FRACTURE DAMAGE AND SOFTENING CONSTITUTIVE RALATION OF BFRC SUBJECTED TO FREEZE-THAW CYCLES
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摘要: 为探讨冻融循环下的玄武岩纤维增强混凝土(BFRC)断裂损伤和本构软化特性,以5种不同的玄武岩纤维体积百分比掺量(0%,0.1%、0.2%、0.3%和0.4%)设计5组试件,对BFRC试件进行不同次数(0,25,50,75,100,125次)的冻融循环试验,再对混凝土试件进行三点弯曲加载试验。试验结果表明:在0.3%体积掺量以内,玄武岩纤维掺量越高,BFRC的起裂韧度、失稳韧度和断裂能越高;纤维掺量超过0.3%后,BFRC起裂韧度增加不明显而失稳韧度和断裂能略有下降;混凝土冻融损伤降低了混凝土的断裂韧度和断裂能,但玄武岩纤维对混凝土的冻融损伤具有一定的抑制作用,纤维掺量越高,BFRC断裂韧度和断裂能的冻融损失越小。拟合试验数据得到了BFRC的冻融损伤计算模型,在Petersson混凝土双线性软化本构关系的基础上,进一步推导获得冻融循环下的BFRC双线性软化本构关系曲线。Abstract: In order to investigate the fracture damage and constitutive softening characteristics of basalt fiber reinforced concrete (BFRC) subjected to freeze-thaw cycles, five groups of specimens with five different basalt fiber volume percentages (0%, 0.1%, 0.2%, 0.3% and 0.4%) were designed and subjected to different freeze-thaw cycles (0, 25, 50, 75, 100 and 125 times), and then the three-point bending loading test was conducted on the concrete specimens. The results showed that when the content of fiber was less than 0.3%, the higher the content of basalt fibers, the higher the initial fracture toughness, instability toughness and fracture energy of BFRC. While the content of fibers more than 0.3%, the increase of initial fracture toughness of BFRC was not obvious, but the instability toughness and fracture energy would decrease slightly. The freeze-thaw damage of concrete reduced the fracture toughness and fracture energy of concrete. Basalt fibers could restrain the freeze-thaw damage of concrete to a certain extent. The higher the content of fibers, the smaller the freeze-thaw loss of fracture toughness and fracture energy of BFRC were. Based on the bilinear softening constitutive relation of Petersson for concrete, the bilinear softening constitutive relation curve of BFRC subjected to freeze-thaw cycles was derived by fitting freeze-thaw damage.
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Key words:
- BFRC /
- three-point bending loading /
- freeze-thaw cycle /
- fracture damage /
- softening constitutive model
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[1] 张廷毅,李庆斌,汪自力,等.钢纤维高强混凝土断裂韧度及影响因素[J]. 硅酸盐学报, 2012,40(5):638-645,650. [2] 张倩倩,魏亚,张景硕,等.钢纤维掺量对活性粉末混凝土断裂性能的影响[J]. 建筑材料学报, 2014,17(1):24-29. [3] 梁宁慧,缪庆旭,刘新荣,等. PFRC断裂韧度及软化本构曲线确定[J]. 吉林大学学报(工学版), 2019, 49(4):1144-1152. [4] 王荣,胡昌斌.玄武岩纤维路面混凝土断裂参数实验研究[J].公路, 2014,(12):249-254. [5] 阮明和,刘宏伟. 玄武岩纤维增强混凝土的力学性能研究[J].公路工程,2017,42(6):275-282. [6] 孟雪桦,蔡迎春,金祖维.玄武岩纤维增强混凝土断裂能研究[J].混凝土与水泥制品,2012(1):33-35. [7] 薛启超, 张井财, 何建, 等. 玄武岩纤维混凝土断裂性能实验研究[J]. 哈尔滨工程大学学报, 2016,37(8):1027-1033. [8] 刘昌勇,王乾峰,侯春平,等.冻融劣化混凝土冰冻状态下单轴动态抗压力学特性研究[J].工业建筑,2020,50(10):111-116,121. [9] 徐世烺.混凝土断裂力学[M].北京:科学出版社,2011. [10] 徐世烺, 熊松波, 李贺东, 等. 混凝土断裂参数厚度尺寸效应的定量表征与机理分析[J]. 土木工程学报,2017(5):57-71. [11] 中华人民共和国发展和改革委员会.水工混凝土断裂试验规程:DL/T 5332-2005[S].北京:中国电力出版社,2006. [12] 管俊峰,刘泽鹏,姚贤华,等. 确定混凝土开裂与拉伸强度及双K断裂参数[J].工程力学,2020,37(12):124-137. [13] 尹阳阳,胡少伟. 小跨高比混凝土三点弯曲梁双K断裂参数研究[J].工程力学,2020,37(12):138-146,170. [14] 李霞,王利民,徐世烺,等. 混凝土软化本构关系与失稳断裂参数的计算[J]. 青岛理工大学学报,2019,40(4):6-12,63. [15] 何胜豪,周华飞,谢子令. 基于扩展有限元的地质聚合物混凝土断裂过程研究[J]. 计算力学学报,2020,37(4):461-469. [16] 岳健广,夏月飞,方华.钢纤维混凝土断裂破坏机理及受拉损伤本构试验研究[J]. 土木工程学报,2021,54(2):93-106. [17] 商效瑀,郑山锁,徐强,等.冻融循环下轴心受压砖砌体损伤本构关系模型[J].建筑材料学报,2015,18(6):1045-1049,1054. [18] 白卫峰,郭磊,陈守开,等.混凝土统计损伤力学[M].北京:中国水利水电出版社,2015. [19] 皇民,赵玉如,毕洁同,等. 冻融作用下BFRC轴向拉伸本构模型研究[J].混凝土与水泥制品,2020(9):47-51. [20] AMIN A, FOSTER S J, MUTTONI A. Derivation of the σ-w Relationship for SFRC from Prism Bending Tests[J]. Structural Concrete, 2015, 16(1):93-105.
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