Please wait a minute...
浙江大学学报(工学版)
Journal of ZheJiang University (Engineering Science)  2022, Vol. 56 Issue (9): 1693-1703    DOI: 10.3785/j.issn.1008-973X.2022.09.002
    
Flexural behavior of RC beams strengthened by textile-reinforced highly ductile concrete
Min ZHANG(),Ming-ke DENG*(),Ao-long ZHI,Shi-fei SONG,Hui CHEN
School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China
Download: HTML     PDF(2049KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

Textile-reinforced highly ductile concrete (TRHDC) was used to strengthen the reinforced concrete (RC) beams, to improve the flexural capacity of RC beams. Two control beams and eight TRHDC-strengthened beams were designed. And the effect of the longitudinal reinforcement ratio, the number of textile layers, and the level of sustained load on the flexural behavior of RC beams were investigated using the four-point bending test. Experimental results showed that TRHDC-strengthened beams failed in flexural with the longitudinal reinforcement yielding, textile fracturing, and compressive concrete crushing. The debonding cracks at the surface between the longitudinal rebar and the concrete were observed in TRHDC-strengthened beams with a longitudinal reinforcement ratio of 0.93%. Compared with RC beams, TRHDC strengthening method significantly improved the cracking load, yielding load, and peak load of beams, with the highest increase rates reaching 1.61 times, 65.9%, and 39.2%, respectively. Furthermore, this method effectively limited the development of cracks while decreasing the displacement ductility index of RC beams in the range of 2.6%-74.5%. The improvement in the yielding load and peak load of the strengthened beam nonlinearly increased with the number of textile layers, which depends on the longitudinal reinforcement ratio. When the sustained load level increased from 50% to 80% of the yielding load of the control beam, the yielding load of the strengthened beam was decreased by 8.6%, and the peak load and the corresponding deflection were increased by 3.2% and 13.9%, respectively. The calculation method for the lag strain of the TRHDC strengthening layer and the flexural capacity of TRHDC-strengthened beams was proposed, and the results was in good agreement with the experimental results.

Key words： textile-reinforced highly ductile concrete(TRHDC)      reinforced concrete (RC) beam      flexural strengthening      secondary load      flexural capacity     
Received: 27 August 2021      Published: 28 September 2022
CLC:  TU 375  
Fund:  国家自然科学基金资助项目(51878545); 西安市科技创新计划项目(20191522415KYPT015JC017)
Corresponding Authors: Ming-ke DENG     E-mail: zhang_miner@126.com;dengmingke@126.com
Service
E-mail this article
Add to my bookshelf
Add to citation manager
E-mail Alert
RSS
Articles by authors
Min ZHANG
Ming-ke DENG
Ao-long ZHI
Shi-fei SONG
Hui CHEN
Cite this article:

Min ZHANG,Ming-ke DENG,Ao-long ZHI,Shi-fei SONG,Hui CHEN. Flexural behavior of RC beams strengthened by textile-reinforced highly ductile concrete. Journal of ZheJiang University (Engineering Science), 2022, 56(9): 1693-1703.

URL:

https://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2022.09.002     OR     https://www.zjujournals.com/eng/Y2022/V56/I9/1693


纤维织物增强高延性混凝土加固RC梁的受弯性能

为了提高钢筋混凝土（RC）梁的受弯承载力，采用纤维织物增强高延性混凝土（TRHDC）对RC梁进行受弯加固，设计2个对比试件和8个TRHDC加固试件. 通过四点弯曲试验，研究纵筋配筋率、织物层数和持载水平对RC梁受弯性能的影响. 试验结果表明：TRHDC加固梁均发生纵筋屈服、织物被拉断、受压区混凝土被压碎的弯曲破坏；纵筋配筋率为0.93%的TRHDC加固梁在纵筋与混凝土界面出现脱黏裂缝. 与RC梁相比，TRHDC加固使梁的开裂荷载、屈服荷载和峰值荷载显著提高，最大提高幅度分别为1.61倍、65.9%和39.2%，裂缝发展被有效限制，但RC梁的位移延性系数降低2.6%~74.5%. 增加织物层数将使加固梁的屈服荷载和峰值荷载的提高幅度非线性增加，该变化与纵筋配筋率有关；当持载水平由对比梁屈服荷载的50%升至80%时，加固梁的屈服荷载减小8.6%，峰值荷载及相应挠度分别增大3.2%和13.9%. 提出TRHDC加固层滞后应变和TRHDC加固梁受弯承载力的计算方法，所得计算结果与试验结果吻合良好.


关键词： 纤维织物增强高延性混凝土(TRHDC),  钢筋混凝土(RC)梁,  受弯加固,  二次受力,  受弯承载力 
试件编号 纵向受拉钢筋/mm ρs/% 加固材料 SL/%
L 基体
B1 2Φ14 0.93 — — —
B2 2Φ14 0.93 1 HDC —
B3 2Φ14 0.93 2 HDC —
B4 2Φ14 0.93 3 HDC —
B5 2Φ18 1.55 — — —
B6 2Φ18 1.55 1 HDC —
B7 2Φ18 1.55 2 HDC —
B8 2Φ18 1.55 3 HDC —
B9 2Φ18 1.55 2 HDC 50
B10 2Φ18 1.55 2 HDC 80
Tab.1 Parameters of beam specimens
Fig.1 Dimension and reinforcement of textile reinforced highly ductile concrete strengthened specimen
Fig.2 Carbon textile
参数 数值 参数 数值
网格间距sct/mm 20 密度ρct/(g·cm?3) 1.74
抗拉强度fct,t/MPa 3600 束截面积Act,0/mm2 0.94
弹性模量Ect/GPa 230 伸长率λct/% 1.5
单束承载力Fct,0/N 3200 — —
Tab.2 Mechanical characteristics of carbon textile
参数 数值 参数 数值
纤维类型 PVA 弹性模量Ef/GPa 40
直径Df/μm 39 密度ρf/(g·cm?3) 1.3
长度Lf/mm 12 伸长率λf/% 7
抗拉强度ff,t/MPa 1600 — —
Tab.3 Performance indicators of short PVA fibers
Fig.3 Dimensions of textile reinforced highly ductile concrete tensile specimen
Fig.4 Stress-strain curves and crack pattern of highly ductile concrete and textile reinforced highly ductile concrete specimen
钢筋类型 D/mm fy/MPa σsu/MPa
HRB400 8 432 612
HRB400 14 430 592
HRB400 18 430 605
Tab.4 Mechanical properties of reinforcement
Fig.5 Loading device and measurement of flexural tests
Fig.6 Cracks distribution and failure pattern of beam specimens
Fig.7 Load-deflection curves of beam specimens
试件编号 开裂点 纵筋屈服点 峰值点 极限点 $\dfrac{ { {P_{\text{m} } } }}{ { {P_{ {\text{m,0} } } } } }$ $ \mu $ 破坏形态
$ {P_{{\text{cr}}}} $/ kN Δcr/ mm $ {P_{\text{y}}} $/ kN Δy/ mm $ {P_{\text{m}}} $/ kN Δm/ mm $ {P_{\text{u}}} $/ kN Δu/ mm
B1 17.15 1.13 73.14 6.11 96.15 41.40 81.73 41.98 — 6.87 A
B2 37.74 1.79 96.57 5.74 109.72 12.17 93.26 38.41 1.141 6.69 B
B3 37.83 1.70 111.38 7.22 118.79 11.60 100.97 39.80 1.235 5.51 B
B4 36.05 1.54 121.31 7.29 133.87 11.46 113.79 12.73 1.392 1.75 B
B5 18.75 0.94 145.64 7.77 164.10 31.39 139.49 36.29 — 4.67 A
B6 40.61 1.37 160.89 7.80 175.52 13.48 149.19 33.00 1.070 4.23 B
B7 43.97 1.37 174.82 8.62 183.64 13.26 156.09 25.64 1.119 2.97 C
B8 48.97 1.67 177.94 8.67 194.30 12.64 165.16 20.47 1.184 2.36 C
B9 — — 160.92 7.32 187.66 14.13 159.51 23.36 1.143 3.19 C
B10 — — 147.14 6.79 193.72 16.09 164.66 19.41 1.180 2.86 C
Tab.5 Major results of flexural tests of beam specimens
Fig.8 Strain distribution of cross-section along beam depth in textile reinforced highly ductile concrete-strengthened beams
Fig.9 Tensile stress-strain curves of rebar, concrete and textile  reinforced  highlyductile concrete
Fig.10 Calculation diagram of lag strain of  textile  reinforced  highlyductile concrete strengthened beams
Fig.11 Stress and strain distribution at section 1-1 of beams with first failure mode
Fig.12 Stress and strain distribution at section 1-1 of beams with second failure mode
试件编号 $ {P_{{\text{u,t}}}} $/ kN $ {P_{{\text{u,cal}}}} $/ kN ${ {P_{ {\text{u,cal} } } } } /{ {P_{ {\text{u,t} } } } }$
B1 96.15 107.32 1.12
B2 109.72 115.43 1.05
B3 118.79 119.12 1.00
B4 133.87 124.76 0.93
B5 164.10 158.89 0.97
B6 175.52 164.46 0.94
B7 183.64 167.03 0.91
B8 194.30 170.99 0.88
B9 187.66 167.03 0.89
B10 193.72 167.03 0.86
Tab.6 Comparison for calculation values and test results of flexural capacity of beam specimens
[1]   AWANI O, EL-MAADDAWY T, ISMAIL N Fabric-reinforced cementitious matrix: a promising strengthening technique for concrete structures[J]. Construction and Building Materials, 2017, 132: 94- 111
doi: 10.1016/j.conbuildmat.2016.11.125
[2]   BOURNAS D A Concurrent seismic and energy retrofitting of RC and masonry building envelopes using inorganic textile-based composites combined with insulation materials: a new concept[J]. Composite Part B: Engineering, 2018, 148: 166- 179
doi: 10.1016/j.compositesb.2018.04.002
[3]   李赫, 徐世烺 纤维编织网增强混凝土薄板力学性能的研究[J]. 建筑结构学报, 2007, 28 (4): 117- 122
LI He, XU Shi-lang A study on thin concrete plate reinforced with textile[J]. Journal of Building Structures, 2007, 28 (4): 117- 122
doi: 10.3321/j.issn:1000-6869.2007.04.016
[4]   徐世烺, 阎轶群 低配网率纤维编织网增强混凝土轴拉力学性能[J]. 复合材料学报, 2011, 28 (5): 206- 213
XU Shi-lang, YAN Yi-qun Mechanical properties of textile reinforced concrete plate at low textile ratios[J]. Acta Materiae Compositae Sinica, 2011, 28 (5): 206- 213
[5]   D'ANTINO T, PAPANICOLAOU C Mechanical characterization of textile reinforced inorganic-matrix composites[J]. Composite Part B: Engineering, 2017, 127 (15): 78- 91
[6]   BRUCKNER A, ORTHLEPP R, CURBACH M Textile reinforced concrete for strengthening in bending and shear[J]. Materials and Structures, 2006, 39 (8): 741- 748
doi: 10.1617/s11527-005-9027-2
[7]   LARBI A S, AGBOSSOU A, HAMELIN P Experimental and numerical investigations about textile-reinforced concrete and hybrid solutions for repairing and/or strengthening reinforced concrete beams[J]. Composite Structures, 2013, 99: 152- 162
doi: 10.1016/j.compstruct.2012.12.005
[8]   ELSANADEDY H M, ABBAS H, ALMUSALLAM T H, et al Organic versus inorganic matrix composites for bond-critical strengthening applications of RC structures: state-of-the-art review[J]. Composite Part B: Engineering, 2019, 174: 106947
doi: 10.1016/j.compositesb.2019.106947
[9]   RAOOF S M, BOURNAS D A TRM versus FRP in flexural strengthening of RC beams: behaviour at high temperatures[J]. Construction and Building Materials, 2017, 154: 424- 437
doi: 10.1016/j.conbuildmat.2017.07.195
[10]   D'AMBRISI A, FOCACCI F Flexural strengthening of RC beams with cement-based composites[J]. Journal of Composite Construction, 2011, 15: 707- 20
doi: 10.1061/(ASCE)CC.1943-5614.0000218
[11]   ESCRIG C, GIL L, BERNAT-MASO E Experimental comparison of reinforced concrete beams strengthened against bending with different types of cementitious-matrix composite materials[J]. Construction and Building Materials, 2017, 137: 317- 29
doi: 10.1016/j.conbuildmat.2017.01.106
[12]   RAOOF S M, KOUTAS L N, BOURNAS D A Textile-reinforced mortar (TRM) versus fibre-reinforced polymers (FRP) in flexural strengthening of RC beams[J]. Construction and Building Materials, 2017, 151: 279- 91
doi: 10.1016/j.conbuildmat.2017.05.023
[13]   YIN S P, CONG X, WANG C Y, et al Research on flexural performance of composited RC beams with different forms of TRC permanent formwork[J]. Structures, 2021, 29: 1424- 1434
doi: 10.1016/j.istruc.2020.12.034
[14]   YU Y L, YIN S P, NA M W Bending performance of TRC-strengthened RC beams with secondary load under chloride erosion[J]. Journal of Central South University, 2019, 26 (1): 196- 206
doi: 10.1007/s11771-019-3993-y
[15]   徐世烺, 尹世平, 蔡新华 纤维编织网增强混凝土加固钢筋混凝土梁受弯性能研究[J]. 土木工程学报, 2011, 44 (4): 23- 34
XU Shi-lang, YIN Shi-ping, CAI Xin-hua Investigation on the flexural behavior of reinforced concrete beam strengthened with textile-reinforced concrete[J]. China Civil Engineering Journal, 2011, 44 (4): 23- 34
[16]   徐世烺, 尹世平 纤维编织网增强细粒混凝土加固RC受弯构件的正截面承载性能研究[J]. 土木工程学报, 2012, 45 (1): 1- 7
XU Shi-lang, YIN Shi-ping Investigation on the bearing capacity of the normal section of RC flexural component strengthened with textile-reinforced concrete[J]. China Civil Engineering Journal, 2012, 45 (1): 1- 7
[17]   董志芳, 邓明科, 张聪 纤维织物增强高延性混凝土单轴拉伸性能试验研究[J]. 土木工程学报, 2020, 53 (10): 13- 25
DONG Zhi-fang, DENG Ming-ke, ZHANG Cong Experimental investigation on uniaxial tension behavior of textile-reinforced highly ductile concrete[J]. China Civil Engineering Journal, 2020, 53 (10): 13- 25
[18]   WEI L Z, WANG Y C, YU J T, et al Feasibility study of strain hardening magnesium oxychloride cement-based composites[J]. Construction and Building Materials, 2018, 165: 750- 760
doi: 10.1016/j.conbuildmat.2018.01.041
[19]   LI B B, XIONG H, JIANG J F, et al Tensile behavior of basalt textile grid reinforced engineering cementitious composite[J]. Composites Part B: Engineering, 2019, 156: 185- 200
doi: 10.1016/j.compositesb.2018.08.059
[20]   HINZEN M, BRAMESHUBER W. Improvement of serviceability and strength of textile reinforced concrete by using short fibres [C]// 4th Colloquium on Textile Reinforced Structures. Dresden: [s. n.], 2009: 261–272.
[21]   BARHUM R, MECHTCHERINE V Effect of short, dispersed glass and carbon fibres on the behaviour of textile-reinforced concrete under tensile loading[J]. Engineering Fracture Mechanics, 2012, 92: 56- 71
doi: 10.1016/j.engfracmech.2012.06.001
[22]   沈玲华, 王激扬, 徐世烺 掺入短切纤维的纤维编织网增强混凝土薄板弯曲力学性能试验研究[J]. 建筑结构学报, 2016, 37 (10): 98- 107
SHEN Ling-hua, WANG Ji-yang, XU Shi-lang Experimental study on bending mechanical behavior of textile reinforced concrete thin-plates with short dispersed fibers[J]. Journal of Building Structures, 2016, 37 (10): 98- 107
[23]   LI V C, LEUNG C K Y Steady-state and multiple cracking of short random fiber composites[J]. Journal of Engineering Mechanics, 1992, 188 (11): 2246- 2264
[24]   寇佳亮, 邓明科, 梁兴文 延性纤维增强混凝土单轴拉伸性能试验研究[J]. 建筑结构, 2013, 43 (1): 59- 64
KOU Jia-liang, DENG Ming-ke, LIANG Xing-wen Experimental study of uniaxial tensile properties of ductile fiber reinforced concrete[J]. Building Structure, 2013, 43 (1): 59- 64
[25]   代洁, 邓明科, 陈佳莉 基于材料延性的高延性混凝土无腹筋梁受剪性能试验研究[J]. 工程力学, 2018, 35 (2): 124- 132
DAI Jie, DENG Ming-ke, CHEN Jia-li Influence of matrix ductility on shear behavior of high ductile fiber reinforced concrete beams[J]. Engineering Mechanics, 2018, 35 (2): 124- 132
[26]   DENG M K, DONG Z F, ZHANG C Experimental investigation on tensile behavior of carbon textile reinforced mortar (TRM) added with short polyvinyl alcohol (PVA) fibers[J]. Construction and Building Materials, 2020, 235: 117801
doi: 10.1016/j.conbuildmat.2019.117801
[27]   ICC-Evaluation Service. Acceptance criteria for masonry and concrete strengthening using fiber-reinforced cementitious matrix (FRCM) composite systems: AC434 [S]. Whittier: [s. n.], 2013: 14–15.
[28]   KOUTAS L N, TETTA Z, BOURNAS D A, et al Strengthening of concrete structures with textile reinforced mortars: state-of-the-art review[J]. Journal of Composites for Construction, 2019, 23 (1): 03118001
doi: 10.1061/(ASCE)CC.1943-5614.0000882
[29]   邓明科, 马向琨. 一种梁式构件持载加固用试验装置: CN202021687914.7 [P]. 2021-04-20.
[30]   过镇海. 钢筋混凝土原理 [M]. 北京: 清华大学出版社, 2013: 122.
[31]   郑宇宙, 王文炜 复材网格-UHTCC复合增强钢筋混凝土梁抗弯性能试验研究[J]. 土木工程学报, 2017, 50 (6): 23- 32
ZHENG Yu-zhou, WANG Wen-wei Experimental research on flexural behavior of RC beams strengthened with FRP grid-UHTCC composite[J]. China Civil Engineering Journal, 2017, 50 (6): 23- 32
[1] Xing-bo HAN,Yong-xu XIA,Yong-dong WANG,Fei YE. Probabilistic degradation model for tunnel lining flexural capacity[J]. Journal of ZheJiang University (Engineering Science), 2019, 53(11): 2175-2184.
[2] ZHANG Zhong-miao, LIU Jun-wei, ZOU Jian, XIE Zhi-zhuan, HE Jing-yu. Experimental study on flexural and shearing property
of reinforced prestressed concrete pipe pile[J]. Journal of ZheJiang University (Engineering Science), 2011, 45(6): 1074-1080.