Method for improving bending and shearing resistance of height difference beam by using CFRP (Carbon Fiber Reinforced Plastics) cloth

Abstract

The invention discloses a method for improving the bending and shearing resistance of a height difference beam through CFRP cloth. The method comprises the steps that a to-be-reinforced position is determined; performing surface treatment; repairing and leveling; pasting the carbon fiber cloth; the surface of the to-be-reinforced area is coated with an interface agent; the method comprises the following steps: uniformly smearing a structural adhesive in a to-be-reinforced area at the top of a structural beam, and adhering carbon fiber cloth to the surface of the to-be-reinforced area; inverted-cone-shaped first chemical anchor bolts and inverted-cone-shaped second chemical anchor bolts are driven into the first chemical anchor bolt holes and the second chemical anchor bolt holes correspondingly; steel plate pressing strips I and II are adhered to the surfaces of the chemical anchor bolts I and II by using structural adhesive; seventhly, the high-angle end and the low-angle end of the structural beam are reinforced; a third inverted-cone-shaped chemical anchor bolt and a fourth inverted-cone-shaped chemical anchor bolt are hit into the third chemical anchor bolt hole and the fourth chemical anchor bolt hole correspondingly; inverted-cone-shaped chemical anchor bolts V and VI are driven into the positions of the chemical anchor bolt holes V and VI respectively; the L-shaped angle steel I and the L-shaped angle steel II which are matched with each other in size are respectively adhered to the outer sides of the high-angle end and the low-angle end by using structural adhesive. According to the method, the bending resistance and the shearing resistance of the height difference beam can be improved at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of building engineering reinforcement, and specifically is a method for improving the bending and shearing resistance of height difference beams by using CFRP cloth. Background Art

[0002] Due to natural factors such as material aging and environmental erosion, human factors such as construction errors and cutting corners, changes in functional requirements, and disasters such as fires and earthquakes, some original buildings no longer meet the current use needs, resulting in a large number of houses that need to be renovated. For these buildings, if the method of directly demolishing and rebuilding is adopted, a large amount of resources, funds and manpower will be consumed, and the economic benefits are poor. A more reasonable way is to carry out reinforcement and renovation work on the original structure based on a correct assessment.

[0003] For some building structures, there are beams with a certain height difference on both sides. When reinforcing such building structures, it is necessary to consider the changes in usage functions and the way loads act, and then select appropriate methods to enhance their bending and shear bearing capacity to meet the requirements of building safety. At present, there is no effective reinforcement method that can meet this requirement. Therefore, it is urgent to provide a reinforcement method that can effectively improve the bending and shear performance of height difference beams. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a method for improving the bending and shearing performance of height difference beams by using CFRP cloth. The method has a simple implementation process, fewer construction procedures, a short construction period and high reinforcement efficiency. The method can reliably reinforce the height difference beams and can simultaneously improve the bending and shearing performance of the height difference beams.

[0005] In order to achieve the above object, the present invention provides a method for improving the bending and shearing performance of a height difference beam by using CFRP cloth, comprising a structural beam, wherein the structural beam is a height difference beam, and the two sides of the top of the structural beam respectively have a high bending surface and a low bending surface, and the intersection of the high bending surface and the low bending surface respectively has a high angle end and a low angle end; and further comprising the following steps: Step 1: Determine the location to be reinforced; S11: First, on the bending surfaces on both sides of the top of the structural beam, according to the size of the carbon fiber cloth used and the actual layout position, expand 1 cm outward from the four sides of the corresponding carbon fiber cloth as the boundary position, and then use ink lines to mark the boundary positions, and use the boundary marked areas as the areas to be reinforced; S12: Determine the position of chemical anchor hole 1 at a position 400 mm away from the high angle end on the high bending surface, and determine the position of chemical anchor hole 2 at a position 400 mm away from the low angle end on the low bending surface; determine the positions of chemical anchor holes 3 and 4 in the longitudinal and transverse directions of the high angle end, respectively, and determine the positions of chemical anchor holes 5 and 6 in the transverse and longitudinal directions of the low angle end, respectively; Step 2: Surface treatment; First, grind the concrete surface of the area to be reinforced until the concrete aggregate layer is exposed, and then use a blower to blow clean the surface of the grinded area; Step 3: Repair and leveling; After grinding, the holes and sunken areas on the concrete surface are filled with repair glue; for deeper holes, high-grade cement slurry is used to fill them. Step 4: Paste the carbon fiber cloth; S41: Apply interface agent on the surface of the area to be reinforced at the top of the structural beam and dry it for a set time; S42: first, evenly apply the structural adhesive to the area to be reinforced on the top of the structural beam, then stick the carbon fiber cloth to the surface of the area to be reinforced, and then use a plastic scraper to perform a reciprocating scraping process along the sticking direction until the surface is scraped to a flat state; Step 5: driving inverted cone-shaped chemical anchor bolts 1 and 2; Inverted cone-shaped chemical anchor bolts 1 and 2 are driven into the positions of chemical anchor bolt holes 1 and 2 respectively, and the connection strength between the carbon fiber cloth and the structural beam in the main area of ​​the bending surface on both sides is strengthened by using the driven chemical anchor bolts 1 and 2; Step 6: Paste steel plate layer strip 1 and steel plate layer strip 2; On the surface of the chemical anchor bolt 1, a steel plate pressure strip 1 is adhered by structural adhesive, and the end of the chemical anchor bolt 1 is fixed by the steel plate pressure strip 1; on the surface of the chemical anchor bolt 2, a steel plate pressure strip 2 is adhered by structural adhesive, and the end of the chemical anchor bolt 2 is fixed by the steel plate pressure strip 2; Step 7: Strengthen the high and low angle ends of the structural beam; Inverted cone-shaped chemical anchor bolts 3 and 4 are driven into the positions of chemical anchor bolt holes 3 and 4 respectively, and the driven chemical anchor bolts 3 and 4 are used to strengthen the connection strength between the carbon fiber cloth and the structural beam at the high-angle end. At the same time, the driven chemical anchor bolts 3 and 4 are used as part of the shear reinforcement and share the shear force of a part of the high-angle end. Inverted cone-shaped chemical anchor bolts 5 and 6 are driven into the positions of chemical anchor bolt holes 5 and 6 respectively, and the driven chemical anchor bolts 5 and 6 are used to strengthen the connection strength between the carbon fiber cloth and the structural beam at the low angle end. At the same time, the driven chemical anchor bolts 5 and 6 are used as part of the shear reinforcement and share the shear force of a part of the low angle end. Step 8: Attach L-shaped angle steel 1 and L-shaped angle steel 2; On the outside of the high angle end, an L-shaped angle steel 1 with matching size is pasted with structural adhesive. In this process, the horizontal section of the L-shaped angle steel 1 is covered on the outside of the end of the chemical anchor bolt 3, and the vertical section of the L-shaped angle steel 1 is covered on the outside of the end of the chemical anchor bolt 4. The carbon fiber surface on the outside of the high angle end of the L-shaped angle steel pair is reinforced, and at the same time, the ends of the chemical anchor bolts 3 and 4 are limited and fixed; On the outside of the low-angle end, an L-shaped angle steel 2 of matching size is pasted with structural adhesive. In this process, the vertical section of the L-shaped angle steel 2 covers the outside of the end of the chemical anchor bolt 5, and the horizontal section of the L-shaped angle steel 2 covers the outside of the end of the chemical anchor bolt 6. The carbon fiber surface on the outside of the low-angle end is reinforced with the L-shaped angle steel 2. At the same time, the ends of the chemical anchor bolts 5 and 6 are limited and fixed.

[0006] Furthermore, in order to improve the grinding efficiency and ensure the grinding effect, in step 2, a grinder is used to grind the concrete surface.

[0007] Furthermore, in order to ensure the anchoring strength and improve the shear strength, in step five, the specifications of chemical anchor one and chemical anchor two are both greater than M10; in step seven, the specifications of chemical anchor three, chemical anchor four, chemical anchor five and chemical anchor six are all greater than M10.

[0008] Furthermore, in order to improve the effect of anti-bending reinforcement, in step 4, the carbon fiber cloth is an orthogonal grid structure with a thickness of 5 to 10 mm and a pore size of 2.5 to 12.5 mm.

[0009] As a preference, the carbon fiber cloth used in step 4 is a single-layer or multi-layer structure. When it is a multi-layer structure, adjacent layers of the carbon fiber cloth are bonded with structural adhesive.

[0010] Furthermore, in order to improve the reinforcement effect, in step five, a plurality of chemical anchor bolts 1 are driven in and are evenly distributed along the width direction of the carbon fiber cloth, and a plurality of chemical anchor bolts 2 are driven in and are evenly distributed along the width direction of the carbon fiber cloth.

[0011] Furthermore, in order to improve the reinforcement effect, in step five, a plurality of chemical anchor bolts three are driven in and are evenly distributed along the width direction of the carbon fiber cloth, a plurality of chemical anchor bolts four are driven in and are evenly distributed along the width direction of the carbon fiber cloth; a plurality of chemical anchor bolts five are driven in and are evenly distributed along the width direction of the carbon fiber cloth, a plurality of chemical anchor bolts six are driven in and are evenly distributed along the width direction of the carbon fiber cloth.

[0012] In the present invention, the top of the structural beam is first polished, which can effectively remove impurities such as floating dust, oil stains and loose concrete on the surface that are not conducive to reinforcement, and is conducive to improving the subsequent bonding effect. By repairing and leveling, the holes and concave areas on the concrete surface can be leveled, which is conducive to further improving the subsequent bonding effect. The interface agent is first applied to the area to be reinforced, and then the carbon fiber cloth is pasted with structural adhesive, which can effectively improve the bonding force between concrete and carbon fiber cloth, which is conducive to preventing the later peeling of the carbon fiber cloth and concrete interface, and thus can ensure the reinforcement effect. Therefore, the carbon fiber cloth tightly pasted on the top of the structural beam can be used to significantly improve the bending strength of the structural beam. A chemical anchor bolt 1 is driven into the position 400mm away from the high angle end on the high bending surface, and a chemical anchor bolt 2 is driven into the position 400mm away from the low angle end on the low bending surface. The chemical anchor bolt 1 can be used to further strengthen the connection strength of the carbon fiber cloth and the structural beam in the main area of ​​the high bending surface, and the chemical anchor bolt 2 can be used to further strengthen the connection strength of the carbon fiber cloth and the structural beam in the main area of ​​the low bending surface. The steel plate strips one and two are attached to the outer surfaces of the chemical anchor bolts one and two by using structural adhesive, and the ends of the chemical anchor bolts can be limited and fixed by using the steel plate strips, which is conducive to ensuring the anchoring effect of the chemical anchor bolts. The horizontal chemical anchor bolts and the longitudinal chemical anchor bolts are driven into the high-angle end and the low-angle end of the structural beam, which can not only use the horizontal and longitudinal chemical anchor bolts to strengthen the connection strength of the carbon fiber cloth at the corner end and the structural beam, but also effectively share the shear force at the corner end, thereby improving the shear strength of the corner end. L-shaped angle steels are attached to the outside of the high-angle end and the low-angle end, and the carbon fiber cloth at the corner end can be reinforced by the attached angle steels. At the same time, the ends of the chemical anchor bolts driven into the corner end can be limited and fixed by using the L-shaped angle steels, thereby ensuring that the carbon fiber cloth at the corner and the corner end of the structural beam can be reliably fixed, and preventing the carbon fiber cloth from warping at the corner. The present invention can ensure that the carbon fiber cloth at the high bending surface, low bending surface, high angle end and low angle end of the structural beam can be more closely fitted with the original structural system through multiple composite reinforcement measures, effectively solving the problem of unsatisfactory reinforcement effect caused by loosely pasting the carbon fiber cloth on the height difference beams on both sides, thereby effectively combining the added carbon fiber cloth with the original structural beam into a whole. At the same time, the pasted carbon fiber cloth can effectively prevent the generation of cracks on the height difference beam, ensuring safety and reliability in subsequent use.

[0013] The method has a simple implementation process, fewer construction procedures, a short construction period and high reinforcement efficiency. The structural beam is jointly reinforced by carbon fiber cloth, chemical bolts and angle steels, which can not only ensure the reliable connection between the carbon fiber cloth and the concrete beam, but also effectively anchor the different bending surfaces and corner inflection points of the height difference beam, and at the same time, improve the bending and shearing properties of the height difference beam. According to experimental research and analysis and on-site construction measurement data, this method can increase the bending bearing capacity of the height difference beam by about 20%, and at the same time, increase the shearing bearing capacity of the height difference beam by about 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention.

[0015] In the figure: 1. carbon fiber cloth, 2. chemical anchor bolt 1, 3. steel plate strip 1, 4. L-shaped angle steel 1, 5. structural beam, 6. high bending surface, 7. low bending surface, 8. high angle end, 9. low angle end, 10. chemical anchor bolt 2, 11. steel plate strip 2, 12. L-shaped angle steel 2, 13. chemical anchor bolt 3, 14. chemical anchor bolt 4, 15. chemical anchor bolt 5, 16. chemical anchor bolt 6. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] like Figure 1 As shown, the present invention provides a method for improving the bending and shearing performance of a height difference beam by using CFRP cloth, comprising a structural beam 5, wherein the structural beam 5 is a height difference beam, and the two sides of the top of the structural beam 5 respectively have a high bending surface 6 and a low bending surface 7, and the intersection of the high bending surface 6 and the low bending surface 7 respectively has a high angle end 8 and a low angle end 9; and further comprising the following steps: Step 1: Determine the location to be reinforced; S11: First, on the bending surfaces on both sides of the top of the structural beam 5, according to the size of the carbon fiber cloth 1 used and the actual arrangement position, the positions corresponding to the four sides of the carbon fiber cloth 1 are extended 1 cm outward as the boundary positions, and then the boundary positions are marked with ink lines, and the boundary marked areas are used as the areas to be reinforced; S12: The position of chemical anchor hole one is determined at a position 8400mm away from the high angle end on the high bending surface 6. In order to ensure the subsequent reinforcement effect, the number of chemical anchor hole one is multiple and they are evenly distributed in sequence along the width direction. The position of chemical anchor hole two is determined at a position 9400mm away from the low angle end on the low bending surface 7. In order to ensure the subsequent reinforcement effect, the number of chemical anchor hole two is multiple and they are evenly distributed in sequence along the width direction; the positions of chemical anchor holes three and four are determined in the longitudinal and transverse directions of the high angle end 8 respectively. In order to ensure the subsequent reinforcement effect, the number of chemical anchor holes three and four are both multiple and they are evenly distributed in sequence along the width direction; the positions of chemical anchor holes five and six are determined in the transverse and longitudinal directions of the low angle end 9 respectively. In order to ensure the subsequent reinforcement effect, the number of chemical anchor holes five and six are both multiple and they are evenly distributed in sequence along the width direction; Step 2: Surface treatment; First, grind the concrete surface of the area to be reinforced until the concrete aggregate layer is exposed, and then use a blower to blow clean the surface of the grinded area; Step 3: Repair and leveling; After grinding, the holes and sunken areas on the concrete surface are filled with repair glue; for deeper holes, high-grade cement slurry is used to fill them. Step 4: Paste carbon fiber cloth 1; S41: Applying an interface agent on the surface of the area to be reinforced at the top of the structural beam 5 and drying it for a set time; S42: first, evenly apply the structural adhesive to the area to be reinforced on the top of the structural beam 5, then stick the carbon fiber cloth 1 to the surface of the area to be reinforced, and then use a plastic scraper to perform a reciprocating flattening process along the sticking direction until the surface is scraped to a flat state; Step 5: driving the inverted cone-shaped chemical anchor bolt 1 2 and chemical anchor bolt 2 10; Inverted cone-shaped chemical anchor bolts 1 2 and 10 are driven into the positions of chemical anchor bolt holes 1 and 2 respectively, and the driven chemical anchor bolts 1 2 and 10 are used to strengthen the connection strength between the carbon fiber cloth 1 and the structural beam 5 in the main area of ​​the bending surface on both sides; Step 6: Paste the steel plate layer strip 1 3 and the steel plate layer strip 2 11; On the surface of the chemical anchor bolt 1, a steel plate pressure strip 13 is pasted with structural adhesive, and the end of the chemical anchor bolt 12 is fixed by the steel plate pressure strip 13; on the surface of the chemical anchor bolt 2, a steel plate pressure strip 211 is pasted with structural adhesive, and the end of the chemical anchor bolt 210 is fixed by the steel plate pressure strip 211; Step 7: Strengthen the high angle end 8 and the low angle end 9 of the structural beam 5; Inverted cone-shaped chemical anchor bolts 3 13 and 4 14 are driven into the positions of chemical anchor bolt holes 3 and 4 respectively, and the driven chemical anchor bolts 3 13 and 4 14 are used to strengthen the connection strength between the carbon fiber cloth 1 and the structural beam 5 at the high angle end 8. At the same time, the driven chemical anchor bolts 3 13 and 4 14 are used as a part of the shear reinforcement and share the shear force of a part of the high angle end 8. Inverted cone-shaped chemical anchor bolts 5 15 and 6 16 are driven into the chemical anchor bolt holes 5 and 6 respectively, and the driven chemical anchor bolts 5 15 and 6 16 are used to strengthen the connection strength between the carbon fiber cloth 1 and the structural beam 5 at the low angle end 9. At the same time, the driven chemical anchor bolts 5 15 and 6 16 are used as a part of the shear reinforcement and share the shear force of a part of the low angle end 9. Step 8: Attach L-shaped angle steel 1 4 and L-shaped angle steel 2 12; On the outside of the high angle end 8, an L-shaped angle steel 4 of matching size is pasted with structural adhesive. In this process, the horizontal section of the L-shaped angle steel 4 is covered on the outside of the end of the chemical anchor bolt 3 13, and the vertical section of the L-shaped angle steel 4 is covered on the outside of the end of the chemical anchor bolt 4 14. The carbon fiber surface 1 on the outside of the high angle end 8 is reinforced with the L-shaped angle steel 4, and at the same time, the ends of the chemical anchor bolt 3 13 and the chemical anchor bolt 4 14 are limited and fixed; On the outside of the low-angle end 9, an L-shaped angle steel 12 of matching size is pasted with structural adhesive. In this process, the vertical section of the L-shaped angle steel 12 covers the outside of the end of the chemical anchor 5 15, and the horizontal section of the L-shaped angle steel 12 covers the outside of the end of the chemical anchor 6 16. The carbon fiber surface 1 on the outside of the low-angle end 9 is reinforced by the L-shaped angle steel 12, and at the same time, the ends of the chemical anchor 5 15 and the chemical anchor 6 16 are limited and fixed.

[0018] In order to improve the grinding efficiency and ensure the grinding effect, in step 2, a grinder is used to grind the concrete surface.

[0019] In order to ensure the anchoring strength and improve the shear strength, in step five, the specifications of chemical anchor 1 2 and chemical anchor 2 10 are both greater than M10; in step seven, the specifications of chemical anchor 3 13, chemical anchor 4 14, chemical anchor 5 15 and chemical anchor 6 16 are all greater than M10.

[0020] In order to improve the effect of anti-bending reinforcement, in step 4, the carbon fiber cloth 1 is an orthogonal grid structure with a thickness of 5 to 10 mm and a pore size of 2.5 to 12.5 mm.

[0021] As a preference, the carbon fiber cloth 1 used in step 4 is a single-layer or multi-layer structure. When it is a multi-layer structure, adjacent layers of the carbon fiber cloth 1 are bonded with structural adhesive.

[0022] In order to improve the reinforcement effect, in step five, a plurality of chemical anchor bolts 2 are driven in and are evenly distributed along the width direction of the carbon fiber cloth 1 , and a plurality of chemical anchor bolts 10 are driven in and are evenly distributed along the width direction of the carbon fiber cloth 1 .

[0023] In order to improve the reinforcement effect, in step five, the number of chemical anchor bolts three 13 driven in is multiple, and they are evenly distributed along the width direction of the carbon fiber cloth 1, the number of chemical anchor bolts four 14 driven in is multiple, and they are evenly distributed along the width direction of the carbon fiber cloth 1; the number of chemical anchor bolts five 15 driven in is multiple, and they are evenly distributed along the width direction of the carbon fiber cloth 1, and the number of chemical anchor bolts six 16 driven in is multiple, and they are evenly distributed along the width direction of the carbon fiber cloth 1.

[0024] In the present invention, the top of the structural beam is first polished, which can effectively remove impurities such as floating dust, oil stains and loose concrete on the surface that are not conducive to reinforcement, and is conducive to improving the subsequent bonding effect. By repairing and leveling, the holes and concave areas on the concrete surface can be leveled, which is conducive to further improving the subsequent bonding effect. The interface agent is first applied to the area to be reinforced, and then the carbon fiber cloth is pasted with structural adhesive, which can effectively improve the bonding force between concrete and carbon fiber cloth, which is conducive to preventing the later peeling of the carbon fiber cloth and concrete interface, and thus can ensure the reinforcement effect. Therefore, the carbon fiber cloth tightly pasted on the top of the structural beam can be used to significantly improve the bending strength of the structural beam. A chemical anchor bolt 1 is driven into the position 400mm away from the high angle end on the high bending surface, and a chemical anchor bolt 2 is driven into the position 400mm away from the low angle end on the low bending surface. The chemical anchor bolt 1 can be used to further strengthen the connection strength of the carbon fiber cloth and the structural beam in the main area of ​​the high bending surface, and the chemical anchor bolt 2 can be used to further strengthen the connection strength of the carbon fiber cloth and the structural beam in the main area of ​​the low bending surface. The steel plate strips one and two are attached to the outer surfaces of the chemical anchor bolts one and two by using structural adhesive, and the ends of the chemical anchor bolts can be limited and fixed by using the steel plate strips, which is conducive to ensuring the anchoring effect of the chemical anchor bolts. The horizontal chemical anchor bolts and the longitudinal chemical anchor bolts are driven into the high-angle end and the low-angle end of the structural beam, which can not only use the horizontal and longitudinal chemical anchor bolts to strengthen the connection strength of the carbon fiber cloth at the corner end and the structural beam, but also effectively share the shear force at the corner end, thereby improving the shear strength of the corner end. L-shaped angle steels are attached to the outside of the high-angle end and the low-angle end, and the carbon fiber cloth at the corner end can be reinforced by the attached angle steels. At the same time, the ends of the chemical anchor bolts driven into the corner end can be limited and fixed by using the L-shaped angle steels, thereby ensuring that the carbon fiber cloth at the corner and the corner end of the structural beam can be reliably fixed, and preventing the carbon fiber cloth from warping at the corner. The present invention can ensure that the carbon fiber cloth at the high bending surface, low bending surface, high angle end and low angle end of the structural beam can be more closely fitted with the original structural system through multiple composite reinforcement measures, effectively solving the problem of unsatisfactory reinforcement effect caused by loosely pasting the carbon fiber cloth on the height difference beams on both sides, thereby effectively combining the added carbon fiber cloth with the original structural beam into a whole. At the same time, the pasted carbon fiber cloth can effectively prevent the generation of cracks on the height difference beam, ensuring safety and reliability in subsequent use.

[0025] The method has a simple implementation process, fewer construction procedures, a short construction period and high reinforcement efficiency. The structural beam is jointly reinforced by carbon fiber cloth, chemical bolts and angle steels, which can not only ensure the reliable connection between the carbon fiber cloth and the concrete beam, but also effectively anchor the different bending surfaces and corner inflection points of the height difference beam, and at the same time, improve the bending and shearing properties of the height difference beam. According to experimental research and analysis and on-site construction measurement data, this method can increase the bending bearing capacity of the height difference beam by about 20%, and at the same time, increase the shearing bearing capacity of the height difference beam by about 10%.

Claims

1. A method for improving the bending and shearing performance of a height difference beam by using CFRP cloth, comprising a structural beam (5), wherein the structural beam (5) is a height difference beam, wherein the two sides of the top of the structural beam respectively have a high bending surface (6) and a low bending surface (7), and the intersection of the high bending surface (6) and the low bending surface (7) respectively has a high angle end (8) and a low angle end (9), wherein the structural beam (5) is characterized in that: The following steps are involved: Step 1: Determine the location to be reinforced; S11: First, on the bending surfaces on both sides of the top of the structural beam (5), according to the size of the used carbon fiber cloth (1) and the actual arrangement position, the positions corresponding to the four sides of the carbon fiber cloth (1) are extended 1 cm outward as boundary positions, and then the boundary positions are marked with ink lines, and the boundary marked areas are used as the areas to be reinforced; S12: determining the position of chemical anchor hole one at a position 400 mm from the high angle end (8) on the high bending surface (6), and determining the position of chemical anchor hole two at a position 400 mm from the low angle end (9) on the low bending surface (7); determining the positions of chemical anchor holes three and four in the longitudinal and transverse directions of the high angle end (8), respectively, and determining the positions of chemical anchor holes five and six in the transverse and longitudinal directions of the low angle end (9), respectively; Step 2: Surface treatment; First, grind the concrete surface of the area to be reinforced until the concrete aggregate layer is exposed, and then use a blower to blow clean the surface of the grinded area; Step 3: Repair and leveling; After grinding, the holes and sunken areas on the concrete surface are filled with repair glue; for deeper holes, high-grade cement slurry is used to fill them. Step 4: Paste the carbon fiber cloth (1); S41: Applying an interface agent to the surface of the area to be reinforced at the top of the structural beam (5) and drying it for a set time; S42: first, evenly apply the structural adhesive to the area to be reinforced on the top of the structural beam (5), then adhere the carbon fiber cloth (1) to the surface of the area to be reinforced, and then use a plastic scraper to perform a reciprocating flattening process along the sticking direction until the surface is scraped to a flat state; Step 5: Driving inverted cone-shaped chemical anchor bolt 1 (2) and chemical anchor bolt 2 (10); Driving inverted cone-shaped chemical anchor bolts 1 (2) and 2 (10) at the locations of chemical anchor bolt holes 1 and 2, respectively, and using the driven chemical anchor bolts 1 (2) and 2 (10) to strengthen the connection strength between the carbon fiber cloth (1) and the structural beam (5) in the main area of ​​the bending surface on both sides; Step 6: Paste the steel plate layer strip 1 (3) and the steel plate layer strip 2 (11); On the surface of the chemical anchor bolt 1 (2), a steel plate pressure strip 1 (3) is adhered by structural adhesive, and the end of the chemical anchor bolt 1 (2) is fixed by the steel plate pressure strip 1 (3); on the surface of the chemical anchor bolt 2 (10), a steel plate pressure strip 2 (11) is adhered by structural adhesive, and the end of the chemical anchor bolt 2 (10) is fixed by the steel plate pressure strip 2 (11); Step 7: Reinforce the high corner end (8) and the low corner end (9) of the structural beam (5); Inverted cone-shaped chemical anchor bolts 3 (13) and 4 (14) are driven into the positions of chemical anchor bolt holes 3 and 4 respectively, and the driven chemical anchor bolts 3 (13) and 4 (14) are used to strengthen the connection strength between the carbon fiber cloth (1) and the structural beam (5) at the high angle end (8). At the same time, the driven chemical anchor bolts 3 (13) and 4 (14) are used as a part of the shear reinforcement and share the shear force of a part of the high angle end (8); Inverted cone-shaped chemical anchor bolts 5 (15) and 6 (16) are driven into the chemical anchor bolt holes 5 and 6, respectively, and the driven chemical anchor bolts 5 (15) and 6 (16) are used to strengthen the connection strength between the carbon fiber cloth (1) and the structural beam (5) at the low angle end (9). At the same time, the driven chemical anchor bolts 5 (15) and 6 (16) are used as a part of the shear reinforcement and share the shear force of a part of the low angle end (9); Step 8: Attach L-shaped angle steel 1 (4) and L-shaped angle steel 2 (12); On the outside of the high angle end (8), an L-shaped angle steel (4) of matching size is glued by structural adhesive. In this process, the horizontal section of the L-shaped angle steel (4) covers the outside of the end of the chemical anchor bolt (13), and the vertical section of the L-shaped angle steel (4) covers the outside of the end of the chemical anchor bolt (14). The carbon fiber surface (1) on the outside of the high angle end (8) is reinforced by the L-shaped angle steel (4). At the same time, the ends of the chemical anchor bolt (13) and the chemical anchor bolt (14) are fixed in position. On the outer side of the low angle end (9), an L-shaped angle steel (12) of matching size is adhered by structural adhesive. In this process, the vertical section of the L-shaped angle steel (12) covers the outer side of the end of the chemical anchor bolt (15), and the horizontal section of the L-shaped angle steel (12) covers the outer side of the end of the chemical anchor bolt (16). The carbon fiber surface (1) on the outer side of the low angle end (9) is reinforced by the L-shaped angle steel (12). At the same time, the ends of the chemical anchor bolt (15) and the chemical anchor bolt (16) are fixed in position.

2. The method for improving the bending and shearing performance of height difference beams by using CFRP cloth according to claim 1, characterized in that: In step 2, a grinder is used to grind the concrete surface.

3. A method for improving the bending and shearing performance of height difference beams by using CFRP cloth according to claim 1 or 2, characterized in that: In step five, the specifications of chemical anchor bolt one (2) and chemical anchor bolt two (10) are both greater than M10; in step seven, the specifications of chemical anchor bolt three (13), chemical anchor bolt four (14), chemical anchor bolt five (15) and chemical anchor bolt six (16) are all greater than M10.

4. The method for improving the bending and shearing performance of height difference beams by using CFRP cloth according to claim 3 is characterized in that: In step 4, the carbon fiber cloth (1) is an orthogonal grid structure, with a thickness of 5 to 10 mm and a pore size of 2.5 to 12.5 mm.

5. The method for improving the bending and shearing performance of height difference beams by using CFRP cloth according to claim 4, characterized in that: The carbon fiber cloth (1) used in step 4 is a single-layer or multi-layer structure. When it is a multi-layer structure, adjacent layers of the carbon fiber cloth (1) are bonded together using structural adhesive.

6. The method for improving the bending and shearing performance of height difference beams by using CFRP cloth according to claim 5, characterized in that: In step five, a plurality of chemical anchor bolts 1 (2) are driven in and are evenly distributed along the width direction of the carbon fiber cloth (1), and a plurality of chemical anchor bolts 2 (10) are driven in and are evenly distributed along the width direction of the carbon fiber cloth (1).

7. The method for improving the bending and shearing performance of height difference beams by using CFRP cloth according to claim 6, characterized in that: In step five, a plurality of chemical anchor bolts three (13) are driven in, and are evenly distributed along the width direction of the carbon fiber cloth (1); a plurality of chemical anchor bolts four (14) are driven in, and are evenly distributed along the width direction of the carbon fiber cloth (1); a plurality of chemical anchor bolts five (15) are driven in, and are evenly distributed along the width direction of the carbon fiber cloth (1); a plurality of chemical anchor bolts six (16) are driven in, and are evenly distributed along the width direction of the carbon fiber cloth (1).

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