(3) In the frame structure, the rigidity of a column is emphasized to be vo to most horizontal forces to reduce the load of other columns.
After the beam and the plate are added with fulcrums in the span, the span is reduced, so that the bearing capacity can be greatly increased, and the flexural deformation of the beam and the plate can be reduced and restricted. It is suitable for the reinforcement of horizontal structures such as beams, slabs, trusses and grids in large-span structures with unrestricted house clearance. The advantage is that it is simple and reliable, and the disadvantage is that the use space will be affected.
The outer steel reinforcement reinforced concrete beam generally adopts the wet outsourcing method, that is, the reinforced epoxy resin grouting method is used to bond the steel section and the reinforced member into a whole body, and the reinforced component has a large increase in the cross-sectional area of the tensioned and pressed steel. Therefore, the normal section bearing capacity and section stiffness are also greatly improved.
Adhesive fiber reinforced plastic reinforcement
In addition to the similar advantages of the bonded outer steel reinforcement method, the reinforced fiber reinforced plastic reinforcement method has the advantages of resistance to turbidity, moisture resistance, almost no increase in structural weight, durability, low maintenance cost, etc., but requires special fire treatment. Suitable for concrete structural members and general structures of various stress properties.
After the reinforcement project is completed, apply a small hammer to gently tap the plate to judge the bonding effect from the sound or use the ultrasonic method to detect the bonding density. If the area of the anchoring area is less than 90%, and the area of the non-anchor area is less than 70%, the paste is invalid and should be peeled off and re-applied.
For major projects, in order to test the reinforcement effect, the load test shall be carried out by sampling. Generally, only the standard load test is used. The load to be unloaded is added all over again, and the deformation and crack development of the structure shall meet the design and use requirements.
Prestressed steel structure technology
Bolting is required to open holes in the base metal near the damaged part, weakening the section and forming a new stress concentration zone; ordinary bolts are easy to loose under dynamic load, and high-strength bolts are prone to stress relaxation, which reduces the repair effect of the structure. The bonded steel reinforcement technology is to use a special structural structural adhesive to adhere the steel plate on the surface of the steel structure, and rely on the structural adhesive to bond it together to work together to improve the structural bearing capacity. The disadvantage is that the weight of the structure is increased a lot, the steel plate is not easy to be formed into various complicated shapes, transportation and installation are not convenient, and the steel plate is easy to rust, affecting the bonding strength and high maintenance cost.