CN118007986B - Reinforcing method for reinforced concrete space frame node after fire disaster - Google Patents
Reinforcing method for reinforced concrete space frame node after fire disaster Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 21
- 239000011150 reinforced concrete Substances 0.000 title claims abstract description 20
- 230000003014 reinforcing effect Effects 0.000 title claims description 50
- 239000010410 layer Substances 0.000 claims abstract description 101
- 239000000835 fiber Substances 0.000 claims abstract description 96
- 239000004567 concrete Substances 0.000 claims abstract description 39
- 230000002787 reinforcement Effects 0.000 claims abstract description 22
- 239000011248 coating agent Substances 0.000 claims abstract description 11
- 238000000576 coating method Methods 0.000 claims abstract description 11
- 239000002344 surface layer Substances 0.000 claims abstract description 7
- 239000007787 solid Substances 0.000 claims abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- 239000004568 cement Substances 0.000 claims description 15
- 239000004698 Polyethylene Substances 0.000 claims description 12
- 239000003638 chemical reducing agent Substances 0.000 claims description 11
- -1 polyethylene Polymers 0.000 claims description 11
- 229920000573 polyethylene Polymers 0.000 claims description 11
- 239000006004 Quartz sand Substances 0.000 claims description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 10
- 239000010881 fly ash Substances 0.000 claims description 10
- 229910021487 silica fume Inorganic materials 0.000 claims description 10
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 9
- 239000011707 mineral Substances 0.000 claims description 9
- 239000000843 powder Substances 0.000 claims description 9
- 239000002994 raw material Substances 0.000 claims description 9
- 239000002562 thickening agent Substances 0.000 claims description 9
- 238000005266 casting Methods 0.000 claims description 6
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- 239000004917 carbon fiber Substances 0.000 claims description 5
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 5
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- 238000010276 construction Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 238000010008 shearing Methods 0.000 description 5
- 239000010959 steel Substances 0.000 description 5
- 238000005336 cracking Methods 0.000 description 3
- 230000000452 restraining effect Effects 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 229920002430 Fibre-reinforced plastic Polymers 0.000 description 2
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G23/00—Working measures on existing buildings
- E04G23/02—Repairing, e.g. filling cracks; Restoring; Altering; Enlarging
- E04G23/0218—Increasing or restoring the load-bearing capacity of building construction elements
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
- E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
- E04B1/18—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons
- E04B1/20—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons the supporting parts consisting of concrete, e.g. reinforced concrete, or other stonelike material
- E04B1/21—Connections specially adapted therefor
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/07—Reinforcing elements of material other than metal, e.g. of glass, of plastics, or not exclusively made of metal
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A30/00—Adapting or protecting infrastructure or their operation
- Y02A30/30—Adapting or protecting infrastructure or their operation in transportation, e.g. on roads, waterways or railways
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Abstract
The invention relates to the technical field of concrete reinforcement engineering in civil engineering, in particular to a reinforcement method after a fire disaster of a reinforced concrete space frame node; the method comprises the following steps: removing the seriously damaged concrete after fire disaster on the surface layer of the reinforced concrete frame node, and leaking out a solid structural layer; carrying out rough treatment on the removed structure surface, coating or pouring a first layer of high-strength ECC on the structure surface subjected to the rough treatment, coating a fiber grating, and coating or pouring a second layer of high-strength ECC after the fiber grating is positioned accurately, so that the reinforcement work can be completed; according to the invention, the fiber grids are stuck to the positions of the node core area and the column ends, the main beam ends and the secondary beam ends which are close to the core area, ECC is poured, and the beam ends are plastically hinged and transferred outside the reinforced area, so that the integral anti-seismic performance and the deformation capacity of the node are improved.
Description
Technical Field
The invention relates to the technical field of concrete reinforcement engineering in civil engineering, in particular to a reinforcement method after a fire disaster of a reinforced concrete space frame node.
Background
The overall performance of the frame structure depends on the stability of the beams and columns, while the stress performance of the joints is more critical. In early frame house construction, the design and construction of the nodes was not considered for the earthquake-proof design, and the nodes were the most vulnerable sites. In particular, the shear load capacity of the node core area is weakened under the influence of high temperature fire, resulting in brittle shear failure. Therefore, in order to reduce social and economic losses, prolong the service life of the structure and ensure the life safety of people, the beam column node reinforcing and repairing technology after a high-temperature fire disaster is urgently needed to be studied.
The reinforcement design and construction experience of the current normal temperature component are rich, and the concrete structure repair after fire is basically to directly apply the normal temperature reinforcement technology. However, problems such as reduced space for use due to wet work of the enlarged section method, problems in connection quality of the clad steel and the original member, difficulty in reinforcing the joint by the wire winding method, complicated installation of the external prestress anchor, peeling of the bonding surface of the bonded steel or the bonded FRP (Fiber Reinforced Polymer) fiber reinforced composite, and the like exist. These problems also tend to occur in the reinforcement of structures after fire, and some defects may even be amplified. For example, the surface of the concrete becomes uneven after high temperature, and the traditional bonding steel or carbon fiber reinforcement method is adopted to cause the problem that the bonding surface is difficult to treat, so that the reinforcement effect is affected.
Disclosure of Invention
Aiming at the defects existing in the prior art, the invention aims to provide a method for reinforcing the reinforced concrete space frame node after fire, fiber grids are stuck at the core area of the node and column ends, main beam ends and secondary beam ends which are close to the core area, and a high-strength high-ductility cement-based composite material is poured, so that the plastic hinge of the beam ends is transferred outside the reinforced area, and the integral shock resistance and deformation capacity of the node are improved. In order to achieve the above object, the present invention is realized by the following technical scheme:
the invention provides a method for reinforcing a reinforced concrete space frame node after a fire disaster, which comprises the following steps: removing the seriously damaged concrete after fire disaster on the surface layer of the reinforced concrete frame node, and leaking out a solid structural layer; and (3) carrying out rough treatment on the removed structure surface, coating or pouring a first layer of high-strength ECC on the structure surface subjected to the rough treatment, coating a fiber grating, and coating or pouring a second layer of high-strength ECC after the fiber grating is positioned accurately, so that the reinforcement work can be completed.
As a further implementation mode, the first layer of high-strength ECC and the second layer of high-strength ECC are both reinforcing layers, and the repair part of the first layer of high-strength ECC after pouring can be restored to the original cross-section size.
As a further implementation, pouring the first layer of high strength ECC, pasting the fiber grid, and pouring the second layer of high strength ECC are performed continuously.
As a further implementation manner, the first layer of high-strength ECC and the second layer of high-strength ECC are composed of the following raw materials in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.009 parts of high-efficiency water reducer; 0.029 parts of polyethylene fiber.
As a further implementation, the first layer of high strength ECC is an adhesive layer for adhering the fiber grating; and the second layer of high-strength ECC is a reinforcing layer, and the repairing part is restored to the original section size after the reinforcing layer is poured.
As a further implementation manner, the first layer of high-strength ECC comprises the following raw materials in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.0009 parts of high-efficiency water reducing agent; 0.029 parts of polyethylene fiber; 0.0005-0.001 parts of thickening agent.
As a further implementation manner, the second layer of high-strength ECC comprises the following raw materials in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.009 parts of high-efficiency water reducer; 0.029 parts of polyethylene fiber; no thickener.
As a further implementation mode, the L-shaped fiber grating is stuck along the longitudinal bar direction of the column, the annular fiber grating is stuck on the column, the fold line type fiber grating is stuck on the folded corner of the node, and the U-shaped fiber gratings are stuck on the main beam end and the secondary beam end.
As a further implementation, the node core corners are notched with high strength ECC levels.
As a further implementation, the fiber grid is carbon fiber.
The beneficial effects of the invention are as follows:
1. The two layers of high-strength high-ductility cement-based composite materials are reinforcing layers, the original cross section size can be recovered after the inner layer high-strength ECC is poured, and the fiber grille is directly stuck on the surface of the reinforced composite materials without waiting for hardening of the inner layer high-strength ECC. And then the outer high-strength ECC can be poured immediately, and after the high-strength ECC is hardened, the stress between the high-strength ECC and the fiber grid is similar to the bonding effect of concrete and steel bars. Although the cross section size is enlarged, the provided reinforcement effect is stronger than that of the original cross section reinforcement, and the bearing capacity of the damaged concrete beam column node after the fire disaster is obviously improved.
2. The high-strength ECC in the inner layer is a bonding layer, the high-strength ECC in the outer layer is a reinforcing layer, and the high-strength ECC can be used as a bonding agent of a fiber grating and a post-fire concrete interface so as to solve the problem that the fiber grating is difficult to adhere due to uneven surface of the post-fire concrete. Can also be used as a protective layer of the grille, and the fire-resistant and corrosion-resistant capabilities of the reinforced nodes are improved. And the section size of the original node is unchanged after reinforcement, so that normal use is not affected. But also can transmit the acting force of the fiber grating to other parts of the structure to form an integral stressed structure.
3. The reinforcing method of the invention not only can fully exert the advantages of light weight, high strength and high durability of the fiber grille, but also can fully utilize the characteristics of high strength ECC strength, high ductility, self-healing and multi-seam cracking, and prolong the service life of the reinforcing structure.
4. The invention uses high-strength ECC material to form a package type for the fiber grating, and the package type material and the fiber grating are jointly acted on the outer surface of the concrete beam column node to form an integral reinforcing layer. By utilizing the bidirectional stress characteristic of the fiber grille, when the post-fire concrete beam column node is stressed, the fiber grille can provide constraint force to restrain the beam and column end concrete, so that the strength of core concrete is remarkably improved. The fiber grating can provide a restraining force when the surface of the post-fire node is pulled, so that the bending resistance of the beam-column node is improved.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention.
FIG. 1 is a flow chart of a method of reinforcing a reinforced concrete frame node after a fire in an embodiment of the invention;
FIG. 2 is a schematic illustration of a fiber grating paste in an embodiment of the invention;
FIG. 3 is a schematic illustration of a fiber grating paste in an embodiment of the invention;
FIG. 4 is a schematic diagram of a high strength ECC casting area in an embodiment of the invention;
Fig. 5 is a schematic diagram of a high strength ECC casting area in an embodiment of the present invention.
In the figure: the mutual spacing or dimensions are exaggerated for the purpose of showing the positions of the various parts, and the schematic illustration is only schematic.
Wherein: 1. a column; 2. a main beam; 3. a secondary beam; 4. a plate; 5. a first L-shaped fiber grid; 6. a second L-shaped fiber grid; 7. a circumferential fiber grid; 8. a folded-line type fiber grating; 9. a first U-shaped fiber grid; 10. a second U-shaped fiber grid; 11. a first reinforcing layer; 12. a second reinforcing layer; 13. a third reinforcing layer; 14. a haunch area; 15. a fourth reinforcing layer; 16. and a fifth reinforcing layer.
Detailed Description
It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
Example 1
The reinforced concrete frame node of the implementation adopts a common concrete beam column 1 node, and comprises a column 1, a plate 4, a main beam 2, a secondary beam 3 and a corresponding reinforcement cage.
In an exemplary embodiment of the present invention, referring to fig. 1, a method for reinforcing a reinforced concrete space frame node after a fire, comprises the steps of: removing the seriously damaged concrete after fire disaster on the surface layer of the reinforced concrete frame node, and leaking out a solid structural layer; and (3) carrying out rough treatment on the removed structure surface, pouring a first layer of high-strength ECC (ECC is a high-ductility cement-based composite material, ENGINEERED CEMENTITIOUS COMPOSITE) on the rough treated structure surface, coating a fiber grating, and pouring a second layer of high-strength ECC after the fiber grating is positioned accurately, so that the reinforcement work can be completed.
The first layer of high-strength ECC and the second layer of high-strength ECC are high-strength ECC made of PE (polyethylene) fibers, and compared with the common ECC, the high-strength ECC has high ductility and high strength, and the fiber grating reinforcing layer is a carbon fiber grating layer wrapped on the outer side of the high-strength ECC.
In this embodiment, the first layer of high-strength ECC and the second layer of high-strength ECC are both reinforcing layers, and the repair part can be restored to the original cross-sectional dimension after the first layer of high-strength ECC is poured. Pouring the first layer of high-strength ECC, pasting the fiber grating and pouring the second layer of high-strength ECC is continuously performed.
Specifically, removing the concrete on the surface layer of the damaged concrete beam column node after fire, wherein the removing range is that the column end, the main beam end and the secondary beam end are close to the node side, and the chiseling depth and the chiseling length are determined according to the fire damage degree. And uniformly coating the prepared high-strength ECC on the surface-treated node area. And winding the carbon fiber grating on the surface of the high-strength ECC according to the shape. And finally, pouring a layer of high-strength ECC on the surface of the fiber grating.
It will be appreciated that the purpose of the first layer of high-strength ECC is to level, fill the chiseled area on the upper concrete surface, and the effect after the first layer of high-strength ECC is smeared is that beam column nodes are restored to the original cross-section size, the first layer of high-strength ECC replaces the concrete removed due to serious damage, meanwhile, the effect of bonding and leveling is achieved, a flat surface is provided for adhering the fiber grating, after that, the fiber grating is directly stuck on the surface of the first layer of high-strength ECC without waiting for the first layer of high-strength ECC to harden, and the fiber grating can be fixed by means of the bonding effect of the fiber grating and the first layer of high-strength ECC and the pre-nailed rivets to clamp the fiber grating. And then immediately pouring a second layer of high-strength ECC (error correction code) by starting the formwork, wherein the second layer of high-strength ECC is covered on the fiber grating to play a role in adhesion protection, and simultaneously participate in node stress, and the node stress and the fiber grating are used for restraining internal concrete together, and after the high-strength ECC is hardened, the stress between the high-strength ECC and the fiber grating is similar to the adhesion effect of the concrete and the steel bars. The fiber grating plays roles of reinforcing steel bar stress and transmission force. Although the cross section size is enlarged, the provided reinforcement effect is stronger than that of the original cross section reinforcement, the bearing capacity of the concrete beam column damaged after the fire disaster is obviously improved, and the reinforced concrete beam column is suitable for buildings such as schools, hospitals and the like with earthquake fortification categories of class A and class B or without using the requirement of clear height.
The first layer high-strength ECC and the second layer high-strength ECC adopted in the embodiment are composed of the following raw materials in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.009 parts of high-efficiency water reducer; 0.029 parts of polyethylene fiber; no thickener. The preparation process comprises the following steps: placing cement, fly ash, quartz sand, a water reducing agent and silica fume into a charging barrel for dry stirring to obtain a uniformly mixed dry material; adding water and a water reducing agent, and stirring until the cement becomes a plastic-flowing state; and (5) adding polyethylene fibers, and stirring uniformly to obtain the high-strength ECC.
An L-shaped fiber grating is stuck along the longitudinal bar direction of the column 1, a circumferential fiber grating 7 is stuck on the column 1, a fold line type fiber grating 8 is stuck on the folded corner of the node, and a U-shaped fiber grating is stuck on the main beam end and the secondary beam end.
Specifically, as shown in fig. 2, a first L-shaped fiber grating 5 and a second L-shaped fiber grating 6 are adhered to the column 1 along the longitudinal rib direction of the column 1 at a position within a 1.5-time column width range near the node core area end, and the fiber gratings extend from the column end to the beam bottom and the plate top along the longitudinal rib direction of the beam within a 1.5-time beam height range near the node end of the main beam or the orthogonal beam end.
The annular dimension grating 7 is stuck within the range of 1.5 times of the column height and the column width, the upper part and the lower part are divided, and the lap joint length is 25% of the column width.
As shown in fig. 3, a broken line type fiber grille 8 is stuck at the broken line type position of the node core area, and the front part and the rear part respectively extend to the height of 1.5 times of the beam along the longitudinal rib direction of the beam towards the main beam or the secondary beam end.
And a first U-shaped fiber grating 9 and a second U-shaped fiber grating 10 are stuck in the height range of 1.5 times of the girder ends and the secondary girder ends, and the two primary and secondary girders are respectively.
The broken line type fiber grille 8 has the function similar to stirrups, so that the constraint function on concrete in the core area is enhanced, and the shearing force born by the core area is shared, so that the shearing bearing capacity of the node is improved. And the U-shaped fiber gratings of the main beams and the secondary beams are connected with the broken-line-shaped fiber gratings stuck to the core area to form an integral hoop, so that the node core area is reinforced.
After the fiber grids are pasted, a reinforcing layer is poured in all node areas wound around the fiber grids. As shown in fig. 4 and 5, the column end is a third reinforcing layer 13, the main beam end is a second reinforcing layer 12, the secondary beam end is a first reinforcing layer 11, and the main beam end and secondary beam end fiber grids on the plate 4 are covered with a fourth reinforcing layer 15 and a fifth reinforcing layer 16, respectively. The node core area corners are haunched with high strength ECC levels to form haunched areas 14. The length of the armpit 14 area is determined according to the reinforcing length of the fiber grille, so that the construction is convenient.
In the reinforced concrete frame node after the high-strength ECC and the fiber grating are compounded and reinforced, the beam, column end high-strength ECC and the fiber grating share the shearing force of an incoming node, and the haunched high-strength ECC and the broken line type fiber grating not only strengthen the restraint effect on the concrete in the core area, but also share the shearing force born by the core area, thereby improving the shearing bearing capacity of the node.
The cement-based composite material can repair a severely damaged concrete surface layer, and the characteristics of strain hardening and multi-joint cracking can improve the deformability of the reinforced beam column joint, so that the durability of the joint in the working process of harmful environments is enhanced. The high-strength ECC is used for horizontally haunching four corners of the node core area, so that the node core area is wrapped while construction is facilitated, and the concrete is restrained to improve the concrete strength of the core area. The high-strength ECC wrapped by the column end and the beam end not only plays a bearing function of common concrete, but also plays a role in reducing crack width due to the multi-crack cracking characteristic of the ECC material, and further improves the durability of the reinforcing body.
The working principle of the reinforcement method is as follows:
And forming a package type fiber grating by using a high-strength ECC material, and jointly acting on the outer surface of the concrete beam column node to form an integral reinforcing layer. By utilizing the bidirectional stress characteristic of the fiber grille, when the post-fire concrete beam column node is stressed, the fiber grille can provide constraint force to restrain the beam and column end concrete, so that the strength of core concrete is remarkably improved. The fiber grating can provide a restraining force when the concrete on the surface of the post-fire node is pulled, so that the bending resistance of the beam column node is improved.
Therefore, the reinforced concrete beam column node reinforcing working principle based on the composite reinforcing layer is to improve the bearing capacity, the deformability and the durability of the node area by utilizing high-strength ECC-fiber grating composite reinforcement, so that the problems that the shock resistance of the beam column node is reduced after a fire is received, and brittle failure is easy to occur are solved, and the safety and the reliability of the structure are ensured.
Example two
Unlike the first embodiment, the first layer of high strength ECC is a tie layer for adhering to the fiber grating; the second layer of high-strength ECC is a reinforcing layer, and the repairing part is restored to the original section size after the reinforcing layer is poured.
The first layer of high-strength ECC comprises the following raw materials in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.0009 parts of high-efficiency water reducing agent; 0.029 parts of polyethylene fiber; 0.0005-0.001 parts of thickening agent.
The second layer of high-strength ECC comprises the following raw materials in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.009 parts of high-efficiency water reducer; 0.029 parts of polyethylene fiber; no thickener.
The bonding layer and the reinforcing layer are mainly different in that the proportion of the thickening agent is changed, the slump and the fluidity of the high-strength ECC overall show a reduced trend along with the increase of the content of the thickening agent, and the high-strength ECC is characterized by strong bonding capability, and the fiber grating can be better attached to the surface of the bonding layer, so that the fixing position is convenient and the reinforcing layer high-strength ECC is further poured.
The bonding layer is used for providing enough bonding force for leveling, the surface layer concrete is dehydrated at high temperature after fire, the strength is obviously reduced, loose concrete is removed, and the loose concrete is replaced by high-strength ECC (error correction code), so that the structural safety can be ensured, and the fiber grating can be positioned. The pouring reinforcing layer can finally restore to the original cross section size of the structure, the problems of small use space, poor appearance and the like near the node after reinforcement are not caused, and the method is suitable for buildings with non-A and non-B earthquake fortification categories such as family houses, office buildings and the like and strict requirements on indoor clear heights.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (5)
1. The method for reinforcing the reinforced concrete space frame nodes after the fire disaster is characterized by comprising the following steps of: removing the seriously damaged concrete after fire disaster on the surface layer of the reinforced concrete frame node, and leaking out a solid structural layer; carrying out rough treatment on the removed structure surface, coating or pouring a first layer of high-strength ECC on the structure surface subjected to the rough treatment, coating a fiber grating, and coating or pouring a second layer of high-strength ECC after the fiber grating is positioned accurately, so that the reinforcement work can be completed;
The two layers of high-strength ECC are reinforcing layers, and the reinforcing layers comprise the following raw materials in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.009 parts of high-efficiency water reducer; 0.029 parts of polyethylene fiber;
Or the first layer of high-strength ECC is a bonding layer, and the raw materials comprise the following components in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.0009 parts of high-efficiency water reducing agent; 0.029 parts of polyethylene fiber; 0.0005-0.001 parts of thickener; the second layer of high-strength ECC is a reinforcing layer, and comprises the following raw materials in parts by weight: 1 part of cement; 0.41 parts of water; 0.26 parts of fly ash; 0.26 parts of silica fume; 0.69 parts of quartz sand; 0.75 parts of mineral powder; 0.009 parts of high-efficiency water reducer; 0.029 parts of polyethylene fiber; no thickening agent;
Pasting an L-shaped fiber grating along the longitudinal bar direction of the column, pasting a circumferential fiber grating on the column, pasting a fold line type fiber grating at the folded angle of the node, and pasting U-shaped fiber gratings at the main beam end and the secondary beam end; the folded corner of the node core area is horizontally haunched by a high-strength ECC;
the high-strength ECC forms a package type for the fiber grating and acts on the outer surface of the concrete beam column node together to form an integral reinforcing layer.
2. The method for reinforcing a reinforced concrete space frame node after a fire disaster according to claim 1, wherein the first layer of high-strength ECC and the second layer of high-strength ECC are both reinforcing layers, the repair part of the first layer of high-strength ECC can be restored to the original cross-sectional dimension after casting, and the repair part of the second layer of high-strength ECC exceeds the original cross-sectional dimension after casting.
3. The method for reinforcing a reinforced concrete space frame node after a fire according to claim 2, wherein the casting of the first layer of high-strength ECC, the pasting of the fiber grid, and the casting of the second layer of high-strength ECC are performed continuously.
4. The method of claim 1, wherein the first layer of high strength ECC is an adhesive layer for adhering to the fiber grid; and the second layer of high-strength ECC is a reinforcing layer, and the repairing part is restored to the original section size after the reinforcing layer is poured.
5. A method of reinforcing a reinforced concrete space frame node after a fire in accordance with claim 1, the fiber grating is characterized in that the fiber grating is carbon fiber.
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