Reliability-based durability design and service life assessment of reinforced concrete deck slab of jetty structures
Reliability-based durability design and service life assessment of reinforced concrete deck slab of jetty structures
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DOI：
10.1080/15732479.2016.1164725
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发表时间：
2017-04
影响因子：
3.7
通讯作者：
M. Akiyama;D. Frangopol;K. Takenaka
中科院分区：
文献类型：
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作者：
M. Akiyama;D. Frangopol;K. Takenaka
摘要海洋环境中钢筋混凝土结构由于氯离子的腐蚀而随时间劣化。由于码头结构的钢筋混凝土桥面板暴露在非常恶劣的环境中，因此可能会出现更高的劣化率。本文提出了基于可靠度的钢筋混凝土码头结构耐久性设计和使用寿命评估方法。对于新的钢筋混凝土码头结构，混凝土质量和混凝土保护层，以防止氯离子引起的钢筋腐蚀，导致整个寿命期间的结构性能恶化，可以确定。基于空气中的氯离子危害取决于从海平面到钢筋混凝土桥面板的垂直距离，估计与钢筋腐蚀开始相关的概率。提供了满足目标可靠度水平的水灰比和混凝土保护层。为了评估在役结构的使用寿命，可以根据钢筋混凝土结构的外观检查提供的条件状态。钢筋混凝土码头结构的劣化过程可以用马尔可夫过程来描述。因此，可以通过目视检查结果来更新构造后的时间t处的转移概率矩阵。给出了用序贯蒙特卡罗模拟方法更新转移概率矩阵的步骤。在一个说明性的例子中，现有的钢筋混凝土甲板板在码头结构的氯离子攻击的生命周期可靠性估计的更新的效果。
Abstract Reinforced concrete (RC) structures in a marine environment deteriorate with time due to chloride-induced corrosion of reinforcing bars. Since the RC deck slabs of jetty structures are exposed to a very aggressive environment, higher deterioration rates can develop. In this paper, a reliability-based durability design and service life assessment of RC jetty structures are presented. For new RC jetty structures, the concrete quality and concrete cover necessary to prevent the chloride-induced reinforcement corrosion causing the deterioration of structural performance during the whole lifetime could be determined. Based on the airborne chloride hazard depending on the vertical distance from the sea level surface to the RC deck slab, the probability associated with the steel corrosion initiation is estimated. The water to cement ratio and concrete cover to satisfy the target reliability level are provided. For evaluating the service life of existing structures, the condition state based on the visual inspection of RC structure can be provided. The deterioration process of the RC jetty structure can be modelled as a Markov process. Therefore, the transition probability matrix at time t after construction can be updated by visual inspection results. A procedure to update the transition probability matrix by the Sequential Monte Carlo Simulation method is indicated. In an illustrative example, the effect of the updating on the life-cycle reliability estimate of existing RC deck slab in a jetty structure subjected to the chloride attack is presented.