The most comprehensive strategy of Concrete column reinforcement

Concrete column is the main load-bearing component in the building. With the increase of the service time of the building, the durability of the concrete column is prone to decline and the strength and rigidity are insufficient due to the early defects or the continuous changes of the load and environment. The failure of concrete column is sudden and easy to cause accidents, so it is necessary to reinforce the defective column.

Enlarged cross-section

A direct reinforcement method to increase the bearing capacity, rigidity and stability of the original member by increasing its section area or adding reinforcement.

Technical points:

1. The new longitudinal stress reinforcement shall be determined by calculation, but the diameter shall not be less than 14mm. The reinforcement shall be set in full length within the range of reinforced floor.
2. The upper and lower ends of the longitudinal stressed reinforcement shall be reliably anchored. The lower end of the longitudinal bar shall extend into the foundation and meet the anchoring requirements; the upper end shall be connected with the upper column through the floor slab or anchored at the roof slab.
3. The holes where the new reinforcement passes through the original structural beam, slab and wall shall be grouted and anchored with adhesive.

Externally bonded steel

The reinforced concrete column is welded into a frame by wrapping steel and flat steel and poured with structural adhesive to achieve the reinforcement method of overall stress and joint work.

Technical points:

1. The longitudinal stress angle of the column shall be determined by calculation, but shall not be less than L75 × 5. The angle steel shall be set in the whole length within the range of the reinforced floor.
2. The upper and lower ends of the longitudinal angle steel shall be reliably anchored. The lower end of angle steel shall be anchored to the foundation, the middle shall pass through each floor, and the upper end shall extend to the bottom of the upper floor of the reinforcement layer or be anchored to the roof top plate.
3. When the column is strengthened by externally bonded steel, the edges and corners of the original component section shall be polished into rounded corners with a radius ≥ 7mm.
4. The glue injection of externally bonded section steel shall be carried out after the welding of section steel frame, and the thickness of glue joint shall be controlled within 3-5mm.

Reinforcement with Carbon fiber( CFRP STRENGTHENING)

It is a direct reinforcement method to improve the bearing capacity and ductility of concrete column by using structural adhesive to paste carbon fiber cloth on the surface of concrete column to form a composite section with integrity.

Technical points:

It is a direct reinforcement method to improve the bearing capacity and ductility of concrete column by using structural adhesive to paste carbon fiber cloth on the surface of concrete column to form a composite section with integrity.

Technical points:

1. It can be used to improve the axial compression bearing capacity, inclined section bearing capacity and displacement ductility of columns.
2. When the bearing capacity of the normal section of the axial compression column is insufficient, the method of continuous pasting fiber cloth along the full length of the column can be used for reinforcement.
3. When the shear bearing capacity of the inclined section of the column is insufficient, the strip of carbon fiber cloth can be pasted into a ring hoop, and the fiber direction is perpendicular to the longitudinal axis of the column.
4. When the ductility of the column is insufficient and the seismic reinforcement is carried out, the hoop girth composed of the hoop pasted fiber cloth can be used as the additional stirrup.

1. It can be used to improve the axial compression bearing capacity, inclined section bearing capacity and displacement ductility of columns.
2. When the bearing capacity of the normal section of the axial compression column is insufficient, the method of continuous pasting fiber cloth along the full length of the column can be used for reinforcement.
3. When the shear bearing capacity of the inclined section of the column is insufficient, the strip of carbon fiber cloth can be pasted into a ring hoop, and the fiber direction is perpendicular to the longitudinal axis of the column.
4. When the ductility of the column is insufficient and the seismic reinforcement is carried out, the hoop girth composed of the hoop pasted fiber cloth can be used as the additional stirrup.