Method for connecting metal-based shape memory alloy plate and structure to be reinforced

Abstract

The invention discloses a connecting method for a metal-based shape memory alloy plate and a to-be-reinforced structure. The metal-based shape memory alloy plate is fixed to the to-be-reinforced structure through an anchoring device. Comprising a first working condition, a second working condition, a third working condition and a fourth working condition, the iron-based shape memory alloy plate is fixed to a to-be-reinforced structure through the anchoring device, and the purpose of connecting the iron-based shape memory alloy plate and the to-be-reinforced structure is achieved. The anchoring device is used for installing an iron-based shape memory alloy plate to the bottom of a structure to be reinforced and mainly comprises a base plate, a bottom plate, a cover plate, a clamping piece and a high-strength bolt. According to the method, four working conditions correspond to different bearing capacities; the method does not need glue coating, instability is reduced, and the connecting device can be repeatedly used; grouting or wet operation is not needed, the reinforcing construction period is greatly shortened, the iron-based shape memory alloy plate is arranged outside the to-be-reinforced structure, and actual construction and maintenance and activation of the iron-based shape memory alloy plate are facilitated.

Description

Technical Field

[0001] The invention relates to a civil engineering reinforcement technical method, and in particular to a method for connecting a metal-based shape memory alloy plate with a structure to be reinforced. Background Art

[0002] At some point during the service life of civil structures such as buildings and bridges, they may need to be repaired or reinforced due to structural aging, change of use or increased load. This problem is widespread around the world, and the repair and reinforcement of structures has become an important research issue in related fields. In the past few decades, a lot of research has been done on different reinforcement methods in order to extend their service life by increasing the bearing capacity of the structure or improving the working performance of the structure. Strengthening and repairing old structures can not only avoid the huge waste of rebuilding new structures, but also reduce the adverse effects of demolition and construction projects on society, the environment and the economy, and ultimately improve the sustainability of building structures.

[0003] The existing structural reinforcement methods mainly include the following: 1. Strengthening by increasing the cross section; 2. Strengthening by gluing steel plates; 3. Strengthening by gluing fiber composite materials; 4. Strengthening by external prestressed tendons; 5. Strengthening by prestressed fiber composite panels; 6. Strengthening by changing the structural system. Among them, the reinforcement method of prestressed carbon fiber composite material (CFRP) panels is a relatively advanced reinforcement method. CFRP has excellent mechanical properties, fatigue properties and durability. It has been widely used in the reinforcement of civil structures and has achieved good reinforcement effects. However, CFRP materials are anisotropic, especially the strength in the thickness direction is very low, which makes it difficult to give full play to its high strength advantage. In addition, the reinforcement method of prestressed CFRP panels requires the introduction of prestress with the help of heavy tensioning machinery and equipment such as jacks and oil pumps and complex anchors. This reinforcement method is difficult to construct, has high cost, and has complex anchors. In addition, the implementation process is easily restricted by the operating space and the original structural form. Therefore, it is urgent to seek a new reinforcement method that is convenient, fast and economical.

[0004] Iron-based shape memory alloy refers to an alloy that deforms under external force within a certain temperature range and can restore its original shape under heating conditions. This shape-recoverable property is called the shape memory effect. If the deformation of the shape memory alloy is restricted during the heating process, a very considerable recovery stress can be generated. This recovery stress can be introduced into the concrete structure as a prestress for structural reinforcement. Iron-based shape memory alloy has the advantages of low cost, high strength, good plasticity, high elastic modulus, and good hot and cold processing performance. It is a structural reinforcement material with great application potential and good development prospects.

[0005] The anchoring device connecting the iron-based shape memory alloy and the structure to be reinforced plays a vital role in the performance of the iron-based shape memory alloy. However, the conventional connection method mainly arranges the iron-based shape memory alloy inside the structure to be reinforced, which requires grooving and grouting of concrete, making it difficult to reuse, and brings great inconvenience to the actual construction process and the activation of the iron-based shape memory alloy. Summary of the invention

[0006] Purpose of the invention: The present invention provides a method for connecting a metal-based shape memory alloy plate to a structure to be reinforced, which is simple to operate, economical and practical. The method does not require grouting or wet work, and arranges the iron-based shape memory alloy plate outside the structure to be reinforced, which is beneficial to actual construction and maintenance as well as activation of the iron-based shape memory alloy plate.

[0007] Technical solution: The method for connecting the metal-based shape memory alloy plate to the structure to be reinforced includes the following steps: fixing the metal-based shape memory alloy plate to the structure to be reinforced by an anchoring device, wherein the anchoring device includes a pad, a base plate, and a cover plate, which are connected and fixed to each other by high-strength bolts, and a clip is provided or not provided between the base plate and the cover plate according to working conditions.

[0008] Further, working condition 1: an undrilled metal-based shape memory alloy plate is clamped using an anchoring device without a clip and installed to the bottom of the structure to be reinforced, using 6 high-strength bolts.

[0009] Further, working condition 2: an undrilled metal-based shape memory alloy plate is clamped using an anchoring device including a clip and installed to the bottom of the structure to be reinforced, using 6 high-strength bolts.

[0010] Further, working condition three: using an anchoring device without a clip to clamp the drilled metal-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 9 high-strength bolts.

[0011] Further, working condition 4: using an anchoring device including a clip to clamp the drilled iron-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 9 high-strength bolts.

[0012] Furthermore, the metal-based shape memory alloy plate includes an iron-based shape memory alloy plate, a nickel-titanium-based shape memory alloy plate or a copper-based shape memory alloy plate.

[0013] Furthermore, the high-strength bolts include bolts and rivets.

[0014] Furthermore, the structure to be reinforced includes a concrete structure, a steel structure, a wooden structure, a masonry structure or a combination of these structures.

[0015] Furthermore, the method for connecting the metal-based shape memory alloy plate to the structure to be reinforced preferably comprises the following steps:

[0016] S1: Pretreatment, including marking, positioning, drilling, cleaning the hole wall, injecting glue and planting reinforcement, etc.

[0017] S2: Drilling of iron-based shape memory alloy plate. For working conditions 3 and 4, it is necessary to perform positioning drilling on the iron-based shape memory alloy plate.

[0018] S3: Install the iron-based shape memory alloy plate into the anchoring device in the order of the pad, the bottom plate, the iron-based shape memory alloy plate and the cover plate. For working conditions 2 and 4, it is necessary to install a clip between the bottom plate and the iron-based shape memory alloy plate, and between the iron-based shape memory alloy plate and the cover plate, respectively.

[0019] S4: Clamp and install the anchor, use high-strength bolts to clamp the anchor, and use nuts to install the anchor and the iron-based shape memory alloy plate to the bottom of the structure to be reinforced.

[0020] Furthermore, the shapes of the pad, base plate, cover plate and clip include rectangle, circle, ellipse or triangle.

[0021] Compared with the prior art, the present invention has the following positive effects: the present invention provides a method for connecting an iron-based shape memory alloy plate to a structure to be reinforced that is simple to operate, economical and practical. The connection method includes four working conditions, corresponding to different bearing capacities; the connection method does not require large-area glue application, which is conducive to reducing the instability of the connection effect, and the connection device is reusable; the connection method does not require grouting or wet operation, which greatly shortens the reinforcement construction period; the connection method arranges the iron-based shape memory alloy plate outside the structure to be reinforced, which is conducive to actual construction and maintenance as well as the activation of the iron-based shape memory alloy plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of an application case of the present invention;

[0023] Figure 2 This is a schematic diagram of the anchor assembly for working condition 1;

[0024] Figure 3 This is the schematic diagram of the anchor assembly for working condition 2;

[0025] Figure 4 It is the schematic diagram of the three anchor assembly of working condition;

[0026] Figure 5 It is a schematic diagram of the four anchor assembly conditions. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further described below.

[0028] The method for connecting the iron-based shape memory alloy plate and the structure to be reinforced in this embodiment is to fix the metal-based shape memory alloy plate to the structure to be reinforced by an anchoring device.

[0029] There are the following working conditions:

[0030] Working condition 1: Use an anchoring device without clips to clamp the undrilled metal-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 6 high-strength bolts. Working condition 2: Use an anchoring device with clips to clamp the undrilled metal-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 6 high-strength bolts. Working condition 3: Use an anchoring device without clips to clamp the drilled metal-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 9 high-strength bolts. Working condition 4: Use an anchoring device with clips to clamp the drilled iron-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 9 high-strength bolts. Furthermore, the metal-based shape memory alloy plate includes an iron-based shape memory alloy plate, a nickel-titanium-based shape memory alloy plate, or a copper-based shape memory alloy plate.

[0031] The high-strength bolts include but are not limited to bolts and rivets.

[0032] Figure 1-Figure 5 The present invention is a schematic diagram of a specific implementation case of a method for connecting an iron-based shape memory alloy plate to a structure to be reinforced.

[0033] The steps to implement the program are as follows:

[0034] Step S1: pretreatment, including marking, positioning, and drilling holes at the bottom of the reinforced structural concrete beam 1, cleaning the hole wall, injecting glue, and planting reinforcement.

[0035] Step S2: drilling holes in the iron-based shape memory alloy plate 2. For working conditions 3 and 4, it is necessary to perform positioning drilling on the iron-based shape memory alloy plate 2.

[0036] Step S3: Install the iron-based shape memory alloy plate. Install the iron-based shape memory alloy plate into the anchoring device in the order of the pad 3, the bottom plate 4, the iron-based shape memory alloy plate and the cover plate 5. For working conditions 2 and 4, it is necessary to install clips between the bottom plate and the iron-based shape memory alloy plate, and between the iron-based shape memory alloy plate and the cover plate, respectively.

[0037] Step S4: Clamp and install the anchor, use high-strength bolts to clamp the anchor, and use nuts to install the anchor and the iron-based shape memory alloy plate to the bottom of the structure to be reinforced.

[0038] The shapes of the backing plate, bottom plate, cover plate and clip include but are not limited to rectangle, circle, ellipse or triangle.

[0039] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.

Claims

1. A method for connecting a metal-based shape memory alloy plate to a structure to be reinforced, characterized in that: The metal-based shape memory alloy plate is fixed to the structure to be reinforced by an anchoring device. The anchoring device includes a pad, a base plate, and a cover plate, which are connected and fixed to each other by high-strength bolts. Depending on the working conditions, a clip is set or not set between the base plate and the cover plate.

2. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to claim 1, characterized in that: Working condition 1: Use an anchoring device without clips to clamp the undrilled metal-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 6 high-strength bolts.

3. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to claim 1, characterized in that: Working condition 2: Use an anchoring device including a clip to clamp the undrilled metal-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 6 high-strength bolts.

4. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to claim 1, characterized in that: Working condition 3: Use an anchoring device without clips to clamp the drilled metal-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 9 high-strength bolts.

5. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to claim 1, characterized in that: Working condition 4: Use an anchoring device including a clip to clamp the drilled iron-based shape memory alloy plate and install it to the bottom of the structure to be reinforced, using 9 high-strength bolts.

6. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to claim 1, characterized in that: The metal-based shape memory alloy plate includes an iron-based shape memory alloy plate, a nickel-titanium-based shape memory alloy plate or a copper-based shape memory alloy plate.

7. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to claim 1, characterized in that: The high-strength bolts include bolts and rivets.

8. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to claim 1, characterized in that: The structure to be reinforced includes a concrete structure, a steel structure, a wooden structure, a masonry structure or a combination of these structures.

9. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Pretreatment, including marking, positioning, drilling, cleaning the hole wall, injecting glue and planting reinforcement, etc. S2: Drilling of iron-based shape memory alloy plate. For working conditions 3 and 4, it is necessary to perform positioning drilling on the iron-based shape memory alloy plate. S3: Install the iron-based shape memory alloy plate into the anchoring device in the order of the pad, the bottom plate, the iron-based shape memory alloy plate and the cover plate. For working conditions 2 and 4, it is necessary to install a clip between the bottom plate and the iron-based shape memory alloy plate, and between the iron-based shape memory alloy plate and the cover plate, respectively. S4: Clamp and install the anchor, use high-strength bolts to clamp the anchor, and use nuts to install the anchor and the iron-based shape memory alloy plate to the bottom of the structure to be reinforced.

10. The method for connecting a metal-based shape memory alloy plate to a structure to be reinforced according to claim 9, characterized in that: The shapes of the pad, bottom plate, cover plate and clip include rectangle, circle, ellipse or triangle.

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