CN206408544U - A kind of hardened system for lifting concrete structure bearing capacity - Google Patents

Abstract

The utility model discloses a kind of hardened system for lifting concrete structure bearing capacity, hardened system includes arch ring, arch springing and girder steel；The girder steel is connected to connection girder steel bottom surface at the top of the bottom surface of reinforced structure girder, the span centre of arch ring, and two ends of arch ring connect the concrete structures of reinforced structure girder both sides by arch springing respectively.The utility model hardened system can increase substantially the bearing capacity of reinforced structure, and hardened system can be adjusted flexibly, and structure stress is more scientific and reasonable, reinforce efficiency high, convenient later maintenance, quick, and fire resistance is good, and service life is long, and overall economic efficiency is high.

Description

A reinforcement system for improving the bearing capacity of concrete structures

technical field

The utility model belongs to the technical field of concrete structure reinforcement, in particular to a reinforcement system for improving the bearing capacity of concrete structures.

Background technique

At present, there are many methods for strengthening concrete structures, such as pasting steel plates, pasting carbon fibers, steel wire mesh-composite mortar external layer reinforcement, enlarging cross-section reinforcement and external prestress reinforcement, but each method has its shortcomings.

The method of pasting the steel plate is to improve the bearing capacity of the beam by pasting the steel plate at the bottom of the reinforced beam body. The method of pasting the steel plate to strengthen the structure has a single form, and the improvement of the bearing capacity is low. The connection between the steel plate and the concrete beam is a key part, and it is also a weak part. It cannot give full play to the mechanical material properties of the steel, and the rationality of the reinforced structure needs to be further improved.

Pasting carbon fiber, the composite material method realizes the improvement of the beam bearing capacity by pasting carbon fiber composite material at the bottom of the reinforced beam. The carbon fiber composite material method has a low improvement in the load-carrying capacity of the beam body, and the utilization rate of material strength is not high. At the same time, carbon fiber materials have durability and aging problems, especially in complex and harsh environments. Carbon fiber composite materials are not fire-resistant, and fire will lead to loss of load-bearing capacity.

Steel wire mesh-composite mortar additional layer reinforcement method: through the adhesion of permeable polymer mortar with excellent bonding strength and bending strength, it is closely integrated with concrete to improve the bearing capacity of the beam. The disadvantages are: (1) The performance and quality requirements for composite mortar are relatively high, and the products (polymer mortar) available on the market generally have poor performance, and safety and quality problems are prone to occur if they are not specially prepared; (2) High-strength mortar The unit price of stainless steel wire and high-performance composite mortar is relatively high, which is insufficient from an economic point of view. In addition, the reinforcement effect on the structural bearing capacity is limited; (3) Before use, a more detailed technical and economic comprehensive evaluation is required to determine its applicability sex.

Enlarging the section reinforcement method is to increase the cross-sectional area of the concrete structure or structure to improve its bearing capacity and meet the normal use. The increase in the bearing capacity of the structure is low, the construction wet operation time is long, and the load needs to be limited during the concrete curing period, which has a relatively large impact on traffic. After reinforcement, the self-weight of the structure increases and the building space decreases.

In the external prestressing reinforcement method, when it is necessary to strengthen the main stressed structure of the bridge, steel bars or steel wire bundles can be arranged outside the beam body (the bottom of the beam and both sides of the beam) and prestressed to improve the stress condition of the bridge and improve the strength of the bridge. bridge carrying capacity. The existing problems are (1) the external cables are arranged outside the cross section, so it is relatively difficult to prevent corrosion and protection, and is easily affected by the outside world. (2) Stress concentration is easy to occur in the anchorage and steering area, and the local stress is large, which requires high anchorage construction. (3) The tensile force of the external cable is small, and the advantages of high strength of the external cable cannot be fully utilized, and the requirements for anchors and clips are very high. (4) The deformation of external prestressed tendons is inconsistent with the deformation of concrete, which is easy to cause the loss of prestress, and the improvement of the structural bearing capacity is low.

Contents of the invention

The technical problem to be solved by the utility model is to provide a structure that can greatly improve the bearing capacity of the reinforced structure, the reinforcement system can be flexibly adjusted, the structural force is more scientific and reasonable, the reinforcement efficiency is high, the later maintenance is convenient and fast, and the fire resistance is good. A reinforcing system and a construction method for improving the bearing capacity of concrete structures with long service life.

The utility model adopts the following technical solutions to solve the above-mentioned technical problems:

A reinforcement system for improving the bearing capacity of concrete structures, including arch rings, arch feet and steel beams; the steel beams are connected to the bottom of the main beam of the reinforced structure; The two ends are respectively connected to the concrete structures on both sides of the main beam of the reinforced structure through arch feet.

The mid-span top of the arch ring is provided with a support pad, the support is placed on the support pad, and the top of the support is connected to the bottom surface of the steel beam.

The inner side of the concrete structure is provided with embedded parts, and the embedded parts are respectively welded to the ends of the steel mesh and the arch ring, and concrete is poured to form the arch foot.

The top surface of the steel beam is glued to the bottom surface of the main beam of the reinforced structure and fastened by bolts.

There are multiple arch rings, and two adjacent arch rings are connected by transverse connecting beams.

A construction method of a reinforcement system for improving the bearing capacity of a concrete structure, comprising the following steps:

① Prefabricated arch ring;

②Surface treatment of arch foot installation

Clean and roughen the surface of the arch foot installation inside the concrete structure;

③Set up formwork and brackets;

④ binding steel mesh;

⑤ Welding embedded parts and installing arch ring

There are embedded parts at the installation place of the arch foot, weld the steel mesh with the embedded parts, then hoist the arch ring, and weld the end of the arch ring with the embedded parts;

⑥Pouring concrete

Concrete is poured at the installation place of the arch foot to form the arch foot;

⑦Complete the installation of all arch rings 12 and transverse connecting beams

Repeat steps ① to ⑥ until the installation of all arch rings is completed; two adjacent arch rings are connected by a transverse connecting beam, and the top surface of the transverse connecting beam is bolted or welded to the bottom surface of the main beam of the reinforced structure;

⑧ Steel beams are installed at the bottom of the main beam of the reinforced structure

The top surface of the steel beam is pasted to the bottom surface of the main beam of the reinforced structure and strengthened by bolts;

⑨Placing bearing pads and bearings on the top of the mid-span of the arch ring

Use a jack to raise the steel beam, place the bearing pad and the bearing on the top of the mid-span of the arch ring in sequence, and then remove the jack, and the construction is completed.

The utility model has the advantages of:

(1) In terms of carrying capacity improvement. The utility model can greatly improve the bearing capacity of the reinforced structure, and can determine the improvement range of the bearing capacity by flexibly adjusting the rise-span ratio, cross-section form, material grade of the arch ring, cross-section form, material grade, and jacking force of the section steel. , and the later adjustment and maintenance are very convenient and fast.

(2) In terms of structural form. Compared with the existing reinforcement method, the force of the reinforcement system of the utility model is more scientific and reasonable, which can not only give full play to the characteristics of the material, but also make good use of the advantages of reasonable structural design.

(3) Force mechanism. Paste steel plate method, paste carbon fiber method, etc. are reinforced on the basis of the primary stress of the reinforced structure, and the reinforcement efficiency is low. The reinforcement effect of the reinforcement system of the utility model can offset the primary stress and secondary stress of the reinforced structure. The reinforcement efficiency can be close to 100%. Compared with the external prestress reinforcement method, the utility model has a remarkable reinforcement effect, especially there is no problem of prestress loss in the later stage.

(4) Later maintenance. Compared with the existing reinforcement methods, the reinforcement system of the utility model can adjust the reinforcement effect at any time in the later stage, which is convenient and quick, and the service life is much longer than other reinforcement methods, and the comprehensive economic benefits are high.

(5) In terms of fire resistance. A notable problem in the carbon fiber pasting method is that it has poor fire resistance, and the bearing capacity will be lost instantly under the action of a fire. The reinforcement system of the present invention has advantages in fire resistance compared with the carbon fiber pasting method.

Description of drawings

Fig. 1 is a structural schematic diagram of the reinforcement system of the present invention installed on the structure to be reinforced.

Fig. 2 is a schematic plan view of the reinforcement system of the present invention.

In the figure, 1: support, 2: support pad, 3: jacking pad, 4: jack, 5, embedded parts, 6: steel mesh, 7: arch foot, 8: steel beam, 9: reinforced Structural main beam, 10: concrete structure, 11: reinforced structural main beam support, 12: arch ring, 13: horizontal connecting beam.

detailed description

The specific implementation of the utility model will be described in detail below in conjunction with the accompanying drawings and specific examples, but this does not constitute a limitation to the protection scope of the claims of the utility model.

A reinforcement system for improving the bearing capacity of a concrete structure, comprising a support 1, a support pad 2, an arch ring 12, an arch foot 7 and a steel beam 8; the steel beam 8 is connected to the bottom surface of the main beam 9 of the reinforced structure, The support pad 2 is placed on the top of the arch ring 12, the support 1 is placed on the support pad 2, and the top of the support 1 is connected to the bottom surface of the steel beam 8; the two ends of the arch ring 12 are respectively connected to the reinforced structure through the arch foot 7 Concrete structures 10 on both sides of the main beam 9. Both ends of the reinforced structure main beam 9 are respectively connected to the top of the concrete structure 10 through the reinforced structure main beam support 11 .

The inner side of the concrete structure 10 is provided with embedded parts 5, and the embedded parts 5 are respectively welded to the ends of the steel mesh 5 and the arch ring 12 and poured concrete to form the arch foot 7.

The top surface of the steel beam 8 is bonded to the bottom surface of the main beam 9 of the reinforced structure and is strengthened by bolts.

There are multiple arch rings, and two adjacent arch rings are connected by transverse connecting beams.

The construction steps of the above-mentioned reinforcement system for improving the bearing capacity of concrete structures:

①Prefabricated arch ring 12

According to the actual conditions and requirements such as the reinforcement effect to be achieved and the clearance under the bridge, the characteristics of the arch ring 12 such as material grade, cross-sectional form, and rise-span ratio are controlled to manufacture the arch ring 12 .

②Surface treatment at pouring place of arch foot 7

The pouring places of arch feet 7 are respectively located inside the concrete structures on both sides of the reinforced structure. During construction, the concrete surface is required to be clean and free from pollution, impurities, oil stains, dust, etc. First, use a chisel machine to chisel the surface of the concrete to be treated, remove the laitance and debris on the surface, and expose the stressed steel bars. Be careful not to damage the steel bars in the original structure, and then clean it with a rotary wire brush cleaner. Use a blower or a vacuum cleaner to remove floating and fine particles, rinse with a high-pressure water gun, and start construction after drying.

③Establish template and bracket

Set up formwork and supports at the pouring place of arch foot 7. The formwork must have sufficient strength, rigidity and stability, and be able to safely and reliably bear various loads that may occur during construction. Secondly, it must ensure the design shape and size of the structure and the accuracy of the positions of each part. Finally, the joint of the formwork The joints must be tightly closed to ensure no leakage of grout during concrete pouring.

④ Binding steel mesh 6

Reinforcement mesh 6 should be bound strictly according to the requirements of the design drawings, pay attention to the accuracy of the spacing and position of the steel bars, and the binding points should be firm to ensure that the stressed steel bars do not move. The steel bars are connected together in the original structure.

⑤ Weld embedded parts 5, install arch ring 12

The pouring place of arch foot 7 is provided with embedded parts 5 . Weld the reinforcement mesh 6 with the embedded part 5, then hoist the arch ring 12, and weld the ends of the arch ring 12 with the embedded part 5 respectively.

⑥Pouring concrete

Arch foot 7 pours concrete. Concrete grades are selected according to specific construction requirements and reinforcement design calculations. During the pouring process, the vibrating rod should avoid direct contact with the embedded parts and steel bars, and vibrate carefully. After the concrete is formed, maintenance needs to be strengthened to ensure the quality of concrete pouring.

⑦Complete the installation of all arch rings 12 and transverse connecting beams 13

Repeat the above construction steps until the installation of all the arch rings 12 is completed, and finally install the horizontal connecting beam 13. The size of the horizontal connecting beam 13 is determined according to the design calculation, and bolting or welding is used between the horizontal connecting beam 13 and each arch ring.

⑧ Build a construction platform

The next step construction platform is set up between each arch ring 12 to ensure that the strength, rigidity and stability meet the safety production and construction standards.

⑨ Steel beam 8 is installed at the bottom of main beam 9 of the reinforced structure

A. Treatment of the bottom surface of the main beam 9 of the reinforced structure

Release a large sample of the reinforcement position on the bottom surface of the main beam 9 of the reinforced structure, chisel off the surface mortar with a thickness of 2 to 5 mm on the concrete surface in the area where the steel beam 8 is placed, so that the solid concrete is exposed and a smooth rough surface is formed. Chisel light chisel leveling. Then use a steel wire wheel to remove the floating slurry on the surface, remove the loose matter on the surface, and finally blow off the surface dust with compressed air, and wipe the surface with toluene or industrial acetone. For the inferior layer with a large area, polymer cement mortar should be used to repair and smooth it after removal. Wipe clean with acetone before hardening.

B. Embedding anchor screws at the bottom of the main beam 9 of the reinforced structure.

C. Install steel beams 8

The steel girder 8 can be made of section steel or steel plate, and the blanking and processing are carried out according to the actual lofting, and the steel girder 8 is punched according to the screw rod planted on site, and then the upper surface of the steel girder 8 is polished with a grinder or a wire brush The grinding machine is used for rust removal and rough treatment. The greater the roughness of the grinding, the better. The grinding lines should be perpendicular to the force direction of the reinforcement device. Wipe the upper surface of the steel beam 8 dry with absorbent cotton dipped in acetone. Fix the steel beam 8 on the screw rod, and ensure that the gap between the upper surface of the steel beam 8 and the bottom surface of the main beam 9 to be reinforced is more than 3mm, so as to ensure that the thickness of the pouring glue layer is more than 3mm, and the joints of welded steel or steel plates ,finish installation.

D. Prepare structural glue.

E. Edge banding

Seal the edge of the steel beam 8 with edge sealing glue.

F, pouring structural glue

Pour structural glue into the gap between the upper surface of the steel beam 8 and the bottom surface of the main beam 9 of the reinforced structure until the filling is dense, and finally block the pouring hole with edge sealing glue.

G. Surface anti-corrosion treatment of steel beam 8

After steel girder 8 is solidified and compacted, all injection nozzles and exhaust pipes are removed, and dirt and rust spots on the surface of steel girder 8 are removed, and the exposed parts of steel girder 8 are subjected to anti-corrosion treatment.

⑩ Place the support pad 2 and the support 1 on the top of the middle span of the arch ring 12

Use a plurality of jacks 4 to lift the steel beam 8 at the same time, install the bearing pad 2 and the bearing 1 on the top of the mid-span of the arch ring 12, and the bearing 1 is placed on the bearing pad 2 . For protecting the arch ring 12, a jacking backing plate 3 can be placed at the bottom of the jack 4. After the support pad 2 and the support 1 are installed, the jack and the lifting pad 3 are removed, and the construction is completed.

The existing reinforcement methods are all reinforced on the basis of primary stress, such as pasting steel plates and carbon fibers, etc., and the reinforcement efficiency is relatively low. The utility model reinforcement system can offset the primary stress and secondary stress of the structure after installation The effect is controllable and the post-adjustment is convenient and fast. This is the biggest difference between the reinforcement system of this utility model and other reinforcement methods. It can greatly improve the structural bearing capacity and has a significant reinforcement effect.

Taking the monolithic beam as an example, using this reinforcement system and adopting a simplified method, under the action of self-weight load, the structural reinforcement system is calculated from two aspects of theory and finite element calculation:

(1) Theoretical calculation of reinforcement system

The reinforcement efficiency formula is:

In the formula:

η: Strengthening efficiency; M _I : Maximum bending moment in the main beam of the reinforced structure before strengthening; M _II : Maximum bending moment in the main beam of the strengthened structure after strengthening.

Among them, M _I and M _II calculation method:

① Before reinforcement, under the action of self-weight load, the maximum bending moment in the main beam of the reinforced structure is:

Maximum positive bending moment:

In the formula:

M _I - the maximum bending moment in the main girder of the reinforced structure before reinforcement;

q ₁ - the self-weight uniform load of the main beam of the reinforced structure;

l- Calculated length of main girder of reinforced structure.

② After strengthening, under the action of self-weight load, the maximum bending moment in the main beam of the reinforced structure is:

Maximum positive bending moment:

In the formula:

M _II - the maximum bending moment in the main beam of the reinforced structure before strengthening; q ₁ - the self-weight uniform load of the main beam of the reinforced structure;

q ₂ - the self-weight uniform load of the steel beam 8 (shaped steel) at the bottom of the main beam of the reinforced structure;

E ₁ - modulus of elasticity of concrete; E ₂ - modulus of elasticity of steel;

I ₁ - the bending moment of inertia of the main beam section of the reinforced structure;

I ₂ - the bending moment of inertia of the steel beam 8 (shaped steel) section at the bottom of the main beam of the reinforced structure;

③Reinforcement efficiency

In actual reinforcement, light and high-strength materials can be used to reduce q ₂ , not limited to steel, but aluminum alloys can be used. E ₂ I ₂ can be increased by rationally arranging cross-sections, so that the reinforcement efficiency is close to 100%.

(2) Calculation of the finite element calculation of the reinforcement system

In order to verify the reinforcement effect of this patent, ANSYS general-purpose finite element software is used for calculation. The cross-sectional size of the calculated beam is 0.4m×0.5m, and the beam span is 10m. Set a node every 1m) See Table 1 for the deflection.

The thickness of the reinforced steel plate is 0.015m, the span of the reinforced arch ring is 10m, and the height of the arch ring is 4m. The steel material is 40#A I-beam, and the size is 400mm×142mm×10.5mm.

Table 1 Comparison of calculated beams before and after reinforcement

Measurement point number Deflection before reinforcement (mm) Deflection after strengthening (mm) Deflection lift value (mm) 1 0 0 0 2 1.6061 0.6933 0.9128 3 3.0382 1.2988 1.7394 4 4.1591 1.7556 2.4035 5 4.8709 2.0302 2.8407 6 5.1147 2.1167 2.9980 7 4.8709 2.0302 2.8407 8 4.1591 1.7556 2.4035 9 3.0382 1.2988 1.7394 10 1.6061 0.6933 0.9128 11 0 0 0

It can be seen from Table 1 that the deflection (stiffness) of the beam body after reinforcement has been greatly improved by adopting the reinforcement system of the utility model. To further improve, at the same time, the model and quantity of the I-beam of the main arch ring, the model and quantity of the transverse connecting beams and other parameters can be adjusted, that is, the reinforcement effect of the beam body can be adjusted according to different reinforcement requirements.

Claims (5)

1. A reinforcement system for promoting the bearing capacity of concrete structures, characterized in that it comprises arch rings, arch feet and steel beams; the steel beams are connected to the bottom surface of the main girder of the reinforced structure, and the top of the span of the arch rings is connected to the steel beams On the bottom surface, the two ends of the arch ring are respectively connected to the concrete structures on both sides of the main beam of the reinforced structure through arch feet. 2. A reinforcement system for improving the bearing capacity of concrete structures as claimed in claim 1, wherein a support pad is provided on the mid-span top of the arch ring, the support is placed on the support pad, and the top of the support is connected to Steel beam underside. 3. A kind of reinforcement system for improving the bearing capacity of concrete structures as claimed in claim 1, wherein the inner side of the concrete structure is provided with embedded parts, and the embedded parts are respectively welded to the ends of the steel mesh and the arch ring, And pour concrete to form the arch foot. 4. A reinforcement system for improving the bearing capacity of concrete structures according to claim 1, wherein the top surface of the steel beam is pasted to the bottom surface of the main beam of the reinforced structure and fastened by bolts. 5. A reinforcement system for improving the bearing capacity of concrete structures as claimed in claim 1, characterized in that there are multiple arch rings, and two adjacent arch rings are connected by transverse connecting beams.