Main diseases and causes of the T-beam bridge

• Crack in the midspan and near the pivot of T beam web

• Partial breakage of T beam

• Concrete fragmentation of T beam wing plate (and bridge deck)

• Vertical cracking and dislocation of the diaphragm

• Bridge pier and abutment disease

  
  

Structural strengthening method

Strengthening technology of main beam

• Repair of cracks by chemical grouting

On the one hand, the technology relies on the cohesive force of the epoxy resin slurry to recombine the internal structure of the structure into the whole and restore the due strength; on the other hand, the air and water are prevented from entering the beam body and avoiding the corrosion of the steel and concrete.

• Repair the damaged part of T beam

The broken concrete should be chiseled out of the part of the damaged part (the main girder must be raised first), and the rust of the corroded reinforcement should be rebuilt with 35 epoxy resin small stone concrete.

For the serious damage of the T beam pivot, in addition to the repair of the No. 35 epoxy resin small stone concrete, the cross section of the 70cm range from the end of the beam should be increased to the horseshoe shape, and the steel plate is added at the lower edge of the cross section to enhance the compression ability of the fulcrum.

For the damaged and perforated wing plates, the loose concrete is chiseled and the original steel bar is retained, and the new steel bars are welded on the top and lower 2 layers of the original steel to strengthen the connection of the main beam and repair the pterygoid concrete.

• Strengthening the connection of T beam diaphragm

The quality of the connections between the diaphragms directly affects whether the main girders can bear forces together, so it is necessary to reinforce the diaphragms effectively. The original outsourced mortar is first chiseled, the steel plate is derusting, and the welded steel plate is repaired. Finally, the measures of coating the epoxy resin cement mortar to prevent the rust from the main beam are strengthened.

• Pasting carbon fiber fabric near the beam pivot

Carbon fiber fabric is light, corrosion resistant, thin, high tensile strength, and can work together with reinforced concrete, so it is very suitable for strengthening concrete components.