R.C. Beams Strengthening

R.C. Beams Strengthening by Carbon Fiber Reinforced Wrap

Project Overview

The main body of a project is a frame shear wall structure C building. The original design beam bottom elevation of the main entrance canopy on the south side of Building C is 6.0m. The owner requested that the canopy be changed to a flat three-story floor. After the design check, the four main beams that have been constructed on the third floor must be reinforced.

RC beam reinforcement scheme

Finally, after careful analysis, comparison and demonstration by the three parties, considering not increasing the size of the original structure, not affecting the normal use in the later stage, meeting economic and reasonable factors, safety in the construction process, environmental protection and construction period requirements, etc., the carbon fiber cloth reinforcement plan was selected. .

Carbon fiber wrapping reinforcement technology has the following obvious technical advantages:

(1) High-strength and high-efficiency, to achieve the purpose of high-efficiency reinforcement.

(2) Corrosion resistance and durability, solve the chemical corrosion problems encountered by other reinforcement methods.

(3) Basically not increase the weight and volume of the components, which is undoubtedly important in an economy and society where every inch of land is worth a lot of money.

(4) Because it is a flexible material, it can be cut arbitrarily, and it is widely used in various structural types, various structural shapes and various parts of the structure.

(5) It is convenient for construction, does not require large construction machinery and turnover materials at the construction site, occupies less space, no wet work, high work efficiency, and good economy.

(6) The construction period is short (the owner requires the construction period to be 8d).

(7) The mechanical performance of the reinforced structure is also very obvious. First of all, the bending and shearing performance of the structure has been greatly improved. Secondly, it can improve the rigidity of the structure and delay the development of cracks. Finally, it can also significantly improve the deformability of the component, increase the ductility of the component, and improve the brittleness of the original concrete against cracking damage.

ud carbon fiber wrap

Carbon fiber material performance evaluation

(I) The modulus of elasticity of carbon fiber is close to that of steel, which is very suitable for the reinforcement and repair of steel bar structure. At the same time, the tensile strength of carbon fiber is 10 times that of ordinary steel. When the same reinforcement effect is achieved, the amount of carbon fiber is more than that of steel. Much less.

(2) The heavy salt of carbon fiber is only 200g/m2, which is about 1/100 of that of 3mm thick steel plate. It hardly increases the weight of the structure and does not cause chain reinforcement of the structure.

(3) In a weak acid environment, after 10,000 freeze-thaw cycles, alternating dry and wet, a certain light time, immersion in 70'C hot water for 30 days, etc. The durability, corrosion resistance, and aging resistance of carbon fiber are not reduced. The fatigue strength still retains 80%.

Reinforcement effect

Because the application of carbon fiber wrap reinforcement in construction is very convenient, the reinforcement construction task was completed within 8 days, which bought time for the construction of the next process. The current condition of use is good, and there is no abnormal phenomenon, indicating that the reinforcement treatment of this project is effective and reliable.