The bond–slip degradation relationship between carbon fiber-reinforced polymer and steel in a freeze–thaw environment is crucial to evaluate the long-term service performance of steel structures strengthened with carbon fiber-reinforced polymer plates. However, limited studies on the durability and long-term performance of the carbon fiber-reinforced polymer-steel-bonded interface are the major obstacle for the application of carbon fiber-reinforced polymer plates in strengthening steel structures. This paper reports an experimental study to investigate the effects of the carbon fiber-reinforced polymer bond length and the freeze–thaw cycles on the bond behavior of the carbon fiber-reinforced polymer-steel-bonded interface. The three-dimensional digital image correlation technique is applied to obtain displacements and strains on the surface of the single-shear specimen. The experimental results present herein include the failure mode, the ultimate load, the carbon fiber-reinforced polymer strain distribution, the displacement distribution, and the bond–slip relationship. The results show that the ultimate load increases with increasing bond length until a certain bond length value is reached, after which the ultimate load remained approximately constant, and the ultimate loads of carbon fiber-reinforced polymer-steel interface decrease gradually under freeze–thaw cycles. The bond–slip parameters degradation models are proposed, and the bond–slip degradation relationship under the freeze–thaw cycles is established. Finally, the bond–slip degradation relationship is confirmed through comparisons with the experimental results.
TavakkolizadehMSaadatmaneshH. Fatigue strength of steel girders strengthened with carbon fiber reinforced polymer patch. J Struct Eng2003; 129: 186–196.
2.
BienJElfgrenLOlofssonJ. Sustainable bridges, assessment for future traffic demands and longer lives, Wroclaw: Dolnoslaskie Wydawnictwo Edukacyjne, 2007.
3.
RenYSLiSP. Experimental study on fatigue performance of aged riveted steel bridge members. Test Technol Test Mach1996; 36: 92–93.
4.
ChuanxiLiLu KeaBJunH, et al.Effects of mechanical properties of adhesive and CFRP on the bond behavior in CFRP-strengthened steel structures. Compos Struct2019; 211: 163–174.
5.
El-SisiAESallamH-ESalimHA, et al.Structural behavior of hybrid CFRP/steel bolted staggered joints. Construct Build Mater2018; 190: 1192–1207.
6.
WangHTWuG. Crack propagation prediction of double-edged cracked steel beams strengthened with FRP plates. Thin-Wall Struct2018; 127: 459–468.
7.
Al-ShawafAZhaoXL. Adhesive rheology impact on wet lay–up CFRP/steel joints’ behaviour under infrastructural sub-zero exposures. Compos Part B Eng2013; 47: 207–219.
8.
ChandrathilakaERKGamageJCPHFawziaS. Mechanical characterization of CFRP/steel bond cured and tested at elevated temperature. Compos Struct2019; 207: 471–477.
9.
NguyenTCBaiYZhaoXL, et al.Mechanical characterization of steel/CFRP double strap joints at elevated temperatures. Compos Struct2011; 93: 1604–1612.
10.
Liu H, Zhao XL, Bai Y, et al. Bond tests of high modulus CFRP/steel double-strap joints at elevated temperatures. In: Proceedings 6th international composites conference (ACUN-6): composite and nanocomposites in civil, offshore and mining infrastructure, Monash University, Clayton, Australia, 2012, pp.139–145.
11.
HashemiSAl-MahaidiR. Experimental and finite element analysis of flexural behavior of FRP-strengthened RC beams using cement-based adhesives. Construct Build Mater2012; 26: 268–273.
12.
DawoodMRizkallaS. Environmental durability of a CFRP system for strengthening steel structures. Constr Build Mater2010; 24: 1682–1689.
13.
YuQ-QGaoR-XGuX-L, et al.Bond behavior of CFRP-steel double-lap joints exposed to marine atmosphere and fatigue loading. Eng Struct2018; 175: 76–85.
14.
NguyenTCBaiYZhaoXL, et al.Mechanical characterization of steel/CFRP double strap joints at elevated temperatures. Compos Struct2011; 93: 1604–1612.
15.
Nguyen T. Environmental durability of bond behaviour between steel and carbon fibre reinforced polymer in double strap joints. PhD Thesis. Monash University, Clayton, Australia, 2012.
16.
KimYJHossainMYoshitakeI. Cold region durability of a two-part epoxy adhesive in double-lap shear joints: experiment and model development. Construct Build Mater2012; 36: 295–304.
17.
AgarwalAFosterSJHamedE, et al.Influence of freeze–thaw cycling on the bond strength of steel–FRP lap joints. Compos: Part B2014; 60: 178–185.
18.
HeshmatiMHaghaniRAl-EmraniM. Durability of CFRP/steel joints under cyclic wet-dry and freeze–thaw conditions. Compos Part B2017; 126: 211–226.
19.
YangYSilvaMAGBiscaiaH, et al.Bond durability of CFRP laminates-to-steel joints subjected to freeze–thaw. Compos Struct2019; 212: 243–258.
20.
WangHTWuGDaiYT, et al.Experimental study on bond behavior between CFRP plates and steel substrates using digital image correlation. J Compos Constr2016; 20: 04016054–04016054.
21.
WangHTWuGDaiYT, et al.Determination of the bond–slip behavior of CFRP-to-steel bonded interfaces using digital image correlation. J Reinf Plastics Compos2016; 35: 1353–1367.
22.
Xia SH and Teng JG. Behaviour of FRP-to-steel bonded joints. In: Proceedings of the international symposium on bond behaviour of FRP in structures (BBFS 2005), Hong Kong, 2005.
23.
WangHTWuG. Bond–slip models for CFRP plates externally bonded to steel substrates. Compos Struct2018; 184: 1204–1214.
24.
Teng JG, Fernando D, Yu T, et al. Debonding failures in CFRP-strengthened steel structures. In: Proceedings of the third Asia-Pacific conference on FRP in structures, Hokkaido University, Japan, 2012.
25.
FernandoDTengJGYuT. Preparation and characterization of steel surfaces for adhesive bonding. J Compos Construct2013; 17: 04013012–04013012.
26.
Fernando D. Bond behavior and debonding failures in FRP-strengthened steel members. PhD Thesis. The Hong Kong Polytechnic University, 2010.
27.
NguyenTCBaiYZhaoXL, et al.Effects of ultraviolet radiation and associated elevated temperature on mechanical performance of steel/CFRP double strap joints. Compos Struct2012; 94: 3563–3573.
28.
KorayemAHLiCYZhangQH, et al.Effect of carbon nanotube modified epoxy adhesive on CFRP-to-steel interface. Compos B Eng2015; 79: 95–104.
29.
HeJXianGJ. Debonding of CFRP-to-steel joints with CFRP delamination. Compos Struct2016; 153: 12–20.
30.
YuTFernandoDTengJG, et al.Experimental study on CFRP-to-steel bonded interfaces. Compos B Eng2012; 43: 2279–2289.
31.
Fernando D. Bond behavior and debonding failures in FRP-strengthened steel members. PhD Thesis. Hong Kong Polytechnic University, Hong Kong, 2010.
32.
WuCZhaoXLDuanWH, et al.Bond characteristics between ultrahigh modulus CFRP laminates and steel. Thin Wall Struct2012; 51: 147–157.
33.
Chinese Standard. Code for design of steel structures. GB 50017-2003. Beijing: China Planning Press, 2003 (in Chinese).
34.
YoshitakeITsudaHItoseJ, et al.Effect of discrepancy in thermal expansion coefficients of CFRP and steel under cold temperature. Construct Build Mater2014; 59: 17–24.
35.
ChataignerS, et al.Design and testing of an adhesively bonded CFRP strengthening system for steel structures. Eng Struct2018; 177: 556–565.
36.
Chinese Standard GB/T 50082. Standard for test methods of long-term performance and durability of ordinary concrete. GB/T 50082-2009. Beijing: China Architecture and Building Press, 2009 (in Chinese).
37.
ASTM C666/C666M. Standard test method for resistance of concrete to rapid freezing and thawing. West Conshohocken, PA: ASTM International, 2015.
38.
ZhuHWuGShiJW. Digital image correlation measurement of the bond–slip relationship between fiber-reinforced polymer sheets and concrete substrate. J Reinf Plastic Compos2014; 33: 1590–1603.
39.
GhiassiBXavierJOliveiraDV, et al.Application of digital image correlation in investigating the bond between FRP and masonry. Compos Struct2013; 106: 340–349.
40.
BiscaiaHCChastreCBorbaIS, et al.Experimental evaluation of bonding between CFRP laminates and different structural materials. J Compos Constr2016; 20: 04015070–04015070.
41.
BiscaiaHCChastreC. Theoretical analysis of fracture in double overlap bonded joints with FRP composites and thin steel plates. Eng Fract Mech2018; 190: 435–460.
