Mechanical experimental study of a new CFRP grid-bamboo scrimber composite plate

Abstract

A novel composite plate made of carbon fiber-reinforced polymer(CFRP)grids and bamboo scrimber, termed CBCP, was developed to enhance the mechanical properties of bamboo scrimber and reduce its anisotropic defects. To investigate the mechanical behavior of CBCP and assess the influence of its composite fabrication method, uniaxial tensile tests were performed on eight sets of CBCP tensile specimens, and pull-out tests were conducted on eighteen groups of CBCP pull-out specimens. Three similar constitutive models were selected to depict the bond stress-slip curves of the pull-out specimens. The critical anchorage lengths between CFRP grids and bamboo scrimber were determined. The effects of the number of CFRP layers, characteristics of transverse CFRP bundles, and anchorage length on the bonding performance between CFRP grids and bamboo scrimber were analyzed. The results reveal that integrating a CFRP grid can increase the tensile strength of bamboo scrimber, both parallel and perpendicular to the grain, by 35.77% and 135.20%, respectively. This enhancement effectively reduces the anisotropic defects of bamboo scrimber. The increase of the number of grid layers and the grid spacing can enhance the tensile performance of CBCP. With the increase of the anchorage length, the average interface bonding strength decreases exponentially while the peak load slip decreases linearly.

Keywords

carbon fiber-reinforced polymer / bamboo scrimber / uniaxial tension test / pull-out test / mechanical properties

References

[1] Xiao Y, Yang R Z, Shan B.Production, environmental impact and mechanical properties of glubam[J]. Construction and Building Materials, 2013, 44: 765-773. DOI: 10.1016/j.conbuildmat.2013.03.087.
[2] Chung K F, Yu W K.Mechanical properties of structural bamboo for bamboo scaffoldings[J]. Engineering Structures, 2002, 24(4): 429-442. DOI: 10.1016/s0141-0296(01)00110-9.
[3] Mahdavi M, Clouston P L, Arwade S R.Development of laminated bamboo lumber: Review of processing, performance, and economical considerations[J]. Journal of Materials in Civil Engineering, 2011, 23(7): 1036-1042. DOI: 10.1061/(asce)mt.1943-5533.0000253.
[4] Sharma B, Gatóo A, Bock M, et al.Engineered bamboo for structural applications[J]. Construction and Building Materials, 2015, 81: 66-73. DOI: 10.1016/j.conbuildmat.2015.01.077.
[5] Lee C H, Chung M J, Lin C H, et al.Effects of layered structure on the physical and mechanical properties of laminated moso bamboo(Phyllosachys edulis)flooring[J]. Construction and Building Materials, 2012, 28(1): 31-35. DOI: 10.1016/j.conbuildmat.2011.08.038.
[6] Lü Q F, Wang W Y, Liu Y.Experimental study on mechanical properties of cross-laminated bamboo slabs after one-sided fire[J]. Journal of Southeast University(Natural Science Edition), 2021, 51(2): 212-218. DOI:10.3969/j.issn.1001-0505.2021.02.004. (in Chinese)
[7] Gong Y C, Zhang C Q, Zhao R J, et al.Experimental study on tensile and compressive strength of bamboo scrimber[J]. Bioresources, 2016, 11(3): 7334-7344. DOI: 10.15376/biores.11.3.7334-7344.
[8] Gu D S, Wu G, Wu Z S.Ultimate flexural strength of normal section of FRP-confined RC circular columns[J]. Journal of Southeast University(English Edition), 2010, 26(1): 107-111. DOI: 10.3969/j.issn.1003-7985.2010.01.022.
[9] Shi J W, Wu Q Q, Wu S X, et al.Analysis on disease repair effects of hollow slab bridge strengthened with prestressed FRP grid[J]. Journal of Southeast University(Natural Science Edition), 2024, 54(2): 407-415. DOI:10.3969/j.issn.1001-0505.2024.02.018. (in Chinese)
[10] Fang H, Xu X, Liu W Q, et al.Flexural behavior of composite concrete slabs reinforced by FRP grid facesheets[J]. Composites Part B:Engineering, 2016, 92: 46-62. DOI: 10.1016/j.compositesb.2016.02.029.
[11] Wang T, Fan X Q, Gao C S, et al.Database-based error analysis of calculation methods for shear capacity of FRP-reinforced concrete beams without web reinforcement[J]. Journal of Southeast University(English Edition), 2023, 39(3): 301-313. DOI: 10.3969/j.issn.1003-7985.2023.03.011.
[12] Fan X C, Huang Y C, Zhang A, et al.Analysis of bonding properties of recycled tire steel fiber reinforced concrete with BFRP bars[J].Journal of Southeast University(Natural Science Edition), 2024, 54(2): 389-397. DOI:10.3969/j.issn.1001-0505.2024.02.016. (in Chinese)
[13] Shen Y R, Huang D S, Zhou A P, et al.An inelastic model for ultimate state analysis of CFRP reinforced PSB beams[J]. Composites Part B:Engineering, 2017, 115: 266-274. DOI: 10.1016/j.compositesb.2016.09.089.
[14] Wei Y, Ji X W, Duan M J, et al.Flexural performance of bamboo scrimber beams strengthened with fiber-reinforced polymer[J]. Construction and Building Materials, 2017, 142: 66-82. DOI: 10.1016/j.conbuildmat.2017.03.054.
[15] Arduini M, Nanni A.Parametric study of beams with externally bonded FRP reinforcement[J]. ACI Structural Journal, 1997, 94(5): 493-501.
[16] Shi J W, Xu B L.Bond behavior and capacity prediction of FRP laminate-to-concrete interface under mixed-mode loading[J]. Journal of Southeast University(Natural Science Edition), 2022, 53(3): 489-496. DOI:10.3969/j.issn.1001-0505.2022.03.009. (in Chinese)
[17] Chun Q, Zhang Y, Pan J W.Experimental study on bending behaviors of timber beams strengthened with near-surface mounted CFRP sheets[J]. Journal of Southeast University(Natural Science Edition), 2012, 42(6): 1146-1150. DOI:10.3969/j.issn.1001-0505.2012.06.023. (in Chinese)
[18] Lü Q F, Wang W Y, Liu Y.Flexural performance of cross-laminated bamboo(CLB)slabs and CFRP grid composite CLB slabs[J]. Advances in Civil Engineering, 2019, 2019: 6980782. DOI:10.1155/2019/6980782.
[19] Huang D S, Bian Y L, Zhou A P, et al.Experimental study on stress-strain relationships and failure mechanisms of parallel strand bamboo made from phyllostachys[J]. Construction and Building Materials, 2015, 77: 130-138. DOI: 10.1016/j.conbuildmat.2014.12.012.
[20] National Forestry and Grassland Administration. Structural bamboo scrimber: LY/T 3194—2020[S]. Beijing: Standards Press of China, 2020.(in Chinese)
[21] National Forestry and Grassland Administration. Bamboo scrimber: GB/T 40247—2021[S].Beijing: Standards Press of China, 2021.(in Chinese)
[22] American Concrete Institute.Guide test methods for fiber-reinforced polymers(FRPs)for reinforcing or strengthening concrete structures: ACI 440.3R-2004[S].Farmington Hill, MI, USA: American Concrete Institute, 2004
[23] China National Institute of Standardization. Fiber-reinforced plastics composites-determination of tensile properties: GB/T 1447—2005[S]. Beijing: Standards Press of China, 2005.(in Chinese)
[24] Cosenza E, Manfredi G, Realfonzo R.Development length of FRP straight rebars[J]. Composites Part B:Engineering, 2002, 33(7): 493-504. DOI: 10.1016/S1359-8368(02)00051-3.
[25] Gao D Y, Zhu H T, Xie J J.The constitutive models for bond slip relation between FRP rebars and concrete[J]. Industrial Construction, 2003, 33(7): 41-43, 82. DOI:10.13204/j.gyjz2003.07.011. (in Chinese)
[26] Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Code for design of concrete structures: GB 50010—2010[S]. Beijing: Standards Press of China, 2010.(in Chinese)