1.中交中南工程局有限公司;2.长沙理工大学 土木工程学院
U443
湖南省科技创新计划项目,(编号：2023RC3142)
1.CCCC Zhongnan Engineering Bureau Co,Ltd,Changsha City,Hunan Province;2.Changsha University of Science and Technology Changsha City,Hunan Province
Science and Technology Innovation Program of Hunan Province (2023RC3142)
锈蚀导致的混凝土开裂和粘结退化,会造成预应力钢绞线回缩滑移、传递长度的改变,锈蚀预应力钢绞线回缩效应的模拟是目前研究的难点。本文建立了基于cohesive接触的锈蚀预应力混凝土(PC)构件数值模型,分析了不同锈蚀位置以及锈蚀率对预应力钢绞线回缩滑移和传递长度的影响。利用已有试验数据验证了该模型的合理性。结果表明,cohesive接触能够有效地模拟在局部锈蚀下预应力钢绞线的回缩效应。钢绞线切割端的回缩滑移随锈蚀率的增加而增加,相较于未锈蚀构件,在端部锈蚀率为35%时回缩滑移增加了16.10%。局部锈蚀率达到35%时,传递长度增加了30.6%；随着锈蚀位置由端部向跨中移动,钢绞线局部锈蚀对传递长度的影响逐渐减弱。
Corrosion-induced cracking and bond degradation of concrete can lead to retraction slip and changes in the transfer length of prestressed steel strands. Simulating the retraction effect of corroded prestressed steel strands remains a challenging area of research. This paper establishes a numerical model of corroded prestressed concrete (PC) components based on cohesive contact elements, analyzing the effects of different corrosion locations and corrosion rates. The model"s validity was confirmed using existing experimental data. The results indicate that the cohesive contact model effectively simulates the retraction effect of prestressed steel strands under localized corrosion. The retraction slip at the cutting end of the steel strand increases with the corrosion rate; compared to uncorroded components, the retraction slip increased by 16.10% when the corrosion rate at the end was 35%. When the localized corrosion rate reached 35%, the transfer length increased by 30.6%. As the corrosion location moved from the end towards the mid-span, the impact of localized corrosion on the transfer length gradually weakened.
