Impact Performance of Reinforced-concrete Beam Strengthened by CFRP

ZHANG Jing-feng1 TONG Chao-kang1 ZHANG Zhi-chao1 FENG Liang1 ZHANG Yu1 LU Tao1 HAN Wan-shui1

(1.School of Highway, Chang’an University, Xi’an, Shaanxi 710064)

【Abstract】The impact performance of reinforced concrete (RC) strengthened by carbon-fiber-reinforced polymer (CFRP) was investigated. An impact test was conducted on six simply supported RC beams using a drop hammer testing facility. An explicit numerical simulation was also performed to regenerate the experimental impact process. The time-varying impact force, reaction force, impact displacement, and cracking development were obtained for various test cases. A thorough investigation was conducted on the damage evolution and dynamic stiffness varying process, CFRP working mechanism, displacement restitution, etc. The CFRP fabric peeled off the bottom of the RC beam at midspan, and other parts of the CFRP slipped with concrete under a drop hammer impact load. The test specimen that was stuck with two layers of CFPR separated from the concrete more easily than that stuck with one layer of CFRP strengthening. The RC beam strengthened by CFRP showed few differences in the cracking damage, impact force, impact displacement, and dynamic stiffness compared with the no strengthened beam. A wedge part formed in the midspan of the No.1 beam under impact loading. The shear-induced oblique crack was clearly reduced for the strengthened RC beam between the midspan and supported position. The restitution coefficient for the impact displacement increased from 0.27 for the non-strengthened beam to more than 0.43 for strengthened ones. The results show that the contribution of CFRP to the flexural capacity of the midspan critical section of the RC beam weakens severely as the CFRP fabric at the midspan peels, which cannot eliminate the impact-induced damage at the impact position during the initial stage. The unseparated CFRP can provide additional shear resistance for the RC beam at the middle and later impact stages. It can also effectively reduce the residual displacement by the elastic restitution effect of CFRP. The increase in the tensional reinforcement ratio can also significantly improve the deformation recovery of RC beams. Three characteristic stages can be classified for the No.1 RC beam impact deformation, i.e., the elastoplastic deformation stage, stiffness degradation stage, and plastic deformation stage, which exhibit a ductile failure pattern. In contrast, the No.2 beam has no plastic deformation during the impact process, and brittle failure can be observed. Perfect interfacial bonding performance is vital for improving the impact performance of RC beams strengthened by CFRP.

【Keywords】 bridge engineering; reinforced concrete (RC) beam; carbon fiber reinforced plastics (CFRP) strengthening; drop hammer impact test; impact performance; bond performance;

【DOI】

【Funds】 National Natural Science Foundation of China(51808048) Natural Science Basic Research of Shanxi Province (2022JM-17, Z2022JZ-32) Fundamental Research Funds for the Central Universities (CHD 300102212911)

Download this article

    References

    [1]YANG Yong-xin,YUE Qing-rui,YE Lie-ping.Calculation for Flexural Debonding Bearing Capacity of RC Beams Strengthened with Carbon Fiber Sheets[J].China Civil Engineering Journal,2004,37(2):23-27,32.

    [2]YE Lie-ping,FENG Peng.Applications and Development of Fiber-reinforced Polymer in Engineering Structures[J].China Civil Engineering Journal,2006,39(3):24-36.

    [3]LORENZIS L D,TENG J G.Near-surface Mounted FRP Reinforcement:An Emerging Technique for Strengthening Structures[J].Composites Part B:Engineering,2007,38(2):119-143.

    [4]PENG Hui,CHOU Jia-xuan,SUN Yi,et al.Bond Behavior of Near Surface Mounted CFRP to Concrete Structure[J].China Journal of Highway and Transport,2019,32(12):156-166.

    [5]HU Kong-guo,YUE Qing-rui,YE Lie-ping,et al.Experimental Research on the Flexural Performance of Concrete Bridge Beam Strengthened by Carbon Fiber Sheets[J].Building Structures,2000,30(7):44-48.

    [6]WU Gang,AN Lin,LV Zhi-tao.Experimental Research on Flexural Strengthening of Reinforced Concrete Beams with Carbon Fiber Reinforced Sheets[J].Building Structures,2000,30(7):3-6.

    [7]YE Lie-ping,CUI Wei,YUE Qing-rui,et al.Analysis on the Flexural Behaviors of Reinforced Concrete Members Strengthened with Carbon Fiber Reinforced Polymer(CFRP)Sheets[J].Building Structures,2001,31(3):3-5,12.

    [8]YANG Yong-xin,YUE Qing-rui.Calculation of Sectional Stieffness of RC Beams Strengthened with Carbon Fiber Sheets(CFSs)[J].Industrial Construction,2001(9):1-4.

    [9]YANG Yong-xin,HU Yun-chang,YUE Qing-rui,et al.Debonded Failure of RC Flexural Members Strengthened with Carbon Fiber Sheets(CFSS)and Its Prevention[J].Industrial Construction,2001,31(6):13-16,19.

    [10]YANG Yong-xin,YUE Qing-rui,HU Yun-chang.Experimental Study on Bond Performance Between Carbon Fiber Sheets and Concrete[J].Journal of Building Structures,2001,22(3):36-42.

    [11]WANG Wen-wei.Study on Flexural Behavior of Reinforced Concrete Beams Strengthened with Fiber Reinforced Plastics(FRP)[D].Dalian:Dalian University of Technology,2003.

    [12]WANG Wen-wei,ZHAO Guo-fan,HUANG Chengkui,et al.An Experimental Study of Strengthening of Initially Loaded Reinforced Concrete Beams Using CFRP Sheets[J].Engineering Mechanics,2004(4):172-178.

    [13]TAN Zhuang,YE Lie-ping.Experimental Research on Shear Capacity of RC Beam Strengthened with Externally Bonded FRP Sheets[J].China Civil Engineering Journal,2003,36(11):12-18.

    [14]SHI Jia-wei,ZHU Hong,WU Zhi-shen,et al.Experimental Study of the Strain Rate Effect of FRP Sheet-concrete Interface[J].China Civil Engineering Journal,2012,45(12):99-107.

    [15]REN Wei,GUO Lin,YANG Yang,et al.String Debonding Effect of Curved RC Member Reinforced by Bonding FRP in Intrados[J].Journal of Traffic and Transportation Engineering,2019,19(1):60-70.

    [16]PENG Hui,SHANG Shou-ping,JIN Yong-jun,et al.Experimental Study of Reinforced Concrete Beam with Prestressed CFRP Plate[J].Engineering Mechanics,2008,25(5):142-151.

    [17]LIU Mu-yu,LI Kai-bing.Fatigue Performance of RC Beams Strengthened with CFRP-Sheets[J].China Civil Engineering Journal,2005,38(9):32-36.

    [18]WU Gang,LIU Hai-yang,WU Zhi-shen,et al.Experimental Study of the Fatigue Performance of Steel Beams Strengthened with Different Fiber Reinforced Polymers[J]. China Civil Engineering Journal,2012,45(4):21-28.

    [19]YE Hua-wen,LI Xin-shun,SHUAI Chun,et al.Fatigue Experimental Analysis of Damaged Steel Beams Strengthened with Prestressed Unbonded CFRP Plates[J].Journal of Southwest Jiaotong University,2019,54(1):129-136.

    [20]CHEN Wan-xiang,YAN Shao-hua.Experimental Study of RC Beams Strengthened with CFRP Under Blast Loading[J].China Civil Engineering Journal,2010,43(5):1-9.

    [21]HUO Jing-si,LIU Jin-tong,ZHAO Ling-yu,et al.Tests for Anti-shear Failure Mechanism of P-strengthened CFRP RC Beams Without Stirrups Under Impact Loading[J].Journal of Vibration and Shock,2017,36(15):187-193.

    [22]CANTWELL W J,SMITH K.The Static and Dynamic Response of CFRP-strengthened Concrete Structures[J].Journal of Materials Science Letters,1999,18(4):309-310.

    [23]TANG T,SAADATMANESH H.Behavior of Concrete Beams Strengthened with Fiber-reinforced Polymer Laminates Under Impact Loading[J].Journal of Composites for Construction,2003,7(3):209-218.

    [24]JEROME D M,ROSS C A.Simulation of the Dynamic Response of Concrete Beams Externally Reinforced with Carbon-fiber Reinforced Plastic[J].Computers&Structures,1997,64(5/6):1129-1153.

    [25]ERKI M,MEIER U.Impact Loading of Concrete Beams Externally Strengthened with CFRP Laminates[J].Journal of Composites for Construction,1999,3(3):117-24.

    [26]PHAM TM,HAO H.Behavior of Fiber-reinforced Polymer-strengthened Reinforced Concrete Beams Under Static and Impact Loads[J].International Journal of Protective Structures,2017,8(1):3-24.

    [27]PHAM T M,HAO H.Impact Behavior of FRPStrengthened RC Beams without Stirrups[J].Journal of Composites for Construction,2016,20(4):1-13.

    [28]LU Xin-zheng,TAN Zhuang,YE Lie-ping,et al.Finite Element Analysis of Debonding at the Interface between FRP Sheet and Concrete[J].Engineering Mechanics,2004(6):45-50.

    [29]ZHANG Pu,GAO Dan-ying,ZHU Hong.Numerical Simulation and Experimental Study on the Performance of Wet-bonding Interface Between FRP Plate and Concrete[J].China Civil Engineering Journal,2013,46(2):108-114.

    [30]PENG Hui,GAO Yong,TANG Xue-song,et al.Numerical Simulation on Damage Evolution Process of FRP-concrete Interface[J].Building Structure,2015,45(9):103-107,25.

    [31]ZHANG Feng,XU Xiang-feng,LI Shu-cai.Bondslip Model for HB-FRP Systems Bonded to Concrete[J].China Journal of Highway and Transport,2015,28(1):38-44,53.

    [32]ZHANG W,TANG Z Z.Numerical Modeling of Response of CFRP-concrete Interfaces Subjected to Fatigue Loading[J].Journal of Composites for Construction,2021,25(5):04021043

    [33]ZHANG Zi-xiao,YE Lie-ping,LU Xin-zheng.Finite Element Analysis of Shear Behavior of RC Beams Strengthened with U-shaped FRP Sheets[J].Engineering Mechanics,2005,22(4):155-162.

    [34]HUANG Z J,CHEN W S,TRANT T,et al.Experimental and Numerical Study on Concrete Beams Reinforced with Basalt FRP Bars Under Static and Impact Loads[J].Composite Structures,2021,263:113648

    [35]TRAN D T,PHAM T M,HAO H,et al.Numerical Study on Bending Response of Precast Segmental Concrete Beams Externally Prestressed with FRP Tendons[J].Engineering Structures,2021,241:112423

    [36]CAMATA G,SPACONE E,ZARNIC R.Experimental and Nonlinear Finite Element Studies of RS Beams Strengthened with FRP Plates[J].Composites Part B:Engineering,2007,38(2):277-288.

    [37][S].JTG 3362—2018,Specifications for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts[S].

    [38]ZHAO De-bo.Response Characteristics and Design Method of Reinforced Concrete Beams Under Impacting Load[D].Changsha:Hunan University,2017.

    [39]Livermore Software Technology Corporation.LSDYNA Keyword User's Manual R8.0[M].Liveimore:Livermore Software Technology Corporation,2015.

This Article

ISSN:1001-7372

CN:61-1313/U

Vol , No. 02, Pages 181-192

February 2022

Downloads:0

Share
Article Outline

Abstract

  • 0 Introduction
  • 1 Experimental program
  • 2 Test results and discussions
  • 3 Finite element simulation and experimental result
  • 4 Conclusion
  • References