The progress of the social economy has enabled the stable development of my country's construction market, and the carbon fiber strengthening reinforcement project in the construction industry has received extensive attention from more professionals. The characteristics of high tensile strength, light weight and easy adhesion make carbon fiber highly valued by researchers in the construction industry. As a new type of reinforcement method, carbon fiber reinforced engineering has the incomparable advantages of structural materials, but also has some problems. This article focuses on discussing the main problems of carbon fiber reinforcement technology and construction engineering, and puts forward important measures to prevent and control carbon fiber reinforcement problems.

In recent years, the scope and number of buildings in our country have been increasing. The traditional reinforcement methods of pasting steel plates and expanding cross-sections cannot adapt to the changes in the building environment. The limitations in use make it replaced by new carbon fiber reinforcement engineering technology. Carbon fiber reinforcement technology can effectively solve the problem of building safety loopholes. When applying carbon fiber to reinforce concrete components, attention should be paid to a series of construction technical issues. It is necessary to pay attention to comprehensive prevention.

Project cases:

There are a total of 100 shops along the street of the Wanda Hotel Group at the site. In order to meet the functional requirements of the subsequent building, a number of steel stairs were added from the first to the second floor, the floor slab was partially removed, and the beams with insufficient bearing capacity were reinforced by carbon fiber. . Among them, there are 27 shops that have been reinforced.

1 Carbon fiber reinforcement common problems

In the usual building construction, the carbon fiber reinforcement project will have the problem of the reinforcement quality not meeting the design requirements and construction specifications. Specifically, there are four aspects.

First, the carbon fiber reinforcement project has not been controlled from the material, resulting in the unqualified quality of the carbon fiber cloth and building structural adhesive in the construction, and the lack of re-inspection of the materials.

Second, in the carbon fiber reinforcement project, the overall construction was not strictly followed by the process, and there was a lack of necessary technical personnel to inspect and supervise.

Third, the surface of concrete structures cannot be treated with correct standards. Unreasonable construction environment temperature and humidity will affect the application status of carbon fiber reinforcement technology.

Fourth, there is no perfect bonding method for building structural adhesives, and the lack of technical bonding methods is not conducive to reinforcement, and there is no effective protection of the reinforced components.

The above four aspects are common problems in carbon fiber reinforcement projects, which restrict the quality of construction.

2 Prevention and treatment of common problems in carbon fiber strengthening reinforced 

2.1 Improve the quality of carbon fiber cloth or building structural adhesive

Highly practical and effective building construction technology includes carbon fiber reinforcement engineering technology. To give full play to its reinforcement role, the quality of carbon fiber cloth or building structural adhesive should be emphasized. Carbon fiber cloth material fluctuates with changes in the environment, and the resulting quality variation can cause quality accidents. Therefore, strictly select building materials, especially carbon fiber cloth and building structural glue, and control the quality of building materials, building components and equipment, and lay a solid foundation for the construction of the project. Before building construction, arrange professional technicians to explain the design drawings and related reinforcement construction specifications, and purchase carbon fiber cloth and building structural adhesive in strict accordance with the design requirements of the building drawings. Production materials with mature technology and quality assurance must undergo corresponding quality supervision and inspection. It can be put into use only when the building requirements and standard specifications are met. In addition, it is important to pay attention to the surface protection of the carbon fiber cloth during the construction process, to ensure that the building structure glue is not damaged and polluted, and to replace the damaged building materials.

2.2 Standardize the surface polishing treatment of concrete structures

To polish the surface of the concrete, you need to reinforce the loose concrete first, use compressed air to clean up the floating dust, remove the rusty layer on the steel bar, apply epoxy mortar to repair a large area of inferior layer, and ensure that the repair mortar is dry during construction. The parts that have not been excavated but need to be reinforced should use sandpaper to remove scum and oil on the surface. The surface of the concrete structure should be polished clean before the construction of the next process to avoid the formation of an isolation layer between the carbon fiber cloth and the structure. The incomplete treatment of the concrete base layer will cause a series of quality problems. Therefore, it is very necessary to adopt correct treatment measures to strengthen to meet the design requirements. Smoothing the protruding parts on the surface of the concrete structure is beneficial to avoid the formation of hollow drums and bubbles from the carbon fiber cloth.

2.3 Determine the correct pasting method of using building structural adhesive

First of all, make technical clarifications to ensure that on-site technicians correctly understand the requirements of the design drawings before construction and master the use of building structural adhesives. Secondly, implement the model first, select the component with the appropriate paste area for on-site paste test, and then conduct large-area paste construction after the test results are qualified. Then, mix the building structural adhesive in a reasonable proportion, put it in and stir according to the placing order, pay attention to the uniformity of mixing, and avoid mixing other impurities. The greater the viscosity of the structural adhesive, the longer the mixing time should be, both greater than 15 minutes. Finally, ensure that the carbon fiber cloth is soaked with the structural adhesive. During placement, avoid bending it at a right angle along the fiber direction to cause stress concentration to ensure the strength of the carbon fiber cloth.

2.4 Avoid damage to the protective layer of carbon fiber cloth

In the process of using carbon fiber cloth for reinforcement, it should be protected from contamination and damage. Set up protection facilities on and around the construction site to do a good job of construction protection. Choose medium-coarse sand that does not contain mud and debris, and evenly spray it on the surface of the carbon fiber cloth to ensure that the structural glue on the protective layer of the stucco mortar is completely solidified. The protective layer should be sprinkled with water for maintenance. Choose a work site with less dust and chemical pollution, and cover and protect it before the structural adhesive is cured. In the storage and transportation of carbon fiber cloth, because the high temperature will cause the resin in the resin-containing carbon fiber cloth to mature, the resin-free carbon fiber cloth should be selected to give full play to the reinforcement effect. As a new type of reinforcement technology, carbon fiber composite material reinforcement and repair has great application and promotion value.

3 concluding remarks

At this stage, although carbon fiber reinforcement technology is widely used, it is very common to have quality problems in building construction. In view of the common problems of carbon fiber reinforcement projects, construction technicians in the relevant construction industry can ensure the construction quality of carbon fiber reinforcement projects on the basis of formulating prevention and control measures in advance, pay attention to the construction application and technical control of carbon fiber materials, and adopt rationalized measures and approaches. Optimizing the overall effect of carbon fiber reinforced engineering construction not only conforms to the acceptance specifications for construction quality of building structure reinforcement engineering, but also is an inevitable measure to improve the quality of building construction technology.