Project overview

After the construction of the multi frame structure, most of the structural beams have structural cracks.

Through field observation and analysis, the cracks are vertical cracks which appear on the beam abdomen and are roughly perpendicular to the longitudinal axis of the beam and abdomen. The upper end of a few cracks extends to the bottom of the beam top, but there is no crack at the bottom of the plate. The lower end of the cracks extends to the bottom of the beam, but there is a small amount of U crack in the bottom of the beam. The cracks are mostly parallel and evenly distributed along the whole span of the beam, and all the cracks are fine as the hair line.

By comparing the structural drawings and the actual situation, we can find that the beam section design is too small, the span of the structure is too large, resulting in the design defects of slenderness ratio, and the change of environmental temperature and humidity can lead to the emergence of structural cracks.

Strengthening method

The structure drawings on foundation reinforcement joint design, give full play to the advantages of construction "durable, quick construction, flexible and simple lightweight steel plate bonded reinforcement, in order to satisfy the requirements for both the duration and quality, considering the construction convenience and feasibility, the scheme of strengthening technology of steel material properties and process and the construction environment and quality control are described in detail and deepening.

Strengthening materials

The steel reinforcement process with expansion bolts (optional screw nut split plate, convenient fastening and disassembly (M6) with length of about 50mm, to 3-4 mm thick steel plate (M8) and the length of about 80mm, to 5-6 mm thick steel plate), using HM-120M steel plate bonding adhesive, A adhesive and B bicomponent products.

(Bond steel plate reinforcement)