CN204357147U - The composite reinforcing structure of prestressed reinforced concrete construction flexural member - Google Patents

Abstract

The composite reinforcement structure of the flexural members of the prestressed concrete structure includes prestressed carbon fiber plates, steel plates, and clamping devices respectively provided on the bottom surfaces of the two ends of the concrete structure. The two ends of the carbon fiber plates are stretched and clamped in a clamping On the device, the upper surface of the carbon fiber plate and the bottom surface of the concrete structure are bonded by carbon fiber special glue. The steel plate is set on the lower surface of the carbon fiber plate. Steel glue bonding, chemical bolts vertically downward through the steel plate are arranged in the concrete structure, two rows of chemical bolts are evenly arranged along the length direction of the concrete structure, and fastening nuts are threaded on the chemical bolts. The utility model can make the two materials better cooperate to bear the force, can greatly improve the bearing capacity of the component, significantly improve the cracking disease of the prestressed concrete structure, reduce the reinforcement construction workload, and accelerate the reinforcement construction work progress.

Description

Composite Strengthening Structure of Prestressed Concrete Structures under Flexural Members

technical field

The utility model belongs to the technical field of civil engineering structure reinforcement, in particular to a composite reinforcement structure of a prestressed concrete structure bending member.

Background technique

The fundamental purpose of strengthening the flexural members of prestressed concrete structures is to restore or improve the flexural bearing capacity of the structure. At present, the common methods for flexural strengthening of prestressed concrete structures include: strengthening the structural section rigidity, such as bonding steel and reinforcing reinforcement methods, enlarging section reinforcement methods, and external prestressing reinforcement methods; increasing auxiliary component reinforcement, such as adding piers, replacing Beam; change the structural system, such as changing simply supported to continuous. These methods can improve the flexural bearing capacity of the structure to a certain extent, increase the section stiffness, optimize the internal force distribution of the structure, and ensure the safe use of the structure, but it is often difficult to effectively control the existing diseases of the structure.

In recent years, prestressed fiber sheet (fiber cloth, fiber board) reinforcement technology based on active reinforcement has been gradually popularized and applied. This method can effectively delay the development of cracks in concrete structures. Limited by the low tensile strength of concrete and the insufficient anchorage of carbon fiber materials by existing anchoring methods, prestressed carbon fiber materials are prone to interface shear slip damage with concrete structures, resulting in peeling of carbon fiber materials and concrete, often accompanied by Sudden local brittle fracture damage of fiber filaments, so the improvement of the ultimate flexural capacity of concrete structures by prestressed fiber sheet reinforcement is relatively limited. Bonded steel reinforcement technology is simple in construction, easy to anchor, high in sensory safety, and saves space. When the steel plate is pasted on the surface of the concrete structure, it has good ductility and can significantly improve the ultimate bending bearing capacity of the reinforced structure. However, bonded steel reinforcement is a passive technology, and there are problems such as the steel plate strain lag, the thickness and number of layers of the steel plate are limited (in actual engineering, one layer is generally pasted, and the thickness is between 2mm and 6mm), which seriously restricts bonded steel reinforcement. The improvement level of technology to ultimate bearing capacity.

Considering the limitations of single reinforcement technology, composite reinforcement technology and methods have become a hot spot in the field of structural reinforcement. The existing methods for flexural composite reinforcement of concrete structures are mainly composite reinforcement methods of carbon fiber cloth and steel plates, and there are two types in total.

The main representative of the first type of reinforcement method is "a composite reinforced concrete bending member" published by the utility model patent CN 201649682U. A steel plate is pasted on the outside of the cloth (the width of the carbon fiber cloth is smaller than the width of the steel plate); steel strips are used as U-shaped hoops between the steel plate and the carbon fiber cloth to anchor at the web position of the concrete bending member. This method has the disadvantages of low strength utilization rate of carbon fiber cloth and low anchoring efficiency of the side of the U-shaped hoop of the steel plate. In addition, limited by the large lateral width of some concrete structures (such as bridges), this method has the problem of being unable to install U-shaped hoops for anchorage.

The main representative of the second type of reinforcement method is the "Concrete Structural Steel Plate-FRP Composite Reinforcement Method" published by the invention patent CN 101994398A. The steel plate is pasted on the outside (the width of the steel plate is greater than that of the carbon fiber cloth); chemical bolts are used to anchor and compact the carbon fiber cloth between the steel plate and the concrete. This method can carry out the closed anchorage of the carbon fiber cloth with a fully pasted surface, and the transverse and longitudinal anchoring effects of the carbon fiber cloth are good. However, this method does not apply prestress to the carbon fiber cloth, which wastes the high-strength properties of the carbon fiber material. In addition, the carbon fiber cloth is thin and soft, and the fiber texture is easy to be misaligned and the flocculation is disordered during the pasting construction, so its integrity is poor, which will lead to uneven horizontal and vertical forces on the fiber filaments. The wire is prone to sudden broken wire damage due to local stress concentration.

Utility model content

In order to solve the deficiencies in the prior art, the utility model provides a composite reinforcement structure of the bending member of the prestressed concrete structure, which can not only give full play to the high-strength characteristics of the carbon fiber material, but also significantly improve the crack resistance of the concrete structure (Delaying the generation and development of new cracks and closing existing cracks), it can also greatly improve the ultimate flexural bearing capacity of prestressed concrete structures; at the same time, the closed anchorage is enclosed by the full bonding surface of the steel plate to the prestressed carbon fiber plate, which not only Strengthen the anti-peeling ability between carbon fiber plate, steel plate and concrete, and also make the two materials of steel plate and carbon fiber plate better cooperate to bear the force, and give full play to the excellent performance of the two reinforcement materials.

In order to solve the above technical problems, the utility model adopts the following technical scheme: the composite reinforcement structure of the bending member of the prestressed concrete structure, including carbon fiber plates, steel plates and clamping devices respectively arranged on the bottom surfaces of the two ends of the concrete structure, and the two ends of the carbon fiber plates They are respectively stretched and clamped on a clamping device. The upper surface of the carbon fiber plate and the bottom surface of the concrete structure are bonded by carbon fiber special glue. The carbon fiber special glue forms a carbon fiber glue layer between the upper surface of the carbon fiber plate and the bottom surface of the concrete structure. On the lower surface of the carbon fiber plate, the width of the steel plate is greater than that of the carbon fiber plate. A bonded steel glue layer is formed between the surfaces, and chemical bolts that pass through the steel plate vertically downwards are arranged in the concrete structure. The chemical bolts are evenly arranged in two rows along the length direction of the concrete structure. Press fit with the lower surface of the steel plate.

The clamping device includes an upper splint and a lower splint, the upper splint is fixed on the bottom surface of the concrete structure by anchor bolts, the lower splint is fixed on the lower surface of the upper splint by fixing bolts, and the two ends of the carbon fiber plate are clamped between the upper splint and the lower splint .

Adopt above-mentioned technical scheme, the main installation steps of the utility model are as follows:

(1) Determine the structural reinforcement plan, and reasonably select the reinforcement amount and paste position of carbon fiber plates and steel plates on the bottom surface of the concrete structure to be reinforced. According to the design drawings and the cross-sectional size of the actual structure, reasonably determine the installation position of the clamping device on the bottom of the concrete structure and the sticking position of the carbon fiber plate and the steel plate, and drill holes on the bottom of the concrete structure to be reinforced to install the chemical anchor bolt and anchor the steel plate.

(2) Process the clamping device and the steel plate for reinforcement. Process the upper splint and the lower splint, and drill holes at the positions of the anchor bolts and fixing bolts at the corresponding positions of the upper splint and the lower splint. Purchase the steel plate for reinforcement, and process the bolt holes of the chemical anchor bolts on the steel plate according to the reinforcement calculation plan. The bolt hole spacing and arrangement of the chemical anchor bolts on the steel plate can be reasonably selected according to the specifications and actual conditions.

(3) Positioning and cleaning of carbon fiber plate and steel plate composite reinforcement paste area. Use lines of different colors on the bottom surface of the concrete structure to be reinforced for positioning, and mark the pasting areas of two different reinforcement materials, carbon fiber plates and steel plates. Use an angle grinder to grind the concrete surface in the pasting area of the two materials, and properly rest or fill up the concrete with raised or depressed parts in the bottom concrete pasting area to ensure the smoothness of the entire concrete bottom bonding area. Remove the floating dust and sundries on the concrete bottom of the marking area, wipe each pasting area with alcohol, and stick the carbon fiber board and steel plate after the alcohol has evaporated.

(4) Cleaning of clamping devices and reinforcement materials - carbon fiber plates and steel plates. Clean the rust and floating dust on the surface of the thinner upper splint, thicker lower splint and carbon fiber board, wipe the carbon fiber board pasting area of each component of the clamping device and the cut carbon fiber board with alcohol, and wait until the alcohol evaporates. Carry out carbon fiber board paste. Carry out overall grinding on the steel plate that has been purchased and processed with holes. Use an angle grinder to remove rust, floating dust, and steel chips on the surface of the steel plate, so that the obvious bright silk lines can be seen in the bonding area between the steel plate and the carbon fiber plate.

(5) Install the clamping device at the fixed end of the prestressed tension of the carbon fiber plate. The main construction sequence is: using steel glue and anchor bolts to install the upper splint on one end of the bottom surface of the concrete structure to be reinforced, brushing the glue area on the upper and lower surfaces of the end of the carbon fiber plate, and clamping the lower surface of the upper splint and the upper surface of the lower splint Apply carbon fiber special glue to the area, and tighten the fixing bolts between the upper splint and the lower splint in time to clamp and fix the carbon fiber plate.

(6) Install the clamping device at the prestressed tension end of the carbon fiber plate. The main construction sequence is: apply carbon fiber special glue to the upper and lower surfaces of the other end of the carbon fiber plate, the lower surface of the upper splint, and the clamping area on the upper surface of the lower splint, and tighten the fixing bolts that fix the two splints in time to clamp and fix the carbon fiber plate. After the carbon fiber special glue reaches the required curing strength, the preparation work for the construction of the prestressed tensioning process of the carbon fiber plate is completed.

(7) Carbon fiber plate prestressed tension construction. The main construction sequence is: install the prestressing device of the carbon fiber plate, brush the carbon fiber special glue on the upper surface of the carbon fiber plate, apply tension to the clamping device at the tension end, and after the carbon fiber plate reaches the tension design control force, use Stick steel glue and anchor bolts to install the upper splint at the tension end on the bottom surface of the concrete structure to be reinforced, and finally remove the prestressing device.

(8) Steel plate pasting and anchoring construction. Brush the steel glue on the upper surface of the processed, polished and cleaned steel plate, and use the fastening nut to tighten the chemical anchor bolt to anchor the steel plate in time. The steel glue is compacted so that the glue fills the gap between the steel plate and the carbon fiber board, ensuring that the steel glue can be seamlessly bonded to the carbon fiber board and concrete.

The utility model is not only applicable to the reinforcement of prestressed concrete beam bridge structures with a certain anti-arch, but also suitable for the reinforcement of long-span prestressed concrete bridge structures such as variable-height continuous beam bridges, and also suitable for the reinforcement of reinforced concrete structural members. Compared with a single reinforcement method - only using carbon fiber boards or bonded steel for reinforcement, the utility model has the following outstanding advantages:

(1) The composite reinforcement of prestressed carbon fiber plate and steel plate makes full use of the advantages of the two reinforcement materials, makes up for the shortcomings of the single reinforcement method, and enables the two materials to better cooperate with the force, which can greatly improve the bearing capacity of the component, significantly Significantly improve the cracking disease of prestressed concrete structure.

(2) Installing the chemical bolt anchor steel plate on the bottom of the prestressed concrete structure can compact and compress the prestressed carbon fiber plate, so that the prestressed carbon fiber plate and the bottom of the prestressed concrete structure can be seamlessly bonded, which not only realizes the full integration of the steel plate on the carbon fiber plate The adhesive surface encloses the closed anchorage, which also enhances the anti-stripping ability of the fiberboard, steel plate and concrete surface.

(3) The prestressed carbon fiber plate and steel plate composite reinforcement technology can realize the seamless bonding between the carbon fiber plate, the steel plate and the reinforced concrete bottom. In particular, when the steel plate is anchored on the bottom of a prestressed concrete structure with a certain anti-arch or the concrete bottom of a variable-height continuous beam bridge, tightening the chemical bolts and nuts will have a better effect of anchoring the steel plate and compacting the carbon fiber plate. Secondary tensioning of carbon fiber sheets. It further improves the crack resistance of the prestressed concrete structure; on the other hand, the use of steel plates to anchor the prestressed carbon fiber panels can provide closed protection for the prestressed carbon fiber panels after the adhesive is applied, improving the durability of the carbon fiber special adhesive material. sex.

(4) In the composite reinforcement technology of prestressed carbon fiber plate and steel plate, chemical bolts are used to anchor the steel plate and compact the prestressed carbon fiber plate, so that the prestressed carbon fiber plate does not need additional anchoring measures, which reduces the reinforcement construction workload and shortens the reinforcement construction time. The construction period has accelerated the progress of the reinforcement construction work.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the bottom view of the utility model;

Fig. 3 is an enlarged view of A in Fig. 1 .

Detailed ways

As shown in Fig. 1, Fig. 2 and Fig. 3, the composite reinforcement structure of the prestressed concrete structure flexural member of the present invention includes a carbon fiber plate 1, a steel plate 2 and clamping devices respectively arranged on the bottom surfaces of both ends of the concrete structure 3, The two ends of the carbon fiber plate 1 are respectively stretched and clamped on a clamping device, the upper surface of the carbon fiber plate 1 and the bottom surface of the concrete structure 3 are bonded by carbon fiber special glue, and the carbon fiber special glue is on the upper surface of the carbon fiber plate 1 and the bottom surface of the concrete structure 3 A carbon fiber adhesive layer 4 is formed between them, the steel plate 2 is arranged on the lower surface of the carbon fiber plate 1, the width of the steel plate 2 is larger than the width of the carbon fiber plate 1, and the upper surface of the steel plate 2 is respectively bonded to the lower surface of the carbon fiber plate 1 and the concrete structure 3 by bonding steel Then, the steel glue layer 5 is formed between the upper surface of the steel plate 2 and the lower surface of the carbon fiber plate 1 and the concrete structure 3, and the concrete structure 3 is provided with a chemical bolt 6 that passes through the steel plate 2 vertically downward. Two rows of bolts 6 are evenly arranged along the length direction of the concrete structure 3 , and fastening nuts 7 are threaded on the chemical bolts 6 , and the fastening nuts 7 are tightly fitted with the lower surface of the steel plate 2 .

The clamping device includes an upper splint 8 and a lower splint 9, the upper splint 8 is fixed on the bottom surface of the concrete structure 3 by anchor bolts 10, the lower splint 9 is fixed on the lower surface of the upper splint 8 by fixing bolts 11, and the two ends of the carbon fiber plate 1 are clamped on the Between the upper splint 8 and the lower splint 9.

The main installation steps of the utility model are as follows:

(1) Determine the structural reinforcement scheme, and reasonably select the reinforcement amount and paste position of the carbon fiber plate 1 and the steel plate 2 on the bottom surface of the concrete structure 3 to be reinforced. According to the design drawings and the cross-sectional size of the actual structure, reasonably determine the installation position of the steel plate 2 anchorage on the bottom of the concrete structure 3 and the sticking position of the carbon fiber plate 1 and the steel plate 2, and drill holes on the bottom of the concrete structure 3 to be reinforced to install chemical Anchor anchor steel plate 2.

(2) Process the clamping device and steel plate 2 for reinforcement. Process the upper clamping plate 8 and the lower clamping plate 9, and drill holes at the positions of the anchor bolts 10 and the fixing bolts 11 at the corresponding positions of the upper clamping plate 8 and the lower clamping plate 9. Purchase the steel plate 2 for reinforcement, and process the bolt holes of the chemical anchor bolts on the steel plate 2 according to the reinforcement calculation plan. The bolt hole spacing and arrangement of the chemical anchor bolts on the steel plate 2 can be reasonably selected according to the specifications and actual conditions.

(3) The carbon fiber plate 1 and the steel plate 2 are compositely reinforced and pasted to locate and clean the area. Lines of different colors are used on the bottom surface of the concrete structure 3 to be reinforced for positioning, and the pasting areas of two different reinforcing materials, the carbon fiber plate 1 and the steel plate 2, are marked respectively. Use an angle grinder to grind the concrete surface in the pasting area of the two materials, and properly rest or fill up the concrete with raised or depressed parts in the bottom concrete pasting area to ensure the smoothness of the entire concrete bottom bonding area. Remove the floating dust and sundries on the concrete bottom in the marked area, and wipe the sticking areas with alcohol. The sticking process of carbon fiber plate 1 and steel plate 2 can only be carried out after the alcohol has evaporated.

(4) Cleaning of the clamping device and reinforcing material - carbon fiber plate 1 and steel plate 2. Clean the rust and floating dust on the surface of the thinner upper splint 8, the thicker lower splint 9 and the carbon fiber plate 1, and wipe the carbon fiber plate 1 pasting area of each component of the steel plate 2 anchorage with alcohol and the carbon fiber plate 1 that has been cut. After the alcohol has evaporated, the carbon fiber board 1 can be pasted. Carry out integral grinding to the steel plate 2 that has purchased and processed hole. Use an angle grinder to remove rust, floating dust, and steel chips on the surface of steel 2, so that obvious bright silk lines can be seen in the bonding area between steel plate 2 and carbon fiber plate 1.

(5) Install the clamping device at the fixed end of the prestressed tension of the carbon fiber plate 1. The main construction sequence is as follows: use steel glue and anchor bolts 10 to install the upper splint 8 on one end of the bottom surface of the concrete structure 3 to be reinforced, and apply glue to the upper and lower surfaces of the end of the carbon fiber plate 1 and the lower surface and lower surface of the upper splint 8 . Apply carbon fiber special glue to the clamping area on the upper surface of the splint 9, and tighten the fixing bolts 11 fixing the two splints in time to clamp and fix the carbon fiber plate 1.

(6) Install the clamping device at the prestressed tension end of the carbon fiber plate 1. The main construction sequence is: apply carbon fiber special glue to the upper and lower surfaces of the other end of the carbon fiber plate 1, the lower surface of the upper splint 8, and the clamping area of the upper surface of the lower splint 9, and tighten the fixing bolts 11 to fix the two splints in time. Hold and fix the carbon fiber board 1, and after the carbon fiber special glue reaches the required curing strength, complete the preparation work for the prestressed tensioning process of the carbon fiber board 1.

(7) Carbon fiber plate 1 prestressed tension construction. The main construction sequence is: install the prestressing device of the carbon fiber plate 1, paint the carbon fiber special glue on the upper surface of the carbon fiber plate 1, apply tension to the clamping device at the tension end, and wait until the carbon fiber plate reaches the tension design control force. , using steel glue and anchor bolts 10 to install the upper splint 8 at the tension end on the bottom surface of the concrete structure 3 to be reinforced, and finally remove the prestressing device.

(8) Steel plate 2 pasting and anchoring construction. The upper surface of the finished, polished and cleaned steel plate 2 is coated with steel glue, and the fastening nut 7 for tightening the chemical anchor is used to fasten the steel plate 2 in time. The steel glue 5 is compacted so that the glue fills the gap between the steel plate 2 and the carbon fiber board 1 to ensure the seamless adhesion between the steel glue and the carbon fiber board 1 and the bottom surface of the concrete structure 3 .

The above embodiments are only used to illustrate and not limit the technical solutions of the present utility model. Although the present utility model has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present utility model can still be modified or equivalently replaced. Any modification or partial replacement without departing from the spirit and scope of the present utility model shall fall within the scope of the claims of the present utility model. the

Claims (2)

1. the composite reinforcing structure of prestressed reinforced concrete construction flexural member, it is characterized in that: comprise carbon fiber board, steel plate and be located at the clamping device of bottom surface, concrete structure two ends respectively, the stretch-draw be clamped on a clamping device respectively of the two ends of carbon fiber board, carbon fiber board upper surface is bonding with concrete structure underrun carbon fiber special glue, carbon fiber special glue forms carbon fiber glue-line between carbon fiber board upper surface and concrete structure bottom surface, steel plate is located at carbon fiber board soffit, steel plate width is greater than carbon fiber board width, upper surface of steel plate connects by steel bonding is gluing respectively and between carbon fiber board and the soffit of concrete structure, steel bonding glue at upper surface of steel plate respectively and form steel bonding glue-line between carbon fiber board and the soffit of concrete structure, be provided with vertically downward through the chemical bolt of steel plate in concrete structure, chemical bolt evenly arranges two rows along the length direction of concrete structure, chemical bolt has been threaded clamp nut, clamp nut and lower surface of steel plate compression fit.

2. the composite reinforcing structure of prestressed reinforced concrete construction flexural member according to claim 1, it is characterized in that: described clamping device comprises train wheel bridge and lower plate, train wheel bridge is fixed on concrete structure bottom surface by anchor bolt, lower plate is fixed on train wheel bridge soffit by set bolt, and carbon fiber board two ends are clamped between train wheel bridge and lower plate.