Title:
Strength of Carbon Fiber-Reinforced Polymer (CFRP) Sheets Bonded to Concrete with CFRP Spike Anchors
Author(s):
Alaa T. Al-Sammari and Sergio F. Breña
Publication:
Structural Journal
Volume:
118
Issue:
1
Appears on pages(s):
153-166
Keywords:
carbon fiber anchors (spike anchors); carbon fiber-reinforced polymer (CFRP) anchor fan; CFRP-concrete joints; CFRP debonding; CFRP finite element modeling; CFRP sheets; fiber-reinforced sheet anchorage; strengthening of concrete structures
DOI:
10.14359/51728084
Date:
1/1/2021
Abstract:
Carbon fiber-reinforced polymer (CFRP) materials in the form of CFRP sheets are widely used to rehabilitate existing concrete structures suffering deterioration. The high tensile strength, light weight, and durability of CFRP material make it a better alternative to steel and other strengthening materials. CFRP sheets are externally bonded to concrete elements to enhance strength and ductility. However, CFRP sheets may debond before reaching the ultimate strength of the CFRP material. This behavior reduces the strengthening efficiency of using CFRP sheets, and therefore, integrated CFRP composite anchors are added to the strengthening system to delay debonding. Yet, the effect of using these anchors is not quantified for design purposes. This research paper presents a new approach that is based on both finite element simulations and previous experimental tests to quantify the additional strength attained due to the use of CFRP anchors. The quantified strength is based on examining several parameters of the anchorage system, including the number of anchors used in the sheet; the distance between anchors, anchor shaft diameter, anchor fan diameter; and CFRP sheet thickness.
Related References:
AASHTO, 2012, “Guide Specifications for Design of Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements,” first edition, American Association of State Highway and Transportation Officials, Washington, DC.
ACI Committee 440, 2017, “Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures (ACI 440.2R-17),” American Concrete Institute, Farmington Hills, MI, 112 pp.
Adhikary, B. B., and Mutsuyoshi, H., 2001, “Study on the Bond between Concrete and Externally Bonded CFRP Sheet,” Proceedings, Fifth International Conference on FRP Reinforcement for Reinforced Concrete Structures (FRPRCS-5), Cambridge, UK, V. 1, No. 1, pp. 371-378.
AFGC, 2011, “Réparation et Renforcement des Structures en Béton au Moyen de Matériaux Composites,” French Association of Civil Engineering Paris, France.
Al-Sammari, A. T., and Breña, S. F., 2018, “Finite Element Simulation and Parametric Study of Anchored Fiber-Reinforced Polymer Sheets,” ACI Structural Journal, V. 115, No. 2, Mar., pp. 365-377. doi: 10.14359/51701094
Ali-Ahmad, M.; Subramaniam, K.; and Ghosn, M., 2006, “Experimental Investigation and Fracture Analysis of Debonding between Concrete and FRP Sheets,” Journal of Engineering Mechanics, ASCE, V. 132, No. 9, pp. 914-923. doi: 10.1061/(ASCE)0733-9399(2006)132:9(914)
Benzeggagh, M. L., and Kenane, M. J. C. S., 1996, “Measurement of Mixed-Mode Delamination Fracture Toughness of Unidirectional Glass/Epoxy Composites with Mixed-Mode Bending Apparatus,” Composites Science and Technology, V. 56, No. 4, pp. 439-449. doi: 10.1016/0266-3538(96)00005-X
Bizindavyi, L., and Neale, K. W., 1999, “Transfer Lengths and Bond Strengths for Composites Bonded to Concrete,” Journal of Composites for Construction, ASCE, V. 3, No. 4, pp. 153-160. doi: 10.1061/(ASCE)1090-0268(1999)3:4(153)
Breña, S. F.; Bramblett, R. M.; Wood, S. L.; and Kreger, M. E., 2003, “Increasing Flexural Capacity of Reinforced Concrete Beams Using Carbon Fiber-Reinforced Polymer Composites,” ACI Structural Journal, V. 100, No. 1, Jan.-Feb., pp. 36-46.
Breña, S. F., and McGuirk, G. N., 2013, “Advances on the Behavior Characterization of FRP-Anchored Carbon Fiber-Reinforced Polymer (CFRP) Sheets Used to Strengthen Concrete Elements,” International Journal of Concrete Structures and Materials, V. 7, No. 1, pp. 3-16. doi: 10.1007/s40069-013-0028-1
Camanho, P. P., and Davila, C. G., “Mixed-Mode Decohesion Finite Elements for the Simulation of Delamination in Composite Materials,” NASA/TM-2002–211737, National Aeronautics and Space Administration, Hampton, VA, 2002, pp. 1-37.
Camata, G.; Spacone, E.; and Zarnic, R., 2007, “Experimental and Nonlinear Finite Element Studies of RC Beams Strengthened with FRP Plates,” Composites. Part B, Engineering, V. 38, No. 2, pp. 277-288. doi: 10.1016/j.compositesb.2005.12.003
Camli, U. S., and Binici, B., 2007, “Strength of Carbon Fiber Reinforced Polymers Bonded to Concrete and Masonry,” Construction & Building Materials, V. 21, No. 7, pp. 1431-1446. doi: 10.1016/j.conbuildmat.2006.07.003
Chajes, M. J.; Januszka, T. F.; Mertz, D. R.; Thomson, T. A.; and Finch, W. W., 1995, “Shear Strengthening of Reinforced Concrete Beams Using Externally Applied Composite Fabrics,” ACI Structural Journal, V. 92, No. 3, May-June, pp. 295-303.
CNR-DT 200/2013, 2013, “Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Existing Structures,” CNR (National Research Council)—Italian Advisory Committee on Technical Recommendations for Constructions, Rome, Italy.
Czaderski, C.; Soudki, K.; and Motavalli, M., 2010, “Front and Side View Image Correlation Measurements on FRP to Concrete Pull-Off Bond Tests,” Journal of Composites for Construction, ASCE, V. 14, No. 4, pp. 451-463. doi: 10.1061/(ASCE)CC.1943-5614.0000106
Dai, J.; Ueda, T.; and Sato, Y., 2005, “Development of the Nonlinear Bond Stress–Slip Model of Fiber Reinforced Plastics Sheet–Concrete Interfaces with a Simple Method,” Journal of Composites for Construction, ASCE, V. 9, No. 1, pp. 52-62. doi: 10.1061/(ASCE)1090-0268(2005)9:1(52)
Fu, B.; Tang, X. T.; Li, L. J.; Liu, F.; and Lin, G., 2018, “Inclined FRP U-Jackets for Enhancing Structural Performance of FRP-Plated RC Beams Suffering from IC Debonding,” Composite Structures, V. 200, pp. 36-46. doi: 10.1016/j.compstruct.2018.05.074
Garden, H. N.; Quantrill, R. J.; Hollaway, L. C.; Thorne, A. M.; and Parke, G. A. R., 1998, “An Experimental Study of the Anchorage Length of Carbon Fibre Composite Plates Used to Strengthen Reinforced Concrete Beams,” Construction and Building Materials, V. 12, No. 4, pp. 203-219. doi: 10.1016/S0950-0618(98)00002-6
ISIS Canada, 2007, “Strengthening Reinforced Concrete Structures with Externally-Bonded Fiber-Reinforced Polymers,” ISIS Canada Design Manuals, Intelligent Sensing for Innovative Structures Canada, Winnipeg, MB, Canada. fib, 2001, “Externally Bonded FRP Reinforcement for RC Structures,” fib Technical Report Bulletin 14, International Federation for Structural Concrete Lausanne, Switzerland.
JSCE, 2001, “Recommendations for Upgrading of Concrete Structures with Use of Continuous Fiber Sheets,” Japan Society of Civil Engineering, Tokyo, Japan.
Lu, X. Z.; Teng, J. G.; Ye, L. P.; and Jiang, J. J., 2005, “Bond–Slip Models for FRP Sheets/Plates Bonded to Concrete,” Engineering Structures, V. 27, No. 6, pp. 920-937. doi: 10.1016/j.engstruct.2005.01.014
Lu, X. Z.; Teng, J. G.; Ye, L. P.; and Jiang, J. J., 2007, “Intermediate Crack Debonding in FRP-Strengthened RC Beams: FE Analysis and Strength Model,” Journal of Composites for Construction, ASCE, V. 11, No. 2, pp. 161-174. doi: 10.1061/(ASCE)1090-0268(2007)11:2(161)
McGuirk, G. N., and Breña, S. F., 2012, “Development of Anchorage System for FRP Strengthening Applications Using Integrated FRP Composite Anchors,” CRC Report No. 54, Concrete Research Council, American Concrete Institute, Farmington Hills, MI, 277 pp.
Mostofinejad, D.; Hosseini, S. M.; Tehrani, B. N.; Eftekhar, M. R.; and Dyari, M., 2019, “Innovative Warp and Woof Strap (WWS) Method to Anchor the FRP Sheets in Strengthened Concrete Beams,” Construction and Building Materials, V. 218, pp. 351-364. doi: 10.1016/j.conbuildmat.2019.05.117
Mostofinejad, D., and Mahmoudabadi, E., 2010, “Grooving as Alternative Method of Surface Preparation to Postpone Debonding of FRP Laminates in Concrete Beams,” Journal of Composites for Construction, ASCE, V. 14, No. 6, pp. 804-811. doi: 10.1061/(ASCE)CC.1943-5614.0000117
Mostofinejad, D.; Mofrad, M. H.; Hosseini, A.; and Mofrad, H. H., 2018, “Investigating the Effects of Concrete Compressive Strength, CFRP Thickness and Groove Depth on CFRP-Concrete Bond Strength of EBROG Joints,” Construction and Building Materials, V. 189, pp. 323-337. doi: 10.1016/j.conbuildmat.2018.08.203
Niemitz, C. W.; James, R.; and Breña, S. F., 2010, “Experimental Behavior of Carbon Fiber-Reinforced Polymer (CFRP) Sheets Attached to Concrete Surfaces Using CFRP Anchors,” Journal of Composites for Construction, ASCE, V. 14, No. 2, pp. 185-194. doi: 10.1061/(ASCE)CC.1943-5614.0000064
Orton, S. L.; Jirsa, J. O.; and Bayrak, O., 2008, “Design Considerations of Carbon Fiber Anchors,” Journal of Composites for Construction, ASCE, V. 12, No. 6, pp. 608-616. doi: 10.1061/(ASCE)1090-0268(2008)12:6(608)
Sebastian, W. M., 2001, “Significance of Midspan Debonding Failure in FRP-Plated Concrete Beams,” Journal of Structural Engineering, ASCE, V. 127, No. 7, pp. 792-798. doi: 10.1061/(ASCE)0733-9445(2001)127:7(792)
Simulia, 2014, “ABAQUS Software and Documentation 6.13.”
Smith, S. T.; Hu, S.; Kim, S. J.; and Seracino, R., 2011, “FRP-Strengthened RC Slabs Anchored with FRP Anchors,” Engineering Structures, V. 33, No. 4, pp. 1075-1087. doi: 10.1016/j.engstruct.2010.11.018
Teng, J. G.; Lu, X. Z.; Ye, L. P.; and Jiang, J. J., 2004, “Recent Research on Intermediate Crack–Induced Debonding in FRP–Strengthened RC Beams,” Proceedings, Fourth International Conference on Advanced Composite Materials for Bridges and Structures (ACMBS IV), Calgary, AB, Canada.
Teng, J. G.; Smith, S. T.; Yao, J.; and Chen, J. F., 2003, “Intermediate Crack-Induced Debonding in RC Beams and Slabs,” Construction and Building Materials, V. 17, No. 6-7, pp. 447-462. doi: 10.1016/S0950-0618(03)00043-6
Wu, Y. F., and Huang, Y., 2008, “Hybrid Bonding of FRP to Reinforced Concrete Structures,” Journal of Composites for Construction, ASCE, V. 12, No. 3, pp. 266-273. doi: 10.1061/(ASCE)1090-0268(2008)12:3(266)
Yao, J.; Teng, J. G.; and Chen, J. F., 2005, “Experimental Study on FRP-to-Concrete Bonded Joints,” Composites. Part B, Engineering, V. 36, No. 2, pp. 99-113. doi: 10.1016/j.compositesb.2004.06.001
Zhang, H. W., and Smith, S. T., 2012, “FRP-to-Concrete Joint Assemblages Anchored with Multiple FRP Anchors,” Composite Structures, V. 94, No. 2, pp. 403-414. doi: 10.1016/j.compstruct.2011.07.025
Zhang, H. W.; Smith, S. T.; Gravina, R. J.; and Wang, Z., 2017, “Modelling of FRP-Concrete Bonded Interfaces Containing FRP Anchors,” Construction and Building Materials, V. 139, No. 1, pp. 394-402. doi: 10.1016/j.conbuildmat.2017.02.080
Zhou, Y.; Wang, X.; Sui, L.; Xing, F.; Huang, Z.; Chen, C.; Li, P.; and Mei, L., 2018, “Effect of Mechanical Fastening Pressure on the Bond Behaviors of Hybrid-Bonded FRP to Concrete Interface,” Composite Structures, V. 204, pp. 731-744. doi: 10.1016/j.compstruct.2018.08.008