海洋环境多因素影响下钢筋混凝土构筑物的全寿命预测  

Whole Service Life Prediction of Concrete Reinforced Construction under Multi-Factors Action in Marine Environment

作　　者：贾桂良 JIA Guiliang(China Railway Shanghai Group Co.,Ltd.,Shanghai 200071,China)

机构地区：[1]中国铁路上海局集团有限公司,上海200071

出　　处：《腐蚀与防护》2025年第1期88-95,共8页Corrosion & Protection

基　　金：中国铁路上海局集团有限公司科研项目(2024146);铁道科学院集团有限公司院基金(2024YJ260)。

摘　　要：基于现代混凝土技术的发展,即使钢筋周围混凝土中的Cl^(-)含量达到临界值,仍可有效延缓钢筋的腐蚀发展,定义海洋环境钢筋混凝土构筑物的全寿命T为钢筋腐蚀诱导阶段t0和腐蚀发展阶段t1之和。分别对t0、t1进行模型预测。在t0阶段,基于Fick第二定律,考虑混凝土对Cl^(-)结合、Cl^(-)扩散时间依赖性与材料缺陷、劣化等对Cl^(-)扩散性影响,建立多因素影响的混凝土Cl^(-)扩散模型。采用反函数等严密推导该模型,计算了保护层厚度达到钢筋开始锈蚀的临界Cl^(-)含量所需时间。在t1阶段,基于弹性与断裂力学,考虑钢筋与混凝土界面间隙层对初期锈胀的缓冲,计算了锈蚀膨胀使钢筋与保护层组成的环状筒体达到其极限拉应力所需的径向临界锈胀应力,预测了产生该锈胀应力所需时间。The advancement of contemporary concrete technology allows for the effective delaying of the corrosion development of steel bars,even in cases where the concentration of Cl^(-)in the concrete surrounding them reaches a critical level.The total of the steel bar corrosion induction stage(t0)and the corrosion development stage(t1)is the whole life T of reinforced concrete structures in marine conditions.Model predictions were made for t0 and t1 respectively.At the t0 stage,a multi-factor concrete Cl^(-)diffusion model was established based on Fick's second law,taking into account the effects of concrete on Cl^(-)binding,Cl^(-)diffusion time dependence,material defects,deterioration,and other factors on Cl^(-)diffusion.The inverse function for the model was rigorously derived to determine how long it would take for the protective layer thickness to reach the critical Cl^(-)concentration at which the steel bars started to corrode.The radial critical rust expansion stress needed for the annular cylinder made of steel bars and protective layer to reach its ultimate tensile stress due to rust expansion was calculated at stage t1 based on elasticity and fracture mechanics,taking into account the buffering effect of the interface gap layer between steel bars and concrete on initial rust expansion.The amount of time needed to produce this rust expansion stress was predicted using Faraday's equation.

关 键 词：混凝土 寿命预测 腐蚀 氯离子 扩散 诱导阶段 发展阶段 

分 类 号：TU528[建筑科学—建筑技术科学]