Recoverable composite constraint reinforced concrete column and concrete composite structure

Abstract

The utility model discloses a recoverable composite constraint reinforced concrete column and a concrete composite structure. The concrete column comprises a cement-based composite structure, a fiber reinforced structure, a concrete structure and a plurality of unbonded longitudinal bars, the multiple unbonded longitudinal bars are embedded in the concrete structure, the cement-based composite structure is arranged around the outer side of the concrete structure, the fiber reinforced structure is spirally arranged in the cement-based composite structure in the longitudinal direction, and the inner side of the cement-based composite structure is connected with the multiple unbonded longitudinal bars; when the recoverable composite constraint reinforced concrete column bears a seismic load, the unbonded longitudinal bars are in an elastic state, the fiber reinforced structure is used for providing lateral constraint force, and the cement-based composite structure is used for inhibiting corrosion of steel bars and improving the ductility of the structure. The durability and the shock resistance toughness of the concrete column are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of building structures, in particular to a recoverable composite restrained reinforced concrete column and a concrete composite structure. Background Art

[0002] Infrastructure in coastal areas is often eroded by multiple factors such as ocean currents, waves, sea erosion, and tides. Especially in such an aggressive environment, the corrosion of steel bars in concrete structures has become one of the main reasons for the degradation of structural performance, which in turn significantly reduces the service life of infrastructure and poses a serious threat to its service safety. Earthquake disasters can cause serious economic losses and casualties, and the concrete materials of existing reinforced concrete column structures in coastal areas are prone to cracking and spalling due to their brittleness, which further leads to steel corrosion. The corrosion of stirrups will cause the structure to lose lateral constraints and be prone to shear brittle failure, seriously affecting the durability and seismic performance of the structure.

[0003] At present, the traditional structural earthquake resistance is based on ductile design to ensure that "small earthquakes will not damage, medium earthquakes can be repaired, and large earthquakes will not collapse". The plastic deformation of the material in the plastic hinge area is used to consume earthquake energy and improve the ductility of the structure. However, the structure will produce large irreversible residual deformation after the earthquake and lack earthquake toughness, which makes it difficult to repair the structure after the earthquake or the repair cost is too high.

[0004] Therefore, the prior art still needs to be improved and developed. Utility Model Content

[0005] The main purpose of the utility model is to provide a recoverable composite restrained reinforced concrete column and a concrete composite structure, aiming to solve the problems of durability and seismic toughness of reinforced concrete columns in harsh environments in the prior art.

[0006] To achieve the above object, the utility model provides a recoverable composite restrained reinforced concrete column, the recoverable composite restrained reinforced concrete column comprising the following steps:

[0007] The utility model provides the following technical solutions to solve the above technical problems:

[0008] A first aspect of an embodiment of the present application provides a restorable composite constrained reinforced concrete column, wherein the restorable composite constrained reinforced concrete column comprises a cement-based composite structure, a fiber-reinforced structure, a concrete structure and a plurality of unbonded longitudinal bars; the plurality of unbonded longitudinal bars are buried in the concrete structure, the cement-based composite structure is arranged around the outer side of the concrete structure, the fiber-reinforced structure is arranged in a longitudinal spiral inside the cement-based composite structure, and the inner side of the cement-based composite structure is respectively connected to the plurality of unbonded longitudinal bars; when the restorable composite constrained reinforced concrete column is subjected to seismic loads, the unbonded longitudinal bars are in an elastic state, the fiber-reinforced structure is used to provide lateral restraint, and the cement-based composite structure is used to inhibit steel bar corrosion and improve structural ductility.

[0009] In some embodiments, the unbonded longitudinal reinforcement includes an unbonded steel bar, a corrugated pipe, an anchor end and a fixed end; the unbonded steel bar is arranged in the corrugated pipe, the anchor end is connected to the concrete structure, and the anchor end is connected to one end of the corrugated pipe, and the fixed end is connected to the other end of the corrugated pipe.

[0010] In some embodiments, the recoverable composite confined reinforced concrete column is one of a round column, a T-shaped column and a chamfered column.

[0011] In some embodiments, the cement-based composite structure and the fiber-reinforced structure connected together are in a ring shape, and the cement-based composite structure and the fiber-reinforced structure connected together are used to provide restraint to the concrete structure.

[0012] In some embodiments, the number of the unbonded longitudinal bars is six, and the six unbonded longitudinal bars are distributed in a circular array on the inner side of the cement-based composite structure.

[0013] In some embodiments, the recoverable composite confined reinforced concrete column further comprises: a column base, in which at least a portion of the cement-based composite structure is installed.

[0014] In some embodiments, the cement-based composite structure includes any one of a PP-ECC structure, a PE-ECC structure, a PVA-ECC structure, a steel fiber-ECC structure, and a UHPC structure.

[0015] In some embodiments, the fiber reinforced structure includes any one of FRP spiral reinforcement, FRP stirrups, and FRP mesh.

[0016] In some embodiments, the fiber reinforced structure includes any one of a BFRP structure, a CFRP structure, a GFRP structure, and an AFRP structure.

[0017] A second aspect of an embodiment of the present application provides a concrete composite structure, wherein the concrete composite structure is applied to a coastal environment, and the concrete composite structure comprises a recoverable composite constrained reinforced concrete column as described in any one of the above-mentioned schemes.

[0018] Beneficial effects of the utility model: The utility model provides a recoverable composite constrained reinforced concrete column and a concrete composite structure, in which the fiber-reinforced structure can provide lateral restraint, and the unbonded longitudinal reinforcement is in an elastic state when subjected to stress, and the fiber-reinforced structure and the cement-based composite structure provide restraint in combination, so that the concrete column can avoid its destruction and collapse when subjected to earthquake loads, thereby improving the durability and seismic toughness of the concrete column.

[0019] In addition to the technical problems solved by the present application, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the recoverable composite constrained reinforced concrete columns and concrete composite structures provided by the present application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic front view of a recoverable composite restrained reinforced concrete column provided in an embodiment of the present application;

[0022] Figure 2 A schematic side view of a recoverable composite restrained reinforced concrete column provided in an embodiment of the present application;

[0023] Figure 3 The recoverable composite restrained reinforced concrete column provided in the embodiment of the present application Figure 1 Schematic cross-sectional view of AA.

[0024] Description of reference numerals:

[0025] 10. Cement-based composite structure; 20. Fiber-reinforced structure; 30. Concrete structure; 40. Unbonded longitudinal reinforcement; 50. Column base;

[0026] 41. Unbonded steel bars; 42. Corrugated pipe; 43. Anchor end; 44. Fixed end.

[0027] The above drawings have shown clear embodiments of the present invention, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and effect of the utility model clearer and more specific, the technical scheme in the embodiment of the present application will be described clearly and completely in combination with the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiment of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0029] In the related art, ECC (Engineered Cementitious Composite) is used as a prefabricated shell to improve the ductility and energy dissipation capacity of the structure, while reducing the amount of ECC to reduce costs, and using FRP (Fiber Reinforced Polymer) bars, FRP grids, FRP tubes and other combinations of different shapes to improve the corrosion resistance and seismic performance of the structure; or the structure is reinforced and repaired after being damaged by spraying ECC and wrapping FRP grids. By using FRP as a pressure-bearing component, this wastes the performance of FRP materials and lacks economy. Existing studies have shown that the compressive performance of FRP materials is far inferior to the tensile performance. The compressive strength of FRP as a compressive steel bar is only about 40% of the tensile strength. Using it as a longitudinal pressure-bearing component cannot give full play to the material advantages, resulting in material waste. In addition, the composite column of the above scheme produces irreversible plastic deformation when the steel bar yields, which will cause the structure to have a large residual deformation after being subjected to an earthquake, lack of seismic toughness, which will lead to problems such as high cost and difficulty of repair after the earthquake.

[0030] To facilitate understanding, the discovery of the related technical shortcomings and the conception of the technical solutions adopted to address the shortcomings are first introduced.

[0031] Reinforced concrete columns are corroded by ocean currents, waves, sea erosion, tides and other factors. In such an aggressive environment, chloride ions enter the concrete through cracks or pores, causing corrosion of the steel bars. The products of steel bar corrosion are larger in volume, which will produce expansion and tensile stress on the concrete around the steel bars, causing cracking or even peeling of the concrete, further accelerating the corrosion of the internal steel bars. ECC materials have ultra-high tensile strain and deformation ability of fine cracks. When they crack, the cracks are particularly small, which can effectively delay the entry of chloride ions to corrode the steel bars. However, the manufacturing cost of ECC materials is high, and large-scale use lacks economy. According to the cross-sectional bending theory in material mechanics, the farther the material is from the neutral axis, the greater the bearing capacity. Therefore, ECC is arranged in the outermost layer to fully utilize the performance advantages of ECC materials and reduce the amount of ECC to reduce costs.

[0032] The transverse stirrups in reinforced concrete columns corrode faster than the longitudinal bars, and the degree of corrosion is more serious. Once the stirrups corrode, the internal concrete will lose its transverse restraint and bearing capacity and collapse, seriously endangering the safety of the structure. FRP bars have good corrosion resistance, but their compressive strength is far inferior to their tensile strength. Using FRP as transverse reinforcement to only bear tensile force can give full play to its material advantages. Combining ECC with FRP to form an ECC-FRP composite constraint layer can delay the corrosion of steel bars in composite columns in corrosive environments. At the same time, FRP transverse steel bars can provide lateral restraint effects to concrete, improve the bearing capacity and seismic performance of composite columns, and thus improve the durability and seismic performance of composite columns.

[0033] ECC-FRP composite confined reinforced concrete columns can show good ductility and energy dissipation capacity when subjected to earthquakes, but the residual deformation after the earthquake is still relatively large, and the cost and difficulty of post-earthquake repair are high. In order to reduce the residual deformation of the composite column, considering that the irreversible residual deformation of the composite column mainly comes from the plastic deformation caused by the yielding of the longitudinal reinforcement, the longitudinal reinforcement is replaced by unbonded high-strength steel bars instead of ordinary steel bars. The high-strength steel bars are always in an elastic state during the stress process of the composite column, and the elastic deformation will completely recover and disappear after unloading. Therefore, after unloading (i.e. after the earthquake), the overall residual deformation of the composite column will become smaller or even disappear, and it will return to its initial position. At the same time, the damage to the structure itself will be reduced, and it has good seismic toughness.

[0034] The purpose of the invention is to improve the durability and seismic toughness of reinforced concrete columns in harsh environments.

[0035] In view of the problems of durability and seismic toughness of reinforced concrete columns in harsh environments in the above-mentioned related technologies, this application provides a recoverable composite constrained reinforced concrete column and concrete composite structure, which are applied to coastal environments. In the concrete column, the fiber-reinforced structure is used as a transverse stirrup to only bear tension, and the unbonded longitudinal reinforcement is in an elastic state when subjected to force. The fiber-reinforced structure and the cement-based composite structure provide a comprehensive constraint force, so that the concrete column can avoid its destruction and collapse when subjected to earthquake loads, thereby improving the durability and seismic toughness of the concrete column. Thus, the technical problems of durability and seismic toughness of reinforced concrete columns in harsh environments in the related technologies are solved.

[0036] The key points of the present invention are: the ECC-FRP composite constraint layer (i.e., cement-based composite structure and fiber-reinforced structure) can effectively delay the corrosion of steel bars, improve the corrosion resistance of the structure, and at the same time provide a constraint effect for the internal concrete to enhance its strength and ductility, thereby improving the durability and seismic performance of the structure; the ECC-FRP composite constraint layer can be manufactured in advance as a prefabricated component, greatly improving the construction efficiency and quality; the internal longitudinal reinforcement adopts unbonded high-strength steel bars, so that the structure has post-earthquake recoverability and seismic toughness such as less damage.

[0037] Compared with the ECC-FRP composite constraint layer adopted in the prior art, FRP is used as both transverse and longitudinal reinforcements. However, the compressive strength of FRP materials is far inferior to their tensile strength. Using FRP as longitudinal reinforcement will bear compressive stress, which is not conducive to the performance of the material. This solution does not take into account the seismic toughness of the structure. The composite columns will produce large residual deformations when subjected to earthquakes, which will lead to difficulties in repairing the actual structure, high repair costs, and lack of economy.

[0038] The present invention optimizes the arrangement of ECC and FRP materials, rationally analyzes the advantages and disadvantages of ECC and FRP materials, and proposes a technical solution for improving seismic toughness, which has the following advantages:

[0039] ① The ECC-FRP composite constraint layer fully and reasonably utilizes the material advantages of ECC and FRP. ECC material has excellent performance but high manufacturing cost. Applying it to the outermost protective layer of the cross section can fully utilize its tensile properties while reducing its dosage and cost.

[0040] ②The ECC-FRP composite constraint layer can be prefabricated in advance, greatly improving the construction quality and efficiency of the components;

[0041] ③FRP structure (fiber reinforced structure) as transverse stirrups only bears tension, avoiding problems such as brittle failure under compression and poor compressive performance;

[0042] ④ The performance of FRP structure (fiber reinforced structure) and ECC structure (cement-based composite structure) is complementary. Although the ECC structure has strong tensile deformation capacity and can improve the ductility and energy consumption of the composite column, its lateral constraint on the internal concrete is small. The FRP structure has high tensile strength, which makes up for the shortcomings of the ECC structure. At the same time, the high tensile deformation capacity and high damage resistance of the ECC structure avoid the hazard of sudden collapse of the composite column due to the loss of lateral constraint of concrete after the FRP tendon breaks, thereby improving the structural bearing capacity and ductility;

[0043] ⑤ The unbonded prestressed tendons (i.e., unbonded longitudinal tendons) are in an elastic state during the stress process. The elastic deformation of the longitudinal tendons will gradually recover and decrease during the unloading process after the earthquake. In this way, the composite columns will return to their original positions after the earthquake, and there will be basically no residual deformation or it will be very small after the earthquake, so that the structure has seismic toughness such as post-earthquake recoverability and less damage.

[0044] The following specific embodiments are used to describe in detail the technical solution of the present application and how the technical solution of the present application solves the above technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0045] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a restorable composite constrained reinforced concrete column, the restorable composite constrained reinforced concrete column comprises a cement-based composite structure 10, a fiber-reinforced structure 20, a concrete structure 30 and a plurality of unbonded longitudinal bars 40; the plurality of unbonded longitudinal bars 40 are buried in the concrete structure 30, the cement-based composite structure 10 is arranged around the outer side of the concrete structure 30, the fiber-reinforced structure 20 is arranged longitudinally spirally in the cement-based composite structure 10, and the inner side of the cement-based composite structure 10 is respectively connected to the plurality of unbonded longitudinal bars 40; when the restorable composite constrained reinforced concrete column is subjected to seismic loads, the unbonded longitudinal bars 40 are in an elastic state, the fiber-reinforced structure 20 is used to provide lateral restraint, and the cement-based composite structure 10 is used to inhibit steel corrosion and improve structural ductility.

[0046] For details, see Figure 1-Figure 3The ECC layer (i.e., cement-based composite structure 10) as the outermost layer can be prefabricated in batches in a prefabrication plant, greatly improving construction efficiency and quality. Its first function is to give full play to its fine cracking behavior advantage, delay the corrosive medium from entering the concrete to corrode the steel bars, thereby improving the corrosion resistance of the composite column; the second function is that the ECC layer can provide a lateral constraint effect on the internal core concrete, increasing the energy dissipation capacity and ductility of the composite column; the third function is that when the ECC layer is combined with the FRP structure (fiber reinforced structure 20), when the bearing capacity of the concrete column decreases after the FRP spiral reinforcement breaks, the ECC layer can still provide a certain lateral constraint force, so that the concrete composite column changes from brittle failure to ductile failure.

[0047] The first function of the FRP structure (i.e., the fiber reinforced structure 20) is that the FRP structure is a material with high tensile strength and high corrosion resistance. Using the FRP structure as a transverse reinforcement can directly prevent the steel bar from rusting and improve the corrosion resistance of the composite column. The second function is that the FRP structure as a transverse reinforcement only bears tensile force, avoiding its poor compressive performance, and provides a continuously increasing constraint reinforcement effect to the internal concrete, thereby improving the bearing capacity and ductility of the composite column. The third function is that the FRP structure is combined with the ECC layer, and the FRP structure can provide a higher constraint force to improve the seismic performance of the column component and make up for the problem of insufficient constraint force of the ECC layer.

[0048] The function of the unbonded longitudinal reinforcement 40 is to ensure that when the composite column is subjected to earthquake loads, the longitudinal reinforcement provides bearing capacity but remains in an elastic state. After the earthquake force is removed, the elastic deformation of the longitudinal reinforcement will be completely restored, so that the composite column returns to its original position after the earthquake, has recoverability, and the degree of damage to the column body is very small, showing good seismic toughness.

[0049] In one embodiment of the present invention, Figure 1 and Figure 3 As shown, the unbonded longitudinal reinforcement 40 includes an unbonded steel bar 41, a corrugated tube 42, an anchor end 43 and a fixed end 44; the unbonded steel bar 41 is arranged in the corrugated tube 42, the anchor end 43 is connected to the concrete structure 30, and the anchor end 43 is connected to one end of the corrugated tube 42, and the fixed end 44 is connected to the other end of the corrugated tube 42.

[0050] Specifically, the unbonded high-strength steel bars, the corrugated tube 42 , the anchoring end 43 and the fixed end 44 form unbonded high-strength longitudinal bars in the concrete composite column.

[0051] It should be noted that the unbonded high-strength steel bars can be replaced by high-strength FRP bars, finished unbonded prestressed steel strands, or a method of isolating the bonding between concrete and prestressed steel bars by outer covering corrugated tubes 42 on ordinary steel strands or prestressed steel bars.

[0052] In an embodiment of the present invention, the recoverable composite restrained reinforced concrete column is one of a circular column, a T-shaped column and a chamfered column.

[0053] It should be noted that, according to the function of the ECC-FRP composite constraint layer, the ECC layer is located at the outermost side of the cross section of the composite column and has a certain thickness. It can change according to the cross-sectional shape of the composite column to other shapes (including rectangular columns, T-shaped columns, and chamfered columns).

[0054] In an embodiment of the present invention, the cement-based composite structure 10 and the fiber-reinforced structure 20 connected together are in a ring shape, and the cement-based composite structure 10 and the fiber-reinforced structure 20 connected together are used to provide restraint force to the concrete structure 30 .

[0055] It should be noted that the cement-based composite structure 10 and the fiber-reinforced structure 20 connected together are the ECC-FRP composite constraining layer.

[0056] In one embodiment of the present invention, Figure 2 As shown, the number of the unbonded longitudinal bars 40 is six, and the six unbonded longitudinal bars 40 are distributed in a circular array on the inner side of the cement-based composite structure 10 .

[0057] In one embodiment of the present invention, Figure 1 and Figure 3 As shown, the recoverable composite confined reinforced concrete column further includes: a column base 50 , in which at least a portion of the cement-based composite structure 10 is installed.

[0058] In an embodiment of the present invention, the cement-based composite structure 10 includes any one of a PP-ECC structure, a PE-ECC structure, a PVA-ECC structure, a steel fiber-ECC structure and a UHPC structure.

[0059] Specifically, the ECC layer can be replaced by an ECC layer composed of different fibers (PP-ECC, PE-ECC, PVA-ECC and steel fiber-ECC, etc.), UHPC and other ultra-high ductility cement-based composite materials.

[0060] It can be understood that PP-ECC is polypropylene fiber reinforced engineering cement-based composite material, PE-ECC is polyethylene fiber reinforced engineering cement-based composite material, PVA-ECC is polyvinyl alcohol fiber reinforced engineering cement-based composite material, steel fiber-ECC is an ECC using steel fiber as a reinforcing material, and UHPC is ultra-high performance concrete (Ultra-High Performance Concrete).

[0061] In an embodiment of the present invention, the fiber reinforced structure 20 includes any one of FRP spiral reinforcement, FRP stirrups, and FRP mesh.

[0062] In an embodiment of the present invention, the fiber reinforced structure 20 includes any one of a BFRP structure, a CFRP structure, a GFRP structure and an AFRP structure.

[0063] Specifically, the FRP structure can be replaced by FRP in different finished shapes such as FRP spiral bars, FRP stirrups, FRP meshes, or FRP made of different fibers such as BFRP, CFRP, GFRP, and AFRP.

[0064] It is understood that FRP can be classified into various types, including carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP), aramid fiber reinforced plastic (AFRP) and basalt fiber reinforced plastic (BFRP).

[0065] Based on the above embodiments, the embodiments of the present application further provide a concrete composite structure for use in a coastal environment, wherein the concrete composite structure comprises a recoverable composite constrained reinforced concrete column as described in any one of the above schemes.

[0066] The concrete composite structure provided by the utility model has all the above beneficial effects because it is provided with the recoverable composite restrained reinforced concrete column described in any of the above technical solutions, which will not be described in detail here.

[0067] In the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0068] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0070] It should be noted that: in this application, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0071] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0072] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A recoverable composite restrained reinforced concrete column, characterized in that: The recoverable composite restrained reinforced concrete column comprises a cement-based composite structure, a fiber-reinforced structure, a concrete structure and a plurality of unbonded longitudinal bars; A plurality of the unbonded longitudinal bars are buried in the concrete structure, the cement-based composite structure is arranged around the outer side of the concrete structure, the fiber-reinforced structure is arranged in a longitudinal spiral in the cement-based composite structure, and the inner side of the cement-based composite structure is respectively connected to the plurality of the unbonded longitudinal bars; When the recoverable composite restrained reinforced concrete column is subjected to earthquake load, the unbonded longitudinal reinforcement is in an elastic state, the fiber reinforced structure is used to provide lateral restraint, and the cement-based composite structure is used to inhibit steel bar corrosion and improve structural ductility.

2. The recoverable composite confined reinforced concrete column according to claim 1, characterized in that: The unbonded longitudinal reinforcement includes an unbonded steel bar, a corrugated pipe, an anchor end and a fixed end; The unbonded steel bar is arranged in the corrugated pipe, the anchor end is connected to the concrete structure, the anchor end is connected to one end of the corrugated pipe, and the fixed end is connected to the other end of the corrugated pipe.

3. The recoverable composite confined reinforced concrete column according to claim 1, characterized in that: The recoverable composite restrained reinforced concrete column is one of a circular column, a T-shaped column and a chamfered column.

4. The recoverable composite confined reinforced concrete column according to claim 3, characterized in that: The cement-based composite structure and the fiber-reinforced structure connected together are in a ring shape, and the cement-based composite structure and the fiber-reinforced structure connected together are used to provide restraint force to the concrete structure.

5. The recoverable composite confined reinforced concrete column according to claim 4, characterized in that: The number of the unbonded longitudinal bars is six, and the six unbonded longitudinal bars are distributed in a circular array on the inner side of the cement-based composite structure.

6. The recoverable composite confined reinforced concrete column according to claim 1, characterized in that: The recoverable composite confined reinforced concrete column further comprises: A column base in which at least a portion of the cementitious composite structure is mounted.

7. The recoverable composite confined reinforced concrete column according to claim 1, characterized in that: The cement-based composite structure includes any one of a PP-ECC structure, a PE-ECC structure, a PVA-ECC structure, a steel fiber-ECC structure and a UHPC structure.

8. The recoverable composite confined reinforced concrete column according to claim 1, characterized in that: The fiber reinforced structure includes any one of FRP spiral reinforcement, FRP stirrups and FRP mesh.

9. The recoverable composite confined reinforced concrete column according to claim 1, characterized in that: The fiber reinforced structure includes any one of a BFRP structure, a CFRP structure, a GFRP structure and an AFRP structure.

10. A concrete composite structure, characterized in that: Applied in a coastal environment, the concrete composite structure comprises a recoverable composite confined reinforced concrete column as claimed in any one of claims 1 to 9.

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