The treatment method of carbonation box for masonry brick concrete is usually used to solve the carbonation problem of concrete and masonry structures exposed to carbon dioxide in the air. Carbonization refers to the reaction between carbon dioxide and calcium hydroxide in concrete, leading to a decrease in alkaline environment, which in turn affects the strength and durability of concrete, especially causing corrosion of steel bars.
1. Understand the phenomenon of carbonization
During the carbonation process, carbon dioxide reacts with calcium hydroxide (Ca (OH) ₂) in cement to produce calcium carbonate (CaCO3). This reaction lowers the pH value of concrete, thereby reducing its corrosion resistance, especially the corrosion resistance of steel bars.
For masonry bricks and concrete structures, carbonization not only affects their physical properties, but also affects the overall stability of the structure. Therefore, it is necessary to regularly inspect and deal with carbonization phenomena.
2. Purpose of carbonization box
Carbonization box is a specially designed testing equipment used to simulate the carbonization process of concrete and masonry materials in a carbon dioxide environment. This equipment can be used to conduct accelerated carbonation tests on concrete and masonry, in order to study their durability, help determine the depth of carbonation that may occur in actual use, and take appropriate protective measures.
The main function of the carbonization chamber is to provide a controlled carbon dioxide environment, exposing the test sample to a certain concentration of carbon dioxide to simulate the carbonization process in the actual environment.
3. Handling methods
1. Monitoring and evaluation
Regular testing: Firstly, the carbonation of wall bricks and concrete structures should be tested. Use specialized carbonation depth testing methods (such as cutting, chemical titration, etc.) to regularly check the depth and range of carbonation on the surface of concrete and masonry.
Assessing the impact of carbonization: By evaluating the depth and extent of carbonization, determine whether the structure has been severely affected. If the steel bars are exposed or the structural strength decreases, immediate repair is required.
2. Use a carbonization chamber for accelerated testing
Preparation of samples: Prepare concrete or wall brick samples, usually cut into specific sizes.
Set up carbonization box: The carbonization box can adjust conditions such as carbon dioxide concentration, temperature, and humidity inside. According to experimental standards, adjust these parameters to simulate the environment of long-term exposure to carbon dioxide.
Acceleration test: Conduct carbonization acceleration test in a controlled environment. Through this method, the carbonization rate and depth of the sample can be quickly obtained.
3. Take protective measures
Surface coating protection: Apply waterproof and anti carbonization coating treatment to the surface of concrete and masonry bricks. Common coatings include waterproof coatings, carbonization protectants, etc. These coatings can effectively prevent carbon dioxide from penetrating into the interior of concrete.
Using alkali resistant materials: For structural elements such as steel bars, the use of alkali resistant materials (such as epoxy coated steel bars) can effectively delay the corrosion of steel bars and reduce the corrosion caused by carbonization.
Increasing the compactness of concrete: By controlling the water cement ratio and using low-permeability materials, the compactness of concrete can be improved and the penetration rate of carbon dioxide can be reduced.
4. Maintenance and repair
If the concrete structure or wall bricks have been damaged by carbonation, the following repair measures should be taken:
Remove carbonation layer: Remove the surface layer affected by carbonation and expose the unaffected concrete.
Repair cracks and holes: Use high-strength repair mortar or polymer repair materials to fill cracks on the surface of concrete and restore its structural strength.
Coating protective layer: After the repair is completed, apply a protective layer to further enhance the durability of the concrete and avoid re carbonization.
5. Preventive measures
Optimize concrete mix ratio: By using cement with low water cement ratio and high strength, increase the impermeability of concrete and reduce the entry of carbon dioxide.
Using high durability materials: For some structures that are exposed to external environments for a long time, materials with higher carbonation resistance, such as high-performance concrete (HPC) and carbonation resistant additives, can be used.
4. Summary
The key to dealing with carbonation boxes in masonry brick concrete lies in regularly monitoring the carbonation situation, using carbonation boxes to accelerate testing and evaluate the durability of materials, and taking corresponding protective and repair measures based on the carbonation situation. Through these methods, the service life of masonry bricks and concrete structures can be effectively extended, ensuring their long-term stability and safety.