Strengthening technology of sticking carbon fiber sheets outside, and strengthening technology of planting steel bars
Underpinning reinforcement technology, non-destructive hole-forming reinforcement technology
Reinforcement and reconstruction technology of micro-deep cracks by grouting
Deviation rectification of building structure and foundation and foundation reinforcement technology
Strengthening technology with external steel plate
Case Classification of Tonghua Special Reinforcement Project —— Building Reinforcement and Reconstruction
Bonding technology of high strength fiber such as carbon fiber and steel plate for beam-slab column wall;
Strengthening technology of beam-column steel sleeve;
Section enlargement technology of components
Spraying steel wire (steel bar) concrete technology
Technology of strengthening high strength steel wire mesh with polymer mortar
Extension and reconstruction technology of building storey-adding
Large bay technology for removing bearing wall of brick-concrete structure
Demolition technology of frame beam and column in large bay
Cutting technology of shear wall, beam, column and plate opening
Crack grouting technology
Reinforcement planting technology
Interface treatment technology of new and old concrete
Fire and post-earthquake reinforcement technology
Seismic strengthening and isolation technology
Nondestructive cutting technology
Bonding steel plate reinforcement method refers to a reinforcement method of sticking steel plate with adhesive outside the component. This method is widely used in the reinforcement, reinforcement and repair of buildings, bridges and other projects. 1, which is suitable for general flexural and tensile members under static action.
2, the use of environmental temperature is not more than 5 ~ 60℃, relative humidity is not more than 70% and no chemical corrosion, otherwise effective protective measures should be taken.
3. When the concrete strength grade of members is lower than Cl5, the reinforcement principle of this method should not be adopted.
The earliest code for concrete structures strengthened with carbon fiber sheets in China is the Technical Specification for Concrete Structures Strengthened with Carbon Fiber Sheets in 2003, numbered CECS 146: 2003. It has been replaced by the latest national standard code "Code for Design of Strengthening Concrete Structures" in 2006, and its number is GB 50367-2006. The carbon fiber sheet is bonded to the surface of the component through a matching bonding material, so that the carbon fiber sheet can bear the tensile force. Fiber cloth has excellent physical properties such as high strength, light weight, corrosion resistance and fatigue resistance, as well as good adhesion and wide applicability. It is a new technology to strengthen concrete structures with carbon fiber sheets instead of steel plates in recent years.
application area
Fiber materials (carbon fiber cloth, carbon fiber board, aramid fiber, glass fiber) are used to strengthen and repair concrete structures, which is to stick carbon fiber cloth on the concrete surface with matching bonding resin to play the role of structural reinforcement and seismic reinforcement. It is widely used in the reinforcement of building beams, slabs, columns and walls, bridges, tunnels, chimneys, silos and other civil engineering.
building technology
Surface treatment → painting primer → repairing and leveling → preparing composite materials → sticking carbon fiber → surface protection → inspection → enlarging cross-section reinforcement technology, also known as concrete wrapping reinforcement technology, is used to increase the cross-section and reinforcement of components to improve their strength, rigidity, stability and crack resistance, and can also be used to repair cracks. This reinforcement technology has a wide range of applications, and can reinforce plates, beams, columns, foundations and roof trusses. According to the stress characteristics of members, the requirements of reinforcement purpose, the geometric size of members and the convenience of construction, it can be designed as one-sided, two-sided or three-sided reinforcement and four-sided wrapping reinforcement.
According to the different purposes and requirements of reinforcement, this technology can be divided into enlarging the cross section, reinforcing with steel bars or both. In order to ensure the normal work of supplementary concrete, structural steel bars should also be properly configured for steel bars with larger cross sections. In order to ensure the normal work of reinforcement, the section size should be appropriately increased according to the structural requirements such as reinforcement spacing and protective layer. During reinforcement, steel bars should be welded to make the new and old concrete combine well.
The disadvantage of increasing section reinforcement technology is that the wet work on site is heavy and the maintenance period is long, which has a certain impact on production and life. This technology increases the section size, which sometimes affects the appearance and clearance of the house. Reinforcement planting technology, also known as reinforcement rooting technology, is to drill holes in the original concrete structure, inject structural glue, and insert new reinforcement into the holes by rotation. This technology is widely used in design changes, adding beams, columns, cantilever beams, slabs and other reinforcement and change projects.
1, anchorage of various equipment foundations;
2. Enlarge the foundation pile caps;
3. Reinforcement planting and anchor bolt anchorage of various building structures;
4, cantilever beam, plate and other structural functions change;
5. Anchorage of railways and rails;
6. Installation and anchorage of curtain wall and chemical equipment, management and billboards;
Anchorages for water conservancy facilities, docks, highways, slope protection, bridges and other projects. Structural underpinning technology refers to the functional transformation of the original load-bearing structure that affects the use function of the building by changing the stress system, in order to obtain a more ideal use space. Structural underpinning methods generally include steel underpinning, reinforced concrete underpinning and truss underpinning.
Foundation underpinning technology refers to the subway or underground tunnel built in the city inevitably passing under the building. In order to avoid demolition and reconstruction, pile foundation underpinning must be carried out for ground buildings. This technology mainly uses the beam transfer floor near the pile cap to transfer the upper load borne by this pile foundation to the new pile foundation outside the tunnel and replace it with the underpinning structure system composed of underpinning beam and new pile. At the same time, in order to ensure that the underpinning buildings will not be damaged due to cracking and inclination after the broken piles and tunnels pass through, technologies such as prestressed tensioning of underpinning beams, jack-up and grouting at the bottom of piles are adopted, and many patented technologies such as miniature rock-socketed steel pipe cast-in-place piles and concrete interface connection technology can be applied to pile foundation underpinning. 1. Before preparing for construction, read the design and construction drawings carefully, and the structural surface must be cleaned. According to the design drawings, the setting-out shall indicate the drilling position of the anchorage point of steel bar, and after indicating the drilling position, the person in charge at the site shall conduct line inspection.
4. According to the requirements of design drawings, specify the anchoring position, aperture and anchoring depth of the drilled bolt.
3. Borehole cleaning
(1). After drilling, clean the dust within a radius of 0.5m around the hole, and clean the hole with an air pump and a brush. This process requires three blows and two brushes, that is, three blows and two wipes. After cleaning, soak the cotton silk in acetone to clean the inner wall of the hole, so that the hole is finally clean and dry; In wet conditions, heating rods must be used for drying.
⑵. If drilling with water: rinse the mud in the hole with clear water, wipe the hole with absorbent cotton, and proceed to the next process after the hole is dry. If the construction period is tight, it can be dried with a heating rod.
(3). Seal the cleaned hole with clean cotton silk to prevent dust and foreign matter from falling in.
(4) The person in charge of the site shall inspect the hole cleaning work, ask the general contractor and the supervisor for acceptance, and make a record of the hidden inspection.
4. Reinforcement cleaning
(1). Mark the corresponding position of the steel bar end, and mark the length range of derusting and cleaning; This length range is required to be 50 mm greater than the required anchorage depth.
⑵. Start the polishing machine, remove rust with a wire brush and clean the surface of the steel bar within the length range until it is polished to metallic luster.
(3) Put the derusted steel bars in a dry place and put them in neat patterns.
(4) Soak cotton silk in acetone, and wipe the surface of steel bar within the length range of derusting and cleaning.
5]. All processed steel bars shall be packed neatly and reported to the person in charge of the site for inspection.
5. Reinforcement embedding.
(1). Preparation of adhesive for steel bar anchorage. (Please refer to the corresponding product description for the specific mixing method, or according to the requirements of the on-site person in charge) Requirements: mix in proportion and stir evenly.
2. Buried in blind hole reinforcement; Inject anchoring glue into 2/3 of the hole; Turn the derusting end of the processed steel bar towards the hole and in the same direction at the same time, and slowly insert the steel bar into the hole until it reaches the bottom of the hole. At this point, if there is no anchor glue overflowing from the hole, it means that the injected glue is not enough, so the steel bar must be pulled out, re-injected and re-inserted until the glue overflows the hole.
⑶. Embedding of through-hole reinforcement: First, insert the processed reinforcement into the hole, and seal both ends of the hole with epoxy mortar. When sealing, one end is reserved with glue injection holes, and the other end is reserved with air holes; High-pressure glue injection can be carried out only after epoxy mortar is solidified. Put the prepared anchoring glue into the glue tube and install the glue nozzle; Injecting anchoring glue into the hole through the glue injection hole until the glue overflows from the air outlet at the other end; Then use epoxy mortar or other materials to block the glue injection hole and air outlet.
(4). When the vertical through-hole reinforcement is planted, the previous steps are the same as Article 3. When injecting glue, the glue should be injected upward from the glue injection port at the bottom of the hole and discharged from the air outlet at the upper part of the hole.
5]. Protect the embedded steel bars and hang obvious signs. In order to prevent the anchoring glue from shaking or colliding during the curing time, the embedding effect is affected.
[6]. Dip the cotton silk in a little acetone, clean up the glue left by the working face, and clean up the garbage on the working face. Note: When cleaning up the residual glue, handle it carefully, and don't shake or bump the steel bar.
Once. Report the inspection to the person in charge of the site.
6. Before the finished protective anchoring glue is cured, the embedded steel bars shall be trimmed and fixed as necessary; Make signs and signs.