Project Overview 

The kindergarten teaching building has a construction area of 2 000 square meters, 3 floors and a floor height of 3.6 m. The main structure is a cast-in-place reinforced concrete frame, beams, columns, slabs, concrete strength grade C25, the filling wall is made of M5 7 Kunhe mortar for sintered hollow bricks. Completed in July 2004.

Earthquake caused house damage

Affected by the 5.12 earthquake, three-dimensional cracks along the cross section appeared in some walls, horizontal cracks appeared in the pillars of the staircase, and long horizontal cracks appeared at the intersection of the filling wall and the frame beam. However, under the continuous influence of the aftershocks of the earthquake, new earthquake damage occurred in the teaching building. The concrete manifestation is that the bottom of the roof slab is cracked. The location of the crack is the cross-over area of the floor slab, and the shape is vertical and horizontal.

After testing, the floor slab and beam are dangerous components, and the degree of damage has affected the normal use of the structure, and must be strengthened.

To ensure the safety of the house structure, whether to demolish and rebuild the house or repair and reinforce the house structure. After repeated demonstrations, it was decided to use structural carbon fiber to repair and strengthen the teaching building after the earthquake to completely reduce or completely eliminate the impact of cracks on structural safety.

Carbon fiber structural reinforcement for seismic retrofit

structural reinforcment materials: 

HM-30 unidirectional carbon fiber fabric

HM-180C3P carbon fiber adhesive

HM-30 unidirectional carbon fiber fabric

HM-180C3P carbon fiber adhesive

Process flow

Construction preparation, scaffolding tower, unloading live load on beam plate, concrete surface treatment, concrete primer, brushing carbon fiber adhesive, sticking carbon fiber wrap, brushing carbon fiber adhesive, standing curing, concealed plastering protection.

Conclusion

Carbon fiber reinforcement material is an effective, fast and ideal new reinforcement materials for seismic retrofit. The application in the construction and repair of the kindergarten house structure after the earthquake fully reflects the characteristics of high utilization of the building space after the reinforcement and strong adaptability to the shape of the reinforced component. The construction process is simple and fast, the reinforcement materials are more flexible, the lap is convenient, and the layout is easy to cross. Reinforcement construction has a shorter construction period and less interference with the environment. It meets the requirements of modern engineering construction on construction technology. The reinforced structure has good durability and corrosion resistance, which can greatly reduce the maintenance cost in the later stage.