Calculation for maximum crack width of concrete beams reinforced with hybrid steel and FRP bars

doi:10.19936/j.cnki.2096-8000.20220328.011

Abstract

Abstract: In order to study the crack calculation of concrete beams reinforced with hybrid (steel/FRP) bars, firstly, the applicability of the existing average crack spacing calculation formulas for hybrid reinforced concrete beams is analyzed using 55 crack relevant test data of hybrid reinforced beams at home and abroad. The multiple regression analysis of 55 test data is carried out using MATLAB, and the relevant undetermined coefficients in the existing formulas are modified. Then, the formula of the average crack spacing for hybrid reinforced concrete beams is established, and the value of the relative bonding characteristic coefficient v_i is given. Secondly, the calculation method of the longitudinal bars strain non-uniform coefficient ψ and the value of the force characteristic coefficient α_cr under short-term load are determined. At the same time, the maximum crack width correction coefficient k₃ is introduced, and the value of k₃ is determined based on the analysis of 45 crack width relevant test data. Then, the calculation formula of the maximum crack width is established. The comparative analysis with the test data shows that the formulas of the average crack spacing and the maximum crack width for the hybrid reinforced concrete beam have good applicability.

Key words: hybrid steel and FRP reinforced concrete beam, average crack spacing, relative bonding characteristic coefficient, maximum crack width, composites

CLC Number:

TB332

ZHOU Man-qing, ZHANG Zhi-mei, WEI Jiu-yi. Calculation for maximum crack width of concrete beams reinforced with hybrid steel and FRP bars[J]. COMPOSITES SCIENCE AND ENGINEERING, 2022, 0(3): 73-80.

References

[1] QU W, ZHANG X, HUANG H. Flexural behavior of concrete beams reinforced with hybrid (GFRP and steel) bars[J]. Journal of Composites for Construction, 2009, 13(5): 350-359.
[2] LAU D, PAM H. Experimental study of hybrid FRP reinforced concrete beams[J]. Engineering Construction, 2010, 32(12): 3857-3865.
[3] KARA I F, ASHOUR A F. Flexural behavior of hybrid FRP/steel reinforced concrete beams[J]. Composite Structures, 2015, 129: 111-121.
[4] BENCARDINO F, CONDELLO A, OMBRES L. Numerical and analytical modeling of concrete beams with steel, FRP and hybrid FRP-steel reinforcements[J]. Composite Structures, 2016,140: 53-65.
[5] 庞蕾, 屈文俊, 李昂. 混合配筋混凝土梁抗弯计算理论[J].中国公路学报, 2016, 29(7): 81-88.
[6] QIN R Y, ZHOU A, LAU D. Effect of reinforcement ratio on the flexural performance of hybrid FRP reinforced concrete beams[J]. Composites Part B Engineering, 2017, 108: 200-209.
[7] MUSTAFA S A, HASSAN H A. Behavior of concrete beams reinforced with hybrid steel and FRP composites[J]. Housing and Building National Research Center, 2017, 14(3): 300-308.
[8] YANG Y, SUN Z Y, WU G, et al. Flexural capacity and design of hybrid FRP-steel-reinforced concrete beams[J]. Advances in Structural Engineering, 2020, 23(7): 1290-1304.
[9] 黄海群. 混杂配筋混凝土梁抗弯性能研究[D]. 上海: 同济大学, 2004.
[10] 陈辉. GFRP筋与钢筋混合配筋混凝土受弯构件的试验研究与理论分析[D]. 四川: 西南交通大学, 2007.
[11] SAFAN M A. Flexural behavior and design of steel-GFRP reinforced concrete beams[J]. ACI Materials Journal, 2013, 110(6): 677-685.
[12] REFAI A E, ABED F, AI-RAHMANI A. Structural performance and serviceability of concrete beams reinforced with hybrid (GFRP and steel) bars[J]. Construction and Building Materials, 2015, 96(15): 518-529.
[13] GU X, DAI Y, JIANG J. Flexural behavior investigation of steel-GFRP hybrid-reinforced concrete beams based on experimental and numerical methods[J]. Engineering Structures, 2020, 206: 110-117.
[14] 陆春华, 阮向杰, 张壮壮. 混合配筋混凝土梁裂缝宽度试验及计算方法探讨[J]. 中国公路学报, 2019, 32(9): 124-142.
[15] 蒙博. GFRP-钢筋混杂配筋混凝土梁受力性能试验研究与理论分析[D]. 吉林: 吉林建筑大学, 2019.
[16] 董志强, 吴刚. 基于试验数据分析的FRP筋混凝土受弯构件最大裂缝宽度计算方法[J]. 土木工程学报, 2017, 50(10): 1-8.
[17] GE W, ZHANG J, CAO D, et al. Flexural behaviors of hybrid concrete beams reinforced with BFRP bars and steel bars[J]. Construction and Building Materials, 2015, 87(15): 28-37.
[18] 屈文俊, 张健, 黄海群. 钢筋-GFRP筋混凝土梁抗弯试验与裂缝和挠度算法研究[J]. 建筑结构, 2006, 36(3): 38-41.
[19] Aiello M A, Ombres L. Structural performances of concrete beams with hybrid (fiber-reinforced polymer-steel) reinforcements[J]. Journal of Composites for Construction, 2002, 6(2): 133-140.
[20] 孔祥清, 于洋, 邢丽丽. BFRP筋与钢筋混合配筋混凝土梁抗弯性能试验研究[J]. 玻璃钢/复合材料, 2018(8): 49-55.