Before construction work begins, rust must be removed from the reinforcement. In fact, if the rust has already begun to corrode, it must be completely removed before pouring the concrete.
The following reasons can lead to reinforcement corrosion:
- Remain exposed to the environment for a long period of time.
- Constant humidity and dryness on the construction site due to inadequate protection.
- In locations close to the sea, the reinforcement must be exposed. If covered incorrectly, rapid corrosion can occur.
What is reinforcing corrosion?
The most common cause of reinforcement deterioration is reinforcement corrosion.
Steel corrosion occurs in the presence of oxygen and moisture. The material begins to decompose, forming rust on the surface.
Furthermore, corrosion of the reinforcement leads to further deterioration of the reinforcement and loss of dimension of the reinforcement bar.
Why should you remove rust from rebar?
Rust on the rebar surface can lead to further corrosion of the reinforcement.
Furthermore, if concrete is placed with rust in the reinforcement, the bond between the concrete and the reinforcement is lost.
This can lead to a reduction in bond strength.
Furthermore, if concrete is placed without cleaning the reinforcing bars, additional corrosion of the reinforcement may occur in the presence of moisture and oxygen.
As we know, concrete cracks due to durability issues. Such cracks could create the necessary environment for corrections in the steel.
For this reason, no concrete can be placed without cleaning the reinforcing bars.
How to Remove Rust From Rebar
When choosing the method of removing rust from reinforcing steel, the type and degree of corrosion are taken into account.
Furthermore, if there is very strong corrosion, the costs of the cleaning process also increase.
Wire brushes
Rebar brushing can be done manually or mechanically.
If the reinforcement is tied to the slab, it cannot be machine cleaned unless it is removed from the slab.
If the reinforcement is not integrated into the slab and there is a cleaning adjustment, it is recommended to clean the reinforcement mechanically.
Additionally, light rust can be removed manually. If it does not spread over the entire bar, it can be cleaned with a wire brush.
The following figure shows the rebar cleaning process.
Part (b) of the illustration above shows cleaning rebar using a wire brush.
Use a high-pressure water jet to remove rust from rebar
If the corrosion is not that severe and there is only a thin layer of rust on the surface of the reinforcements, water jet cleaning can be used for cleaning.
High pressure water can be used consistently to remove the rust layer from reinforcing bars.
This should be repeated for several patients and care should be taken to clean the entire surface.
Close monitoring is also necessary during the cleaning process. If the rebar is wet, it is difficult to know whether the rust has been removed.
Otherwise, cleaning must be repeated until the reinforcements are properly cleaned.
The following video shows how to clean rebar.
Apply chemicals to remove rust from rebar
There are chemicals that can be used to remove rust from reinforcements.
They are first applied to the reinforcement.
Then they are kept for some time so that they can react.
Then cleaning takes place. The cleaning method can be water injection or other method. Product supplier specifications must be followed.
If you use a larger amount of booster and use branded products, the cleaning process will cost more.
Regardless of whether it is expensive or not, we need to clean rebar. A suitable method with low cost can be selected.
Rebar blasting to remove rust
Sandblasting is not commonly used to clean rebar. It is generally used to clean corroded steel.
However, if the rebar is badly corroded, it will be very difficult to clean it properly. Therefore, a quick method of cleaning rebar is necessary.
Manual brushing with a wire brush or applying chemicals is a bit difficult and time-consuming.
Furthermore, the cleaning guarantee is sometimes questionable. Unless chemicals are used throughout the bar, these areas will not be cleaned.
In comparison, sandblasting is a good alternative. The following video shows sandblasting.
As shown in the video above, rebar can be cleaned in the field as well as in the shop.
It is advisable to cover the area where the reinforcements will be cleaned to prevent dust from forming.
Furthermore, if the reinforcement is severely corroded, it is advisable to protect it from corrosion. Immediately after cleaning, a suitable anti-corrosion agent must be applied to the reinforcement.
Furthermore, a higher quality concrete could be used to achieve the durability of the concrete structure.
Additionally, if the structure is built near the sea, chloride-resistant cement can be used to improve durability.
More information about Sandblasting also known as lightning from the Wikipedia article Lightning .
