| 摘要: |
| 采用自然浸泡法模拟海洋水下区环境，研究了玄武岩/聚丙烯纤维增强混凝土（BPFRC）的氯离子扩散性能.通过固液萃取法和电位法测试了不同侵蚀时间下BPFRC中的氯离子含量，分析了纤维种类、掺量和混杂形式对氯离子含量分布、表面氯离子含量（Cs）和氯离子扩散系数的影响；此外，采用Rapid Air 457测定了BPFRC的孔径分布，并计算了其孔结构分形维数.结果表明：BPFRC中的氯离子含量随着侵蚀龄期的增加而增大；当纤维体积分数为0.10%时，玄武岩纤维对混凝土中氯离子含量的降低作用大于聚丙烯纤维，适量的混杂纤维能够减小混凝土中的氯离子含量，过量的混杂纤维则增大了混凝土中不同深度处的氯离子含量；BPFRC中的Cs在侵蚀初期增长较快、后期增长较慢，与侵蚀时间为幂函数关系；BPFRC的孔结构表现出明显的分形特征，分形维数范围为2.301~2.446，分形维数与氯离子扩散系数具有较强的正相关性. |
| 关键词: 玄武岩纤维 聚丙烯纤维 纤维增强混凝土 氯离子扩散性能 孔结构分形维数 |
| DOI：10.3969/j.issn.1007-9629.2022.01.007 |
| 分类号:TU528.01 |
| 基金项目:国家自然科学基金重大项目支课题（51590914）；陕西省自然科学基础研究计划项目（2019JQ-481） |
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| Chloride Diffusion Performance of Basalt/Polypropylene Fiber Reinforced Concrete in Marine Environment |
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SU Li1, NIU Ditao1,2, HUANG Daguan1, FU Qiang1,2
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1.School of Civil Engineering， Xi'an University of Architecture and Technology， Xi'an 710055， China;2.State Key Laboratory of Green Building in Western China， Xi'an University of Architecture and Technology， Xi'an 710055， China
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| Abstract: |
| The chloride diffusion performance of basalt/polypropylene fiber reinforced concrete （BPFRC） was studied by using natural immersion method to simulate the marine underwater area. The chloride content in BPFRC under different exposure time was measured by solid-liquid extraction and potentiometric method， and the effects of fiber type， its content and hybrid form on chloride content profile， surface chloride content （Cs） and chloride diffusion coefficient were investigated. In addition， the pore size distribution of BPFRC was measured using Rapid Air 457， and the fractal dimension of pore structure was calculated. The results show that the chloride content in BPFRC increases with increasing exposure time. When the fiber volume fraction is 0.10%， the effect of basalt fiber on reducing chloride content in concrete is greater than that of polypropylene fiber， and an appropriate amount of hybrid fiber can reduce the chloride content in concrete. The excessive hybrid fiber increases the chloride content at different depths in concrete. The Cs of BPFRC increases gradually with increasing exposure time， and the relationship between Cs and exposure time is a power function. The pore structure of BPFRC shows obvious fractal characteristics， and the fractal dimension ranges from 2.301 to 2.446. The fractal dimension has a strong positive correlation with chloride diffusion coefficient. |
| Key words: basalt fiber polypropylene fiber fiber reinforced concrete chloride diffusion performance pore structure fractal dimension |
