The main elements to cause the corrosion of hollow anchor bar are the environmental condition and the material composition. The environmental elements include the geologic situation and the corrosive effect of the underground water. The corrosion of the metal material is the essential problem.
The corrosion of the hollow anchor bar impact the useful life and construction cost immediately. If the corrosion is serious, it will be detrimental to the safety. Therefore, the anti-corrosion of the hollow anchor bar should be enhanced:
1)When selecting material of the hollow anchor bar, low carbon steel should be preferred for its reliable quality, good toughness and it does not easily affected by stress and hydrogen embrittlement.
2)When installing a hollow anchor bar, avoid dry-wet alternate environment, and take the drainage system to reduce the corrosion speed.
3)In the construction process, control the ratio of water and cement. The cracks of cement barrier should be less than 0.1 mm to improve solid density and penetration resistance of the anchor solid.
4)If the hollow anchor bar is used in the permanent construction environment, it can be galvanized or processed by epoxy coating. 