Apart from improving the quality of the concrete raw materials and construction techniques, if the strength is found to be insufficient after production, what emergency treatment methods can be used? We will explain them one by one below…
1. Changing external forces
There are four ways to reinforce concrete with insufficient strength: direct reinforcement, increasing the cross-section reinforcement, external steel reinforcement and changing the structural force transmission path reinforcement.
2. Direct reinforcement
Direct reinforcement means increasing the structural resistance through various methods.
3. Reinforcement by increasing the cross-section
Reinforcement by increasing the cross-section is a method of reinforcement that increases the cross-sectional area of a structure or structure to improve its load-bearing capacity and stiffness to meet normal use.
4. Reinforcement by external steel
Reinforcement by external steel is a method of reinforcement in which steel sections are wrapped around the perimeter of concrete, masonry and other components.
5. Reinforcement by changing the structural force transmission path
The method of changing the structural force transmission path is a reinforcement method that reduces the calculated span of the structure and changes the force transmission path to reduce deformation and improve its load-bearing capacity. It is suitable for structural reinforcement of larger spans where the headroom of the building is not restricted.
Maintenance
1. Brushing with a strengthening agent
A special strengthening agent is first brushed onto the concrete surface. The main purpose is to increase the strength, so that the entire surface can be closer to the design specifications. The role of the strengthening agent is to make the concrete hard and solid, as if a layer of mesh has been added.
2. Apply a strength-restoring agent
to the concrete surface to reinforce it. This material is a colorless, transparent liquid that is applied directly to the concrete surface. It dries after 24 hours and has strong penetrating power, which has a good effect on the hardness, density and compressive strength of the concrete. After construction, the concrete is less likely to spall or crack.
3. Steam curing
If the standard is not too high, you can increase the intensity of the maintenance. Steam curing is a common method of concrete maintenance. Pay attention to the four stages, each of which has strict temperature requirements. The initial static phase should maintain a temperature of 5°C or higher, and the temperature should not be raised until 6 hours after pouring. The temperature should not be raised by more than 10°C per hour. During the constant temperature period, the internal temperature should be kept below 60°C. After the maintenance is complete, the temperature should not be lowered by more than 10°C per hour.
4. Natural curing
For concrete used in open-air construction such as roads, natural curing is generally used, which means curing with the form in place. The form must be kept wrapped during the curing period, and watering and sprinkling must be carried out to maintain moisture. Water loss must be prevented at the joints of the formwork. Generally, the formwork should be slightly loosened 24-48 hours after pouring, which ensures that the formwork can be removed and demoulded well later. After loosening, watering and moisturizing maintenance should also be carried out.
