海洋环境下带裂缝PHC管桩中钢筋锈蚀初始时间预测  

Prediction on corrosion initiation time of embedded steel in cracked PHC piles exposed to marine environments

作　　者：邵伟[1,2] 李镜培[1,2] 

机构地区：[1]同济大学,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《土木工程学报》2014年第3期123-129,共7页China Civil Engineering Journal

基　　金：国家自然科学基金(51178341)

摘　　要：依据Fick第二定律,建立氯离子在带裂缝PHC管桩中的扩散方程,结合初始和边界条件,采用分离变量法和Bessel函数得到带裂缝PHC管桩中氯离子扩散方程的解析解,并推导氯离子在带裂缝PHC管桩中的扩散系数,最后分析裂缝宽度和数目对氯离子在带裂缝PHC管桩中的扩散系数、分布规律及钢筋锈蚀初始时间的影响。结果表明:当裂缝数目较少时,随着裂缝宽度的增大,D/D0的增加幅度较小,相同深度位置处的氯离子浓度随裂缝宽度的增大而无明显增加,钢筋锈蚀初始时间的减幅较小;随着裂缝数目的增多,D/D0的增长趋势加快,相同深度位置处的氯离子浓度随裂缝宽度的增大而增长较快,钢筋锈蚀初始时间随裂缝宽度的增大而减幅加大。Based on Fick＇ s second law, the diffusion equation of chloride ions in cracked prestressed high-strength concrete （PHC） piles was established. According to initial and boundary conditions, analytical solution of the diffusion equation of chloride ions in cracked PHC piles was derived by employing the method of separation of variables and Bessel functions, and then the diffusion coefficient of chloride ions in cracked PHC piles was obtained. Finally, the effects of crack width and number of cracks on diffusion coefficient, chloride concentration profiles and corrosion initiation time of embedded steel in cracked PHC piles were analyzed, respectively. The analysis results show that for a small number of cracks, with the increase of crack width, the increase in DIDo is slight and the increase of chloride concentration at the same depth is unobvious, and the decrease in corrosion initiation time of embedded steel is not significant. With the increase in number of cracks, DIDo and chloride concentration at the same depth increases significantly, and the corrosion initiation time of embedded steel decreases obviously.

关 键 词：PHC管桩 裂缝 氯离子 扩散系数 锈蚀初始时间 

分 类 号：TU473.13[建筑科学—结构工程]