海洋水下区纤维混凝土中氯离子的扩散性能

Research on Chloride Ion Diffusion of Fiber Concrete in Marine Underwater Area

采用室内长期浸泡的方法模拟海洋水下区,以纤维掺量为参数,开展了聚丙烯纤维混凝土的氯离子侵蚀试验研究.试验结果表明：海洋水下区氯离子通过毛细吸附和扩散作用在纤维混凝土中迁移,毛细吸附的影响深度为8~10 mm;纤维掺量为0.1%（体积分数）的混凝土内部致密,随纤维掺量继续增大,试件的抗氯离子侵蚀能力减弱;纤维混凝土的结合氯离子在毛细吸附影响深度之前对试件中总氯离子含量影响较大.运用Fick第二扩散定律解析解对试件中的氯离子进行非线性拟合,纤维掺量影响氯离子扩散系数,掺量为0.1%（体积分数）的纤维混凝土氯离子扩散系数最小.

Resistance of Polypropylene fiber（PPF） concrete to chloride ion corrosion was tested simulating marine underwater by indoor immersion. The results indicates that C1 migrates in PPF concrete by capillary adsorption and diffusion with a depth of adsorption at about 8 - 10 mm. The O. 1% PPF reinforced concrete has internal density, and its resistance to chloride ion corrosion decreases with the increase of fiber concentration. The bound chloride in PPF concrete has the maximum impact on the total chloride before it reaches the depth of adsorption. Diffusion coefficient of chloride ion is influenced by fiber concentration. Solution of Fickg second law of diffusion applied to the nonlinear fitting of the chloride concentration in PPF concrete in marine underwater shows that 0. 1% PPF reinforced concrete has the minimal diffusion coefficient of chloride ion.