Ningbo Lishe International Airport jet Terminal Engineering

Engineering overview

Ningbo Lishe International Airport's official aircraft terminal project two column KZ8. During the construction process, the non seismic steel bar was used as the aseismic reinforcement, and the column has been poured. According to the inspection report of steel, yield ratio and super ratio by calculation are consistent with the requirements of seismic reinforcement, as another index of elongation at maximum force cannot be calculated, in order to ensure the structural safety of the column, the column needs to adopt seismic reinforcement with CFRP composite materials.

Strengthening material 

Carbon fiber cloth with 300g/ square meters, the thickness of 0.167mm, the tensile strength standard value of not less than 3000MPa, the tensile elastic modulus is not less than 210000MPa, elongation of not less than 1.5%.

The carbon fiber cloth is pasted with A grade adhesive 

The reinforcement method 

First applies the 300mm wide carbon fiber cloth to the column edge and the carbon fiber cloth hoop along the column height. The width of the hoop is 100mm, the center distance is 300mm, the spacing between the encryption zones is 200mm, the lap length of the girth is 100mm, the joints are staggered. The reinforced calculation area is about 7 square

Technical requirements for strengthening construction of CFRP composite materials 

>>The treatment of concrete surface

The cosmetic layer, oil, dirt etc. Of concrete surface should be chiseled off and then rubbed off 1 ~2 mm thick surface layer with the angle grinder, concrete components should be handled by chamfering on the corner, dust was blew out with compressed air after the completion Of polishing, and finally the surface was wiped by cotton cloth dipped in acetone, and kept dry for use. If the concrete needed to strengthen existed cracks, first choose HM-120M perfusion adhesive or HM-120L pouring crack adhesive to perfuse according to the size of crack, and then strengthen.

>>Primer construction

When construction, two components of primer A and B were weighed according to the stipulated proportion of preparing glue, and dumped into a clean container and stirred to uniformity (when mixing, best mix along the same direction to avoid the air from forming air bubbles.) Brush or roller brush was used to evenly brush on the concrete surface, after the glue surface layer dried, it should be brushed several times depending on the particular circumstances, but the coating thickness did not exceed 0.4 mm, and it should not be missed out to brush, or have flowing or bubbles, waiting for glue curing (curing time was depended on the site temperature,it was appropriate when finger felt dry, generally not less than 2 hours), then the next process was proceeded. The glue prepared every time should be used up one time during the applicable period of the glue.

>>Leveling construction

The pores and defects on concrete surface were filled by leveling adhesive.When depression area was existed, the prepared leveling adhesive was used to repair and fill through scraper embedding and scraping, the position emerging altitude difference such as the joint of templates should be filled by leveling adhesive, which tried to minimize the height difference. The treatment of corner was that it was repaired to smooth arc through leveling adhesive, its radius was not more than 20mm. After the leveling adhesive cured (curing time was depended on the site temperature, it was appropriate when finger felt dry, generally not less than 2 hours), the next process should be proceeded further.

>>Paste of carbon fiber cloth

Carbon fiber impregnated adhesive was smeared to the pasted area evenly,the corner site was more smeared appropriately. Paste after hauling carbon fiber cloth tight and alignment, use a plastic scraper or roller (a paint roller that the villus was removed outside) to roll repeatedly along the same direction, until the glue compound exuded. And then smear impregnated adhesive to the outside surface of the carbon fiber cloth evenly, and roll repeatedly, 50 that the impregnated adhesive can immerse the carbon fiber cloth in two ways,if it is multi-paste, until your fingers touch dry, the next layer of paste can be beginner. If the carbon fiber cloth needs overlapping

>>Curing and conservation

Prevent rain or moisture 24 hours after the completion of construction, and pay attention to protection against a hard Object bumping into the surface of the construction. When the average air temperature is 20 , 25 ℃ , the curing time is not less than 3 days; when the average air temperature is 10 ℃, the curing time is not less than 7 days.