Under the long-term influence of natural and usage environments, the function of concrete will inevitably weaken. Therefore, the reinforcement of concrete will become an important task. Let's learn some knowledge about concrete reinforcement together.

Concrete reinforcement method

The common method of indirect reinforcement

1. Pre stressing reinforcement method: This method can reduce the stress level of the reinforced components, not only improving the reinforcement effect, but also significantly enhancing the overall bearing capacity of the structure. However, the reinforcement has a certain impact on the appearance of the original structure; Suitable for the reinforcement of large-span or heavy-duty structures, as well as the reinforcement of concrete components under high stress and strain conditions. However, without protection, it cannot be used in environments with temperatures above 600 ℃, nor is it suitable for structures with large compressive strain of concrete.

2. Growth support reinforcement method: This method is simple and reliable, but it can easily damage the original appearance and functional use of the building, and may reduce the use space; Suitable for reinforcing concrete structures under detailed conditions.

The general method of direct reinforcement

1. The method of increasing cross-section reinforcement has a simple construction process, strong adaptability, and mature design and construction lessons; Suitable for reinforcing concrete in beams, slabs, columns, walls, and normal structures; However, the construction time of on-site construction is long, which has a certain impact on production and life, and the net clearance of the reinforced building is reduced to a certain extent.

2. The advantages of the replacement concrete reinforcement method are similar to those of the enlarged section method, and the reinforcement does not affect the clearance of the building, but it also has the problem of long wet operation time during construction; Suitable for reinforcing concrete load-bearing components such as beams and columns with low concrete strength or significant drawbacks in the compression zone.

Issues to be noted in concrete reinforcement construction

(1) In the repair construction, the main focus is to strengthen the quality control of the combination of new and old concrete, ensure the overall stress of the new and old concrete, and also consider the degree of embedding at both ends of the newly added parts. Before construction, chisel and clean the parts that need to increase the cross-section, requiring the creation of pits or trenches, removing all soft surfaces and floating soil, using wire brushes to clean the overlapping contact surfaces, and rinsing them with clean water before concrete construction. The original surface of the component should be kept moist, but without water accumulation, to avoid interlayer between new and old concrete. Before pouring concrete, the original concrete surface should be treated with interface agents such as cement mortar to strengthen the bond between new and old concrete.

(2) When the strength of the newly added concrete does not meet the design requirements, it is strictly prohibited to increase external additional loads. For horizontal components such as structural beams, unloading supports and formwork supports shall not be removed when the strength does not meet the requirements.

(3) When using the three or four sided wrapping method to reinforce beams or columns, the edges and corners of the beams or columns should be knocked off, and floating debris and dust should be removed at the same time.

(4) The newly added load-bearing steel bars should be firmly welded with short steel bars and the original main steel bars of the components. The welding parts must be strictly inspected and accepted according to the specifications and regulations to ensure the construction quality. If welding is not required, the method of adding stirrups can also be used.

What are the precautions to be taken in the replacement concrete reinforcement method?

1. When using the replacement concrete reinforcement method to reinforce concrete components, the strength grade of the original component concrete in the non replacement part should not be lower than the strength grade specified at the time of construction of the concrete structure according to the on-site inspection results.

2. When the interface treatment and construction quality of the replacement part of the concrete test component meet the requirements of the specifications, its joint surface can be calculated as the overall stress.

3. When using the replacement concrete reinforcement method to reinforce beam components, effective support should be provided to the original components. When using this method to reinforce columns, walls, and other components, the bearing state of the original structure and components should be verified, observed, and controlled throughout the construction process. The concrete at the replacement interface should not experience tensile stress. If control is difficult, measures such as top support should be taken for unloading.

4. The replacement concrete reinforcement method is suitable for local reinforcement of load-bearing components with low concrete strength or serious defects in the compression zone.