西安建筑科技大学学报(自然科学版)

混凝土碳化问题是目前基础设施长期服役中最为普遍的病害问题,也是相应结构耐久性设计的重点所在.碳化作用发展与环境温湿度关系紧密,在亚热带湿热环境中碳化问题尤为显著.现有研究难以考虑真实环境参数的复杂时变影响,在描述碳化作用空间随机分布和病害涌现时机方面存在不足.因此,本研究聚焦多尺度计算效率精度瓶颈以及亚热带湿热环境时变输入的仿真难点,建立材料碳化机理与结构服役退化的高效传递模型,提出适用于复杂服役环境下大体积混凝土结构碳化分析的扩散路径映射方法.研究依托我国东南沿海地区某桥梁锚碇结构开展细观碳化分析,对长期服役过程碳化深度和钢筋锈蚀概率特征进行预测,求解效率和精度均实现大幅提升.结合具体工程养护策略,预测了防护措施对耐久性能的提升效果,也展现了该方法在大体积混凝土结构耐久性能分析方面的优势.

Concrete carbonization is the most common problem in the long-term service of infrastructure, and it is also the key point in the durability design of the corresponding structure. The concrete carbonization is closely related to environmental temperature and humidity, especially in subtropical humid and hot environment. Currently, it is difficult to consider the complex time-varying effects of actual environmental states, and there are deficiencies in describing the spatial random distribution of carbonation and the timing of disease emergence. Therefore, this study focuses on the multi-scale calculation efficiency accuracy and the time-varying input of subtropical humid and hot environment, establishes an efficient transfer model of material carbonation mechanism and structural service degradation, and proposes a diffusion path mapping method suitable for carbonation analysis of large volume concrete structures in complex service environment. Based on the detailed carbonization analysis of a bridge anchorage system in the southeast coastal area of China, the carbonization depth of long-term service process and the probability characteristics of reinforcement corrosion were predicted, and the solving efficiency and accuracy were greatly improved. Combined with specific engineering maintenance strategies, the durability improvement effect of protective measures is predicted, and the advantages of this method in the durability analysis of mass concrete structures are also presented.

引言
1 考虑环境影响的混凝土碳化细观模型
2 大体积混凝土构件碳化作用分析
3 大体积混凝土构件碳化防护效能分析
4 结论

图1 扩散路径映射方法流程图<br/>Fig.1 Flow chart of diffusion path mapping method

图1 扩散路径映射方法流程图
Fig.1 Flow chart of diffusion path mapping method

图2 锚碇结构侧视图与正视图<br/>Fig.2 Side view and front view of anchorage structure

图2 锚碇结构侧视图与正视图
Fig.2 Side view and front view of anchorage structure

图3 桥址位置环境温湿度数据<br/>Fig.3 Data of environmental temperature and humidity at bridge site

图3 桥址位置环境温湿度数据
Fig.3 Data of environmental temperature and humidity at bridge site

图4 锚碇结构关键截面建模与代理模型求解<br/>Fig.4 Modeling of key section of anchorage structure and solving of surrogate model

图4 锚碇结构关键截面建模与代理模型求解
Fig.4 Modeling of key section of anchorage structure and solving of surrogate model

图5 锚碇结构长期服役碳化作用映射结果<br/>Fig.5 Mapping results of carbonation effect of anchorage structure in long-term service

图5 锚碇结构长期服役碳化作用映射结果
Fig.5 Mapping results of carbonation effect of anchorage structure in long-term service

图6 亚热带湿热环境碳化作用细观模拟与简化模拟结果差异<br/>Fig.6 Differences in results of mesoscopic simulation and simplified simulation of carbonization in subtropical humid environment

图6 亚热带湿热环境碳化作用细观模拟与简化模拟结果差异
Fig.6 Differences in results of mesoscopic simulation and simplified simulation of carbonization in subtropical humid environment

表1 考虑亚热带气候影响与简化环境输入的碳化深度差异<br/>Tab.1 Difference of carbonization depth considering influence of subtropical environment and simplified environment state

表1 考虑亚热带气候影响与简化环境输入的碳化深度差异
Tab.1 Difference of carbonization depth considering influence of subtropical environment and simplified environment state

图7 考虑亚热带湿热气候影响与简化气候环境的锚碇碳化深度对比<br/>Fig.7 Comparison of carbonation depth considering influence of subtropical environment and simplified environment state

图7 考虑亚热带湿热气候影响与简化气候环境的锚碇碳化深度对比
Fig.7 Comparison of carbonation depth considering influence of subtropical environment and simplified environment state

图8 桥梁锚碇结构涂层防护过程(摄于2020年10月)<br/>Fig.8 Coating protection process of bridge anchorage structure(taken in October 2020)

图8 桥梁锚碇结构涂层防护过程(摄于2020年10月)
Fig.8 Coating protection process of bridge anchorage structure(taken in October 2020)

图9 不同防护方案下锚碇局部碳化作用<br/>Fig.9 Local carbonization of anchorage under different protection schemes

图9 不同防护方案下锚碇局部碳化作用
Fig.9 Local carbonization of anchorage under different protection schemes

图10 不同防护方案下锚碇碳化深度概率密度分布<br/>Fig.10 Probability density distribution of anchorage carbonization depth under different protection schemes

图10 不同防护方案下锚碇碳化深度概率密度分布
Fig.10 Probability density distribution of anchorage carbonization depth under different protection schemes

表2 不同防护方案下锚碇碳化深度统计<br/>Tab.2 Statistics of carbonation depth of anchorage under different protection schemes

表2 不同防护方案下锚碇碳化深度统计
Tab.2 Statistics of carbonation depth of anchorage under different protection schemes

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备注

引言

1 考虑环境影响的混凝土碳化细观模型

2 大体积混凝土构件碳化作用分析

3 大体积混凝土构件碳化防护效能分析

4 结论

期刊信息