This paper aims to realize a full scale modelling of reinforced concrete (RC) beam enhanced by externally bonded fibre reinforced polymer (EBRFP), considering both longitudinal bars and stirrups. To this end, several previous revisions to Fick’s second law of diffusion were incorporated to establish a revised diffusion model. During the modelling, the following factors were taken into account simultaneously: time-dependent diffusion coefficient, time-dependent surface chloride ion content, chloride binding effect, material inhomogeneity and load effect. Then, the boundary conditions were properly changed to fit the enhancement behaviour. Later, the revised diffusion model was numerically solved by the FEA on Abaqus, aiming to reveal the effect of enhancement on chloride diffusion, the effect of longitudinal bars and stirrups on chloride diffusion, and the results and efficiencies of 2D and 3D models. Through the analysis of simulation results, the author drew the following conditions: First, the EBRFP enhancement led to an obvious decrease of chloride ion content, thus extending the initial time of rebar corrosion; Second, the longitudinal rebars greatly boosted the chloride ion content at the front faces of rebars, while the effect of stirrups can be neglected if the longitudinal rebars have been considered; Third, 2D model is more recommended than 3D model if the surface chloride ion content remains invariant along the RC beam.
externally bonded fibre reinforced polymer (EBFRP), enhanced reinforced concrete (RC) beam, chloride diffusion, longitudinal bars, stirrups
 Chen W, Pham TM, Sichembe H. (2018). Experimental study of flexural behaviour of RC beams strengthened by longitudinal and U-shaped basalt FRP sheet. Composites Part B Engineering 134: 114-126. https://doi.org/10.1016/j.compositesb.2017.09.053
 Coelho M, Neves L, Sena-Cruz J. (2018). Designing NSM FRP systems in concrete using partial safety factors. Composites Part B Engineering 139: 12-23. https://doi.org/10.1016/j.compositesb.2017.11.031
 Li MM, Chen C, Mao J, Yang C, Li SL, Gao Y, Shen JS. (2018). Experimental research on the improvement effect of ECE treatment on durability of early concrete with chloride. Concrete 2018(1): 12-14. https://doi.org/10.3969/j.issn.1002-3550.2018.01.004
 Thomas RJ, Ariyachandra E, Lezama D. (2018). Comparison of chloride permeability methods for Alkali-Activated concrete. Construction & Building Materials 165:104-111. https://doi.org/10.1016/j.conbuildmat.2018.01.016
 Tuutti K. (1982). Corrosion of steel in concrete. Swedish Foundation for Concrete Research Stockholm 20(5): 105-119.
 Yu H, Himiob RJ, Hartt WH. (2007). Effects of reinforcement and coarse aggregates on chloride ingress into concrete and time-to-corrosion: Part 2-spatial distribution of coarse aggregates. Corrosion 63(9): 843-849. https://doi.org/10.5006/1.3278310
 Yu H, Hartt WH. (2007). Effects of reinforcement and coarse aggregates on chloride ingress into concrete and time-to-corrosion: Part 1-spatial chloride distribution and implications. Corrosion 63(9): 843-849. https://doi.org/10.5006/1.3278434
 Hansen E, Saouma V. (1999). Numerical simulation of reinforced concrete deterioration-Part I: Chloride diffusion. ACI Materials Journal 96(2): 173-180.
 Wang Y, Li Q, Lin CA. (2015). Chloride diffusion analysis of concrete members considering depth-dependent diffusion coefficients and effect of reinforcement presence. Journal of Materials in Civil Engineering 28(5): 04015183.
 Oh BH. (2003). Chloride diffusion analysis of concrete structures considering effects of reinforcements. ACI Materials Journal 100(2): 143-149. https://doi.org/10.14359/12554
 Kranc SC, Sagues AA, Presuel-Moreno FJ. (2002). Decreased corrosion initiation time of steel in concrete due to reinforcing bar obstruction of diffusional flow. ACI Materials Journal 99(1): 51-53. https://doi.org/10.14359/11316
 Wang XL, Ma GS, Qi CL. (2010). Numerical simulation method for predicting chloride concentration distributing around reinforcement in concrete. Advanced Materials Research 163-167: 3138-3142. https://doi.org/10.4028/www.scientific.net/amr.163-167.3138
 Yu H, Hartt WH. (2011). Correction of chloride threshold concentration and time-to-corrosion due to reinforcement presence. Materials and Corrosion 62(5): 423-430. https://doi.org/10.1002/maco.200905516
 Collepardi M, Marcialis A, Turriziani R. (1970). The kinetics of penetration of chloride ions into the concrete. II Cemento 67(1): 157-164.
 Collepardi M, Marcialis A, Turriziani R. (1972). Penetration of chloride ions into cement pastes and concretes. Journal of the American Ceramic Society 55(10): 534-535. https://doi.org/10.1111/j.1151-2916.1972.tb13424.x
 Mangat P, Limbachiya M. (1999). Effect of initial curing on chloride diffusion in concrete repair materials. Cement and Concrete Research 29(9): 1475-1485. https://doi.org/10.1016/s0008-8846(99)00130-1
 Maage M, Helland S, Poulsen E, Vennesland Ø, Carlsen JE. (1996). Service life prediction of existing concrete structures exposed to marine environment. ACI Materials Journal 93(6): 602-608. https://doi.org/10.14359/9866
 Thomas MD, Bamforth PB. (1999). Modelling chloride diffusion in concrete: effect of fly ash and slag. Cement and Concrete Research 29(4): 487-495.
 Amey SL, Johnson DA, Miltenberger MA, Farzam H. (1998). Predicting the service life of concrete marine structures. an environmental methodology. Structural Journal 95(2): 205-214. https://doi.org/10.14359/540
 Kassir MK, Ghosn M. (2002). Chloride-induced corrosion of reinforced concrete bridge decks. Cement and Concrete Research 32(1): 139-143. https://doi.org/10.1016/s0008-8846(01)00644-5
 Nilsson L, Massat M, Tang L. (1994). Effect of non-linear chloride binding on the prediction of chloride penetration into concrete structures. ACI Special Publication 45(2): 469-486.
 Saito M, Ishimori H. (1995). Chloride permeability of concrete under static and repeated compressive loading. Cement and Concrete Research 19(4): 803-808. https://doi.org/10.1016/0008-8846(95)00070-s
 Lim C, Gowripalan N, Sirivivatnanon V. (2000). Microcracking and chloride permeability of concrete under uniaxial compression. Cement and Concrete Composites 22(5): 353-360. https://doi.org/10.1016/s0958-9465(00)00029-9
 Gowripalan N, Sirivivatnanon V, Lim C. (2000). Chloride diffusivity of concrete cracked in flexure. Cement and Concrete Research 30(5): 725-730. https://doi.org/10.1016/s0008-8846(00)00216-7
 Uji K, Matsuoka Y, Maruya T. (1990). Formulation of an equation for surface chloride content of concrete due to permeation of chloride. Elsevier Applied Science 36(5): 258-267.
 Taffesea WZ, Sistonen E. (2013). Service life prediction of repaired structures using concrete recasting method: state-of-the-art. Procedia Engineering 57(1): 1138-1144. https://doi.org/10.1016/j.proeng.2013.04.143
 Song HW, Shim HB, Petcherdchoo A, Park SK. (2009). Service life prediction of repaired concrete structures under chloride environment using finite difference method. Cement and concrete composites 31(2): 120-127. https://doi.org/10.1016/j.cemconcomp.2008.11.002
 Paulsson-Tralla J. (2001). Service life prediction of concrete bridge decks repaired with bonded concrete overlays. Materials and Structures 34(1): 34-41. https://doi.org/10.1617/13534
 Xi Y, Bazant ZP. (1999). Modeling chloride penetration in saturated concrete. Journal of Materials in Civil Engineering 11(1): 58-65.
 Weyers RE, Fitch M, Larsen E, Al-Qadi I, Chamberlin W, Hoffman P. (1994). Concrete bridge protection and rehabilitation: Chemical and physical techniques: Service life estimates. Concrete Bridges.
 Zhang Y, Sun W, Liu Z, Chen S. (2011). One and two dimensional chloride ion diffusion of fly ash concrete under flexural stress. Journal of Zhejiang University SCIENCE A 12(9): 692-701. https://doi.org/10.1631/jzus.a1100006
 Yu H, Sun W, Yan L, Ma H. (2002). Study on prediction of concrete service life I-Theoretical model. Journal of the Chinese Ceramic Society 30(6): 686-690.
 Pigeon M, Garnier F, Pleau R, Aitcin P. (1993). Influence of drying on the chloride ion permeability of HPC. Concrete International 15(2): 65-69.
 Liu J, Xing F, Dong BQ, Ding Z, Ma HY. (2010). Diffusion of chloride ions into concrete in salt spray environment. Journal of Shenzhen University 27(2): 192-198.
 Locke CE. (1983). Effect of impressed current on bond strength between steel rebar and concrete. Corrosion 83.
 Bourguiba A, Ghorble E, Dhaoui W. (2015) Epoxy resin/recycled sand mortars’ resistance to chloride ions diffusion. Concret Creep 10: 843-852. https://doi.org/10.1061/9780784479346.100
 Shekarchi M, Rafiee A, Layssi H. (2009). Long-term chloride diffusion in silica fume concrete in harsh marine climates. Cement and Concrete Composites 31(10): 769-775. https://doi.org/10.1016/j.cemconcomp.2009.08.005
 Li G, Yang B, Guo C, Du J, Wu X. (2015). Time dependence and service life prediction of chloride resistance of concrete coatings. Construction and Building Materials 83: 19-25. https://doi.org/10.1016/j.conbuildmat.2015.03.003
 Farahani A, Taghaddos H, Shekarchi M. (2015). Prediction of long-term chloride diffusion in silica fume concrete in a marine environment. Cement and Concrete Composites 59: 10-17. https://doi.org/10.1016/j. cemconcomp.2015.03.006
 Yu HF, Sun W, Ma HY. (2002). Study on prediction of concrete service life II-model’s examination and application. Journal of the Chinese Ceramic Society 30(6): 691-695.