1. Definitions

Prestressed steel strand

Prestressed steel strand, according to the bonding method, can be divided into bonded prestressed, unbonded prestressed and slow bonded prestressed. The pre-compression stress is generated before, so as to control the tensile stress level of the component, and even make the component in a state of compression.

Prestressed carbon fiber plate

The prestressed carbon fiber plate reinforcement system, its principle of use is to prestress the components that need to be reinforced, use carbon fiber plates coated with carbon plate glue to prestress the components to repair the problems of the components, so that the carbon fiber plates and the components form a unified whole, and improve the bearing capacity of the components .

2. Apply

Prestressed steel strand

It is suitable for the reinforcement of reinforced concrete with small reinforcement section or due to insufficient reinforcement in bending, tension and large eccentric compression members to improve the bearing capacity of building sections.

Prestressed carbon fiber plate

1. It is suitable for the reinforcement of large-span reinforced concrete bridges to improve the bearing capacity;

2. It is suitable for external prestress reinforcement of hollow slab beams, box beams and T beams.

3. It is suitable for buildings such as workshops, and large-span beams are flexurally reinforced.

4. It is suitable for the reinforcement of reinforced concrete bending, tension and large eccentric compression members with small cross-section or insufficient reinforcement.

3. Materials

Prestressed steel strand

The main materials are: prestressed steel strands, anchors, anchor bolts, oil pumps, jacks, tension rods, jacks, etc.

Prestressed carbon fiber plate

The main materials are: prestressed carbon fiber plate, anchors, structural carbon plate glue, tensioning equipment, beading, etc.

4. Process

Prestressed steel strand

Construction preparation → beam and slab formwork support → laying and binding of reinforcing bars under non-prestressed conditions → laying of unbonded prestressed reinforcing bars, installation of end nodes →Laying and binding of non-prestressed steel bars → unbonded prestressed arching and binding → hidden inspection and acceptance → concrete pouring and vibrating → concrete curing → tensioning → end treatment

Prestressed carbon fiber plate

Positioning and lay-out→drilling→grooving→planting anchor bolt→installing limit frame→installing anchor block→cutting carbon plate→installing carbon plate→installing jack and high-strength screw→pretensioning→applying carbon plate glue→prestressing tension →Remove the screw →Fix the tablet →Protection treatment

5. Advantages

Prestressed steel strand

1. The stress change is small, which is beneficial to the stress of the structure;

2. It has a wide range of applications, has no restrictions on the distance of large spans, and is more suitable for the reinforcement of complex sections;

3. The prestressed arrangement is flexible, and local reinforcement can be carried out, which is convenient for component replacement and later maintenance operations.

Prestressed carbon fiber plate

1. The density is close to 1/5 of that of steel, and the structural weight is hardly increased after reinforcement.

2. The pre-tension of a single strip is small, the anchoring seat is light and simple, and no large-scale construction equipment is required;

3. The overall performance is superior, which can reduce the deflection and deformation of the structure while increasing the strength and rigidity of the structure;

4. The durability is much better than that of steel, and the later maintenance cost is low.

6. Disadvantages

Prestressed steel strand

1. In contrast, the construction is more complicated;

2. The tensile strength is not as good as that of carbon fiber plate, which is not suitable for the reinforcement of components with large deformation;

3. There are risks of corrosion and creep in the later stage, and the maintenance is more complicated.

Prestressed carbon fiber plate

1. It needs to be used together with structural adhesive, and has certain requirements for temperature.

2. The distance between the tension end and the fixed end of the carbon fiber plate reinforcement system may be limited, and the reinforcement of large-span components requires segmented construction.