A concrete column reinforcement device and method based on embedded Fe SMA strips

Abstract

This application discloses a concrete column reinforcement device and method based on embedded Fe SMA strips. The reinforcement device includes Fe SMA strips and a heat-conducting copper plate. Each Fe SMA strip is fixedly arranged around the concrete column. Before being fixed to the concrete column, the Fe SMA strips undergo pre-stretching treatment with a pre-stretch strain controlled at 3%~5%, causing the Fe SMA strips to undergo martensitic phase transformation and store the energy required for shape memory effect. The heat-conducting copper plate is disposed on the outside of each Fe SMA strip and is tightly fitted to it. The heat-conducting copper plate has a built-in serpentine circulation pipe for passing a heating medium. The inlet and outlet of the serpentine circulation pipe are located on the surface of the heat-conducting copper plate. The Fe SMA strips achieve thermal excitation based on the circulating flow of the heating medium within the heat-conducting copper plate, generating initial prestress and completing the reinforcement of the concrete column. This achieves efficient, reliable, and long-term dynamic reinforcement of the concrete column.

Description

Technical Field

[0001] This application belongs to the field of building structure reinforcement and renovation technology, and in particular relates to a concrete column reinforcement device and reinforcement method based on embedded Fe SMA strips. Background Technology

[0002] Existing concrete columns in buildings are prone to problems such as insufficient load-bearing capacity, stiffness degradation, and deterioration in seismic performance under long-term service, load changes, seismic action, or material aging. Therefore, reinforcement technologies are urgently needed to improve structural safety and durability. Traditional concrete column reinforcement methods mainly include increasing the cross-section, external steel reinforcement, and FRP strip bonding reinforcement. These methods have significant drawbacks: increasing the cross-section significantly increases the structural weight, occupies building space, and has a long construction period; external steel reinforcement has poor corrosion resistance, high maintenance costs, and cannot actively apply prestress; FRP reinforcement is a passive reinforcement method, only bearing stress after the concrete column deforms, making it difficult to fully utilize the material's properties and unable to achieve prestress control.

[0003] Iron-based shape memory alloys (Fe SMAs), as novel intelligent reinforcement materials, possess excellent shape memory effect, superelasticity, and high load-bearing capacity. Through pre-stretching followed by thermal excitation, they can generate stable active prestress, effectively constraining concrete column deformation and improving the column's axial load-bearing capacity and seismic ductility, making them a research hotspot in structural reinforcement. However, existing Fe SMA reinforcement technologies for concrete columns still face several core technical bottlenecks: First, Fe SMA strips are mostly installed externally, making them susceptible to environmental erosion and external force damage, resulting in poor anchoring reliability. Second, prestress can only be applied through a one-time thermal excitation during the installation phase; after long-term service, prestress loss occurs due to material relaxation and structural deformation, making secondary compensation impossible. Third, if embedded slotted closed reinforcement is used, the sealed cement mortar blocks the thermal excitation channel; current technologies lack secondary excitation devices suitable for closed conditions, preventing the long-term effectiveness of Fe SMA's active control advantages. Fourth, single anchoring methods are prone to strip slippage, resulting in low prestress transfer efficiency and difficulty in achieving stable reinforcement effects.

[0004] Based on the shortcomings of the existing technologies, there is an urgent need to develop an embedded Fe SMA reinforced concrete column technology with high anchoring reliability and the ability to achieve prestressed secondary excitation, which takes into account the convenience of construction, long-term durability, and fills the technical gap of Fe SMA secondary excitation after closure. Summary of the Invention

[0005] The purpose of this application is to overcome the defects of existing concrete column reinforcement methods, such as cumbersome construction, unreliable fixing, and uneven heating. This application discloses a concrete column reinforcement device and method based on embedded Fe SMA strips, which realizes efficient, reliable, and long-term dynamic reinforcement of concrete columns, improves the load-bearing capacity and crack resistance of concrete columns, and extends the service life of the structure.

[0006] On the one hand, the objective of this application is achieved through the following technical solution: A concrete column reinforcement device based on embedded Fe SMA strips, the concrete column reinforcement device comprising: Fe SMA strips and a heat-conducting copper plate; Each Fe SMA strip is fixedly installed around the concrete column. Before the Fe SMA strip is fixed to the concrete column, the Fe SMA strip is pre-stretched with a pre-stretch strain controlled at 3% to 5% to induce a martensitic phase transformation in the Fe SMA strip and store the energy required for the shape memory effect. The thermally conductive copper plate is disposed on the outer side of each Fe SMA strip and is tightly attached to the Fe SMA strip; and the thermally conductive copper plate has a built-in serpentine circulation pipe for passing the heating medium, with the inlet and outlet of the serpentine circulation pipe located on the surface of the thermally conductive copper plate. The Fe SMA strips achieve thermal excitation based on the circulating flow of the heating medium within the thermally conductive copper plate, generating initial prestress and completing the reinforcement of the concrete column.

[0007] According to a preferred embodiment, the surface of the concrete column is provided with a plurality of annular grooves along the circumference, and each Fe SMA strip and thermally conductive copper plate is embedded in the annular groove.

[0008] According to a preferred embodiment, concrete is poured on the outside of the heat-conducting copper plate to complete the sealing of the annular groove; and the liquid inlet and outlet extend out of the concrete on the outside of the heat-conducting copper plate.

[0009] According to a preferred embodiment, the Fe SMA strip and the thermally conductive copper plate are bolted to the surface of the concrete column.

[0010] According to a preferred embodiment, structural adhesive is further provided between the Fe SMA strip and the annular groove.

[0011] On the other hand, this application also discloses: A method for strengthening concrete columns based on embedded Fe SMA strips, the method comprising the following steps: S1: Pre-treatment of concrete column grooving: Based on the degree of damage to the concrete column and the reinforcement requirements, several annular grooves are opened on the surface of the concrete column. S2: Pre-stretching and fixing of Fe SMA strips. Fe SMA strips are selected and pre-stretched. The pre-stretching strain is controlled at 3%~5% to induce the Fe SMA strips to undergo martensitic phase transformation and store the energy required for shape memory effect. The pre-stretched Fe SMA strips are then embedded in the annular groove of the concrete column and bonded to the concrete column with structural adhesive. S3: Heat-conducting copper plate installation: Select a heat-conducting copper plate with an internal serpentine circulation pipe. The inlet and outlet of the serpentine circulation pipe extend to the outside of the annular groove. The heat-conducting copper plate is attached to the surface of the Fe SMA strip by bolts and is fixed to the concrete column by bolts. S4: The first thermal excitation generates prestress. Heat-conducting oil heated to 300°C is injected into the serpentine circulation pipe of the heat-conducting copper plate. The heat-conducting oil circulates in the serpentine heat-conducting pipe and evenly transfers heat to the Fe SMA strip through the heat-conducting copper plate. This thermally excites the Fe SMA strip, causing it to undergo a phase transformation from martensite to austenite, generating shape recovery stress. The corresponding recovery stress acts as prestress on the concrete column, achieving the initial reinforcement of the concrete column. Furthermore, the initial thermal excitation time is controlled within 30 to 60 minutes. After the stress of the Fe SMA strip stabilizes, the injection of high-temperature heat transfer oil is stopped, and the heat transfer oil is cooled and discharged or recycled. S5: Annular groove sealing. The annular groove of the concrete column is sealed with cement mortar that can withstand high temperatures of 300℃. The cement mortar is filled to be flush with the surface of the concrete column, and there are no gaps or cracks between the cement mortar and the concrete column, Fe SMA strip, and thermally conductive copper plate. S6: Secondary thermal excitation reinforcement involves long-term monitoring of the concrete column. When it is detected that the concrete column continues to expand due to stress relaxation cracks and the crack width exceeds the limit specified in the standard, heat transfer oil heated to 300℃ is injected again into the serpentine circulation pipe of the heat transfer copper plate to perform secondary thermal excitation on the Fe SMA strips. This causes the Fe SMA strips to generate shape recovery stress again, supplementing the prestress, inhibiting crack expansion, and achieving long-term dynamic reinforcement of the concrete column.

[0012] According to a preferred embodiment, step S1 further includes: grinding and cleaning the inner wall of the annular groove to remove floating dust, debris and loose concrete, and then applying a primer to the inner wall of the annular groove to enhance the bonding performance between the structural adhesive and the concrete. The width of the annular groove is the width of the Fe SMA strip + 10~20mm, and the depth of the annular groove is the thickness of the Fe SMA strip + 15~20mm.

[0013] According to a preferred embodiment, in step S2, the pre-stretching speed is controlled at 1~2 mm / min to ensure that the Fe SMA strip is stretched uniformly; The structural adhesive is a high-temperature resistant silicone structural adhesive with a peak temperature resistance of not less than 300℃, a room temperature shear strength ≥20MPa, and a high temperature shear strength ≥1MPa.

[0014] According to a preferred embodiment, in step S3, the width and length of the heat-conducting copper plate are consistent with the Fe SMA strip, the thickness is 5~6mm, the diameter of the serpentine circulation pipe is 3~4mm, and the pipe spacing is 20~30mm. In step S4, the heat transfer oil has a high temperature resistance of not less than 350℃, a thermal conductivity of ≥0.15W / (m·K), is non-corrosive, and can be reused; the circulation speed of the heat transfer oil is controlled at 0.5~1m / s.

[0015] According to a preferred embodiment, step S5 further includes curing the post-poured cement mortar for a period of not less than 7 days to ensure that the cement mortar reaches the design strength. The cement mortar is made by blending 42.5 grade silicate cement and sulfoaluminate refractory cement in a 3:1 ratio, and adding 8% redispersible latex powder, 3 kg / m³ of organosilicon-modified polycarboxylate superplasticizer and 15% aluminum hydroxide flame retardant. Its 28-day compressive strength is ≥3.0 MPa, thermal conductivity is ≤0.08 W / (m·K), combustion performance rating is A1, and long-term service temperature is not lower than 300℃.

[0016] The aforementioned main solution and its various further alternative solutions can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application. Those skilled in the art, after understanding the solution of this application, will realize that there are many combinations based on the prior art and common general knowledge, all of which are technical solutions to be protected in this application, and will not be exhaustively listed here.

[0017] The beneficial effects of this application are: The structure or steps described in this application provide a significant and reliable reinforcement effect for concrete columns. The combination of bolts and high-temperature structural adhesive with a primer prevents loosening and effectively transfers prestress. The use of a heat-conducting copper plate with a serpentine circulation pipe and 300°C heat-conducting oil ensures uniform heating of the Fe SMA strips, combining safety and economy. Long-term dynamic reinforcement can be achieved through secondary and multiple thermal excitations, addressing stress relaxation and crack propagation issues. The construction process is simple, with small groove dimensions, minimal disturbance to the original structure, and no impact on the building's appearance or functionality. Fe SMA materials are inexpensive and can be mass-produced, suitable for concrete columns of various cross-sections and degrees of damage, and have broad application value in multiple fields. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the concrete column before reinforcement and repair. Figure 2This is a schematic diagram of a grooved concrete column; Figure 3 This is a diagram of the Fe SMA strip mounting in this application; Figure 4 This is the installation diagram of the thermally conductive copper plate in this application; Figure 5 yes Figure 4 Schematic diagram of section 1-1; Figure 6 This is a schematic diagram showing the completed reinforcement of the concrete column; Among them, 1-concrete column, 11-crack, 12-annular groove, 2-high temperature resistant structural adhesive, 3-Fe SMA strip, 31-Fe SMA strip threaded hole, 4-thermal conductive copper plate, 41-liquid inlet, 42-liquid outlet, 43-serpentine thermal conductive pipe, 44-thermal conductive copper plate threaded hole, 5-bolt. Detailed Implementation

[0019] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] Furthermore, it should be noted that unless otherwise specified in this application, the specific structures, connections, positions, power sources, etc. involved are all things that a person skilled in the art can know without creative effort based on the prior art.

[0025] Example 1 refer to Figures 1 to 6 As shown, this application discloses a concrete column reinforcement device based on embedded Fe SMA strips, the concrete column reinforcement device comprising: Fe SMA strips 3 and heat-conducting copper plates 4.

[0026] Each Fe SMA strip 3 is fixedly installed around the concrete column 1. Before the Fe SMA strip 3 is fixed to the concrete column 1, the Fe SMA strip 3 is pre-stretched, and the pre-stretch strain is controlled at 3%~5% to make the Fe SMA strip 3 undergo martensitic phase transformation and store the energy required for shape memory effect.

[0027] A thermally conductive copper plate 4 is disposed on the outer side of each Fe SMA strip 3 and is tightly attached to the Fe SMA strip 3; and the thermally conductive copper plate 4 has a built-in serpentine circulation pipe for passing heating medium, and the inlet 41 and outlet 42 of the serpentine circulation pipe are disposed on the surface of the thermally conductive copper plate 4.

[0028] The Fe SMA strip 3 achieves thermal excitation based on the circulating flow of the heating medium inside the thermally conductive copper plate 4, thereby generating initial prestress and completing the reinforcement of the concrete column 1.

[0029] Preferably, the surface of the concrete column 1 is provided with a plurality of annular grooves 12 along the circumference, and each Fe SMA strip 3 and heat-conducting copper plate 4 is embedded in the annular grooves 12.

[0030] Furthermore, structural adhesive is provided between the Fe SMA strip 3 and the annular groove 12.

[0031] Preferably, concrete is poured on the outside of the heat-conducting copper plate 4 to complete the sealing of the annular groove 12; and the liquid inlet 41 and the liquid outlet 42 extend out of the concrete on the outside of the heat-conducting copper plate 4.

[0032] Preferably, the Fe SMA strip 3 and the thermally conductive copper plate 4 are fixed to the surface of the concrete column 1 by bolts 5.

[0033] Example 2 Based on Example 1, this example discloses a method for reinforcing concrete columns based on embedded Fe SMA strips 3, the method comprising the following steps.

[0034] Step S1: Grooving pretreatment of concrete column 1. Based on the degree of damage and reinforcement requirements of concrete column 1, several annular grooves 12 are opened on the surface of concrete column 1.

[0035] Grind and clean the inner wall of the annular groove 12 to remove dust, debris and loose concrete, ensuring that the inner wall of the groove is flat and clean. Then apply a layer of primer to the inner wall of the annular groove 12 to enhance the adhesion between the structural adhesive and the concrete.

[0036] Preferably, the width of the annular groove 12 is the width of the Fe SMA strip 3 + 10~20 mm, and the depth of the annular groove 12 is the thickness of the Fe SMA strip 3 + 15~20 mm. The number of annular grooves 12 is determined according to the cross-sectional dimensions of the concrete column and the reinforcement requirements, and they are evenly distributed around the perimeter of the concrete column 1.

[0037] Step S2: Pre-stretching and fixing of Fe SMA strip 3. Select Fe SMA strip 3 and pre-stretch it. The pre-stretch strain is controlled at 3%~5% to make Fe SMA strip 3 undergo martensitic phase transformation and store the energy required for shape memory effect. Embed the pre-stretched Fe SMA strip 3 into the annular groove 12 of concrete column 1 and bond it to concrete column 1 with structural adhesive.

[0038] Preferably, the Fe SMA strip has a thickness of 2-5 mm, a width of 50-80 mm, and a length consistent with the perimeter of the concrete column. Pre-stretching is performed using specialized stretching equipment, with the stretching speed controlled at 1-2 mm / min to ensure uniform stretching of the Fe SMA strip and avoid localized stress concentration that could damage the material. The structural adhesive is made of high-temperature resistant silicone, with a short-term peak temperature resistance of no less than 300℃, a room temperature (-5℃-40℃) shear strength ≥20MPa, and a high temperature shear strength (300℃) ≥1MPa, thus ensuring that it does not soften or debond during thermal excitation and can effectively transfer stress.

[0039] Step S3: Install the heat-conducting copper plate 4. Select a heat-conducting copper plate 4 with an internal serpentine circulation pipe. The inlet 41 and outlet 42 of the serpentine circulation pipe extend to the outside of the annular groove 12. The heat-conducting copper plate 4 is attached to the surface of the Fe SMA strip 3 by bolts 5 and is connected and fixed to the concrete column 1 by bolts 5.

[0040] The dimensions of the thermally conductive copper plate 4 are matched with the dimensions of the Fe SMA strip 3. The arrangement density of the serpentine circulation pipes must meet the requirement of uniform heating of the Fe SMA strip 3, ensuring that the temperature of each part of the Fe SMA strip 3 is consistent during the thermal excitation process, and avoiding excessively high or low local temperatures that would affect the performance of the shape memory effect.

[0041] The process of fixing Fe SMA strip 3 and thermally conductive copper plate 4 is as follows: First, apply high-temperature resistant structural adhesive to the bonding surface of Fe SMA strip 3 and the inner wall of the annular groove 12 to ensure that the adhesive layer evenly covers the inner wall of the annular groove 12 and the bonding surface of Fe SMA strip 3. Then, fix Fe SMA strip 3 and thermally conductive copper plate 4 to the concrete column with bolts 5. After the structural adhesive has completely cured, the fixing of Fe SMA strip 3 and thermally conductive copper plate 4 is completed. The double fixing method can effectively avoid the phenomenon of detachment and loosening between Fe SMA strip 3 and concrete column 1, and improve the fixing reliability.

[0042] In step S3, the width and length of the heat-conducting copper plate 4 are the same as those of the Fe SMA strip 3, the thickness is 5~6mm, the diameter of the serpentine circulation pipe is 3~4mm, and the pipe spacing is 20~30mm; Step S4: The first thermal excitation generates prestress. Mineral-based heat transfer oil heated to 300°C is injected into the serpentine circulation pipe of the heat-conducting copper plate 4. The mineral-based heat transfer oil circulates in the serpentine heat transfer pipe 43 and uniformly transfers heat to the Fe SMA strip 3 through the heat-conducting copper plate 4. The Fe SMA strip 3 is thermally excited, causing the Fe SMA strip 3 to undergo a phase transformation from martensite to austenite, generating shape recovery stress. The corresponding recovery stress acts as prestress on the concrete column 1, realizing the initial reinforcement of the concrete column 1.

[0043] Furthermore, the initial thermal excitation time is controlled within 30-60 minutes. After the stress of Fe SMA strip 3 stabilizes, the injection of high-temperature heat transfer oil is stopped, and the heat transfer oil is cooled and discharged or recycled. Fe SMA strip 3 can generate stable recovery stress at a high temperature of 300℃, meeting the prestressing requirements for the initial reinforcement of concrete columns.

[0044] In step S4, the mineral-based heat transfer oil has a high temperature resistance of not less than 350℃, a thermal conductivity of ≥0.15W / (m·K), good thermal conductivity and stability, is non-corrosive, and can be reused; the circulation speed of the heat transfer oil is controlled at 0.5~1m / s to ensure uniform heat transfer.

[0045] Step S5: Seal the annular groove 12. Use cement mortar that can withstand high temperatures of 300℃ to seal the annular groove 12 of the concrete column 1. Fill the cement mortar to the same level as the surface of the concrete column 1, and ensure that there are no gaps or cracks between the cement mortar and the concrete column 1, Fe SMA strip 3, and thermally conductive copper plate 4.

[0046] After sealing, the cement mortar is cured for no less than 7 days to ensure that it reaches the design strength. The cement mortar can effectively protect the Fe SMA strips and thermally conductive copper plates from external environmental erosion, while also enhancing the overall integrity of the reinforced structure.

[0047] Preferably, the cement mortar is made by compounding 42.5 grade silicate cement and sulfoaluminate refractory cement in a 3:1 ratio, and adding 8% redispersible latex powder, 3 kg / m³ of organosilicon-modified polycarboxylate superplasticizer and 15% aluminum hydroxide flame retardant. Its 28-day compressive strength is ≥3.0 MPa, thermal conductivity is ≤0.08 W / (m·K), combustion performance rating is A1, and long-term service temperature is not lower than 300℃, ensuring that it does not fall off or crack during thermal excitation and can effectively protect internal components.

[0048] Step S6: Secondary thermal stimulation reinforcement. Long-term monitoring of concrete column 1 is conducted. When the crack 11 in concrete column 1 continues to expand due to stress relaxation, and the width of crack 11 exceeds the limit specified in the standard (≥0.3mm), heat-conducting oil heated to 300℃ is injected again into the serpentine circulation pipe of the heat-conducting copper plate 4 to perform secondary thermal stimulation on the Fe SMA strip 3. This causes the Fe SMA strip 3 to generate shape recovery stress again, replenishing prestress, inhibiting the further expansion of crack 11, and improving the load-bearing capacity of the concrete column, thus achieving long-term dynamic reinforcement of concrete column 1. The operation procedure for secondary thermal stimulation is the same as that for the first thermal stimulation and can be repeated multiple times depending on the damage condition of the concrete column.

[0049] This application demonstrates a significant and reliable method for reinforcing concrete columns. The dual-fixation method, combining bolts and high-temperature structural adhesive with a primer, prevents loosening and effectively transfers prestress. The use of a heat-conducting copper plate with a serpentine circulation pipe and 300°C heat-conducting oil ensures uniform heating of the Fe SMA strips, combining safety and economy. Long-term dynamic reinforcement can be achieved through secondary and multiple thermal excitations, addressing stress relaxation and crack propagation. The construction process is simple, requiring small groove sizes, minimizing disturbance to the existing structure and not affecting the building's appearance or functionality. Fe SMA material is inexpensive and can be mass-produced, suitable for concrete columns of various cross-sections and degrees of damage, and has broad application value in multiple fields.

[0050] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An embedded Fe-SMA strip based concrete column strengthening device, characterized in that, The concrete column reinforcement device includes: Fe SMA strip (3) and thermally conductive copper plate (4). Each Fe SMA strip (3) is fixedly installed around the concrete column (1). Before the Fe SMA strip (3) is fixed to the concrete column (1), the Fe SMA strip (3) is pre-stretched and the pre-stretch strain is controlled at 3%~5% so that the Fe SMA strip (3) undergoes martensitic phase transformation and stores the energy required for shape memory effect. The heat-conducting copper plate (4) is disposed on the outside of each Fe SMA strip (3) and is tightly attached to the Fe SMA strip (3); and the heat-conducting copper plate (4) has a built-in serpentine circulation pipe for passing the heating medium, and the liquid inlet (41) and liquid outlet (42) of the serpentine circulation pipe are disposed on the surface of the heat-conducting copper plate (4); The Fe SMA strip (3) is based on the circulating flow of the heating medium inside the thermally conductive copper plate (4) to achieve thermal excitation, generate initial prestress, and complete the reinforcement of the concrete column (1).

2. The concrete column reinforcement apparatus of claim 1, wherein The concrete column (1) has several annular grooves (12) along the circumferential direction on its surface, and each Fe SMA strip (3) and heat-conducting copper plate (4) is embedded in the annular groove (12).

3. The concrete column reinforcement apparatus of claim 2, wherein, The outer side of the heat-conducting copper plate (4) is also filled with concrete to complete the sealing of the annular groove (12); and the liquid inlet (41) and liquid outlet (42) extend out of the concrete setting on the outer side of the heat-conducting copper plate (4).

4. The concrete column reinforcement apparatus of claim 2, wherein, The Fe SMA strip (3) and the thermally conductive copper plate (4) are bolted to the surface of the concrete column (1).

5. The concrete column reinforcement apparatus of claim 4, wherein, Structural adhesive is also provided between the Fe SMA strip (3) and the annular groove (12).

6. A method for reinforcing a concrete column based on embedded Fe-SMA strips, characterized in that, The concrete column reinforcement method includes the following steps: S1: Grooving pretreatment of concrete column (1): According to the degree of damage and reinforcement requirements of concrete column (1), several annular grooves (12) are opened on the surface of concrete column (1). S2: Pre-stretching and fixing of Fe SMA strip (3): Fe SMA strip (3) is selected and pre-stretched. The pre-stretch strain is controlled at 3%~5% to make the Fe SMA strip (3) undergo martensitic phase transformation and store the energy required for shape memory effect. The pre-stretched Fe SMA strip (3) is embedded in the annular groove (12) of the concrete column and bonded to the concrete column (1) with structural adhesive. S3: Heat-conducting copper plate (4) installation: Select a heat-conducting copper plate (4) with a serpentine circulation pipe inside. The inlet (41) and outlet (42) of the serpentine circulation pipe extend to the outside of the annular groove (12). The heat-conducting copper plate (4) is attached to the surface of the Fe SMA strip (3) by bolts (5) and is fixed to the concrete column (1) by bolts (5). S4: The first thermal excitation generates prestress. Heat-conducting oil heated to 300°C is injected into the serpentine circulation pipe of the heat-conducting copper plate (4). The heat-conducting oil circulates in the serpentine heat-conducting pipe and transfers heat evenly to the Fe SMA strip (3) through the heat-conducting copper plate (4). The Fe SMA strip (3) is thermally excited, causing the Fe SMA strip (3) to undergo a phase transformation from martensite to austenite, generating shape recovery stress. The corresponding recovery stress acts as prestress on the concrete column (1) to achieve the initial reinforcement of the concrete column (1). The first thermal excitation time is controlled at 30~60min. After the stress of the Fe SMA strip (3) stabilizes, the injection of high temperature heat transfer oil is stopped, and the heat transfer oil is cooled and discharged or recycled. S5: The annular groove (12) is closed. The annular groove (12) of the concrete column (1) is sealed with cement mortar that can withstand high temperatures of 300℃. The cement mortar is filled to be flush with the surface of the concrete column (1), and there are no gaps or cracks between the cement mortar and the concrete column (1), Fe SMA strip (3), and thermally conductive copper plate (4). S6: Secondary thermal stimulation reinforcement, long-term monitoring of concrete columns, when it is detected that the concrete column cracks continue to expand due to stress relaxation and the crack width exceeds the limit specified in the standard, heat transfer oil heated to 300°C is injected again into the serpentine circulation pipe of the heat transfer copper plate (4) to perform secondary thermal stimulation on the Fe SMA strip (3), so that the Fe SMA strip (3) generates shape recovery stress again, supplements prestress, inhibits crack expansion, and realizes long-term dynamic reinforcement of concrete columns.

7. The method of concrete column reinforcement of claim 6, wherein, Step S1 also includes grinding and cleaning the inner wall of the annular groove (12) to remove floating dust, debris and loose concrete, and then applying a layer of primer to the inner wall of the annular groove (12) to enhance the bonding performance between the structural adhesive and the concrete. The width of the annular groove (12) is the width of the Fe SMA strip (3) plus 10~20mm, and the depth of the annular groove (12) is the thickness of the Fe SMA strip plus 15~20mm.

8. The method of concrete column reinforcement of claim 6, wherein, In step S2, the pre-stretching speed is controlled at 1~2 mm / min to ensure that the Fe SMA strip (3) is stretched uniformly; The structural adhesive is a high-temperature resistant silicone structural adhesive with a peak temperature resistance of not less than 300℃, a room temperature shear strength ≥20MPa, and a high temperature shear strength ≥1MPa.

9. The method of concrete column reinforcement of claim 6, wherein, In step S3, the width and length of the heat-conducting copper plate (4) are the same as those of the Fe SMA strip (3), the thickness is 5~6mm, the diameter of the serpentine circulation pipe is 3~4mm, and the pipe spacing is 20~30mm; In step S4, the heat transfer oil has a high temperature resistance of not less than 350℃, a thermal conductivity of ≥0.15W / (m·K), is non-corrosive, and can be reused; the circulation speed of the heat transfer oil is controlled at 0.5~1m / s.

10. The method of concrete column reinforcement of claim 6, wherein, Step S5 also includes curing the post-poured cement mortar for no less than 7 days to ensure that the cement mortar reaches the design strength. The cement mortar is made by blending 42.5 grade silicate cement and sulfoaluminate refractory cement in a 3:1 ratio, and adding 8% redispersible latex powder, 3 kg / m³ of organosilicon-modified polycarboxylate superplasticizer and 15% aluminum hydroxide flame retardant. Its 28-day compressive strength is ≥3.0 MPa, thermal conductivity is ≤0.08 W / (m·K), combustion performance rating is A1, and long-term service temperature is not lower than 300℃.

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