Reinforcing method of concrete member and anchoring seat of tensioning end

Abstract

The application provides a reinforcing method for a concrete member and a tension end anchorage seat, and the reinforcing method comprises the following steps: S10, selecting a tension end anchorage seat, a fixed end anchorage seat and a carbon fiber plate with a preset specification; S20, polishing the base surface of the concrete member; S30, fixing an anchor bolt on the concrete member; S40, installing the tension end anchorage seat, the fixed end anchorage seat and the carbon fiber plate, and placing a limiting block between the tension end anchorage seat and the concrete member; S40, welding the tension end anchorage seat and the corresponding anchor bolt; S50, reserving an injection port which is in communication with a pouring space; S60, injecting grouting liquid into the pouring space from the injection port and solidifying; and S70, completing installation. The reinforcing method for the concrete member and the tension end anchorage seat provided by the application reduce the risk of shear pry damage of the concrete when the carbon fiber plate is tensioned.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bridge reinforcement, and particularly relates to a reinforcing method for a concrete member and a tensioning end anchorage seat. BACKGROUND

[0002] With the gradual formation of the national road network, the work focus of the transportation infrastructure construction industry gradually shifts from new construction to both construction and maintenance. Bridge reinforcement and reconstruction is a hot industry emerging under this background. Carbon fiber plates are popular in structural reinforcement and strengthening projects due to their high-quality material properties and convenient and efficient practical performance. The prestressed carbon fiber plate reinforcement technology is a more active and efficient reinforcement technology with a broad application prospect and value, which is derived from the design idea of prestressed reinforced concrete and combines the light weight and high strength characteristics of the carbon fiber plate reinforcement technology.

[0003] However, bridge reinforcement design is different from new design and is subject to many limitations of the existing structure. Since the carbon fiber plate tensioning is first performed by punching and planting a steel bar in the two-end carbon fiber plate anchorage seat and the tensioning process, the fixed-end anchorage seat is usually located near the end support of the reinforced beam body. At this time, the fixed-end anchorage seat is in the compression zone due to the influence of the negative bending moment. However, the tensioning-end anchorage seat is prone to be in the transition section of the tension zone and the compression zone of the reinforced beam due to the need for arranging the tensioning tooling and reserving the tensioning space, that is, the tensioning-end anchorage seat is subjected to shear force. Although the high tensile strength of the steel bar and the excellent compressive performance of the concrete can provide good bearing capacity and durability in the tension zone and the compression zone, in the shear zone, the load-carrying capacity of the steel bar and the concrete itself decreases, and the internal stress of the reinforced concrete is unbalanced. In this area, the concrete is filled with a large number of micro cracks, and the brittle failure of the concrete around the hole after punching and planting a steel bar is prone to occur. The concrete is also prone to shear failure during the tensioning of the prestressed carbon fiber plate. SUMMARY

[0004] The embodiments of the present application provide a reinforcing method for a concrete member and a tensioning-end anchorage seat, which aims to realize the mixed reinforcement of the bending resistance and the normal section compression resistance of the concrete member, reduce the risk of shear failure of the concrete during the tensioning of the carbon fiber plate, and improve the tensioning safety and the load-holding stability of the reinforced member.

[0005] In a first aspect, the embodiments of the present application provide a reinforcing method for a concrete member, which comprises the following steps.

[0006] S10: selecting a tensioning-end anchorage seat, a fixed-end anchorage seat, and a carbon fiber plate of a preset specification;

[0007] S20: polishing the base surface of the concrete member;

[0008] S30: fixing an anchor bolt on the concrete member;

[0009] S40: install the tension end anchorage seat, the fixed end anchorage seat and the carbon fiber plate, when installing the tension end anchorage seat, place a limiting block between the tension end anchorage seat and the concrete member to form a pouring space with a spacing d between the tension end anchorage seat and the concrete member;

[0010] S40: weld the tension end anchorage seat and the corresponding anchor bolt;

[0011] S50: seal the periphery of the tension end anchorage seat with edge sealing glue, and reserve an injection port in communication with the pouring space;

[0012] S60: inject grouting liquid into the pouring space from the injection port, and solidify;

[0013] S70: complete the installation and complete the reinforcement by tensioning the carbon fiber plate.

[0014] Compared with the prior art, the scheme shown in the embodiments of the application has the following effects:

[0015] (1) By injecting grouting liquid into the grouting space, the grouting liquid after solidification forms a force whole with the tension end anchorage seat and the reinforced concrete member, reducing the risk of shear pry damage of the concrete during tensioning of the carbon fiber plate; the shear zone of the concrete member is given a compressive force of the normal section by the adhesion of the tension end anchorage seat and the pressure grouting of the grouting liquid, relieving the problem of stress imbalance between the internal concrete and the steel bar;

[0016] (2) Most of the existing road and bridge reinforced bridges are hollow slab beams poured, and the base thickness of the reinforced surface is generally only about 200mm. When prestressed carbon fiber plates are used for reinforcement, the anchor bolts used for the anchorage seat are generally M16, M20, M24 specifications. According to GB 50367, the M16 anchoring depth is 125mm, the M20 anchoring depth is 165mm, and the M24 anchoring depth is 195mm. It can be found that the anchoring depth is extremely close to the base thickness. In addition, the main reinforcement in the concrete is arranged in the deep part of the concrete, and the anchoring depth cannot meet the standard requirements when punching and anchoring the steel bar. Through the thickness of the grouting space and the thickness of the tension end anchorage seat, and the close combination with the concrete, the anchoring depth of the anchor bolt is increased, and the shear pry resistance of the concrete in this area is further improved, reducing the safety hazards in construction;

[0017] (3) In the tensioning process, the tensioning end anchorage seat is arranged in the transition zone of the tension and compression area. In the tensioning process, due to the difference between the steel and the concrete elastic modulus under the action of shear force, the stress in this area is unbalanced, and a large number of micro cracks are filled. In the process of injecting the grouting liquid, the viscosity and pressure of the grouting liquid can be conveniently controlled to solve the problem that the internal concrete of the shear area is filled with a large number of micro cracks. The grouting liquid can penetrate into the cracks to repair the existing cracks, which is beneficial to improve the anchoring shear strength of the concrete during tensioning.

[0018] (4) The tensioning end anchorage seat and the corresponding anchor are further connected by welding. Specifically, the anchor hole can be sealed by brazing, so that the tensioning end anchorage seat and the anchor cooperate with each other during tensioning to improve the tensioning strength.

[0019] In combination with the first aspect, in a possible implementation manner, the S20 step includes:

[0020] S21: The carbon fiber plate and the fixed end anchorage seat are ground to the base surface of the concrete member.

[0021] S22: The surface loose layer of the concrete member corresponding to the tensioning end anchorage seat is ground to expose the new aggregate, and then the surface is roughened.

[0022] In combination with the first aspect, in a possible implementation manner, the S30 step includes:

[0023] Drilling holes in the concrete member, anchoring the anchor by using anchoring glue or chemical agents, ensuring the perpendicularity of the anchor, and solidifying.

[0024] In some embodiments, when the anchoring glue is used, the anchoring glue is solidified by using a first solidifying agent, the grouting liquid is solidified by using a second solidifying agent, and the first solidifying agent and the second solidifying agent are of the same type and have the same solidifying mechanism.

[0025] In combination with the first aspect, in a possible implementation manner, the viscosity of the grouting liquid is ≤200 MPa, and the grouting pressure is 0.5-1 MPa.

[0026] In combination with the first aspect, in a possible implementation manner, a plurality of limiting blocks are arranged in an array, and the spacing between adjacent limiting blocks is 50-100 mm.

[0027] In some embodiments, the height of the limiting block is the spacing d, and the spacing d is 5-10 mm.

[0028] In combination with the first aspect, in a possible implementation manner, the limiting block is a semi-elliptical member, and the long axis direction of the limiting block coincides with the tensioning direction.

[0029] In a second aspect, the embodiments of the present application further provide a tensioning end anchorage seat, comprising:

[0030] a seat body; and

[0031] a limiting block arranged on a mounting side of the seat body, the mounting side being used for mounting towards a concrete member.

[0032] In combination with the second aspect, in a possible implementation manner, a plurality of limiting blocks are arranged in an array, the limiting blocks are semi-elliptical block members, and a long axis direction is used for coinciding with a tensioning direction. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 a use state schematic diagram of the tensioning end anchorage seat provided by the embodiments of the present application;

[0034] Fig. 2 a three-dimensional structure schematic diagram of the tensioning end anchorage seat provided by the embodiments of the present application.

[0035] MARK NUMBER EXPLANATION:

[0036] 10, a tensioning end anchorage seat; 11, a seat body; 12, a limiting block;

[0037] 20, a fixed end anchorage seat;

[0038] 30, a carbon fiber plate. DETAILED DESCRIPTION

[0039] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly understood, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0040] The prestressed carbon fiber plate reinforcement system in the technical field mainly comprises an anchorage seat, a carbon fiber plate 30, a tensioning machine and a pressing strip and the like components, and its use principle is that, for a member to be reinforced, a carbon fiber plate 30 coated with carbon plate glue is prestressed and tensioned, so that the carbon fiber plate 30 and the member (for example, a concrete member) form a unified whole, and the load bearing capacity of the member is improved.

[0041] Now, the reinforcement method of the concrete member provided by the present application will be described. The reinforcement method of the concrete member comprises the following steps:

[0042] S10: selecting a tensioning end anchorage seat 10, a fixed end anchorage seat 20 and a carbon fiber plate 30 of a preset specification;

[0043] S20: polishing a base surface of the concrete member;

[0044] S30: fixing the anchor bolt on the concrete member;

[0045] S40: installing the tension end anchorage seat 10, the fixed end anchorage seat 20 and the carbon fiber plate 30, when installing the tension end anchorage seat 10, placing the limiting block 12 between the tension end anchorage seat 10 and the concrete member to form a pouring space with a spacing d between the tension end anchorage seat 10 and the concrete member;

[0046] S40: welding the tension end anchorage seat 10 with the corresponding anchor bolt;

[0047] S50: sealing the periphery of the tension end anchorage seat 10 with edge sealing glue, and reserving an injection port communicating with the pouring space;

[0048] S60: injecting grouting liquid into the pouring space from the injection port, and solidifying;

[0049] S70: completing the installation, and completing the reinforcement by tensioning the carbon fiber plate 30.

[0050] It should be noted that the tensioning of the carbon fiber plate 30 described in step S70 is according to the process in the existing prestressed carbon fiber plate reinforcement technology, and the carbon fiber plate 30 is tensioned and fixed to improve the load-bearing capacity of the concrete member.

[0051] The reinforcement method of the concrete member provided in the embodiment has the following effects compared with the prior art:

[0052] (1) By injecting grouting liquid into the grouting space, the solidified grouting liquid forms a force whole with the tension end anchorage seat 10 and the reinforced concrete member, reducing the risk of shear pry damage of the concrete during tensioning of the carbon fiber plate 30; the adhesion of the tension end anchorage seat 10 and the pressure grouting of the grouting liquid give the shear zone of the concrete member a compressive force of the normal section, relieving the problem of force imbalance between the internal concrete and the steel, and realizing the mixed reinforcement of the bending resistance and the normal section compression resistance of the concrete member;

[0053] (2) The existing bridge reinforcement bridge is mostly hollow slab beam pouring, and the base surface thickness of the reinforcement surface is generally only about 200 mm. When using prestressed carbon fiber plate reinforcement, the anchor bolt used by the anchor seat is generally M16, M20, M24 specifications. According to GB 50367, the M16 anchoring depth is 125 mm, the M20 anchoring depth is 165 mm, and the M24 anchoring depth is 195 mm. It can be found that the anchoring depth is extremely close to the base surface thickness. In addition, the main reinforcement in the concrete is arranged in the deep part of the concrete, and the anchoring depth cannot meet the standard requirements when punching the steel bar. Through the thickness of the grouting space and the thickness of the tension end anchor seat 10, and the close combination with the concrete, the anchoring depth of the anchor bolt is increased, and the shear resistance of the concrete in this area is further improved, reducing the safety hazards in construction.

[0054] (3) During the tensioning process, the tension end anchor seat 10 is arranged in the transition zone of the tension and compression region. During the tensioning process, due to the difference in stress between the steel bar and the concrete, the stress in this area is unbalanced, and there are a large number of micro cracks. During the injection of the grouting liquid, the viscosity and pressure of the grouting liquid can be easily controlled, and the problem of a large number of micro cracks in the shear zone of the concrete can be solved. The grouting liquid can penetrate into the cracks to repair the existing cracks, which is beneficial to improve the shear resistance of the concrete during tensioning and reduce the risk of shear failure.

[0055] (4) The tension end anchor seat 10 and the corresponding anchor bolt are further connected by welding, and the anchor bolt hole can be sealed by brazing, so that the tension end anchor seat 10 and the anchor bolt can bear force together during tensioning, and the tensioning strength is improved.

[0056] In some embodiments, the above S20 step S20 step includes:

[0057] S21: The carbon fiber plate 30 and the fixed end anchor seat 20 corresponding to the concrete member base surface are ground and treated.

[0058] S22: The surface loose layer of the concrete member base surface corresponding to the tension end anchor seat 10 is ground and treated after exposing the new aggregate.

[0059] In the specific implementation process, the fixed end anchor seat 20 is fixed by anchor bolts, and the tension end anchor seat 10 is also fixed by anchor bolts, but it also needs to be sealed and grouting liquid is injected. The carbon fiber plate 30 is fixed between the fixed end anchor seat 20 and the tension end anchor seat 10, and is bonded to the corresponding base surface after tensioning. By grinding and treating the base surface corresponding to the carbon fiber plate 30, the fixed end anchor seat 20 and the tension end anchor seat 10, the bonding strength of the tension end anchor seat 10 and the base surface can be improved, and the reinforcement effect can be improved.

[0060] In some embodiments, the S30 step described above comprises:

[0061] Drilling holes on the concrete member, anchoring the anchor by anchoring glue or chemical agent, ensuring the perpendicularity of the anchor, and solidifying.

[0062] The installation process of the anchor is reinforced by anchoring glue or chemical agent (containing reaction resin, curing agent and quartz particles), etc., to improve the installation strength and stability of the tensioning end anchor seat 10, thereby meeting the stress conditions during tensioning, ensuring the normal construction, and reducing safety hazards.

[0063] Specifically, the drilling depth on the concrete member is at least: the standard anchoring depth h' - the height of the stopper d' - the thickness of the support b.

[0064] In some embodiments, one specific implementation of the above anchor and grouting liquid can be solidified in the following way: when using anchoring glue, the anchoring glue is solidified by a first curing agent, and the grouting liquid is solidified by a second curing agent, the first and second curing agents are of the same type and have the same solidification mechanism. The types of the first and second curing agents are the same, but they are not necessarily the same model. The anchoring glue and the grouting liquid use the same type of curing agent to form the same solidification system, and the strength and modulus are also the same, which can ensure that the contact surface between the anchoring glue and the grouting liquid forms a chemical bond, improves the compatibility, and enhances the load capacity of the entire device.

[0065] In some embodiments, one specific implementation of the above grouting liquid, the viscosity of the grouting liquid is ≤200MPa, and the grouting pressure is 0.5-1MPa. The limitation of the viscosity of the grouting liquid and the grouting pressure can improve the reinforcement effect, which is conducive to improving the concrete anchor shear strength during tensioning. The viscosity range belongs to low viscosity, and the grouting pressure in this range can effectively repair existing cracks.

[0066] In some embodiments, one improved implementation of the above stopper 12 can adopt the structure as shown in Figs. 1-2 Referring to Figs. 1-2 , the stopper 12 is provided with a plurality of stoppers 12, and the plurality of stoppers 12 are arranged in an array, and the spacing between adjacent stoppers 12 is 50-100mm. The stopper 12 is provided with a plurality of stoppers 12, which can ensure the horizontal degree of the tensioning end anchor seat 10 during installation, and reduce the installation difficulty; and the uniform distribution of the stopper 12 can control the uniformity of the grouting liquid and improve the grouting effect.

[0067] It should be noted that the multiple limiting blocks 12 can be arranged in a rectangular array or a ring array. When the multiple limiting blocks 12 are arranged in a rectangular array, the distance between one of the limiting blocks 12 and the surrounding adjacent limiting blocks 12 is 50 to 100 mm. When the multiple limiting blocks 12 are arranged in a ring array, the distance between adjacent limiting blocks 12 along the radial direction of the ring array is 50 to 100 mm.

[0068] In some embodiments, an improved implementation of the aforementioned limiting block 12 may employ, as follows: Figs. 1-2 The structure shown. See also Figs. 1-2 The height of the limiting block 12 is the aforementioned spacing d, and the value of spacing d ranges from 5 to 10 mm. That is, the height of the limiting block 12 is the thickness of the pouring space. By adjusting the height of the limiting block 12, the thickness of the pouring space can be changed, and the amount of grout poured can be adjusted to meet the requirements of the positive section compressive strength reinforcement of concrete.

[0069] In some embodiments, a specific implementation of the aforementioned limiting block 12 may employ the following method: Figs. 1-2 The structure shown. See also Figs. 1-2 The limiting block 12 is a semi-elliptical component, and its major axis coincides with the tensioning direction. The alignment of the major axis with the tensioning direction ensures the maximum area of ​​the grouting material in the tensioning direction.

[0070] In some embodiments, one of the steps in S10 above includes the following steps:

[0071] S11: Select the appropriate anchor bolt size based on the required tensile load capacity.

[0072] Tensile load N = φ * f * A1

[0073] Where: N - Design value of tensile load on the anchor bolt (N / mm²) 2 );

[0074] φ - Seismic reduction coefficient for tensile load on anchor bolts: 1.00 for seismic intensity zone 6 and below; 0.85 for seismic intensity zone 7; 0.75 for Class I, II and III sites in seismic intensity zone 8.

[0075] f-Anchor bolt strength design value for tensile calculations (N / mm²) 2 The standards adopted are shown in Table 1.

[0076] A1 - Effective cross-sectional area of ​​the anchor bolt (mm²) 2 ).

[0077] Table 1

[0078]

[0079] S12: According to the selected anchor specification, the anchoring depth h of the anchor is determined according to GB 50367;

[0080] S13: According to the distance s >= 3.0h, the value of the distance s is selected, and the ideal conical projection area A2 = s*s is calculated;

[0081] S14: Position the center line, and determine the bolt hole positions of the tension end and the fixed end based on the length and elongation of the carbon fiber plate 30;

[0082] The distance between the anchoring holes of the tension end and the fixed end = the working length of the carbon fiber plate 30 + the length of the anchoring block on both sides + the elongation of the carbon fiber plate 30 + the reserved length + the hole edge distance on the anchoring seat.

[0083] By selecting the specification of the anchor, and then calculating the ideal conical projection area, a tension end anchoring seat 10 with a larger area than the ideal conical projection area A2 can be selected, thereby obtaining a tension end anchoring seat 10 of a predetermined specification, and avoiding the problem of shear failure of the carbon fiber plate 30 during tensioning due to the shear resistance of the concrete.

[0084] Based on the same inventive concept, the embodiments of the present application also provide a tension end anchoring seat 10, which comprises a seat body 11 and a limiting block 12, the limiting block 12 is arranged on the installation side of the seat body 11, and the installation side is used for installation towards the concrete member.

[0085] Compared with the prior art, the tension end anchoring seat 10 is installed on the corresponding concrete member (also called beam body), then the fixed end anchoring seat 20 is installed correspondingly, because the limiting block 12 abuts on the concrete member, the gap with the limiting block 12 is formed between the tension end anchoring seat 10 and the concrete member, then the grouting liquid is poured into the gap, the installation of the tension end anchoring seat 10 is completed after the grouting liquid is solidified, then the carbon fiber plate 30 is installed between the tension end anchoring seat 10 and the fixed end anchoring seat 20, and the normal tensioning reinforcement work can be carried out. The tension end anchoring seat 10 is integrally arranged with the limiting block 12, the grouting space is formed at the same time when the tension anchoring seat is installed, the position of the limiting block 12 on the tension end anchoring seat 10 is fixed, the limiting block 12 does not need to be fixed one by one, the installation steps are simple, and the installation efficiency is improved; the grouting space is formed between the tension end anchoring seat 10 and the concrete member through the limiting block 12, the reinforced concrete member after grouting is conveniently formed into a stress whole, and the risk of shear pry damage of the concrete during tensioning of the carbon fiber plate 30 is reduced; the shear zone concrete member is given the positive section compression reinforcement force through pressure grouting of the grouting liquid, the problem of stress imbalance between the internal concrete and the steel bar is relieved, and in general, the mixed reinforcement of the bending resistance and the positive section compression of the concrete member is realized, so that the risk of shear pry damage of the concrete during tensioning of the carbon fiber plate is reduced through concrete micro-crack repair, component exposed surface reinforcement and increased anchoring depth, and the tensioning safety and the load holding stability after component reinforcement are improved.

[0086] In some embodiments, one improved embodiment of the limiting block 12 can adopt the structure as shown in Figs. 1-2 Referring to Figs. 1-2 , the limiting block 12 is provided with a plurality of arrayed limiting blocks 12, the limiting block 12 is a semi-elliptical block member, and the long axis direction is used to coincide with the tensioning direction. The limiting block 12 is provided with a plurality of limiting blocks 12, which can ensure the horizontal degree during installation of the tension end anchoring seat 10, and reduce the installation difficulty; and the uniform distribution of the limiting block 12 can control the uniformity of the grouting liquid and improve the grouting effect; the long axis is consistent with the tensioning direction, and the area of the grouting material in the tensioning direction can be ensured to be maximum.

[0087] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for reinforcing concrete members, characterized in that, Includes the following steps: S10: Select the tension end anchor, the fixed end anchor, and the carbon fiber plate of the preset specifications; S20: Grind the base surface of the concrete component; S30: Secure anchor bolts to the concrete member; S40: Install the tension end anchor, the fixed end anchor, and the carbon fiber plate. The tension end anchor is arranged in the transition zone between the tension and compression areas. When installing the tension end anchor, a limiting block is placed between the tension end anchor and the concrete component to form a pouring space with a spacing of d between the tension end anchor and the concrete component. The limiting block is a semi-elliptical component, and the major axis of the limiting block coincides with the tensioning direction. The thickness of the pouring space is changed by adjusting the height of the limiting block, thereby adjusting the amount of grout poured. S50: Weld the tensioning end anchorage to the corresponding anchor bolt; S60: Seal the perimeter of the tensioning end anchor seat with edge sealing adhesive and reserve an injection port that communicates with the casting space; S70: Inject grout into the pouring space from the injection port and allow it to solidify; S80: Installation complete, reinforcement achieved by tensioning carbon fiber plates.

2. The method for strengthening concrete members as described in claim 1, characterized in that, Step S20 includes: S21: The concrete component base surface corresponding to the carbon fiber plate and the fixed end anchor is ground smooth; S22: The loose layer on the surface of the concrete component base corresponding to the tensioning end anchor is ground away to expose the new aggregate, and then roughened.

3. The method for strengthening concrete members as described in claim 1, characterized in that, Step S30 includes: Holes are drilled in the concrete member, and the anchor bolts are anchored using anchoring adhesive or chemical agents to ensure the verticality of the anchor bolts, and then cured.

4. The method for strengthening concrete members as described in claim 3, characterized in that, When using anchoring adhesive, the anchoring adhesive is cured by a first curing agent, and the grouting liquid is cured by a second curing agent. The first curing agent and the second curing agent are of the same type and have the same curing mechanism.

5. The method for strengthening concrete members as described in claim 1, characterized in that, The viscosity of the grouting fluid is ≤200MPa, and the grouting pressure is 0.5~1MPa.

6. The method for strengthening concrete members as described in claim 1, characterized in that, The limiting blocks are provided in multiple ways, and the multiple limiting blocks are arranged in an array. The distance between adjacent limiting blocks is 50~100mm.

7. The method for strengthening concrete members as described in claim 6, characterized in that, The height of the limiting block is the spacing d, and the value of the spacing d is in the range of 5~10mm.

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