Comprehensive office building reinforcement

The integrated office building was completed in 1997. During the quality inspection in August 2006, it was found that there were obvious oblique cracks in the beam ends of some frame beams, which caused potential safety hazards. According to the size and development of the cracks, the designer recommends that the owner adopt carbon fiber reinforcement treatment to some beams of this building to increase the shear strength of the frame beams.

Carbon fiber uses HM-20 produced by Horse construction. Its performance indicators are: unidirectional fiber direction, unit mass 200g/m², thickness 0.111mm, tensile strength 3950MPa, elastic modulus 2.35×10⁵MPa. Resin glue HM-180C3P for carbon fiber paste, its performance indicators are: tensile strength 30MPa, shear strength 10MPa, adhesive strength 2.0MPa, and the use time is 20~120min. After the beam is strengthened, the shear capacity of the beam is increased by 43%~62%.

Since CFRP has physical, mechanical and chemical properties that traditional materials cannot match, coupled with the availability of raw materials, its price has gradually approached that of traditional materials, and it has been widely used in the field of building reinforcement.