Language: English
Wharf Strengthening
Carbon Fiber Strengthening
The application of carbon fiber in the reinforcement of prestressed concrete beams of the harbour wharf fully demonstrates that carbon fiber reinforcement is an ideal reinforcement method for reinforced concrete structures of the harbour, which fully embodies the advantages of carbon fiber.
During the use of the beam, due to the impact load and overload, some beams cracked in the middle of the span, and the cracks of the beams were not closed after the unloading of the external load. The maximum width of the cracks of the beams could reach about 3 mm (the width of the cracks after the unloading of the external load), and the tensile steel bar had residual deformation.
Load
Living Load on Beam: 30kN/m2
Loading of the center plate over the beam: 70kN/m2
Safety Factor Burnout Bureau Requirements: 1.5
Design Compressive Strength Grade of Concrete: C40
Steel Bar
The design strength of steel bar is 530N/mm2. In checking calculation, according to crack width of beam and considering factors such as secondary stress lag, the available strength coefficient of steel bar is 0.6. Fy=530N/mm2*0.6=318N. Tensile Design Strength of Carbon Fiber Cloth Fcf=2100N/mm2
Calculation Results
According to the above calculation, the area of 0.167 mm thick carbon fiber cloth to be pasted on the edge of the beam is 260 mm2, and the area of 0.167 mm thick 2*300 mm wide carbon fiber cloth to be pasted on the edge of the beam is 300 mm2.
Reinforcement Technology of Carbon Fiber Cloth
Grass-roots treatment
Cleaning Treatment of Beam Surface
Treatment of cracks in beams
Primer Coating and Surface Treatment of Beams
Sticking carbon fiber cloth
Carbon Fiber Cloth Protection
Bearing Capacity Test of Beams under Ultimate Normal Service Conditions
In order to test the actual reinforcement effect of beams, we carried out a load test on the pre-stressed beams of wharf strengthened with carbon fiber. The test results show that the bearing capacity of beams under 2800 kn load meets the bearing capacity requirements under the normal service limit state. Under the limit state of normal service, the measured deflection of the beam meets the requirements of the national code, and the reinforced prestressed concrete beam can be used safely.
Concluding remarks
The application of carbon fiber in the reinforcement of prestressed concrete beams of the harbour wharf fully demonstrates that carbon fiber reinforcement is an ideal reinforcement method for reinforced concrete structures of the harbour, which fully embodies the advantages of carbon fiber.
