Damage location and quantitative evaluation method of corroded reinforced concrete beams

Abstract

The invention discloses a method for locating and quantifying the damage of a corroded reinforced concrete beam. In the method, the beam structure is segmented first, and the vertical displacement and rotation angle of the segmented structure are tested under the action of a known load. The displacement and rotation angle test values ​​under the known load are back-calculated to obtain the flexural stiffness and shear stiffness of each beam structure, and finally the actual flexural stiffness and shear stiffness of the beam structure are compared with the design values, so as to carry out Component damage location and damage assessment. The invention only needs the vertical displacement and rotation angle test values ​​under the known load to realize the identification of the bending resistance and shear stiffness of the corroded reinforced concrete beam structure, and has the advantages of strong operability and simplicity; in addition, the invention Using the analytical method does not need to establish a complex finite element model for multiple iterations, which is more efficient and has wide applicability.

Description

technical field [0001] The invention belongs to the technical field of civil engineering and relates to concrete beam structures, in particular to a damage location and quantitative evaluation method for corroded reinforced concrete beams. Background technique [0002] Reinforced concrete structure combines the two material properties of steel and concrete. It has the advantages of high rigidity, fire resistance and corrosion resistance, and good integrity. It is the most commonly used structural form in civil engineering and is widely used in various high-rise buildings, bridges, dams, power stations, etc. . Due to the protective effect of concrete on steel bars and the chemical stability of concrete itself, people have paid attention to the strength of reinforced concrete structures and neglected their durability for quite a long time. However, due to the influence of external environment such as chlorine salt erosion, carbonization, and alkali-aggregate reaction, steel r...

AI Technical Summary

Problems solved by technology

However, due to the influence of external environment such as chlorine salt erosion, carbonization, and alkali-aggregate reaction, steel reinforcement corrosion occurs inside many reinforced concrete structures, resulting in degradation of structural performance, and even early exit from work, resulting in loss of life and property

[0003] The three key factors that steel bar corrosion affects the resistance of concrete structures include: ① steel bar corrosion leads to the reduction of the cross-sectional area of ​​the steel bar itself, which in turn affects the normal mechanical properties of the steel bar; The rust swelling force, which in turn makes the thickness of the reinforcement protective layer crack and peel off, greatly reducing the effective cross-section of reinforced concrete; ③The corrosion products also destroy the original bonding force between the reinforcement and the concrete, resulting in the degradation of the bite force between the reinforcement and the concrete. Greatly affect the normal service life of the structure

The existing research results show that the corrosion of steel bars not only affects the bending performance of concrete structures, but also weakens the shear performance of structures. However, because steel bars are wrapped in concrete, its initial corrosion (concrete has not peeled off due to steel bar rust) is difficult to be eliminated. It is found that even if the corrosion of steel bars can be monitored by non-destructive means, the degree of corrosion and its impact on concrete structures are not easy to quantify and evaluate

Images