by Due to improper maintenance or construction quality, the house will have different degrees of problems, and some serious problems even endanger the structural safety.
Facing different degrees of defects in various environments, it is necessary to select appropriate reinforcement methods.
In view of the insufficient bearing capacity of members, there are a variety of mature reinforcement methods to choose.
The following is a brief introduction to several conventional member reinforcement methods.
1.
Increasing section reinforcement method: it is a direct reinforcement method to increase the section of the original member or add reinforcement to improve its bearing capacity, stiffness and stability, or change its natural vibration frequency.
2.
Replacement concrete reinforcement method: it is a direct reinforcement method to remove the concrete in the low-strength or defective section of the original component, and pour the concrete of the same variety but higher strength grade for local reinforcement, so as to restore the bearing capacity of the original component.
3.
Externally bonded section steel reinforcement method: the reinforced concrete beam and column are welded into a frame with section steel and flat steel and poured with structural adhesive to achieve the overall stress and work together.
4.
Bonding steel plate reinforcement method: it is a direct reinforcement method to use structural adhesive to paste the steel plate on the concrete surface of the original component to form an integral composite section to improve its bearing capacity.
5.
Bonding composite fiber material reinforcement method: it is a direct reinforcement method that uses structural adhesive to paste fiber composite material on the concrete surface of the original component to form an integral composite section, so as to improve its bearing capacity and ductility.
Comparison of application scope, advantages and disadvantages of member reinforcement methods.
A traditional Chinese medicine hospital was built in 2000.
The building is a reinforced concrete frame shear wall structure with one floor underground, There are 12 floors above the ground (13 floors in some parts), with a height of 47.05m.
Due to the use demand, the owner needs to change the indoor room pattern and room function in many areas of the building, and carry out the overall decoration and transformation of the building.
The load changes greatly before and after the transformation.
According to the appraisal and test report and relevant design drawings, the modeling and checking calculation of the building are carried out, and the results show that: 1) The axial compression ratio of some column members exceeds the limit 2) the bearing capacity of some column beam slab members is not satisfied.
Calculation program of main structure calculation model: yjk2 0.2.
Calculation program of the main structure.
The problems after the decoration and reconstruction of the building mainly include that the bearing capacity of the components is not satisfied due to the increase of load and the axial compression ratio of some columns exceeds the limit.
Most components only need to improve the bearing capacity, so the reinforcement is mainly strengthened by sticking profile steel, steel plate and carbon fiber cloth.
Using this series of reinforcement methods to improve the bearing capacity of components has the advantages of short construction period and little impact on building space.
Due to the large increase of load in some areas, the above reinforcement methods are not suitable for the members in this area.
Therefore, the increased section reinforcement method or new laminated plates which can greatly improve the bearing capacity are adopted for reinforcement.
Various member reinforcement methods: (1) column member reinforcement: for individual column members whose bearing capacity is not satisfied due to large load increase and whose axial compression ratio is obviously high, the increased section reinforcement method is adopted for reinforcement, and the other columns that need to be reinforced are reinforced by externally bonded section steel reinforcement method.
Schematic diagram of external bonded section steel reinforcement schematic diagram of increased section reinforcement (2) beam member reinforcement: beams that do not meet the requirements of bearing capacity are mainly strengthened with beam bonded steel plate.
It should be noted that when the bonded steel plate reinforcement method is adopted, the increase of flexural bearing capacity of normal section shall not exceed 40%.
For some beam members that need to greatly improve the bearing capacity, the increased section reinforcement method is adopted for reinforcement.
Schematic diagram of pasting steel plate reinforcement schematic diagram of beam increasing section reinforcement (3) plate member reinforcement: the plates that do not meet the requirements of bearing capacity are mainly pasted with carbon fiber cloth.
It should be noted that when the pasting carbon fiber reinforcement method is adopted for reinforcement, the increase of the flexural bearing capacity of the normal section should not exceed 40%.
For the plate members that need to greatly improve the bearing capacity, new laminated plates are adopted for reinforcement.
The application scope and reinforcement effect of different component reinforcement methods are different, so the selection of reinforcement methods should be determined according to the actual situation of the building.
Comparing and optimizing the reinforcement methods and selecting reasonable reinforcement methods can shorten the reinforcement construction period, reduce investment and ensure the reinforcement effect.
Source: structural safety consultant of Guangdong Provincial Hospital..
