Chloride penetration in nonsaturated concrete
Chloride penetration in nonsaturated concrete
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DOI：
10.1061/(asce)0899-1561(2003)15:2(183
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发表时间：
2003-03-01
影响因子：
3.2
通讯作者：
Xi, YP
中科院分区：
文献类型：
--
作者：
Ababneh, A;Benboudjema, F;Xi, YP
建立了氯离子在非饱和混凝土中扩散的两个控制方程。材料模型的控制方程中涉及的四个材料参数，包括氯离子结合能力，氯离子扩散系数，水分容量，水分扩散系数。计划的尝试是首先根据分析结果建立材料模型，如果这是不可能的，则基于不同尺度水平的主导物理或化学机制开发经验模型，并通过相关的测试数据校准单个模型。采用交替方向隐式（ADI）有限差分法求解耦合的二维水分扩散和氯离子渗透方程。数值解与90天积水试验（AASHTO T259 - 80）的试验结果进行了比较。数值预报结果与试验结果吻合较好。给出了混凝土板不同深度和不同龄期的自由氯离子浓度分布。详细分析了两种不同初始相对湿度的极限情况，研究了非饱和混凝土中氯离子扩散对水分扩散的依赖性。
The two governing equations that describe the diffusion of chloride ions into nonsaturated concrete are established. Material models for the four material parameters involved in the governing equations are developed, including chloride binding capacity, chloride diffusion coefficient, moisture capacity, and moisture diffusion coefficient. The planned attempt is to establish material models based on analytical results first, and if this is not possible, to develop empirical models based on dominant physical or chemical mechanism(s) at different scale levels and calibrate the individual model by related test data. The alternating-direction implicit (ADI) finite-difference method was employed for solving coupled two-dimensional moisture diffusion and chloride penetration equations. The numerical solutions are compared with the experimental results obtained by the 90-day ponding test (AASHTO T259-80). The numerical prediction agrees very well with the test data. Free chloride concentration profiles at different depths and different ages of concrete slab are presented. Two limiting cases for different initial relative humidity levels are analyzed in detail to study the dependence of the chloride diffusion on the moisture diffusion in nonsaturated concrete.