Hiệu suất chịu cắt mỏi của dầm bê tông được gia cường bằng thanh thép và thanh polymer gia cường sợi thủy tinh

Peng Zhu1, Jiajing Xu2, Wenjun Qu1
1Department of Structural Engineering, Tongji University, Shanghai, China
2School of Transportation and Civil Engineering, Nantong University, Nantong, China

Tóm tắt

Các dầm bê tông gia cường bao gồm cả thanh thép và thanh polymer gia cường sợi thủy tinh cho thấy sức mạnh, khả năng phục vụ và độ bền tuyệt vời. Tuy nhiên, hiệu suất chịu cắt mỏi của những dầm này vẫn chưa rõ ràng. Do đó, các dầm với các thanh dọc và kích thước cắt hỗn hợp đã được thiết kế và thực hiện các thử nghiệm chịu cắt mỏi. Đối với các mẫu nghiệm thất bại do chịu cắt mỏi, tất cả các kích thước cắt bằng polymer gia cường sợi thủy tinh và một số kích thước cắt bằng thép đã bị gãy tại vết nứt chéo quan trọng. Đối với mẫu nghiệm thất bại qua thử nghiệm tĩnh sau 8 triệu chu kỳ mỏi, khả năng tĩnh sau mỏi không giảm đáng kể so với giá trị tính toán. Mức độ mỏi ban đầu có ảnh hưởng lớn hơn đến sự phát triển vết nứt và tuổi thọ mỏi hơn là mức độ mỏi trong giai đoạn sau. Sức chịu cắt mỏi của các kích thước cắt bằng polymer gia cường sợi thủy tinh trong các mẫu nghiệm có phần thấp hơn so với các thử nghiệm căng trục dọc trên thanh polymer gia cường sợi thủy tinh ở không khí và các thử nghiệm hàn nối trên thanh polymer gia cường sợi thủy tinh, và các chế độ thất bại là khác nhau. Các kích thước cắt bằng polymer gia cường sợi thủy tinh đã chịu tải mỏi và cắt, và thất bại do cắt.

Từ khóa

#dầm bê tông #polymer gia cường sợi thủy tinh #chịu cắt mỏi #sức chịu cắt #thí nghiệm mỏi

Tài liệu tham khảo

Arya C, Ofori-Darko F K, Pirathapan G. FRP rebars and the elimination of reinforcement corrosion in concrete structures. In: Taerwe L, ed. Proceedings of the Second International RILEM Symposium (FRPRCS-2). London: RILEM, E&FN Spon, 1995, 227–234 Aiello M A, Ombres L. Structural performances of concrete beams with hybrid (fiber-reinforced polymer-steel) reinforcements. Journal of Composites for Construction, 2002, 6(2): 133–140 Qu W J, Zhang X L, Huang H Q. Flexural behavior of concrete beams reinforced with hybrid (GFRP and steel) bars. Journal of Composites for Construction, 2009, 13(5): 350–359 El Refai A, Abed F, Al-Rahmani A. Structural performance and serviceability of concrete beams reinforced with hybrid (GFRP and steel) bars. Construction & Building Materials, 2015, 96: 518–529 Newhook J P. Design of under-reinforced concrete T-sections with GFRP reinforcement. In: Humar J, Razaqpur A G, eds. Proceedings of the 3rd International Conference on Advanced Composite Materials in Bridges and Structures. Montreal: Canadian Society for Civil Engineering, 2000, 153–160 Lau D, Pam H J. Experimental study of hybrid FRP reinforced concrete beams. Engineering Structures, 2010, 32(12): 3857–3865 Pang L, Qu W J, Zhu P, Xu J J. Design propositions for hybrid FRP-steel reinforced concrete beams. Journal of Composites for Construction, 2016, 20(4): 04015086 Kara I F, Ashour A F, Köroğlu M A. Flexural behavior of hybrid FRP/steel reinforced concrete beams. Composite Structures, 2015, 129:111–121 Bencardino F, Condello A, Ombres L. Numerical and analytical modeling of concrete beams with steel, FRP and hybrid FRP-steel reinforcements. Composite Structures, 2016, 140: 53–65 Zhu P, Xu J J, Qu W J, Hao H. Experimental study of fatigue flexural performance of concrete beams reinforced with hybrid GFRP and steel bars. Journal of Composites for Construction, 2017, 21(5): 04017036 Xu J J, Zhu P, Ma Z J, Qu W J. Fatigue flexural analysis of concrete beams reinforced with hybrid GFRP and steel bars. Engineering Structures, 2019, 199: 109635 Li L J, Hou B, Lu Z Y, Liu F. Fatigue behaviour of sea sand concrete beams reinforced with basalt fibre-reinforced polymer bars. Construction & Building Materials, 2018, 179: 160–171 Zhao J, Li G H, Wang Z K, Zhao X L. Fatigue behavior of concrete beams reinforced with glass- and carbon-fiber reinforced polymer (GFRP/CFRP) bars after exposure to elevated temperatures. Composite Structures, 2019, 229: 111427 Zhang X L. Flexural and shear behavior of concrete beams reinforced with hybrid (FRP and steel) bars. Dissertation for the Doctoral Degree. Shanghai: Tongji University, 2010 (in Chinese) Pang L. Investigation of concrete members reinforced with steel and FRP bars for sectional equal durability. Dissertation for the Doctoral Degree. Shanghai: Tongji University, 2016 (in Chinese) Ruhnau J. Influence of repeated loading on the stirrup stress of reinforced concrete beams. ACI Special Publications, 1974, 42(7): 169–181 Okamura H, Farghaly S A, Ueda T. Behaviors of reinforced concrete beams with stirrups failing in shear under fatigue loading. In: Proceedings of the Japan Society of Civil Engineers. Tokyo: Japan Society of Civil Engineers, 1981, 109–122 Ueda T. Behavior in shear of reinforced concrete beams under fatigue loading. Dissertation for the Doctoral Degree. Tokyo: University of Tokyo, 1982 Kwak K H, Park J G. Shear-fatigue behavior of high-strength reinforced concrete beams under repeated loading. Structural Engineering and Mechanics, 2001, 11(3): 301–314 Teng S, Ma W, Wang F. Shear strength of concrete deep beams under fatigue loading. ACI Structural Journal, 2000, 97(4): 572–580 Isojeh B, El-Zeghayar M, Vecchio F J. High-cycle fatigue life prediction of reinforced concrete deep beams. Engineering Structures, 2017, 150: 12–24 ACI 440.1R-15. Guide For The Design And Construction of Structural Concrete Reinforced With FRP Bars. Farmington Hills: American Concrete Institute, 2015 GB/T 228.1-2010. Metallic Materials-Tensile Testing-Part 1: Method of Test at Room Temperature. Beijing: General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China, 2010 GB/T 30022-2013. Test Method For Basic Mechanical Properties Of Fiber Reinforced Polymer Bar. Beijing: General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China, 2013 GB/T 50081-2002. Standard for Test Method of Mechanical Properties on Ordinary Concrete. Beijing: China Building Industry Press, 2002 ACI Committee 318-14. Building Code Requirements for Structural Concrete and Commentary. Farmington Hills: American Concrete Institute, 2014 Bischoff P H. Reevaluation of deflection prediction for concrete beams reinforced with steel and fiber reinforced polymer bars. Journal of Structural Engineering, 2005, 131(5): 752–767 Alsayed S H, Al-Salloum Y A, Almusallam T H. Performance of glass fiber reinforced plastic bars as a reinforcing material for concrete structures. Composites. Part B, Engineering, 2000, 31(6–7): 555–567 Rafi M M, Nadjai A, Ali F, Talamona D. Aspects of behaviour of CFRP reinforced concrete beams in bending. Construction & Building Materials, 2008, 22(3): 277–285 Zhang J, Stang H, Li V C. Fatigue life prediction of fiber reinforced concrete under flexural load. International Journal of Fatigue, 1999, 21(10): 1033–1049 ACI Committee 215. Considerations for design of concrete structures subjected to fatigue loading. ACI 215R-74 (Revised 1992/ Reapproved 1997). Farmington Hills: American Concrete Institute, 1997 Heffernan P J, Erki M A. Fatigue behavior of reinforced concrete beams strengthened with carbon fiber reinforced plastic laminates. Journal of Composites for Construction, 2004, 8(2): 132–140 Noël M, Soudki K. Fatigue behaviour of GFRP reinforcing bars in air and in concrete. Journal of Composites for Construction, 2014, 18(5): 04014006 AASHTO Committee. AASHTO LRFD Bridge Design Specifications. 7th ed. Washington, DC: American Association of State Highway and Transportation Officials, 2014 Hanson J M, Hulsbos C L, VanHorn D A. Fatigue tests of prestressed concrete I-beams. Journal of the Structural Division, 1970, 96(11): 2443–2464