Calculation of bearing capacity of polypropylene-steel fiber reinforced concrete column under large eccentric loading
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摘要: 对270个聚丙烯纤维掺量(体积分数)分别为0vol%、0.1vol%、0.2vol%、0.3vol%、0.4vol%、0.5vol%、钢纤维掺量(体积分数)分别为0vol%、0.5vol%、1vol%、1.5vol%、2vol%的聚丙烯-钢纤维/混凝土试块进行立方体抗压试验、轴心抗压试验和劈裂抗拉试验,基于复合材料力学理论,考虑纤维的取向系数、长度有效系数和界面黏结系数,对其建立强度预测模型并进行机制分析,同时选取掺量分别为0vol%、0.1vol%、0.3vol%的聚丙烯纤维、掺量分别为0vol%、1.5vol%的钢纤维制作6根聚丙烯-钢纤维/混凝土柱,对其进行大偏心受压试验,在强度预测模型的基础上进行承载力计算,提出聚丙烯-钢纤维/混凝土承载力计算方法。结果表明:钢纤维对聚丙烯-钢纤维/混凝土立方体抗压强度、轴心抗压强度和劈裂抗拉强度均有提高;聚丙烯纤维可提高聚丙烯-钢纤维/混凝土的劈裂抗拉强度,但不能提高聚丙烯-钢纤维/混凝土的抗压强度;聚丙烯-钢混杂纤维加入混凝土柱可有效提高其极限承载力。Abstract: The cube compressive test, axial compressive test and splitting tensile test were conducted on 270 polypropylene-steel fiber/concrete test blocks with polypropylene fiber content (volume fraction) of 0vol%, 0.1vol%, 0.2vol%, 0.3vol%, 0.4vol%, 0.5vol% and steel fiber content (volume fraction) of 0vol%, 0.5vol%, 1vol%, 1.5vol% and 2vol% respectively. Based on the mechanical theory of polypropylene-steel fiber/concrete composites, the strength prediction model was established considering the fiber orientation coefficient, effective length coefficient and interfacial bond coefficient. The mechanism was also analyzed. Six polypropylene-steel fiber/concrete columns were made from polypropylene fiber with a content of 0vol%, 0.1vol%, 0.3vol% and steel fiber with a content of 0vol%, 1.5vol% to perform large eccentric compression test. On the basis of strength prediction model, the bearing capacity of polypropylene-steel fiber/concrete was calculated. The results show that steel fiber can improve the compressive strength, axial compressive strength and splitting tensile strength of polypropylene-steel fiber/concrete. Polypropylene fiber can improve the splitting tensile strength of polypropylene-steel fiber/concrete, but can’t improve the compressive strength. The ultimate bearing capacity of concrete columns can be effectively increased by adding polypropylene-steel fibers.
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表 1 锂渣的化学成分
Table 1. Chemical composition of lithium slag
wt% SiO2 Al2O3 Fe2O3 CaO MgO SO3 K2O Na2O Li2O 54.39 19.83 1.40 7.98 0.24 8.30 0.14 0.26 0.77 表 2 聚丙烯纤维和钢纤维的主要参数
Table 2. Parameters of polypropylene fibers and steel fibers
Fiber type Length/mm Diameter/μm Density/(g·cm−3) Elasticity modulus /GPa Tensile strength/MPa Steel fiber 33 300 7.82 210 ≥600 Polypropylene fiber 19 33 0.91 >3.5 530 表 3 混凝土配比
Table 3. Mix proportions of concrete
kg·m–3 Water Cement Sand Cobblestone Water reducer Lithium slag C50 concrete composition 150 530 656 1 170 5.3 — Concrete composition used in test 150 424 656 1 170 5.3 106 表 4 聚丙烯-钢纤维/混凝土劈裂抗拉强度试验值及计算值
Table 4. Test values and calculation values of splitting tensile strength of polypropylene-steel fiber/concretes
Test number Volume fraction of polypropylene fiber/vol% Volume fraction of steel fiber/vol% Test value of split tensile strength/MPa Calculated value of split tensile strength/MPa Test value/Calculated value P0S0 0 0 2.92 2.92 1.00 P0S1 0 0.5 3.51 3.59 0.98 P0S2 0 1 4.19 4.27 0.98 P0S3 0 1.5 4.84 4.94 0.98 P0S4 0 2 5.68 5.61 1.01 P1S0 0.1 0 3.07 2.97 1.03 P1S1 0.1 0.5 3.72 3.64 1.02 P1S2 0.1 1 4.30 4.31 1.00 P1S3 0.1 1.5 5.11 4.99 1.02 P1S4 0.1 2 5.74 5.66 1.01 P2S0 0.2 0 3.14 3.02 1.04 P2S1 0.2 0.5 3.44 3.69 0.93 P2S2 0.2 1 4.11 4.36 0.94 P2S3 0.2 1.5 5.01 5.04 0.99 P2S4 0.2 2 5.88 5.71 1.03 P3S0 0.3 0 3.03 3.07 0.99 P3S1 0.3 0.5 4.02 3.74 1.07 P3S2 0.3 1 4.17 4.41 0.95 P3S3 0.3 1.5 4.78 5.09 0.94 P3S4 0.3 2 5.97 5.76 1.04 P4S0 0.4 0 3.46 3.12 1.11 P4S1 0.4 0.5 4.22 3.79 1.11 P4S2 0.4 1 4.38 4.46 0.98 P4S3 0.4 1.5 5.17 5.13 1.01 P4S4 0.4 2 6.12 5.81 1.05 P5S0 0.5 0 3.35 3.16 1.06 P5S1 0.5 0.5 3.49 3.84 0.91 P5S2 0.5 1 4.03 4.51 0.89 P5S3 0.5 1.5 5.05 5.18 0.97 P5S4 0.5 2 6.03 5.86 1.03 表 5 聚丙烯-钢纤维/混凝土立方体抗压强度试验值及计算值
Table 5. Test values and calculated values of cube compressive strength of polypropylene-steel fiber/concrete
Test number Volume fraction of polypropylene fiber/vol% Volume fraction of
steel fiber/vol%Test value of cube compressive strength/MPa Calculated value of cube compressive strength/MPa Test value/
Calculated valueP0S0 0 0 62.8 62.80 1.00 P0S1 0 0.5 64.2 67.96 0.94 P0S2 0 1 69.0 73.12 0.94 P0S3 0 1.5 78.3 78.28 1.00 P0S4 0 2 84.1 83.44 1.01 P1S0 0.1 0 58.2 61.45 0.95 P1S1 0.1 0.5 69.2 66.61 1.04 P1S2 0.1 1 74.2 71.77 1.03 P1S3 0.1 1.5 80.5 76.93 1.05 P1S4 0.1 2 86.0 82.09 1.05 P2S0 0.2 0 61.2 60.10 1.02 P2S1 0.2 0.5 66.3 65.26 1.02 P2S2 0.2 1 69.1 70.42 0.98 P2S3 0.2 1.5 74.8 75.58 0.99 P2S4 0.2 2 82.4 80.74 1.02 P3S0 0.3 0 60.0 58.76 1.02 P3S1 0.3 0.5 62.0 63.91 0.97 P3S2 0.3 1 70.4 69.07 1.02 P3S3 0.3 1.5 77.3 74.23 1.04 P3S4 0.3 2 80.3 79.39 1.01 P4S0 0.4 0 59.2 57.41 1.03 P4S1 0.4 0.5 62.5 62.57 1.00 P4S2 0.4 1 68.7 67.73 1.01 P4S3 0.4 1.5 69.5 72.88 0.95 P4S4 0.4 2 77.2 78.04 0.99 P5S0 0.5 0 58.1 56.06 1.04 P5S1 0.5 0.5 64.1 61.22 1.05 P5S2 0.5 1 65.5 66.38 0.99 P5S3 0.5 1.5 69.3 71.54 0.97 P5S4 0.5 2 70.8 76.70 0.92 表 6 聚丙烯-钢纤维/混凝土轴心抗压强度试验值及计算值
Table 6. Test values and calculated values of axial compressive strength of polypropylene-steel fiber/concretes
Test
numberVolume fraction of polypropylene fiber/vol% Volume fraction of steel fiber/vol% Test value of axial compressive strength/MPa Calculated value of axial compressive strength/MPa Test value/
Calculated valueP0S0 0 0 43.3 43.30 1.00 P0S1 0 0.5 47.7 47.13 1.01 P0S2 0 1 50.4 50.97 0.99 P0S3 0 1.5 55.7 54.80 1.02 P0S4 0 2 58.9 58.63 1.00 P1S0 0.1 0 42.8 42.64 1.00 P1S1 0.1 0.5 51.6 46.47 1.11 P1S2 0.1 1 52.4 50.31 1.04 P1S3 0.1 1.5 57.5 54.14 1.06 P1S4 0.1 2 60.1 57.97 1.04 P2S0 0.2 0 38.8 41.98 0.92 P2S1 0.2 0.5 51.0 45.81 1.11 P2S2 0.2 1 51.0 49.65 1.03 P2S3 0.2 1.5 53.3 53.48 1.00 P2S4 0.2 2 55.8 57.31 0.97 P3S0 0.3 0 43.5 41.32 1.05 P3S1 0.3 0.5 48.1 45.15 1.07 P3S2 0.3 1 49.7 48.99 1.01 P3S3 0.3 1.5 51.0 52.82 0.97 P3S4 0.3 2 53.0 56.65 0.94 P4S0 0.4 0 39.6 40.66 0.97 P4S1 0.4 0.5 47.3 44.49 1.06 P4S2 0.4 1 50.7 48.33 1.05 P4S3 0.4 1.5 50.3 52.16 0.96 P4S4 0.4 2 54.7 55.99 0.98 P5S0 0.5 0 38.2 40.00 0.96 P5S1 0.5 0.5 45.7 43.83 1.04 P5S2 0.5 1 47.3 47.67 0.99 P5S3 0.5 1.5 50.4 51.50 0.98 P5S4 0.5 2 52.5 55.33 0.95 表 7 聚丙烯-钢纤维/混凝土柱极限承载力试验值及计算值
Table 7. Test values and calculation values of ultimate bearing capacity of polypropylene-steel fiber/concrete column
Test
numberVolume fraction of
polypropylene
fiber/vol%Volume fraction
of steel
fiber/vol%Equivalent
compression
zone height/mmTest value
of bearing
capacity/kNCalculated value
of bearing
capacity/kNTest value/
Calculated
valueP0S0 0 0 80.43 564.6 529.2 0.94 P1S0 0 0.001 81.60 572.0 561.4 0.98 P3S0 0 0.003 84.00 600.2 603.5 1.01 P0S3 0.015 0 78.95 638.4 576.8 0.91 P1S3 0.015 0.001 79.81 654.2 605.0 0.93 P3S3 0.015 0.003 81.58 651.7 609.5 0.94 -
[1] 徐礼华, 夏冬桃, 夏广政, 等. 钢纤维和聚丙烯纤维对高强混凝土强度的影响[J]. 武汉理工大学学报, 2007, 29(4):58-60, 98. doi: 10.3321/j.issn:1671-4431.2007.04.018XU Lihua, XIA Dongtao, XIA Guangzheng, et al. Effect of steel fiber and polypropylene fiber on the strength of high strength concrete[J]. Journal of Wuhan University of Technology,2007,29(4):58-60, 98(in Chinese). doi: 10.3321/j.issn:1671-4431.2007.04.018 [2] 高丹盈, 赵军, 汤寄予. 掺有纤维的高强混凝土劈拉性能试验研究[J]. 土木工程学报, 2005, 38(7):21-26. doi: 10.3321/j.issn:1000-131X.2005.07.005GAO Danying, ZHAO Jun, TANG Jiyu. An experimental study on the behavior of fiber reinforced high-strength concrete under splitting tension[J]. China Civil Engineering Journal,2005,38(7):21-26(in Chinese). doi: 10.3321/j.issn:1000-131X.2005.07.005 [3] 潘慧敏, 马云朝. 钢纤维混凝土抗冲击性能及其阻裂增韧机理[J]. 建筑材料学报, 2017, 20(6):956-961. doi: 10.3969/j.issn.1007-9629.2017.06.021PAN Huimin, MA Yunchao. Impact resistance of steel fiber reinforced concrete and its mechanism of crack resistance and toughening[J]. Journal of Building Materials,2017,20(6):956-961(in Chinese). doi: 10.3969/j.issn.1007-9629.2017.06.021 [4] 李传习, 聂洁, 石家宽, 等. 纤维类型对混凝土抗压强度和弯曲韧性的增强效应及变异性的影响[J]. 土木与环境工程学报(中英文), 2019, 41(2):147-158.LI Chuanxi, NIE Jie, SHI Jiakuan, et al. Effect of fiber type on compressive strength and flexural toughness of concrete and analysis of variability[J]. Journal of Civil and Environmental Engineering,2019,41(2):147-158(in Chinese). [5] 赵秋山, 徐慎春, 刘中宪. 钢纤维增强超高性能混凝土抗压性能的细观数值模拟[J]. 复合材料学报, 2018, 35(6):1661-1673.ZHAO Qiushan, XU Shenchun, LIU Zhongxian. Microscopic numerical simulation of the uniaxial compression of steel fiber reinforced ultra-high performance concrete[J]. Acta Materiae Compositae Sinica,2018,35(6):1661-1673(in Chinese). [6] 赵纪生, 陶夏新, 师黎静, 等. 钢纤维混凝土弯压构件承载力试验与理论分析[J]. 土木工程学报, 2005, 38(3):12-16. doi: 10.3321/j.issn:1000-131X.2005.03.003ZHAO Jishen, TAO Xiaxin, SHI Lijin, et al. Experimental and theoretical studies on the bearing capacities of steel-fiber reinforced structural members under compressive bending[J]. China Civil Engineering Journal,2005,38(3):12-16(in Chinese). doi: 10.3321/j.issn:1000-131X.2005.03.003 [7] 徐礼华, 黄乐, 韦翠梅, 等. 钢-聚丙烯混杂纤维混凝土柱抗震承载力试验研究[J]. 建筑结构学报, 2014, 35(8):95-103.XU Lihua, HUANG Le, WEI Cuimei, et al. Experimental Tests of seismic bearing capacity of steel-polypropylene hybrid fiber reinforced concrete columns[J]. Journal of Building Structures,2014,35(8):95-103(in Chinese). [8] 朱海堂, 程晟钊, 高丹盈, 等. BFRP筋钢纤维高强混凝土梁受弯承载力试验与理论[J]. 复合材料学报, 2018, 35(12):3313-3323.ZHU Haitang, CHENG Shengzhao, GAO Danyin, et al. Exprimental and theoretical study on the flexural capacity on high-strength concrete beams reinforced with BFRP bars and steel fiber[J]. Acta Materiae Compositae Sinica,2018,35(12):3313-3323(in Chinese). [9] TOKGOZ S, DUNDAR C, TANRIKULU A K. Experimental behaviour of steel fiber high strength reinforced concrete and composite columns[J]. Journal of Constructional Steel Research,2012,74:98-107. doi: 10.1016/j.jcsr.2012.02.017 [10] 中国工程建设标准化协会. 纤维混凝土试验方法标准: CECS 13∶2009[S]. 北京: 中国计划出版社, 2010.China Association for Engineering Construction Standardization. Standard test methods for fiber reinforced concrete: CECS 13∶2009[S]. Beijing: China Planning Press, 2010(in Chinese). [11] 中华人民共和国住房和城乡建设部. 普通混凝土力学性能试验方法标准: GB/T 50081—2002[S]. 北京: 中国建筑工业出版社, 2003.Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Standard for test method of mechanical properties of ordinary concrete: GB/T 50081—2002[S]. Beijing: China Architecture & Building Press, 2003(in Chinese). [12] GANESAN N, INDIRA P V, SABEENA M V. Bond stress slip response of bars embedded in hybrid fiber reinforced high performance concrete[J]. Construction and Building Materials,2014,50:108-115. doi: 10.1016/j.conbuildmat.2013.09.032 [13] 中国工程建设标准化协会. 纤维混凝土结构技术规程: CECS 38∶2004[S]. 北京: 中国计划出版社, 2005.China Association for Engineering Construction Standardization. Technical specification for fiber reinforced concrete structures: CECS 38∶2004[S]. Beijing: China Planning Press, 2005(in Chinese). [14] 李秋义, 樊红, 赵景海. 三维乱向分布钢纤维方向效能系数的理论值[J]. 哈尔滨建筑大学学报, 1998, 31(1):83-86.LI Qiuyi, FAN Hong, ZHAO Jinghai. Theoretical value of efficiency coefficient of three dimensional random distribution steel fiber direction[J]. Journal of Harbin University of Civil Engineering and Architecture,1998,31(1):83-86(in Chinese). [15] 慕儒, 马艳奉, 李辉, 等. 定向钢纤维混凝土中的钢纤维分布X-ray CT分析[J]. 电子显微学报, 2015, 34(6):487-491. doi: 10.3969/j.issn.1000-6281.2015.06.007MU Ru, MA Yanfeng, LI Hui, et al. Analysis of the distribution of steel fiber in aligned steel fiber reinforced concrete using digital X-ray CT scanning[J]. Journal of Chinese Electron Microscopy Society,2015,34(6):487-491(in Chinese). doi: 10.3969/j.issn.1000-6281.2015.06.007 [16] 俞家欢, 刘琼阳. 水泥基复合材料中纤维拉拔的变位约束细观力学模型[J]. 复合材料学报, 2008, 25(5):147-150. doi: 10.3321/j.issn:1000-3851.2008.05.024YU Jiahuan, LIU Qiongyang. Meso-scale variable engagement model for single fiber reinforced concrete under uniaxial tension[J]. Acta Materiae Compositae Sinica,2008,25(5):147-150(in Chinese). doi: 10.3321/j.issn:1000-3851.2008.05.024 [17] 罗洪林, 杨鼎宜, 周兴宇, 等. 不同长径比聚丙烯纤维增强混凝土的力学特性[J]. 复合材料学报, 2019, 36(8):1935-1948.LUO Hongling, YANG Dingyi, ZHOU Xingyu, et al. Mechanical properties of polypropylene fiber reinforced concrete with different aspect ratios[J]. Acta Materiae Compositae Sinica,2019,36(8):1935-1948(in Chinese). [18] 王力, 徐礼华, 邓方茜, 等. 波纹型钢纤维-混杂纤维混凝土界面粘结性能[J/OL]. 建筑材料学报:1-15 [2020-08-10]. http://kns.cnki.net/kcms/detail/31.1764.TU.20190716.1323.009.html.WANG Li, XU Lihua, DENG Fangqian, et al. The bonding performance of corrugated steel fiber-hybrid fiber concrete matrix interface[J]. Journal of Building Materials:1-15 [2020-08-10]. http://kns.cnki.net/kcms/detail/31.1764.TU.20190716.1323.009.html(in Chinese). [19] 李秋义, 李家和, 袁杰. SFRC兼有阻裂作用的复合理论[J]. 哈尔滨建筑大学学报, 2002, 35(4):81-83, 107.LI Qiuyi, LI Jiahe, YUAN Jie. Composite theory of SFRC accompanied with action of crack arrest[J]. Journal of Harbin University of Civil Engineering and Architecture,2002,35(4):81-83, 107(in Chinese). [20] 郑建岚, 郑作樵. 钢纤维钢筋高强混凝土柱的变形与延性计算[J]. 工程力学, 1999, 16(1):56-66.ZHENG Jianlan, ZHENG Zuoqiao. Calculation of deformation and ductility of steel fiber reinforced high strength concrete columns[J]. Engineering Mechanics,1999,16(1):56-66(in Chinese).