Double shear tests and shear bearing capacity calculation of perforated GFRP ribs
-
摘要: 玻璃纤维增强树脂复合材料(GFRP)开孔板连接件是GFRP-混凝土组合梁中一种常用的抗剪连接件。开展了5组共15个GFRP开孔板连接件试件的双剪试验,试验参数包括与GFRP开孔板连接件粘结的GFRP型材接触面打磨深度(0.5 mm/1.0 mm)、孔中横向贯通GFRP筋(无/配置)、贯通GFRP筋直径(9.5 mm/13.0 mm)和混凝土强度等级(C30/C50)。试验表明:打磨深度0.5 mm和1.0 mm的试件分别发生开孔板与GFRP型材之间的粘结层破坏和板肋剪切破坏,孔中横向贯通GFRP筋和混凝土榫均完好;开孔板连接件的剪力-滑移曲线可分为微滑移段和滑移段;与打磨深度0.5 mm开孔板连接件相比,相应的打磨深度1.0 mm开孔板连接件的受剪刚度较高;配置横向贯通GFRP筋、提高混凝土强度可显著提高开孔板连接件的受剪刚度;打磨深度1.0 mm开孔板连接件受剪承载力比相应的0.5 mm开孔板连接件高44.82%,配置横向贯通GFRP筋的开孔板连接件受剪承载力比相应的未配置横向贯通筋的开孔板连接件高20%左右,而横向贯通GFRP筋直径和混凝土强度对开孔板连接件受剪承载力的影响不显著。基于最大剪应力失效准则,推导了GFRP开孔板连接件的受剪临界破坏面,提出了板肋剪切破坏下开孔板连接件受剪承载力计算公式,计算值与国内外已有试验结果对比吻合良好。
-
关键词:
- GFRP开孔板连接件 /
- 双剪试验 /
- 受剪承载力 /
- 剪力-滑移曲线 /
- 受剪临界破坏面
Abstract: Perforated glass fiber reinforced polymer (GFRP) ribs is a common interfacial shear connector in GFRP-concrete hybrid beams. Fifteen double shear tests, divided into five groups, were performed to study the shear behavior of perforated GFRP ribs. Test parameters included the griding depth on GFRP profiles (0.5 mm/1.0 mm), the existence of penetrating GFRP bars, the diameter of penetrating GFRP bars (9.5 mm/13.0 mm), and concrete strength (C30/C50). Test results show that the failure modes of specimens with a grinding depth of 0.5 mm and 1.0 mm on GFRP profile are classified into debonding failure and shearing failure of perforated GFRP ribs without broken of penetrating GFRP bars and concrete wedge, respectively. The shear force-slip curves for perforated GFRP ribs are composed of micro-slippage section and slippage section. The shear stiffness of specimens with 1.0 mm grinding depth on GFRP profiles is higher than specimens with 0.5 mm grinding depth. In addition, the shear stiffness increases with the increment in concrete strength and the existence of penetrating GFRP bars. The shear resistance of specimens with 1.0 mm grinding depth on the GFRP profile is about 44.82% higher than that of specimens with 0.5 mm grinding depth on the GFRP profile. And the shear resistance of specimens with penetrating GFRP bars is about 20% higher than that of specimens without penetrating GFRP bars. The concrete strength and diameter of penetrating GFRP bars have little effect on the shear capacity of perforated GFRP ribs. Finally, on the basis of the maximum shear stress criterion, the critical shear failure position on perforated GFRP ribs is derived and a calculation approach for shear capacity under debonding failure is proposed, which is in good agreement with the experimental results. -
图 4 GFRP开孔板连接件剪力-横向贯通GFRP筋应变曲线
sb1—Strain gage at the upper of penetrating GFRP bar near the hole; sb2—Strain gage at the bottom of penetrating GFRP bar near the hole; sb3—Strain gage at the upper of penetrating GFRP bar away from the hole; sb4—Strain gage at the bottom of penetrating GFRP bar away from the hole
Figure 4. Shear load-strain curves of GFRP transverse bars in perforated GFRP ribs specimens
图 9 混凝土榫与GFRP开孔板孔壁的接触压应力分布
Figure 9. Distribution of the contact press between concrete wedge and perforated GFRP ribs
Fp—Shear force per concrete wedge; p—Contact stress between concrete wedge and perforated GFRP ribs; px—Constitution of p in the fiber direction; py—Constitution of p perpendicular to the fiber direction; β—Angle
表 1 玻璃纤维增强树脂复合材料(GFRP)开孔板连接件试件参数
Table 1. Parameters of perforated glass fiber reinforced polymer (GFRP) ribs
Specimen Griding depth/mm GFRP bars diameter/mm Concrete
gradeFP-1, 2, 3 0.5 9.5 C50 FP-4, 5, 6 1.0 9.5 C50 FP-7, 8, 9 1.0 – C50 FP-10, 11, 12 1.0 13.0 C50 FP-13, 14, 15 1.0 9.5 C30 Note: FP—FRP beams and perforated GFRP ribs (PFR). 表 2 混凝土力学性能
Table 2. Mechanical properties of concrete
Concrete grade Cube strength
fcu/MPaPrism strength
fc/MPaTensile strength
ft/MPaElastic modulus
Ec/GPaC50 51.9 42.4 3.5 39.8 C30 36.7 29.5 3.0 29.2 表 3 GFRP筋力学性能
Table 3. Mechanical properties of GFRP bars
Diameter d/mm Tensile strength ffu/MPa Tensile modulus Ef/GPa Shear strength ffv/MPa 9.5 910 51.8 152 13.0 860 50.8 143 表 4 GFRP开孔板力学性能
Table 4. Mechanical properties of perforated GFRP ribs
Part Direction Tensile strength σtu/MPa Tensile modulus Etu/GPa Compressive strength
σcu/MPaShear strength
τxy/MPaShear modulus
Gxy/GPaWebs Transverse 112.8 27.1 131.5 68.3 13.1 Longitudinal 489.7 31.7 230.0 Flanges Longitudinal 698.0 17.4 161.3 – – 表 5 GFRP开孔板连接件推出试验结果
Table 5. Double shear test results of perforated GFRP ribs
Specimen Failure mode Pu/kN Su/mm FP-1, 2, 3 Debonding failure 81.99 0.46 FP-4, 5, 6 Shearing failure of PFR 118.74 0.64 FP-7, 8, 9 Shearing failure of PFR 95.86 1.06 FP-10, 11, 12 Shearing failure of PFR 113.91 0.83 FP-13, 14, 15 Shearing failure of PFR 113.44 1.24 Notes: Pu—Average shearing capacity of GFRP shear connector; Su—Average slip at the peak load; PFR—Perforated FRP rib. 表 6 GFRP开孔板连接件试件计算结果与试验结果对比
Table 6. Comparisons between test results and theoretical results of perforated GFRP ribs
Literature Specimen Pu/kN lp/mm t/mm τxy/MPa D/mm n Vu1/Pu Vu2/Pu Vu3/Pu Vu/Pu [17] LJ1-1 17.46 250 3.6 23.0 20 2 3.75 1.00 1.16 1.08 LJ1-2 18.42 250 3.6 23.0 20 2 3.56 0.94 1.10 1.02 LJ2-1 21.55 250 3.6 23.0 20 2 3.04 0.81 0.94 0.87 LJ2-2 21.85 250 3.6 23.0 20 2 3.00 0.80 0.93 0.86 LJ3-2 16.87 250 3.6 23.0 20 2 3.97 1.03 1.20 1.11 [25] P8 87.50 500 6.0 25.4 16 2 0.85 0.82 0.92 0.84 [24] TR-H4-R4 333.00 500 10.0 52.0 35 2 0.91 0.91 1.12 0.95 TR-H8-R8 295.00 500 10.0 52.0 35 4 1.33 0.90 1.17 1.00 This paper FP4-6 118.74 250 8.0 68.3 30 2 0.89 0.87 1.05 0.99 FP10-12 113.91 250 8.0 68.3 30 2 1.32 0.91 1.10 1.03 FP13-15 113.44 250 8.0 68.3 30 2 0.92 0.92 1.10 1.04 Average 2.14 0.90 1.08 0.98 Standard deviation 1.560 0.005 0.009 0.007 Notes: Pu—Average shearing capacity of GFRP shear connector; lp—Length of the perforated GFRP ribs (mm); t—Thickness of the perforated GFRP ribs (mm); τxy—Shear strength of perforated GFRP ribs (MPa); D—Hole diameter (mm); n—Number of hole in perforated GFRP ribs; Vu1, Vu2, Vu3, Vu—Results deprive from equation (1), (2), (3), (11) respectively. -
[1] 聂建国, 陶慕轩, 吴丽丽, 等. 钢-混凝土组合结构桥梁研究新进展[J]. 土木工程学报, 2012, 45(6):110-122.NIE Jianguo, TAO Muxuan, WU Lili, et al. Advances of research on steel-concrete composite bridges[J]. China Civil Engineering Journal,2012,45(6):110-122(in Chinese). [2] 叶列平, 冯鹏. FRP在工程结构中的应用与发展[J]. 土木工程学报, 2006(3):24-36. doi: 10.3321/j.issn:1000-131X.2006.03.004YE Lieping, FENG Peng. Applications and development of fiber-reinforced polymer in engineering structures[J]. China Civil Engineering Journal,2006(3):24-36(in Chinese). doi: 10.3321/j.issn:1000-131X.2006.03.004 [3] 王文炜, 黄辉, 戴建国, 等. 钢-GFRP-混凝土组合梁受弯性能试验[J]. 中国公路学报, 2016, 29(9):45-52. doi: 10.3969/j.issn.1001-7372.2016.09.006WANG Wenwei, HUANG Hui, DAI Jianguo, et al. Experiment on flexural behavior of steel-GFRP-concrete compo-site beams[J]. China Journal of Highway and Transport,2016,29(9):45-52(in Chinese). doi: 10.3969/j.issn.1001-7372.2016.09.006 [4] BAI J P. Advanced fibre-reinforced polymer (FRP) compo-sites for structural applications[M]. Elsevier: Woodhead Publishing, 2013: 631-661. [5] ZOU X, LIN H, FENG P, et al. A review on FRP-concrete hybrid sections for bridge applications[J]. Composite Structures,2020, 262:113336. [6] CHENG L J, KARBHARI V M. New bridge systems using FRP composites and concrete: A state-of-the-art review[J]. Progress in Structural Engineering and Materials,2006,8(4):143-154. doi: 10.1002/pse.221 [7] ZUO Y, CAO Y, ZHOU Y, et al. A state-of-the-art review on hybrid GFRP-concrete bridge deck systems[J]. Advances in Materials Science and Engineering,2021, 2021:1-17. [8] DESKOVIC N, TRIANTAFILLOU T C, MEIER U. Innovative design of frp combined with concrete-short-term behavior[J]. Journal of Structural Engineering-ASCE,1995,121(7):1069-1078. doi: 10.1061/(ASCE)0733-9445(1995)121:7(1069) [9] NORDIN H, TALJSTEN B. Testing of hybrid FRP composite beams in bending[J]. Composites Part B: Engineering,2004,35(1):27-33. doi: 10.1016/j.compositesb.2003.08.010 [10] SAIIDI M, GORDANINEJAD F, WEHBE N. Behavior of graphite/epoxy concrete composite beams[J]. Journal of Structural Engineering,1994,120(10):2958-2976. doi: 10.1061/(ASCE)0733-9445(1994)120:10(2958) [11] CORREIA J R, BRANCO F A, FERREIRA J. GFRP-concrete hybrid cross-sections for floors of buildings[J]. Engineering Structures,2009,31(6):1331-1343. doi: 10.1016/j.engstruct.2008.04.021 [12] GONG J W, ZOU X X, XIA P. Experimental investigation of the natural bonding strength between stay-in-place form and concrete in FRP-concrete decks/beams[J]. Applied Sciences,2019,9(5):913. doi: 10.3390/app9050913 [13] ZOU X X, FENG P, WANG J Q, et al. FRP stay-in-place form and shear key connection for FRP-concrete hybrid beams/decks[J]. Composite Structures,2018,192:489-499. doi: 10.1016/j.compstruct.2018.03.011 [14] ZOU X, FENG P, WANG J. Bolted shear connection of FRP-concrete hybrid beams[J]. Journal of Composites for Construction,2018,22(3):04018012. doi: 10.1061/(ASCE)CC.1943-5614.0000845 [15] NGUYEN H, MUTSUYOSHI H, ZATAR W. Push-out tests for shear connections between UHPFRC slabs and FRP girder[J]. Composite Structures,2014,118:528-547. doi: 10.1016/j.compstruct.2014.08.003 [16] HALL J E, MOTTRAM J T. Combined FRP reinforcement and permanent formwork for concrete members[J]. Jour-nal of Composites for Construction,1998,2(2):78-86. doi: 10.1061/(ASCE)1090-0268(1998)2:2(78) [17] 薛伟辰, 张赛, 葛畅. FRP混凝土组合梁抗剪连接件试验研究[J]. 公路交通科技(应用技术版), 2014, 10(1):207-210.XUE Weichen, ZHANG Sai, GE Chang. Experimental study on shear connectors of FRP concrete composite beams[J]. Journal of Highway and Transportation Research and Development,2014,10(1):207-210(in Chinese). [18] ZIEHL P H, ENGELHARDT M D, FOWLER T J, et al. Design and field evaluation of hybrid FRP/reinforced concrete superstructure system[J]. Journal of Bridge Engineering,2009,14(5):309-318. doi: 10.1061/(ASCE)BE.1943-5592.0000002 [19] ULLOA F V, MEDLOCK R D, ZIEHL P H, et al. Hybrid bridges in texas[J]. Concrete International, 2004, 26(5): 38-43. [20] 邵忠民, 冯鹏. GFRP材料的工程应用实例[J]. 市政技术, 2012, 30(2):125-128. doi: 10.3969/j.issn.1009-7767.2012.02.052SHAO Zhongmin, FENG Peng. Case study of GFRP application in an engineering project[J]. Municipal Engineering Technology,2012,30(2):125-128(in Chinese). doi: 10.3969/j.issn.1009-7767.2012.02.052 [21] LIU T, FENG P, LU X, et al. Flexural behavior of novel hybrid multicell GFRP-concrete beam[J]. Composite Structures,2020,250:112606. [22] CORREIA J R, BRANCO F A, FERREIRA J G. Flexural behaviour of GFRP-concrete hybrid beams with interconnection slip[J]. Composite Structures,2007,77(1):66-78. doi: 10.1016/j.compstruct.2005.06.003 [23] NAM J H, YOON S J, OK D M, et al. Perforated FRP shear connector for the FRP-concrete composite bridge deck[J]. Key Engineering Materials,2007:381-384. [24] HUANG H L, LI A, CHEN L, et al. Push-out tests for shear connectors in GFRP-concrete composite bridge deck slabs[J]. Journal of Advanced Concrete Technology,2018,16(8):368-381. doi: 10.3151/jact.16.368 [25] ZOU X X, FENG P, WANG J Q. Perforated FRP ribs for shear connecting of FRP-concrete hybrid beams/decks[J]. Composite Structures,2016,152:267-276. doi: 10.1016/j.compstruct.2016.05.039 [26] MEDBERRY S B, SHAHROOZ B M. Perfobond shear connector for composite construction[J]. Engineering Journal,2002,39(1):2-11. [27] GWON S C, KIM S H, YOON S J, et al. An experimental study on the shear strength of FRP perfobond shear connector[C]//IOP Conference Series: Materials Science and Engineering. 2018 International Conference on Material Strength and Applied Mechanics. Kitakyushu: IOP Publishing, 2018: 012042. [28] 中华人民共和国住房和城乡建设部. 纤维增强复合材料建设工程应用技术规范: GB 50608—2020[S]. 北京: 中国标准出版社, 2020.Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Technical standard for fiber reinforced polymer (FRP) in construction: GB 50608—2020[S]. Beijing: China Standards Press, 2020(in Chinese). [29] European Committee for Standardization. Eurocode 4: Design of composite steel and concrete structures: Part 1—1: General rules and rules for buildings: EN 1994-1-1[S]. Brussels: CEN, 2004.