Language: English
Frame Beam Reinforced
Unidirectional Carbon Fiber Wrap Reinforced
The carbon fiber wrap reinforcement of the project comprehensively considered factors such as the rationality of the force, the convenience of construction, and the economy. The construction was completed and put into use in December 2018.
A 6-story commercial residential building with a frame structure caught fire in October 2018. The fire lasted for about 1.5 hours; the prefabricated slab on the third floor was cracked in many places and there was hollowing. Part of the floor tiles on the third floor burst. The diagonal cracks in the partition wall were up to 1.3m long and the maximum crack width was 3.4mm.
Damaged beam reinforcement design
Detect and analyze the damaged beam, the concrete and steel bars in the tension area of the beam are damaged, and analyze the force of the beam
Through calculation and analysis, carbon fiber wrap is used to strengthen the damaged beam. Substituting the known conditions into the formula is: Af=47.64mm2, and it is calculated that three layers of carbon fiber wrap are required. Add a strip of carbon fiber wrap on the side of the beam, and add three strips at the end of the beam
Construction technology
1) Construction preparation. Remove all loads in the house, prepare carbon fiber wrap, structural glue, scissors and other tools.
2) Base surface treatment. Chisel and clean the reinforced parts.
3) Apply primer to repair the adhesive surface.
4) Paste the carbon fiber wrap. Apply structural glue, paste carbon fiber wrap, and roll several times with rollers. After pasting three layers of carbon fiber wrap, scrape the surface glue to make the surface glue fully penetrate into the carbon fiber.
5) Apply fire-proof and heat-insulating paint. Apply TB thin fire-resistant and heat-insulating paint to the area where the carbon fiber wrap is pasted several times until the design requirement is 6mm thick. The brushing range should be 5mm～10mm beyond the boundary of the carbon fiber wrap to ensure the fire and heat insulation effect.
Concluding remarks
The reinforcement of the project comprehensively considered factors such as the rationality of the force, the convenience of construction, and the economy. The construction was completed and put into use in December 2018. After a year of testing, the cracks of beams, slabs, and slab tiles did not continue to develop, which meets the requirements of the specification and can be used as a reference for similar projects.
