Chloride Diffusion-Convection into Unsaturated RC Hollow Cylinder Piles in Marine Tidal Zones
Chloride Diffusion-Convection into Unsaturated RC Hollow Cylinder Piles in Marine Tidal Zones
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DOI：
10.1007/s10706-018-00793-x
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发表时间：
2019-01
影响因子：
1.7
通讯作者：
W. Shao;Danda Shi;Lin Li
中科院分区：
文献类型：
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作者：
W. Shao;Danda Shi;Lin Li
氯离子在钢筋混凝土空心圆柱桩中的渗透是引起钢筋锈蚀、影响桩的工作性能和使用性能的主要因素之一。海洋潮汐区非饱和钢筋混凝土空心圆柱桩中氯离子渗透是扩散和对流耦合作用的结果。本研究之目的为探讨海洋感潮区非饱和钢筋混凝土空心圆柱桩之氯离子扩散-对流特性。推导了氯离子扩散-对流机制的控制方程，并采用有限差分法进行了数值求解。通过算例，预测了潮汐区非饱和钢筋混凝土空心圆柱桩中氯离子浓度的分布。通过参数分析，研究了主要参数对非饱和钢筋混凝土空心圆柱桩中氯离子浓度分布的影响。分析结果表明，对流作用对对流区氯离子的渗透有明显的影响。氯离子扩散对流导致氯离子浓度的增加，并且在固定暴露深度下，对流区的增加比稳定扩散区的增加更显著。对流区深度对氯离子浓度分布的影响不如对流区深度对氯离子扩散系数和对流速度的影响显著。
Chloride penetration into reinforced concrete (RC) hollow cylinder piles has been identified as one of major factors to cause corrosion of reinforcing steel and to affect the performance and serviceability of piles. Chloride penetration into unsaturated RC hollow cylinder piles in marine tidal zones involves the coupling of diffusion and convection mechanisms. The goal of this study is to investigate the chloride diffusion-convection behavior into unsaturated RC hollow cylinder piles in marine tidal zones through numerical modeling. The governing equation to model the chloride diffusion-convection mechanism was derived and solved numerically using the finite difference method. An illustrative example was demonstrated to predict the chloride concentration distributions in unsaturated RC hollow cylinder piles in the marine tidal zones. Parametric analysis was performed to examine the influence of the main parameters on the chloride concentration distributions in unsaturated RC hollow cylinder piles. The analysis results indicated that the convection action had an obvious effect on the chloride penetration in the convection zone. Chloride diffusion-convection resulted in an increase in the chloride concentration, and the increase in the convection zone was more significant compared to that in the steady diffusion zone at a fixed exposure depth. The influence of the convection zone depth on the chloride concentration distributions was not as significant as the effects of chloride diffusion coefficient and convection velocity in unsaturated RC hollow cylinder piles.