Cathodic protection cross-sea bridge

Bridges are an important infrastructure for national economic construction, and reinforced concrete structures are widely used in bridges. Chloride ions from seawater are an important factor in causing premature corrosion and damage to bridge steel pipe pile structures. Taking cost-effective measures to prevent and control the corrosion damage of the bridge steel pipe pile structure is a research topic of general concern in all countries. Cathodic protection is an electrochemical anti-corrosion technology to prevent metal corrosion. Cathodic protection is a technology that can have an important impact on the corrosion process that causes the deterioration of the bridge structure.

When a large area of damage occurs, remove the concrete to the top layer of reinforcing steel mesh, then spray the first layer of concrete, fix the anode on this layer, and then spray the second layer of concrete. If a large area of old concrete is still very strong, the anode can be attached to it and finally embedded with sprayed concrete. The anode must supply the required protection current, and must be strong in structure. During the spraying process or operation, the bond between the old concrete and the newly sprayed concrete must not be damaged.

When initially repairing the road concrete pavement contaminated by chloride ions, the ferrosilicon anode is embedded in a layer of coke slag, or a precious metal wire embedded in a conductive mineral embedding material is used to connect the current.

When designing the cathodic protection of concrete structures, it is more convenient to divide the surface to be protected into several separate areas, which must take into account the area of local steel in the unit volume of concrete and the distribution of moisture. The control of cathodic protection is achieved by measuring the potential, and the built-in reference electrode and the moving electrode on the surface are used for potential measurement.