Projects

Hydropower station is one of a series of small hydropower projects developed and constructed under the rural power supply plan, mainly supplying electricity to nearby residential areas. Initially installed two single-unit capacity 1MW horizontal hydro-turbine generator units; the expansion installed a third unit with a capacity of 1MW, and two units with a capacity of 1MW were expanded again; at present, the total installed capacity of the power station is 5MW.

Due to long years of operation, some existing hydraulic structures of the power station were damaged. Most of the equipment is outdated and aging, backward in technology, low in automation, poor overall coordination and operation, inconvenient operation and maintenance, which affects the safe and stable operation of the power station and restricts the power generation efficiency of the power station. The power generation capacity of the power station is far from meeting the development needs of the power supply area. . To this end, it is planned to repair and expand the power station to extend its service life and expand its installed capacity to 10MW to meet the power demand of the power supply area. The expansion plan is to expand the capacity of Units 1 to 5 from 1MW to 1.1MW, and build a new plant with two 2.25MW hydro-turbine generators with a total installed capacity of 10MW.

The old factory building of the existing hydropower station is a ground-type factory building with a single-story reinforced concrete frame structure. According to the requirements of the contract, a 7.5t manual bridge crane in the built plant needs to be replaced with a 10t electric bridge crane. The original 7.5t manual bridge crane girder structure needs to be strengthened as soon as possible.

Excellent performance of CFRP for concrete strengthening reinforcement

(1) High strength and high elastic modulus. The strength of CFRP is high, the ultimate tensile strength is about 10 times that of steel, and the modulus of elasticity is similar to that of steel. Therefore, in strengthening and repairing concrete structures, it can make full use of its high strength and high elastic modulus characteristics to improve the bearing capacity and ductility of concrete structures and components. Improve their stress performance and achieve the purpose of strengthening and repairing.

(2) Strong corrosion resistance and good durability. CFRP materials have stable chemical properties and do not react with acids, alkalis, salts and other chemical substances. Therefore, the reinforced concrete structure reinforced by CFRP has good corrosion resistance and durability, which solves the chemical corrosion problems encountered by other reinforcement methods. At the same time, the regular anti-rust maintenance required for sticking steel reinforcement is eliminated, saving maintenance costs.

3) The coefficient of thermal expansion is small. The thermal expansion coefficient of CFRP material is very small, and its thermal expansion coefficient in the fiber direction is almost equal to zero. This feature is unmatched by any other material at present. Although the coefficient of thermal expansion perpendicular to the fiber direction is relatively large, it is the smallest among all products of the same sex compared with other materials.

(4) Easy construction and high work efficiency. CFRP cloth reinforcement does not require large construction machinery and heavy equipment, construction takes up less space and does not require wet operations. The carbon fiber cloth has good flexibility and can be cut arbitrarily with scissors or blades according to the design size. The operation is simple and the construction speed is fast. According to relevant statistics, the reinforcement efficiency of pasting CFRP is 4 to 8 times that of pasting steel reinforcement.

(5) The construction quality is easy to guarantee. CFRP cloth is a flexible material. Even if the surface of the reinforced member is not very smooth, after repair, the effective bonding rate can reach more than 95%.

(6) Small impact on structure. The CFRP material is light in weight and thin in thickness. The reinforced and repaired components increase the weight and size of the original structure, and basically do not affect the use space of the structure

(7) Wide application range. Can be used for different structural types (such as buildings, structures, bridges, tunnels, culverts, etc.), different structural shapes (such as rectangles, circles, curved structures, etc.), components of different materials (such as concrete structures, wooden structures, steel structures, etc.) ). It can also be used to strengthen different parts of components (such as beams, plates, columns, nodes, arches, shells, piers, etc.) and different weak factors. It is especially important that for some large civil engineering structures, such as the piers, beams and decks of large bridges, tunnels, etc., the use of old reinforcement methods can hardly be implemented, but the use of this reinforcement technology can be solved smoothly.

In addition, CFRP materials have some other advantages, such as electromagnetic wave penetration, heat insulation, etc., which makes carbon fiber reinforcement technology produce good comprehensive benefits in concrete structure reinforcement.

Reinforcement effect of CFRP reinforcement strengthening

The concrete structure of the old powerhouse of the hydropower station has a relatively narrow space, and the bridge crane track beam is reinforced with carbon fiber composite(CFRP) materials.

1) The construction area is not large

2) The plant and track have lightning protection and grounding measures, so construction is safe

3) High efficiency

4) Good reinforcement effect

After 3 days of curing, it can bear the load, and everything has been normal so far, which creates favorable conditions for the early installation of the old plant.

In short, carbon fiber(CFRP) material reinforcement technology has incomparable superiority and good economic and social benefits compared with other traditional reinforcement methods. CFRP reinforcement strengthening technology will be more and more widely used in the fields and applications of concrete structural defect reinforcement, erosion and wear resistance, and enhanced anti-cracking measures, and it has great development potential.