Durability is a critical concern for concrete structures externally bonded with fiber-reinforced polymer reinforcement. This paper presents the results from an experimental study which compared the bond durability of epoxy-bonded CFRP sheets and cement-bonded CFRP grids to concrete interfaces subjected to water immersion. Totally twelve groups of CFRP sheet or grid-strengthened concrete beams with a notch at their midspan were carefully fabricated through epoxy- and cement-based bonding systems and tested under monotonic loading before and after water immersion exposure, respectively. The cement binder included polymer cement mortar (PCM) and ductile engineered cementitious composite (ECC). The CFRP grids and sheets were designed with the similar tensile stiffness. The duration of water immersion ranged from 0 to 6 months. The test results indicated that debonding in concrete adjacent to the concrete-adhesive interface in accompany with a diagonal concrete crack near the notch was the main failure mode of the beams strengthened with epoxy-bonded CFRP sheet and ECC-bonded CFRP grid, while the tearing off of CFRP grids from the PCM matrix was the main failure mode of the beams strengthened with PCM-bonded CFRP grids. After water immersion exposure, the ultimate loads of the beams with cement-based CFRP grids were at least 50% higher than their epoxy-bonded counterparts, confirming the superior moisture durability of cement based bond to epoxy-bonded ones. The interfacial fracture energy was found to exhibit an exponential decline trend with water immersion duration.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
Tax calculation will be finalised during checkout.
Li J, Wu J, Chen J (2014) Stochastic damage mechanics of concrete structures. Science Press, Beijing
Teng J, Chen J, Smith S, et al. (2002) FRP-strengthened RC structures. Wiley.
Dai J, Ueda T, Sato Y et al (2005) Development of the nonlinear bond stress-slip model of fiber reinforced plastics sheet-concrete interfaces with a simple method. J Compos Construct 9(1):52–62
Zhang D, Gu X, Yu Q et al (2018) Fully probabilistic analysis of FRP-to-concrete bonded joints considering model uncertainty. Compos Struct 185:786–806
Ouyang Z, Wan B (2008) Experimental and numerical Study of moisture effects on the bond fracture energy of FRP/Concrete joints. J Reinf Plast Compos 27(2):205–223
Dai J, Yokota H, Iwanami M et al (2010) Experimental investigation of the influence of moisture on the bond behavior of fibre reinforced polymer (FRP) to concrete interfaces. J Compos Construct 14(6):834–844
Fernandes PM, Senacruz J, Xavier J et al (2018) Durability of bond in NSM CFRP-concrete systems under different environmental conditions. Compos Part B Eng 138:19–34
Shrestha J, Ueda T, Zhang D (2015) Durability of FRP concrete bonds and its constituent properties under the influence of moisture conditions. J Mater Civ Eng 27(2):4014009
Pan Y, Shi J, Xian G (2019) Experimental and numerical study of the CFRP-to-concrete bonded joints after water immersion. Compos Struct 218:95–106
Lu Y, Zhu T, Li S et al (2018) Bond behavior of wet-bonded carbon fiber-reinforced polymer-concrete interface subjected to moisture. Int J Polym Sci 2018:1–11
Dai J, Murnir S and Ding Z. (2014) Comparative study of different cement-based inorganic pastes towards the development of FRiP strengthening technology. Journal of Composites for Construction, 18, Special Issue: 10th Anniversary of IIFC, A4013011.
Awani O, Elmaaddawy T, Ismail N et al (2017) Fabric-reinforced cementitious matrix: a promising strengthening technique for concrete structures. Constr Build Mater 132:94–111
Trapko T (2014) Effect of eccentric compression loading on the strains of FRCM confined concrete columns. Constr Build Mater 61:97–105
Faleschini F, Zanini MA, Hofer L et al (2020) Experimental behavior of reinforced concrete columns confined with carbon-FRCM composites. Constr Build Mater 243:118296
Ding Z, Xu M, Dai J et al (2019) Strengthening concrete using phosphate cement-based fiber-reinforced inorganic composites for improved fire resistance. Constr Build Mater 212:755–764
Gao W, Dai J, Teng J (2018) Three-level fire resistance design of FRP-strengthened RC beams. J Compos Construct 22(3):05018001
Guo R, Pan Y, Cai L et al (2018) Bonding behavior of CFRP grid-concrete with PCM shotcrete. Eng Struct 168:333–345
Yang X, Gao W, Dai J et al (2018) Flexural strengthening of RC beams with CFRP grid-reinforced ECC matrix. Compos Struct 189:9–26
Yang X, Gao W, Dai J et al (2020) Shear strengthening of RC beams with FRP grid-reinforced ECC matrix. Compos Struct 241:112120
Wang B, Uji K, Wu T et al (2019) Experimental investigation of stress transfer and failure mechanism between existing concrete and CFRP grid-sprayed PCM. Constr Build Mater 215:43–58
D’Ambrisi A, Feo L, Focacci F (2013) Experimental analysis on bond between PBO-FRCM strengthening materials and concrete. Compos B Eng 44(1):524–532
Al-Lami K, D’Antino T, Colombi P (2020) Durability of fabric-reinforced cementitious matrix (FRCM) composites: a review. Appl Sci 10:1714
Donnini J, Bompadre F, Corinaldesi V (2020) Tensile behavior of a glass FRCM systems after different environmental exposures. Process 8:1074
GB 50010-2010 Code for design of concrete structures (2015 Edition). Beijing: China Architecture and Building Press, 2015
Zhang F, Li X, Wang Z et al (2017) Experimental study on seismic behavior of earthquake-damaged RC frame strengthened by ECC. J Build Struct 38(6):61–69
GB 50728–2011 Technical code for safety appraisal of engineering structural strengthening materials. Beingjing: China Architecture and Building Press, 2011.
Li V, Wang S, Wu C (2001) Tensile strain-hardening behavior of polyvinyl alcohol engineered cementitious composite (PVA-ECC). ACI Mater J 98(6):483–492
Guo R, Pan Y, Cai L et al (2018) Study on design formula of shear capacity of RC beams reinforced by CFRP grid with PCM shotcrete method. Eng Struct 166:427–440
ASTM D 7958–17. Standard test method for evaluation of performance for FRP composite bonded to concrete substrate using beam test1. West Conshohocken, PA: ASTM, 2017.
Gartner A, Douglas EP, Dolan CW et al (2011) Small beam bond test method for CFRP composites applied to concrete. J Compos Construct 15(1):52–61
D’Ambrisi A, Focacci F (2011) Flexural strengthening of RC beams with cement-based composites. J Compos Construct 15(5):707–720
This research was supported financially by the National Key R&D Program (Grant No. 2017YFC0702900) and Hong Kong RGC General Research Fund (Project code: 15219919).
Conflict of interests
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Zhang, F., Dai, JG., Wang, Z. et al. Bond durability of epoxy and cement- bonded CFRP reinforcement to concrete interfaces subject to water immersion. Mater Struct 54, 53 (2021). https://doi.org/10.1617/s11527-021-01641-w
- CFRP reinforcement
- Water immersion
- Bond durability
- Interfacial fracture energy