Behavior and modeling of FRP-strengthened RC structures under extreme mechanical/environmental loading

Fiber-reinforced polymer (FRP) composites have been widely used as externally bonded materials to strengthen existing reinforced concrete (RC) structures through research and development over the past few decades. The behaviors of FRP-strengthened RC structures under normal service environments have been extensively studied, especially regarding the mechanisms of FRP-bonded interfaces and FRP-confined concrete.

 

Our recent research mainly focuses on the behavior and modeling of FRP-strengthened RC structures under extreme mechanical (e.g., seismic and impact) and environmental (e.g. moisture, elevated temperature and fire) loadings.

 

Below are some newly completed and on-going research topics:

  • Durability of FRP-strengthened RC structures under combined mechanical and environmental loadings;

  • Large rupture strain (LRS) FRP composites for strengthening of RC structures under seismic and impact loading (Fig.1.1);

  • Fire-resistance design of FRP-strengthened RC members (Fig.1.2); and

  • FRP-strengthened RC structures through cement-based bonding system [also termed as “fiber reinforced cement matrix” (FRCM)] (Fig.1.3).

1.1.PNG
Fig.1.1 Behavior and modeling of LRS FRP-strengthened RC Columns
1.2.PNG
Fig.1.2 Fire Resistance Design of FRP-strengthened RC structures
1.3.PNG
Fig.1.3 FRP-strengthened RC structures through cement-based bonding

 Selected Publications

  1.  Guo, D., Gao, W.Y.* and Dai, J.G.* (2022), Effects of temperature variation on intermediate crack-induced debonding and stress intensity factor in FRP-retrofitted cracked steel beams: An analytical study, Composite Structures, 279, 114776.  (DOI)

  2. Zhu, H.*, Wang, Q., Dai, J.G., Wang, C.L. and Wu, G. (2022), Innovative additional aluminum alloy ribs anchorage for improving the bond reliability of pretensioned CFRP bar: A feasibility study, Composite Structures, 114916. (DOI) 

  3. Bai, Y.L., Zhang, Y.F., Jia, J.F.*, Mei, S.J., Han, Q. and Dai, J.G. (2022), Simplified plasticity damage model for large rupture strain (LRS) FRP-confined concrete, Composites Structures, 114916. (DOI)

  4. Guo, D., Gao, W.Y.*, Fernando, D. and Dai, J.G. (2021), Effect of temperature variation on the plate-end debonding of FRP-strengthened beams: A theoretical study, Advances in Structural Engineering, (DOI)

  5. Jia, D.G., Gao, W.Y.*, Duan, D.X., Yang, J. and Dai, J.G. (2021), Full-range Behavior of FRP-to-Concrete Bonded Joints Subjected to Combined Effects of Loading and Temperature Variation, Engineering Fracture Mechanics, 254, 107928. (DOI)

  6. Wang, Z.L, Dai, J.G., Wang, M.Q., Chen, L.Z., Zhang, F.W. and Xu, Q.F.*(2021), Residual bond strengths of epoxy and cement-bonded CFRP reinforcements to concrete interfaces after elevated temperature exposure, Fire Safety Journal, 124: 103393. (DOI)

  7. Zhang, F. Dai, J.G., Wang, Z., Wang, M., Leng, Y. and Xu, Q. (2021), Bond Durability of Epoxy and Cement-Bonded CFRP Reinforcement to Concrete Interfaces Subject to Water Immersion, Materials and Structures, 54(2): 1-12. (DOI)

  8.  Zhou, H., Fernando, D. and Dai, J.G. (2021), The Bond Behavior of CFRP-to-Concrete Bonded Joints under Fatigue Cyclic Loading, An experimental study, Construction and Building Materials, 273, 121674, (DOI)

  9. Jirawattanasomkul, T., Minakawa, H., Likitlersuang, S.*, Ueda, T., Dai, J.G., Wuttiwannasak, N. and Kongwang, N. (2021), Use of Water Hyacinth Waste to Procude Fibre-reinforced Polymer Composites for Concrete Confinement: Mechanical Performance and Environmental Assessment, Journal of Cleaner Production, 292, 126041. (DOI)

  10. Zheng, J.J., Li, Q.B., Dai, J.G.* (2020), Analytical Solution for FRP-to-Concrete Bonded Joints Considering Local Unloading and Reloading, Engineering Fracture Mechanics, 235, 107185. (DOI)

  11. Wang, H.P.*, Dai, J.G., Wang, X.Z. (2021), Improved Temperature Compensation of Fiber Bragg Grating-based Sensors Applied to Structures under Different Loading Conditions, Optical Fiber Technology, 63, 102506, (DOI)

  12.  Zheng, J.J., Li, Q.B., Dai, J.G.* (2020), Analytical Solution for FRP-to-Concrete Bonded Joints Considering Local Unloading and Reloading, Engineering Fracture Mechanics, 235, 107185. (DOI)

  13.  Yang, X., Gao, W.-Y.*, Dai, J.-G., Lu, Z.-D. (2020). Shear strengthening of RC beams with FRP grid-reinforced ECC matrix.  Composite Structures 241, 112120. (DOI)

  14. Bai, Y.-L., Yan, Z.-W., Ozbakkaloglu, T., Han, Q.*, Dai, J.-G., Zhu, D.-J. (2020). Quasi-static and dynamic tensile properties of large-rupture-strain (LRS) polyethylene terephthalate fiber bundle. Construction and Building Materials, 232, 117241. (DOI)

  15. Mohammadi, M., Dai, J. G., Wu, Y. F.*, and Bai, Y. L. (2019). Development of extended Drucker–Prager model for non-uniform FRP-confined concrete based on triaxial tests. Construction and Building Materials, 224, 1-18. (DOI)

  16. Wang, H.-P., Ni, Y.-Q.*, Dai, J.-G., Yuan, M.-D.(2019) Interfacial debonding detection of strengthened steel structures by using smart CFRP-FBG composites.  Smart Materials and Structures, 28(11),115001. (DOI)

  17. Wang, G. L., Dai, J. G.*, and Bai, Y. L. (2019). Seismic retrofit of exterior RC beam-column joints with bonded CFRP reinforcement: An experimental study. Composite Structures, 224, 111018. (DOI)

  18.  Bai, Y. L., Dai, J. G.*, Mohammadi, M., Lin, G., and Mei, S. J. (2019). Stiffness-based design-oriented compressive stress-strain model for large-rupture-strain (LRS) FRP-confined concrete. Composite Structures, 223, 110953. (DOI)

  19. Bai, Y. L., Yan, Z.W.,Ozbakkaloglu, T., Dai, J. G., Jia, J.F.*, Jia, J.B. (2019). Dynamic behavior of PET FRP and its preliminary application in impact strengthening of concrete columns, Applied Science, 9(23), 4987. (DOI)

  20. ​ Ding, Z., Xu, M. R., Dai, J. G.*, Dong, B. Q., Zhang, M. J., Hong, S. X., and Xing, F. (2019). Strengthening concrete using phosphate cement-based fiber-reinforced inorganic composites for improved fire resistance. Construction and Building Materials, 212, 755-764. (DOI)

  21.  Wang, H., and Dai, J. G.* (2019). Strain transfer analysis of fiber Bragg grating sensor assembled composite structures subjected to thermal loading. Composites Part B: Engineering, 162, 303-313. (DOI)

  22.  Wang, C.F.*, Wen, B., Dai, J.G., Liu, J.X., Liu, Y.Z. (2018), Experimental Study on Force Sensitivity of the Conductibility of Carbon Nanotubes-Modified Epoxy Resins, Materials, 11(7). (DOI)

  23.  Gao, W.Y., Hu, K.X., Dai, J.G.*, Dong, K., Yu, K.Q. and Fang, L.J. (2018), Repair of Fire-damaged RC Slabs with Basalt Fibric-Reinforced Shotcrete, Construction and Building Materials, 185: 79-92. (DOI)

  24. ​ Gao, W.Y., Dai, J. G.* and Teng, J.G. (2018), Three-level Fire Resistance Design of FRP-strengthened RC Beams, ASCE, Journal of Composites for Construction, 22(3), 05018001 (DOI)

  25. ​  Yang, X., Gao, W.Y., Dai, J.G.*, Lu, Z.D. and Yu, K.Q. (2018), Flexural strengthening of RC beams with CFRP grid-reinforced ECC matrix, Composites Structures, 189: 9-26. (DOI)

  26.  Bai, Y.L., Dai, J.G.* and Ozbakkaloglu, T. (2017), Cyclic stress-strain model incorporating buckling effect for steel reinforcing bars embedded in FRP-confined concrete, Composite Structures, 182: 54-66. (DOI)

  27.  Bai, Y.L., Dai, J.G.* and Teng, J.G. (2017), Monotonic Stress–Strain Behavior of Steel Rebars Embedded in FRP-Confined Concrete Including Buckling, ASCE, Journal of Composites for Construction, 21(5): 04017043. (DOI)

  28.  Bai, Y.L., Dai, J.G.* and Teng, J.G. (2017), Buckling of Steel Reinforcing Bars in FRP-confined RC Columns: An experimental study, Construction and Building Materials, 140: 403-415. (DOI)

  29. Gao, W.Y., Dai, J.G.*, Teng, J.G. (2017), Fire Resistance of RC Beams under Design Fire Exposure, Magazine of Concrete Research, 69(8): 402-423. (DOI)

  30.  Huang, H. and Wang, W.W.* and Dai, J.G. and Brigham, John C. (2017), Fatigue behavior of reinforced concrete beams strengthened with externally bonded prestressed CFRP sheets, ASCE, Journal of Composites for Construction, 21 (3): 04016108. (DOI)

  31.  Yu, H., Bai, Y.L.* Dai, J.G. and Gao, W.Y. (2017), Finite Element Modeling for Debonding of FRP-to-Concrete Interfaces Subjected to Mixed-Mode Loading, Polymers, 9(9): 438. (DOI)

  32.  Zheng, J.J., Dai, J.G.* and Fan, X.L. (2016), Fracture Analysis of FRP-plated Notched Concrete Beam Subjected to Three-Point Bending, ASCE, Journal of Engineering Mechanics, 142(3), 04015096. (DOI)

  33.  Gao, W.Y., Dai, J.G.*, Teng, J.G. (2016), Fire Resistance Design of Un-protected FRP-strengthened RC Beams, Materials and Structures, 49(12): 5357-5371. (DOI)

  34.  Gao. W.Y, Dai, J.G.* and Teng, J.G. (2015), Simple Method for Predicting Temperatures in Insulated Fiber-Reinforced Polymer (FRP)-Strengthened Reinforced Concrete Members Exposed to a Standard Fire, ASCE, Journal of Composites for Construction, 19(6), 04015013-1-16. (DOI)

  35.  Dai, J.G.*, Gao, W.Y. and Teng, J.G. (2015), Finite Element Modeling of Insulated FRP-strengthened Reinforced Concrete Beams Exposed to Fire, ASCE, Journal of Composites for Construction, 19(2), 01014046:1-15. (DOI)

  36.  Shi, J.W., Zhu, H., Dai, J.G., Wang, X. and Wu, Z.S.* (2015), Effect of Rubber Toughening Modification on the Tensile Behavior of FRP Composites in Concrete-based Alkaline Environment, ASCE, Journal of Materials in Civil Engineering, 27(12), 04015054, 1-9. (DOI)

  37. Sun, X.Y., Dai, J.G., Wang, H.L.*, Dong, W.W. and Wang, J. (2015), Decision-support System for Optimizing the Maintenance of RC Girder Bridge Superstructures in Consideration of the Carbon Foot Print, ASCE, Journal of Bridge Engineering, 20(12), 04015022: 1-11. (DOI

  38. Gao, W.Y., Dai, J.G.* and Teng, J.G. (2015), Analysis of Mode II Debonding Behavior of Fiber-Reinforced Polymer-to-substrate Bonded Joints Subjected to Combined Thermal and Mechanical Loading, Engineering Fracture Mechanics, 136: 241-264. (DOI)

  39. Sun X.Y., Dai, J.G., Wang, H.L.* and Xu, C. (2015), Static and Fatigue Behavior of CFRP-Strengthened RC Bridge Girders Subjected to Vehicle Overloading, Advanced Steel Construction. 11(3): 359-371. (DOI)

  40. Mohammadi, T., Wan, B.L.*, Dai, J.G. and Zhu, C. (2015), Prediction of Load Capacity Variation in FRP Bonded Concrete Specimens Using Brownian Motion, Mathematical Problems in Engineering, Volume 2015(2015), Article ID 632912, 9 pages. (DOI)

  41.  Zheng, J.J. and Dai, J.G.* (2014) Prediction of the Nonlinear Pull-out Response of FRP Ground Anchors using an Analytical Transfer Matrix Method, Engineering Structures, 81: 377-386. (DOI)

  42. Gao, W.Y., Dai, J.G.* and Teng, J.G. (2014), Simple Method for Predicting Temperatures in Reinforced Concrete Beams Exposed to a Standard Fire, Advances in Structural Engineering, 17(4), 573-589. (DOI)

  43.  Zheng, J.J. and Dai, J. G.* (2014), Analytical Solution for the Full-Range Pull-out Behavior of FRP Ground Anchors, Construction and Building Materials, 58(5), 129-137. (DOI)

  44.  Wang, W.W., Dai, J. G.*, Harries, Kent A. and Zhang, L. (2014), Prediction of Prestress Losses in RC Beams Externally Strengthened with Prestressed CFRP Sheets/ Plates, Journal of Reinforced Plastics and Composites, 33(8), 1-15. (DOI)

  45.  Dai, J.G.*, Murnir, S. and Ding, Z. (2014), Comparative Study of Different Cement-based Inorganic Pastes towards the Development of FRiP Strengthening Technology, ASCE, Journal of Composites for Construction, 18, Special Issue: 10th Anniversary of IIFC, A4013011. (DOI)

  46.  Bai, Y.L., Dai, J.G.* and Teng, J.G. (2014), Cyclic Compressive Behavior of Concrete Confined with Large Rupture Strain FRP Composites, ASCE, Journal of Composites for Construction, 18(1), 04013025. (DOI)

  47.  Jirawattansomkul, T., Dai, J.G., Zhang, D.W., Senda, M. and Ueda, T.* (2014), Experimental Study on Shear Behavior of Reinforced Concrete Members Fully Wrapped with Large Rupture Strain FRP Composites, ASCE, Journal of Composites for Construction, 18, Special Issue: 10th Anniversary of IIFC, A4013009. (DOI)

  48.  Ding Z.*, Dai, J.G. and Munir, S. (2014), Study on an Improved Phosphate Cement Binder for the Development of Fiber-Reinforced Inorganic Polymer Composites, Polymers, 6: 2819-2831. (DOI)

  49.  Wang, W.W.*, Dai, J.G. and Harries, Kent A. (2013), Intermediate Crack-Induced Debonding in RC Beams Externally Strengthened with Prestressed FRP Laminates, Journal of Reinforced Plastics and Composites, 32(23), 1859-1874. (DOI)

  50.  Dai, J.G.*, Gao, W.Y. and Teng, J.G. (2013), Bond-slip Model for FRP Laminates Externally Bonded to Concrete at Elevated Temperature, ASCE, Journal of Composites for Construction, 17(2), 217-228. (DOI)

  51. Wang, W.W.*, Dai, J. G., Harries, Kent, A. (2013), Performance Evaluation of RC Beams Strengthened with an Externally Bonded FRP System under Simulated Vehicles Loads, ASCE, Journal of Bridge Engineering, 18(1), 76-82. (DOI)

  52.  Gao, W.Y., Dai, J.G.*, Teng, J.G. and Chen, G.M. (2013), Finite Element Modeling of Reinforced Concrete Beams Exposed to Fire, Engineering Structures, 52, July 2013, 488-501. (DOI)

  53.  Wang, W.W. and Dai, J.G.* (2013), Self-stressed Steel Fiber Reinforced Concrete as Negative Moment Connection for Strengthening of Multi-span Simply-Supported Girder Bridges, Advances in Structural Engineering, 16(6), 1113-1127. (DOI)

  54. Teng, J.G.*, Zhang, S.S., Dai, J.G. and Chen, J.F. (2013), Three-Dimensional Meso-scale Finite Element Modeling of Bonded Joints between a Near-Surface Mounted FRP Strip and Concrete, Computers and Structures, 117: 105-117. (DOI)

  55.  Gao, W.Y., Teng, J.G.* and Dai, J. G. (2012), Effect of Temperature Variation on the Full-Range Behavior of FRP-to-concrete Bonded Joints, ASCE, Journal of Composites for Construction, 16(6), 671-683. (DOI)

  56.  Wang, W.W.*, Dai, J. G., Harries, Kent, A. and Bao, Q. H.(2012), Prestress Losses and Flexural Behavior of Reinforced Concrete Beams Strengthened with Post-tensioned CFRP Sheets, ASCE, Journal of Composites for Construction, 16(2), 207-216. (DOI)

  57.  Wang, G. L., Dai, J. G.* and Teng, J.G. (2012), Shear Strength Model for RC Beam-Column Joints under Seismic Loading, Engineering Structures, 40, July 2012, 350-360. (DOI)

  58.  Dai, J. G.*, Ueda, T., Sato, Y. and Nagai, K. (2012), Modeling of Tension Stiffening Behavior in FRP-Strengthened RC Members Based on Rigid Body Spring Networks, Computer-Aided Civil and Infrastructure Engineering, 27 (6), 406-418. (DOI)

  59.  Dai, J. G.*, Lam, L. and Ueda, T. (2012), Seismic Retrofit of Square RC Columns with Polyethylene Terephthalate (PET) Fibre Reinforced Polymer Composites, Construction and Building Materials, 27(1), 206-217. (DOI)

  60.  Dai, J. G.*, Bai, Y.L. and Teng, J.G. (2011), Behavior and Modeling of Concrete Confined with FRP Composites of Large Deformability, ASCE, Journal of Composites for Construction, 15(6), 963-973. (DOI)

  61.  Wang, W.W.*, Dai, J. G., Li, G. and Huang, C.K. (2011), Long-term Behavior of Prestressed Old-New Concrete Composite Beams, ASCE, Journal of Bridge Engineering, 16(2), 275-285. (DOI)

  62.  Wang, W.W.*, Dai, J. G., Li, G. and Huang, C.K. and Bao, Q.H.(2011), Strengthening Mutiple Span Simply-Supported Girder Bridges using Post-tensioned Negative Moment Connection Technique, Engineering Structures, 33(2), 663-673. (DOI)

  63.  Dai, J. G.*, Yokota, H., Iwanami, M. and Kato, E. (2010), Experimental Investigation of the Influence of Moisture on the Bond Behavior of Fibre Reinforced Polymer (FRP) to Concrete Interfaces, ASCE, Journal of Composites for Construction, 14(6), 834-844. (DOI)

  64.  Dai, J. G.*, Yokota, H. and Ueda, T. (2009), A Hybrid Bonding System for Improving Structural Performance of FRP Flexurally Strengthened Concrete Beams, Advances in Structural Engineering, 12(6), 809-820. (DOI)

  65.  Dai, J. G.*, Wan, B. L., Yokota, H. and Ueda, T. (2009), Fracture Criterion for Carbon Fibre Reinforced Polymer Sheet to Concrete Interface Subjected to Coupled Pull-out and Push-off Actions, Advances in Structural Engineering, 12(5), 663-682. (DOI)

  66.  Dai, J. G.*, Harries, Kent A. and Yokota, H. (2008), A Critical Steel Yielding Length Model for Predicting Intermediate Crack-induced Debonding in FRP-strengthened RC Members, Steel and Composite Structures, 8(6), 457-473. (DOI)

  67.  Dai, J. G.*, Ueda, T. and Sato, Y. (2007), Bonding Characteristics of Fiber Reinforced Polymer Sheet-Concrete Interfaces under Dowel Load, ASCE, Journal of Composites for Construction, 11(2), 138-149. (DOI)

  68.  Anggawidjaja, D., Ueda, T.*, Dai, J. G., and Nakai, H.(2006), Ultimate Deformation of RC Piers Wrapped with New Fiber-Reinforced Polymer with Large Fracture Strain, Cement and Concrete Composites, 28(10), 914-927. (DOI)

  69.  Dai, J.G.*, Ueda, T. and Sato, Y. (2006), Unified Analytical Approaches for Determining Shear Bond Characteristics of FRP-Concrete Interfaces through Pullout Tests, Journal of Advanced Concrete Technology, 4(1), 133-145. (DOI)

  70.  Ueda, T.* and Dai, J. G. (2005), Interface Bond between FRP Sheets and Concrete Substrates: properties, numerical modeling and roles in member behavior, Progress in Structural Engineering and Materials, 7(1), 27-43. (DOI)

  71.  Dai, J. G.*, Ueda, T. and Sato, Y. (2005), Development of Nonlinear Bond Stress-Slip Model of FRP Sheet-concrete Interfaces with a Simple Method, ASCE, Journal of Composites for Constructions, 9(1), 52-62. (Best Basic Research Paper Award, Most Cited Paper) (DOI)

  72. Mohammadi, T., Wan, B. and Dai, J. G. (2011), Modeling of CFRP-Concrete Interface Subjected to Coupled Pull-out and Push-off Actions, American Concrete Institute Special Publication SP-275: Fiber-Reinforced Polymer Reinforcement for Concrete Structures, ACI SP-275-19, 18 pages.

  73. Dai, J.G., Saito, Y., Ueda, T. and Sato, Y. (2005), Static and Fatigue Bond Characteristics of Interfaces between CFRP Sheets and Frost Damage Experienced Concrete, American Concrete Institute Special Publication SP-230: Fiber-Reinforced Polymer Reinforcement for Concrete Structures, ACI SP-230-86, 16 pages.

  74. Zheng, Y., Wang, W., Dai, J. and Zhu, Z. (2019), Experimental Study on Mechanical Performance of Reinforced Concrete Beams Shear-Strengthened with FRP-UHTCC Composite 【FRP-UHTCC复合层抗剪增强钢筋混凝土梁受力性能试验研究】, Journal of Building Structures 【建筑结构学报】, 40(8): 118-126. 

  75. Wang, W.W., Dai, J. G. and Zhang, L. (2012), Experimental Study and Analytical Modeling of Prestress Losses of Reinforced Concrete Beams Strengthened with Post-tensioned CFRP Sheets 【后张预应力碳纤维布加固钢筋混凝土梁预应力损失试验及计算方法研究】, China Civil Engineering Journal 【土木工程学报】, 45(11), 88-94. 

  76. Tateishi, A., Yokota, H., Iwanami, M, Kato, E., Kobayashi, A. and Dai, J.G. (2010), Strengthening of port steel structure by CFRP strand sheet under marine environments【水中施工の可能な FRP を用いた港湾鋼構造物の補強実験】, JSCE, Journal of Structural Engineering【構造工学論文集】,Vol. 56(A), 644-655. 

  77. Jaqin, H., Nakai, H., Ueda, T. and Sato, Y. and Dai, J.G. (2005), Seismic Retrofitting of RC Piers using Continuous Fiber Sheet with Large Fracturing Strain, JSCE, Journal of Structural Engineering【構造工学論文集】, 51(A), 893-901.

 Selected Projects
 

  • RGC GRF 2019/2020 Round, PI, A New Avenue for Fire Protection of Fiber-Reinforced Polymer-Strengthened Reinforced Concrete Structures, HK$748,300, Project Code: 15219919.

  • RGC GRF 2015/2016 Round, PI, Large Rupture Strain FRP Composite-Confined Rectangular Reinforced Concrete Columns Subjected to Seismic Loading: Behavior and modeling, HK$695,788, Project Code: 15217115, Co-Is: Prof. S. Kunnath (UC Davis) and Prof. J.G. Teng (PolyU).

  • RGC GRF 2013/2014 Round, PI, A PopTube Technology-Enabled New Fiber Reinforced Inorganic Polymer (FRiP) System for Strengthening of Concrete Structures, HK$836,450, Project Code: 514513, Co-Is: Prof S.P. Shah (Northwestern University), Dr JL Wang (Alabama University) and Dr Z. Ding (Shenzhen University).

  • RGC GRF 2009/2010 Round, PI, Durability of Bond between FRP and Concrete Exposed to a Humid Subtropical Environment: experimental study and predictive modeling, HK$853,530, Project code: 516509, Co-I: Prof JG Teng (PolyU).

  • RGC GRF 2014/2015 Round, PI, Interfacial Debonding in FRP-strengthened Steel/Concrete Structures Subjected to Combined Thermal and Mechanical Loading, CNY 800,000. Project code: 51478406.

  • NSFC 2012/2013 Round, PI, FRP Grid Reinforced UHTCC for Strengthening of RC Structures, CNY800,000, Project code: 51278441, Co-I: Dr Eddie S.S. Lam (PolyU).

Dai Group on Sustainable
           Concrete Infrastructure
                         -Emerging Materials and Structural Systems