| The long span cable-stayed bridge is a widespread style in the modern construction of bridge due to its distinguished advantages such as single framework, well dynamically stability in the air and relative light weight with a long span, and so on. In the long span cable-stayed bridge, it is the cables which endure most of the loads and thus play an important role in the bridge safety. Generally, the cables must endure alternative loads for a long time. So in natural environment, especially in air polluted aera including a large amount of SO42-, Cl- and other corrosion factors, the cables are prone to be corroded, which accounts for the deterioration and collapse of the bridge and causes serious economic loss and safety accident. Therefore, it is important to study the corrosion behaviors of the cables and avoid corrosion factor in order to improve endurance and security of bridge.The influence of stresses and pH values on corrosion behaviors of the bare, galvanized and rust-prevention oil galvanized steel wires were investigated via stress– deformation test, mass loss test, linear polarization and Tafel polarization curve measurement. After Salt Spray Test (SST), the surface morphologies of the bare and galvanized steel wires were characterized by SEM, and the corrosion products were analyzed by XRD and TG-DTA. The main conclusions are as follows:①The present development, research situation and importance of cable's corrosion behavior in the long span cable-stayed bridge are introduced in brief; the effect of scan speed on corrosion rate is investigated, the results show that the optimal speed for linear polarization measurement is 0.1mV·s-1, and 1mV·s-1 for Tafel polarization curve measurement.②In the artificial acid rain solution with the pH value of 4.5, the corrosion parameters of the bare, galvanized and rust-prevention oil galvanized steel wires are distinctly different in the presence of different stresses via linear polarization and Tafel polarization curve measurement. When the stress is increased, the polarization resistance is decreased and the corrosion current density is increased; the pH value of the artificial acid rain solution has biggish effects on the corrosion parameters of the bare, galvanized and rust-prevention oil galvanized steel wires when the stress is fixed as 1100MPa. When the pH value is decreased (being more acidic solution), the corrosion current density is increased, the polarization resistance is decreased, and the equilibrium potential shifts significantly negatively, the corrosion rate increase.③The increase of the stress can also cause a significant increase in weight loss and average corrosion rates of the bare and galvanized steel wires in SST. The corrosion rates of the galvanized steel wire are less than tenth of the bare steel wire's. The anti-corrosion property of the galvanized steel wire is much better than the bare steel wire's. There are lots of corrosion pits with different sizes and the corrosion products on the surface of the bare and galvanized steel wires after SST.④In SST, different electrochemistry reactions take place, the corrosion products on the surface of the bare steel wires are different from the galvanized steel wires'. The main corrosion products of the bare steel wires are Fe(OH)3,Fe2O3·H2O and a few amount of Fe2(SO4)3·8H2O (red rust), but the main corrosion products of galvanized steel wires are (Zn(OH)2)3·ZnSO4·5H2O (white rust), and a few amount of Fe2(SO4)2O·7H2O, Fe2(SO4)3, Fe2O3·H2O (red rust).
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