在Fick第二定律公式的基础上,综合考虑了时间、氯离子的结合作用、温度、湿度、劣化效应、预应力、保护层脱落以及氯离子的对流区等因素的影响,建立了氯离子的侵蚀模型,给出了侵蚀模型的数学解.在该公式基础上,对钢筋初锈时间的各参数作了敏感性分析,经研究发现,当温度、湿度与矿渣掺量变化相同的倍数时,温度对氯离子侵入的敏感性最强.最后基于Monte-Carlo理论,利用本模型计算了一座实桥的初锈时间概率及其可靠度。
Based on the Fick's second law, a multi-factor model of the chloride ion corrosion is established. In this model, the influence of time, chloride ion binding, temperature, de- terioration of concrete, prestress, sag of protecting coating, chloride convectiveregion are taken into accounts, and the mathematic solution is given. Based on this model, a sensitivi- ty analysis about the corrosion initiation time of the steel bar has been conducted, and it has been found that temperature is the most sensitive factor for chloride ion corrosion when it has the same change with humidity and quantity of mixed slag. Probability of the initiation time and its reliability of a bridge are predicted based on the revised model using Monte- Carlo simulation.