Study of Anticorrosion System and Anticorrosion Mechanism for the Main Cable of Suspension Bridge: Fid-Bau Portal

Study of Anticorrosion System and Anticorrosion Mechanism for the Main Cable of Suspension Bridge

Chen, Wei / Shen, Ruili / Wang, Hui / Gong, Wang

There are many problems in the commonly used anticorrosion technologies of the main cable, which has been difficult to meet the anticorrosion requirements of the main cable. In order to solve the problems, a new dehumidification system of conveying dry air from the inside of the main cable is put forward. The dehumidification system delivers dry air through the composite air supply conduit embedded in the main cable, and the dry air takes away the moisture in the main cable during the flow process, so as to achieve the purpose of anticorrosion and dehumidification. In this study, the influence of the temperature and humidity environment on the corrosion rate of the high strength steel wire is investigated. Then a dehumidification test of the main cable is carried out. The temperature and humidity variation, dry air pressure distribution, and dehumidification time of the main cable are tested. The anticorrosion effect and mechanism of the new dehumidification system are studied. The results show that the corrosion of the high strength steel wire is very slow in a humidity environment which is below 60%, and the corrosion rate increases with the increase of the temperature and humidity. The dry air of the new dehumidification system can achieve the full section coverage of the main cable, and the relative humidity at each position of the main cable can be reduced to less than the critical humidity of the high strength steel wire corrosion (RH = 60%). So the entire main cable can be well protected against corrosion. The dehumidification time of the main cable calculated by theory is basically consistent with that of the dehumidification test. With the increase of the dry air delivery velocity, the dehumidification time of the main cable is shorter. Therefore, the dehumidification efficiency of the main cable can be improved by properly increasing the delivery velocity of the dry air. The new dehumidification system can provide a more effective anticorrosion method for the main cable of the suspension bridge.