Whether the steel bars for reinforced concrete can be treated by hot dip galvanizing
Reinforced concrete often causes rusting of steel and peeling of concrete due to external environment; for example, vehicle impact, insufficient protective layer, neutralization of concrete, misuse of sea sand and environmental factors, etc., causing rusting of concrete or immersion of concrete gaps Causes the steel bars to rust.
The method of preventing rusting of steel bars can be divided into strengthening concrete quality and protecting steel bars to protect concrete structures. Of course, if concrete can control some components, such as water, chloride, oxygen, carbon dioxide, etc., or even to the surface of the steel bar, or to truly implement the construction quality of the reinforced concrete structure project, the steel bar can be achieved without any protection. Use quality.
However, these influencing factors are often seen everywhere during the project, so the steel bars should be protected as much as possible.
Reinforced steel protection, generally hot dip galvanized and coated epoxy.
These two methods have their own advantages and disadvantages. A large number of experimental results show that the hot dip galvanized steel bar has better processing performance in the field, and can exert its superior characteristics in engineering, improve engineering reliability and corrosion resistance. To make the project more economical.
Hot-dip galvanized steel reinforced zinc layer and bismuth combination reaction content
Alternatives to the thickness of the protective layer still need to be used correctly and properly, and the combined reaction of zinc and antimony includes:
（1） Reaction of zinc with Ca（OH）2.
（2） Pure state of the zinc surface.
（3） Hydrogen production.
Because of its high alkaline environment （pH=12.5～13.2）, it forms a pure protective layer on the surface of the steel bar, which is an effective barrier to corrosion of steel bars. Like it protects steel bars, zinc is an amphoteric element （can be used with acid, The alkali reacts）, and the lowest corrosion rate is PH = 12.5, which is equivalent to the pH value of cement hydration.
Zinc will dissolve at pH=8~12.5. After the hydrazine is hardened, the reaction between zinc and alkaline environment can be stopped.
The net reaction of zinc with calcium hydroxide forms a zinc-passivated zinc-calcium hydroxide barrier layer, but it is also accompanied by the generation of hydrogen gas, which may be caused by the ”bonding“ of the crucible and the steel bar and the resulting pores. Adding a small amount of chromate （70-100ppm） to the cement can overcome the hydrogen generation, and only need to prevent the construction workers from being damaged by chromic acid or chromate during work.