrofitted Reinforced Concrete Beams with Geopolymer Concrete Composites”, International Journal of Material and Mechanical Engineering, 3(3): 62, (2014). DOI:10.14355/ijmme.2014.0303.02
31. [31] Yacob, N. S., ElGawady, M. A., Sneed, L. H., and Said, A., “Shear strength of fly ash-based geopolymer reinforced concrete beams”, Engineering Structures, 196: 109298, (2019). DOI:10.1016/j.engstruct.2019.109298
32. [32] Ahmed, H. U., Mahmood, L. J., Muhammad, M. A., Faraj, R. H., Qaidi, S. M., Sor, N. H., ... and Mohammed, A. A., “Geopolymer concrete as a cleaner construction material: An overview on materials and structural performances”, Cleaner Materials, 100111, (2022).
33. [33] Visintin, P., Ali, M. M., Albitar, M., and Lucas, W., “Shear behaviour of geopolymer concrete beams without stirrups”, Construction and Building Materials, 148: 10-21, (2017). DOI:10.1016/j.conbuildmat.2017.05.010
34. [34] Ng, T. S., Amin, A., and Foster, S. J., “The behaviour of steel-fibre-reinforced geopolymer concrete beams in shear”, Magazine of Concrete Research, 65(5): 308-318, (2013). DOI:10.1680/macr.12.00081
35. [35] Ozturk, M., and Arslan, G., “Flexural Behavior of GBFS-Based Geopolymer-Reinforced Concrete Beams”, Buildings, 13(1): 141, (2023). DOI:10.3390/buildings13010141
36. [36] Ozturk, M., and Arslan, G., “Shear Behavior of Granulated Blast Furnace Slag-Based Geopolymer-Reinforced Concrete Beams”, Buildings, 12(12): 2053, (2022). DOI:10.3390/buildings12122053
37. [37] Grande, E., Imbimbo, M., and Rasulo, A., “Effect of Transverse Steel on the Response of RC Beams Strengthened in Shear by FRP: Experimental Study”, Journal of Composites for Construction, 13(5): 405-414, (2009). DOI:10.1061/(asce)1090-0268(2009)13:5(405)
38. [38] Bousselham, A., and Chaallal, O., “Mechanisms of Shear Resistance of Concrete Beams Strengthened in Shear with Externally Bonded FRP”, Journal of Composites for Construction; 12(5): 499-512, (2008). DOI:10.1061/(ASCE)1090-0268(2008)12:5(499)
39. [39] Bousselham, A., and Chaallal, O., “Effect of transverse steel and shear span on the performance of RC beams strengthened in shear with CFRP”, Composites Part B: Engineering, 37(1): 37-46, (2006). DOI:10.1016/j.compositesb.2005.05.012
40. [40] Benzeguir, Z. E. A., El-Saikaly, G., and Chaallal, O., “Influence of size on the behavior of RC T-beams strengthened in shear with externally bonded CFRP”, 9th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering (CICE 2018), (2018).
41. [41] Jayaprakash, J., Samad, A. A. A., Abbasovich, A. A., and Ali, A. A. A., “Shear capacity of precracked and non-precracked reinforced concrete shear beams with externally bonded bi-directional CFRP strips”, Construction and Building Materials, 22(6): 1148-1165, (2008). DOI:10.1016/j.conbuildmat.2007.02.008
42. [42] Teng, J. G., Chen, G. M., Chen, J. F., Rosenboom, O. A., and Lam, L., “Behavior of RC Beams Shear Strengthened with Bonded or Unbonded FRP Wraps”, Journal of Composites for Construction, 13(5): 394-404, (2009). DOI:10.1061/(asce)cc.1943-5614.0000040
43. [43] Li, W., and Leung, C. K., “Shear Span–Depth Ratio Effect on Behavior of RC Beam Shear Strengthened with Full-Wrapping FRP Strip”, Journal of Composites for Construction, 20(3): 4015067, (2016). DOI:10.1061/(ASCE)CC.1943-5614.0000627
44. [44] Bousselham, A., and Chaallal, O., “Behavior of reinforced concrete T-beams strengthened in shear with carbon fiber-reinforced polymer-an experimental study”, ACI structural Journal, 103(3), 339, (2006).
45. [45] Khalifa, A., Belarbi, A., and Nanni, A., “Shear performance of RC members strengthened with externally bonded FRP wraps”, Proc., 12th World Conference on Earthquake Engineering New Zealand, 9, (2000).
46. [46] Li, W., and Leung, C. K., “Effect of shear span-depth ratio on mechanical performance of RC beams strengthened in shear with U-wrapping FRP strips”, Composite Structures, 177: 141-157, (2017). DOI:10.1016/j.compstruct.2017.06.059
47. [47] Benzeguir, Z. E. A., El-Saikaly, G., and Chaallal, O., “Size Effect in RC T-Beams Strengthened in Shear with Externally Bonded CFRP Sheets: Experimental Study”, Journal of Composites for Construction, 23(6): 4019048, (2019). DOI:10.1061/(ASCE)CC.1943-5614.0000975
48. [48] Benzeguir, Z. E. A., El-Saikaly, G., and Chaallal, O., “Size Effect of RC T-Beams Strengthened in Shear with Externally Bonded CFRP L-Shaped Laminates”, Journal of Composites for Construction; 24(4): 4020031, (2020). DOI:10.1061/(ASCE)CC.1943-5614.0001045
49. [49] Li, A., Diagana, C., and Delmas, Y., “CRFP contribution to shear capacity of strengthened RC beams”, Engineering Structures, 23(10): 1212-1220, (2001). DOI:10.1016/S0141-0296(01)00035-9
50. [50] Li, A., Diagana, C., and Delmas, Y., “Shear strengthening effect by bonded composite fabrics on RC beams”, Composites Part B: Engineering, 33(3): 225-239, (2002). DOI:10.1016/S1359-8368(02)00003-3
51. [51] Khalifa, A., Tumialan, G., Nanni, A., and Belarbi, A., “Shear strengthening of continuous RC beams using externally bonded CFRP sheets”, In American Concrete Institute, Proc., 4th International Symposium on FRP for Reinforcement of Concrete Structures (FRPRCS4), Baltimore, MD , 995-1008, (1999).
52. [52] Allam, S. M., and Ebeido, T. I., “Retrofitting of RC beams predamaged in shear using CFRP sheets”, Alexandria Engineering Journal, 42(1): 16, (2003). http://files/483/Allam ve Ebeido - 2003 -Retrofitting of RC beams predamaged in shear using.pdf
53. [53] Leung, C. K., Chen, Z., Lee, S., Ng, M., Xu, M., and Tang, J., “Effect of Size on the Failure of Geometrically Similar Concrete Beams Strengthened in Shear with FRP Strips”, Journal of Composites for Construction, 11(5): 487-496, (2007). DOI:10.1061/(ASCE)1090-0268(2007)11:5(487)
54. [54] Panda, K. C., Bhattacharyya, S. K., and Barai, S. V., “Effect of transverse steel on the performance of RC T-beams strengthened in shear zone with GFRP sheet”, Construction and Building Materials, 41: 79-90, (2013). DOI:10.1016/j.conbuildmat.2012.11.098
55. [55] Sundarraja, M. C., and Rajamohan, S., “Strengthening of RC beams in shear using GFRP inclined strips - An experimental study”, Construction and Building Materials, 23(2): 856-864, (2009). DOI:10.1016/j.conbuildmat.2008.04.008
56. [56] Keskin, R. S. O., Arslan, G., and Sengun, K., “Influence of CFRP on the shear strength of RC and SFRC beams”, Construction and Building Materials, 153: 16-24, (2017). DOI:10.1016/j.conbuildmat.2017.06.170
57. [57] Sengun, K., and Arslan, G., “Parameters affecting the behaviour of RC beams strengthened in shear and flexure with various FRP systems”, Structures, 40: 202-212, (2022). DOI:10.1016/j.istruc.2022.04.024
58. [58] Sengün, K., and Arslan, G., “Influence of CFRP on the strength of retrofitted RC beams without stirrups”, Sigma Journal of Engineering and Natural Sciences, 35(1): 77–85, (2017).
59. [59] Sengun, K., and Arslan, G., “Investigation of the parameters affecting the behavior of RC beams strengthened with FRP”, Frontiers of Structural and Civil Engineering, 16(6): 729-743, (2022). DOI:10.1007/s11709-022-0854-9
60. [60] Akkaya, H. C., Aydemir, C., and Arslan, G., “Investigation on shear behavior of reinforced concrete deep beams without shear reinforcement strengthened with fiber reinforced polymers”, Case Studies in Construction Materials,17(June):e01392, (2022). DOI:10.1016/j.cscm.2022.e01392
61. [61] Akkaya, H. C., Aydemir, C., and Arslan, G., “An experimental research on reinforced concrete deep beams fully wrapped with fiber reinforced polymers against shear”, Case Studies in Construction Materials, 17: e01198, (2022). DOI:10.1016/j.cscm.2022.e01198
62. [62] Alacali, S., Akkaya, H. C., Sengun, K., and Arslan, G., “Proposal and evaluation of new models for predicting the FRP contribution to shear strength in reinforced concrete beams using gene expression programming”, Neural Computing and Applications, 36(25), 15515–15544, (2024). DOI: 10.1007/s00521-024-09892-8
63. [63] Ozturk, M., Sengun, K., and Arslan, G., “CFRP contribution to load-carrying capacity of retrofitted geopolymer concrete beams”, Structures, 48: 1391-1402, (2023). DOI:10.1016/j.istruc.2023.01.028
64. [64] Sengun, K., and Arslan, G., “Performance of RC Beams Strengthened in Flexure and Shear with CFRP and GFRP”, Iranian Journal of Science and Technology - Transactions of Civil Engineering, 0123456789, (2023). DOI:10.1007/s40996-023-01305-5
65. [65] Akkaya, H. C., Aydemir, C., and Arslan, G., “Evaluation of shear behavior of short-span reinforced concrete deep beams strengthened with fiber reinforced polymer strips”. Engineering Structures, 299: 117145, (2024). DOI: 10.1016/j.engstruct.2023.117145
66. [66] Cakir, F., Aydin, M. R., Acar, V., Aksar, B., and Akkaya, H. C., “An experimental study on RC beams shear-strengthened with Intraply Hybrid U-Jackets Composites monitored by digital image correlation (DIC)”, Composite Structures, 323: 117503, (2023). DOI: 10.1016/j.compstruct.2023.117503
67. [67] Seyhan, E. C., Goksu, C., Saribas, I., and Ilki, A., “Hybrid Use of Externally Embedded FRP Reinforcement for Seismic Retrofitting of Substandard RC Columns”, Journal of Composites for Construction, 27(3): 04023022, (2023). DOI:10.1061/JCCOF2.CCENG-3906
68. [68] Chen, J. F., and Teng, J. G., “Shear capacity of FRP-strengthened RC beams: FRP debonding”, Construction and Building Materials, 17(1), 27-41, (2003a). DOI: 10.1016/S0950-0618(02)00091-0
69. [69] Khalifa, A., and Nanni, A., “Rehabilitation of rectangular simply supported RC beams with shear deficiencies using CFRP composites”, Construction and Building Materials, 16(3): 135-146, (2002). DOI:10.1016/S0950-0618(02)00002-8
70. [70] Mofidi, A., and Chaallal, O., “Shear Strengthening of RC Beams with EB FRP: Influencing Factors and Conceptual Debonding Model”, Journal of Composites for Construction, 15(1): 62-74, (2011). DOI:10.1061/(asce)cc.1943-5614.0000153
71. [71] Nagan, S., and Karthiyaini, S., “A Study on Load Carrying Capacity of Fly Ash Based Polymer Concrete Columns Strengthened Using Double Layer GFRP Wrapping”, Advances in Materials Science and Engineering, 2014: 1-6, (2014). DOI:10.1155/2014/312139
72. [72] Rathinam, K., Mohanram, B. B. K., and Kanagarajan, V., “Geopolymer concrete beam strengthening with glass fibre reinforced polymer”, Građevinar, 68(01): 11-18, (2016). DOI:10.14256/JCE.1143.2014
73. [73] CNR-Italian Research Council, Advisory Committee on Technical Recommendations for Construction, Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Existing Structures. Materials, RC and PC Structures, Masonry Structures (CNR-DT 200/2013). Rome, Italy. (2013).