The prestressed CFRP laminate is a kind of active reinforcement technology applied to bridge, long span beam and other flexural members. It does not increase the weight of the original component and can be strengthened without unloading, so it is favored.

In order to achieve better results, the construction of prestressed CFRP laminate has a lot of attention, the following is the summary of the attention, I believe you will gain.

• Strength of concrete

The concrete strength of the reinforced concrete structural members can not be less than C25, and the tensile bond strength of the concrete surface should not be less than 2.0MPa.

• Requirements for sticking surface 

The surface of prestressed CFRP plate on the surface of concrete component should be protected. Surface protective materials should be harmless to fibers and adhesives.

• Requirements for the force of sticking prestressed CFRP plate

When carbon fiber reinforced polymer composite plates are bonded to reinforced concrete(RC) structural members, the stress of carbon fiber composite plates should be designed to be subjected to tensile stress only.

• Requirements for structural adhesives for bonding CFRP plate

When the reinforced concrete(RC) structure is strengthening by the prestressed CFRP composite plate, the structural adhesive should be painted between the plate surface and the concrete outside the anchorage part.

• Ambient temperature

The concrete structure strengthened by this method should not be higher than 60 C for a long time. When the concrete structure in special environment (such as high temperature, high humidity, dynamic load, medium erosion, radiation and so on) is strengthened by this method, the corresponding protective measures should be adopted according to the current regulations of the state.

• Fire protection requirements

When the surface of the reinforced component is required for fire protection, the adhesive and carbon fiber composite plate should be protected according to the fire resistance grade and the fire resistance limit required by the current national standard

• Requirements for bonding prestressed CFRP plates

When using prestressed carbon fiber composite plate to reinforce concrete structural members, the fiber composite panels should be directly pasted on the concrete surface. It is not recommended to use the embedded pasting method.

• Design of shear stress of anchor bolt

The design should check the shear strength of the anchor bolts, and the design shear stress of the bolt should not be 0.6 times greater than the design value of the shear strength of the anchor material.

• Requirements for tension of anchorage and the fixed end of the anchorage

When the prestressed carbon fiber composite plate is used to reinforce the reinforced concrete(RC) structure, at least one end of the anchorage should be a free moving end.

• Prestress requirement

Measures to remove live loads on reinforced structures may not be taken.

• Tension control stress requirements

The tension control stress value of prestressed carbon fiber composite material should be 0.6 times -0.7 times of the tensile strength design value of the fiber composite material.

• Protection requirements for anchorage

Anticorrosive measures should be taken to protect exposed anchorage.

• Requirements for anchorage and tensile end surface

The carbon fiber of anchoring end and tension end should be straight and no surface defects.

• Matters of attention in the tensioning process

When there is a significant slip phenomenon in the tension process or fail to design tensile stress, the bolt fastening force should be adjusted and re stretched. When the tension process is smooth and the design stress is reached, the tension device is loosened, the adhesive is coated, and the tension is stretched to the design stress value for the two time.