Study on internal pore structure and dynamic mechanical properties of carbon fiber reinforced concrete under high temperature

doi:10.19936/j.cnki.2096-8000.20220828.008

Abstract

Abstract: In order to study the changes of internal pore structure and dynamic mechanical properties of carbon fiber reinforced concrete with different lengths (0 mm, 3 mm, 6 mm and 12 mm) under high temperature (25 ℃, 100 ℃, 200 ℃ and 400 ℃),the T₂ spectrum distribution, pore diameter and porosity of the specimen were analyzed by nuclear magnetic resonance (NMR), the dynamic uniaxial impact compression tests of concrete specimens under different high temperatures are carried out by using Hopkinson compression bar, and the effects of carbon fiber length and temperature on the dynamic mechanical properties of concrete are analyzed. The results show that when the fiber length is 6 mm, the reinforcement effect of concrete is the best, and the increase of temperature will reduce the strength and quality of specimens. The T₂ spectrum curve of carbon fiber reinforced concrete is bimodal. When the fiber length is 0 mm, the T₂ spectrum peak value of the specimen is the largest, the number of pores is the largest, and the peak value is the lowest when the fiber length is 6 mm. The addition of fiber can effectively reduce the number of pores. With the increase of temperature, the peak value of T₂ spectrum increases, the number of pores in the specimen increases, the porosity increases, and the temperature effect causes the deterioration of the specimen. The addition of carbon fiber can enhance the dynamic compressive strength of specimens and reduce the ultimate strain. The rise of temperature will cause damage to carbon fiber reinforced concrete, reduce its dynamic compressive strength and strain rate effect, and DIF will decrease.

Key words: carbon fiber reinforced concrete, high temperature, nuclear magnetic resonance, number of pores, SHPB, dynamic mechanical properties

CLC Number:

TB332

ZHANG Jing-li, JIU Yong-zhi. Study on internal pore structure and dynamic mechanical properties of carbon fiber reinforced concrete under high temperature[J]. COMPOSITES SCIENCE AND ENGINEERING, 2022, 0(8): 58-63.

References

[1] MA Q M, GUO R X, ZHAO Z M, et al. Mechanical properties of concrete at high temperature A review[J]. Construction and Building Materials, 2015, 93: 371-383.
[2] 彭小芹, 马铭彬, 吴芳. 土木工程材料[M]. 3版. 重庆: 重庆大学出版社, 2013: 76.
[3] 陈磊, 李彬, 滕桃居, 等. 混凝土高温力学性能分析[J]. 混凝土, 2003(7): 26-28.
[4] 胡婧. 纤维高强混凝土耐久性试验研究[D]. 郑州: 郑州大学,2018.
[5] 赵庆新, 董进秋, 潘慧敏, 等. 玄武岩纤维增韧混凝土冲击性能[J]. 复合材料学报, 2010, 27(6): 120-125.
[6] CHEN W G, ZHU H T, HE Z H, et al. Experimental investigation on chloride-ion penetration resistance of slag containing fiber-reinforced concrete under drying-wetting cycles[J]. Construction and Building Materials, 2021, 274: 121829.
[7] 张丽辉, 刘建忠, 周华新, 等. 聚甲醛纤维对混凝土性能的影响[J]. 混凝土与水泥制品, 2018(1): 58-62.
[8] 刘露, 侯帅, 吴静, 等. 聚甲醛纤维增强混凝土抗折性能研究[J]. 武汉纺织大学学报, 2013, 26(3): 35-38.
[9] 侯帅, 王文年, 曾宪森, 等. 聚甲醛纤维增强混凝土劈裂抗拉强度的研究[J]. 武汉纺织大学学报, 2013, 26(3): 39-42.
[10] 王伯昕, 黄承逵. 大直径合成纤维增强混凝土抗冲击性能的研究[J]. 建筑材料学报, 2006(5): 608-612.
[11] 贾方方, 贺奎, 安明喆, 等. 粗合成纤维活性粉末混凝土抗弯韧性试验[J]. 建筑科学与工程学报, 2014, 31(3): 79-84.
[12] HSIE M, TU C, SONG P S. Mechanical properties of polypropylene hybrid fiber-reinforced concrete[J]. Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing, 2008, 494(1-2): 153-157.
[13] 张恩, 路国运, 杨会伟, 等. 聚丙烯纤维增强橡胶混凝土工作性能及力学性能试验研究[J]. 混凝土, 2021(3): 86-89.
[14] ALBERTI M G, ENFEDAQUE A, GALVEZ J C. The effect of fibres in the rheology of self-compacting concrete[J]. Construction and Building Materials, 2019, 219: 144-153.
[15] 史才军, 何稳, 吴泽媚, 等. 纤维对UHPC力学性能的影响研究进展[J]. 硅酸盐通报, 2015, 34(8): 2227-2236, 47.
[16] 杨富花, 石宵爽, 栾晨晨, 等. 聚甲醛纤维增强地聚物再生混凝土的力学性能研究[J]. 新型建筑材料, 2021, 48(5): 52-56, 70.
[17] 李曈, 张晓东, 范锦泽, 等. 高吸水树脂玄武岩纤维混凝土力学性能试验研究[J]. 玻璃钢/复合材料, 2019(12): 29-33.
[18] 张培辉, 方圣恩, 洪华山. 不同纤维增强混凝土力学性能和破坏形态对比试验[J]. 玻璃钢/复合材料, 2019(6): 73-79.
[19] 陈宝春, 林毅焌, 杨简, 等. 超高性能纤维增强混凝土中纤维作用综述[J]. 福州大学学报(自然科学版), 2020, 48(1): 58-68.
[20] DEY V, KACHALA R, BONAKDAR A, et al. Mechanical properties of micro and sub-micron wollastonite fibers in cementitious composites[J]. Construction and Building Materials, 2015, 82: 351-359.
[21] 国家市场监督管理总局, 国家标准化管理委员会. 水泥混凝土和砂浆用合成纤维: GB/T 21120—2018[S]. 北京: 中国标准出版社, 2018.
[22] 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): 147-58.
[23] 中华人民共和国国家发展和改革委员会. 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.
[24] 徐世烺, 吴智敏, 丁生根. 砼双K断裂参数的实用解析方法[J]. 工程力学, 2003(3): 54-61.
[25] 王志杰, 李瑞尧, 徐君祥, 等. 混杂复合纤维高性能混凝土断裂性能研究[J]. 路基工程, 2020(3): 81-85.
[26] 金轶凡, 陶燕, 柴栋, 等. 玄武岩纤维混凝土三点弯曲梁的断裂性能[J/OL]. 土木与环境工程学报(中英文): 1-8[2021-09-15]. http://kns.cnki.net/kcms/detail/50.1219.TU.20210802.0848.002.html.
[27] 孔德成, 安明喆, 贾方方. 聚丙烯粗纤维超高性能混凝土的断裂性能[J]. 公路, 2021, 66(5): 281-285.