Sayan Sirimontree1, Charinrat Aiamlaoo1, Amaras Mathuros2, Min Jae Park3, and Chanachai Thongchom1This email address is being protected from spambots. You need JavaScript enabled to view it.
1Thammasat University Research Unit in Structural and Foundation Engineering, Department of Civil Engineering, Thammasat School of Engineering, Thammasat University, Klongluang, Pathumthani 12120, Thailand.
2Department of Construction Engineering Technology, Faculty of Industrial Technology, Chiang Rai Rajabhat University, Chiang Rai 57100, Thailand.
3Department of Architectural Engineering, College of Engineering, Pukyong National University, Nam-gu, Busan 48513, Republic of Korea.
Received: July 18, 2025 Accepted: January 14, 2026 Publication Date: March 21, 2026
Copyright The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited.
Precast concrete slabs are extensively used in construction, with Carbon Fiber Reinforced Polymer (CFRP) laminates effectively enhancing their structural performance. This study investigates the flexural performance of precast concrete slabs and overlays strengthened with CFRP laminates through four-point bending tests. Four specimens were tested, including one unreinforced slab and three CFRP-strengthened slabs with varying overlay configurations. The slabs measured 2500 mm in length, 350 mm in width, and 50 mm in thickness, and were strengthened with CFRP alone or combined with 50 mm and 100 mm concrete overlays. Results indicate that CFRP strengthening significantly enhanced structural performance, achieving a 195% increase in load-bearing capacity compared to unreinforced slabs, and 296% when combined with reinforced overlays. Increasing overlay thickness from 50 mm to 100 mm improved stiffness and reduced midspan deflection by 26%, albeit with a slight reduction in ductility. Reinforced overlays improved load capacity by 34% and ductility by 27% compared to regular overlays. These findings highlight the effectiveness of CFRP laminates and concrete overlays in optimizing the flexural performance of precast concrete slabs for high-performance structural applications.
[1] R. L’Hermite, (1977) “Use of bonding techniques for reinforcing concrete and masonry structures" Matériaux et Construction 10(2): 85–89. DOI: https: //doi.org/10.1007/BF02474856.
[2] Z. OuyangandB. Wan, (2009) “An analytical model of FRP-concrete bond deterioration in moist environment" Advances in Structural Engineering 12(6): 761–769. DOI: https: //doi.org/10.1260/136943309790327680.
[3] M. Shahawy, M. Arockiasamy, T. Beitelman, and R. Sowrirajan, (1996) “Reinforced concrete rectangular beams strengthened with CFRP laminates" Composites Part B: Engineering 27(3-4): 225–233. DOI: https: //doi.org/10.1016/1359-8368(95)00044-5.
[4] W. Xue, Y. Tan, and L. Zeng, (2008) “Experimental studies of concrete beams strengthened with prestressed CFRP laminates." PCI journal 53(5): DOI: https: //doi.org/10.15554/pcij.09012008.70.85.
[5] C. A. Neagoe. “Concrete beams reinforced with CFRP laminates". (mathesis). Universitat Politècnica de Catalunya, 2011.
[6] H. -C. Wu and C. D. Eamon,(2017) “Strengthening of concrete structures using fiber reinforced polymers (FRP): design, construction and practical applications":
[7] A. A. Yee and P. Eng, (2001) “Structural and economic benefits of precast/prestressed concrete construction" PCI journal 46(4): 34–43.
[8] R. Al-Rousan, M. Issa, and H. Shabila, (2012) “Performance of reinforced concrete slabs strengthened with different types and configurations of CFRP" Composites Part B: Engineering 43(2): 510–521. DOI: https: //doi.org/10.1016/j.compositesb.2011.08.050.
[9] J. G. Teng, J. F. Chen, S. T. Smith, and L. Lam, (2003) “Behaviour and strength of FRP-strengthened RC structures: a state-of-the-art review" Proceedings of the institution of civil engineers-structures and buildings 156(1): 51–62. DOI: https: //doi.org/10.1680/stbu.2003.156.1.51.
[10] P. O. Awoyera, F. Althoey, A. Bahrami, P. U. Apuye, B. S. Alotaibi, M. A. Abuhussain, et al., (2024) “Structural retrofitting of RC slabs using bamboo fibre laminate: Flexural performance and crack patterns" Heliyon 10(2): DOI: https: //doi.org/10.1016/j.heliyon.2024.e23999.
[11] A. S. Azevedo, J. P. Firmo, J. R. Correia, R. M. Firouz, and J. A. Barros, (2023) “Fire behaviour of reinforced concrete slab strips strengthened with prestressed NSM CFRP laminates" Engineering Structures 297: 116982. DOI: https: //doi.org/10.1016/j.engstruct.2023.116982.
[12] M.Naser, R. Hawileh, and J. Abdalla, (2019) “Fiber reinforced polymer composites in strengthening reinforced concrete structures: A critical review" Engineering Structures 198: 109542. DOI: https: //doi.org/10.1016/j.engstruct.2019.109542.
[13] W. Ibrahim, M. El-adawy, and G. Ghanem. “Be haviour of reinforced concrete slabs strengthened by concrete overlays”. In: Construction Materials and Structures. IOS Press, 2014, 956–962. DOI: https: //doi.org/10.3233/978-1-61499-466-4-956.
[14] P. Mongkhonsang, (2018) “Carbon Fiber Reinforced Polymers (CFRP) for Strengthening of Reinforced Concrete Structure":
[15] T. Mohammadi, B. Wan, K. A. Harries, and M. E. Sweriduk, (2017) “Bond behavior of FRP–concrete in presence of intermediate crack debonding failure" Journal of CompositesforConstruction21(5): 04017018. DOI: https: //doi.org/10.1061/(ASCE)CC.1943-5614.0000797.
[16] Y. M. Amran, R. Alyousef, R. S. Rashid, H. Alabduljabbar, and C.-C. Hung. “Properties and applications of FRP in strengthening RC structures: A review”. In: Structures. 16. Elsevier. 2018, 208–238. DOI: https: //doi.org/10.1016/j.istruc.2018.09.008.
[18] A. Siddika, M. A. Al Mamun, R. Alyousef, and Y. M. Amran, (2019) “Strengthening of reinforced concrete beams by using fiber-reinforced polymer composites: A review" Journal of Building Engineering 25: 100798. DOI: https: //doi.org/10.1016/j.jobe.2019.100798.
[19] S. May, O. Steinbock, H. Michler, and M. Curbach. “Precast slab structures made of carbon reinforced concrete”. In: Structures. 18. Elsevier. 2019, 20–27. DOI: https: //doi.org/10.1016/j.istruc.2018.11.005.
[20] W. Derkowski and M. Surma, (2016) “Composite action of precast hollow core slabs with structural topping" Czasopismo Techniczne:
[21] S. Swathy, R. Preetha, J. Ashok Kumar, et al., (2024) “Strengthening of Polypropylene fiber reinforced flat slab using BFRP fan and laminate against line loading." Pro cedia Structural Integrity 60: 591–603. DOI: https: //doi.org/10.1016/j.prostr.2024.05.079.
[22] A. ASTM, (2019) “C39/c39m-18 standard test method for compressive strength of cylindrical concrete specimens. 2018" ASTM International: West Conshohocken, PA:
[23] A. Standard, (2021) “A421; Standard Specification for Stress-Relieved Steel Wire for Prestressed Concrete" ASTM International: West Conshohocken, PA, USA:
[24] R. J. A. Syril and D. Rajkumar, “Experimental Investigation of Ferrogeopolymer Confinement for Enhancing Brick Masonry Column Resilience under Axial Compres sion":
[25] A. ASTM,(2020) “615/A 615M (2008),“Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement”" ASTM International 100: 19428–2959.
[26] A. Standard, (2018) “ASTM A370-18: Standard Test Methods and Definitions for Mechanical Testing of Steel Products":
[27] V. H. Hoang, T. A. Do, A. T. Tran, and X. H. Nguyen, (2024) “Flexural capacity of reinforced concrete slabs retrofitted with ultra-high-performance concrete and fiber reinforced polymer" Innovative Infrastructure Solutions 9(4): 113. DOI: https: //doi.org/10.1007/s41062024-01410-y.
[28] B. El-taly, Y. Hasab Elnaby, and N. Meleika, (2018) “Structural performance of precast–prestressed hollow core slabs subjected to negative bending moments" Asian Journal of Civil Engineering 19(6): 725–740. DOI: https: //doi.org/10.1007/s42107-018-0061-0.
[29] M. A. Aiello, L. Ascione, A. Baratta, F. Bastianini, U. Battista, A. Benedetti, V. P. Berardi, A. Bilotta, A. Borri, B. Briccoli, et al., (2014) “Guide for the design and construction of externally bonded FRP systems for strengthening existing structures":
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