预应力束局部区域锈蚀及锈断后应力的传递和锚固性能
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1.Effect of corrosion on degradation of mechanical behavior of prestressing strands
- 关键词：
- Prestressing;Pitting;Normal distribution;Corrosive effects;Artificial climate;Climate condition;Corrosion degree;Corrosion loss;Corrosion morphology;Corrosion pits;Corrosion time;Mechanical behavior;Prestressing strands;Stress levels
- Dai, L.Z.;Li, T.;Wang, L.;Hu, Z.;Yi, S.C.;Zhang, J.R.
- 《7th International Symposium on Life-Cycle Civil Engineering, IALCCE 2020》
- 2020年
- October 27, 2020 - October 30, 2020
- Shanghai, China
- 会议
This paper investigates the corrosion morphology and the degradation of mechanical behavior of corroded prestressing strand under artificial climate conditions. Nineteen specimens with different corrosion degrees were obtained by controlling chloride ion concentration, stress level and corrosion time. Results show that the corrosion loss of strand increases with the increase of stress levels, corrosion time and concentration of chloride ion. The geometry of corrosion pit can be mainly divided into three types: the pyramid shape, spheroridicity shape and saddle shape. Meanwhile, the depth-width ratio of corrosion pit follows logarithmic normal distribution. It is also observed that the corrosion has a more significant effect on ultimate strength of strand than that on elastic modulus of strand. For slightly corroded strand, the constitutive model can be modeled as the elastic-hardening bilinear model. When the corrosion loss of strand exceeds the critical value, its constitutive relationship will degenerate into a single-linear model. © 2021 Taylor & Francis Group, London.
...2.Effect of strand fracture on flexural behavior of locally corroded post-tensioned concrete beams
- 关键词：
- Prestressing;Electrochemical corrosion;Prestressed beams and girders;Prestressed concrete;Anchorages (foundations);Life cycle;Reinforced concrete;Concrete beams and girders;Concrete buildings;Accelerated corrosion;Concrete beam;Electrochemicals;End anchorage;Flexural behavior;Fracture position;Local fractures;Post-tensioned concrete;Prestressing forces;RC beams
- Wang, L.;Chen, Y.;Dai, L.Z.;Yuan, P.;Zhang, J.R.
- 《7th International Symposium on Life-Cycle Civil Engineering, IALCCE 2020》
- 2020年
- October 27, 2020 - October 30, 2020
- Shanghai, China
- 会议
This paper investigates the flexural behavior of locally corroded post-tensioned concrete beams under strand fracture. The electrochemical accelerated corrosion method was conducted to obtain the local fracture of strand at different positions. Results shows that the prestressing force produced by secondary anchorage of broken strand and the flexural behavior of locally corroded beams are related to the fracture position of strand. Strand fractured in end anchorage region has little influence on the flexural behavior of locally corroded beams, and the prestressing force produced by secondary anchorage decreases less relative to the initial prestressing force. With the strand fracture positions moves to the mid-span region, the flexural behavior and the prestressing force decreases continuously. When strand fractured in mid-span region, the prestressing force is basically lost, and the flexural behavior of locally corroded beams will degenerate to be similar to that of RC beam. © 2021 Taylor & Francis Group, London.
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