Strengthening the carparking

Project overview

(1) the measured value of the electric slag pressure welding of the two - story frame column of the 1 - 8 - axle frame column of the composite building is less than the standard value.

(2) one layer of A/11, B/12, D/9, two layers of B/12, C/11, D/9 frame column spacing do not meet the standard requirements, and the two layer B/12 frame column protection layer is too small.

(3) the spacing of steel bars of C/14, A/8 and B/2 frame columns on the first floor of the building does not meet the requirements of the standard.

(4) the garage C/3, A/1, B/1, the distance between the frame columns of the A/7, A/1 and B/2 frame of the engineering garage does not meet the requirements of the standard.

(5) cut off the lower part of three frame columns of 10/A, 10/B and 10/C in the first floor of the comprehensive building

Maintenance and reinforcement scheme

The maintenance and reinforcement of building structures should be designed according to the principles of safety, applicability, economy, advanced technology, reliability, durability, environmental protection, sustainable development and beauty. At present, there are three effective reinforcement schemes for building frame columns：

1.Reinforced frame column method with enlarged cross section

That is to increase the concrete cast-in-place layer in the compression area of reinforced concrete flexural member, increase the section area, improve the normal section bending resistance, the diagonal section shear capacity and the section rigidity, and play the role of reinforcement and reinforcement. The wet working time of this method is long, which has a certain influence on the production and life, and the net space of the building after reinforcement is reduced to a certain extent.

2.Carbon fiber reinforced frame column method 

Carbon fiber cloth will use high performance epoxy adhesive to bond to the surface of concrete components, and use fiber material's good tensile strength to enhance the bearing capacity and stiffness of components. The CFRP reinforced frame column method is simple in operation and good in stability, but the cost is relatively high.

3.Reinforcement of frame columns by epoxy bonded steel plate 

The section steel and steel plate are wrapped on the outer side of the reinforced frame column, and the structural steel is tightly bonded to the original structure through the structural adhesive. The purpose of improving the bearing capacity and stiffness of the frame column is achieved through the joint work of the steel plate and the original frame column. The steel plate reinforcement method has the advantages of convenient construction, short cycle, no need for large machinery, small occupying space, no change in the shape of the structure, and no influence on the appearance, etc., and the relative cost is small, so the steel plate reinforcement method is economical and applicable.

Referring to the actual situation of the project, the method of increasing the cross section to reinforce the frame column will occupy part of the preset use space, and the construction is difficult and the feasibility is not high. Therefore, the method of sticking steel plate or CFRP is applied to reinforce the frame column.

COLUMN STRENGTHENING BY CFRP FABRIC