A thin-walled structure reinforced with UHPC thin layer and a processing method thereof

Abstract

The present application discloses a thin-walled structure reinforced with a UHPC thin layer and a processing method, which relates to the technical field of engineering structure reinforcement, including a thin-walled structure, a UHPC thin layer is arranged on both sides or one side of the thin-walled structure, and a rebar hole is arranged on the thin-walled structure, and the rebar unit is fixed in the rebar hole by epoxy glue with different elastic moduli. Therefore, the present application adopts the above-mentioned thin-walled structure reinforced with a UHPC thin layer and a processing method, which solves the technical problem of how to strengthen the thin-walled structure more stably without destroying the original thin-walled structure, and is suitable for thin-walled reinforced concrete structures with rough surface treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering structure reinforcement, and in particular to a UHPC thin-layer reinforced thin-wall structure and a processing method thereof. Background Art

[0002] The use of ultra-high performance concrete (Ultra High Performance Concrete, referred to as UHPC) to strengthen concrete structures is currently the most commonly used reinforcement method for concrete structures. While optimizing the structural size and increasing the spanning capacity, it also improves the structural bearing capacity, durability and service life. When ordinary concrete structures are reinforced by existing technologies, they usually adopt the method of increasing the cross-section, the method of gluing steel plates, the method of gluing fiber composite materials, and the method of external prestressing. After the reinforcement by gluing carbon fiber cloth, the structural reinforcement is directional, the increase in bearing capacity and stiffness is limited, and the development of cracks is difficult to further suppress. After the reinforcement by gluing steel plates, due to the large difference in the elastic modulus of the materials, the gluing interface is prone to failure, and the steel plate itself has durability problems. The external prestressing reinforcement method is very easy to damage thin-walled structures during reinforcement, so this method is not suitable for thin-walled structures. The conventional method of increasing the cross-section reinforcement requires rough treatment of the thin-walled structure and reinforcement by the method of planting steel bars. However, the conventional method of planting steel bars has a high density and is easy to damage the thin-walled structure. There are problems such as poor effect in suppressing interface cracks, damage to the original structure, and failure to fully exert the strength of the reinforcement materials. Summary of the invention

[0003] The purpose of the present invention is to provide a thin-walled structure reinforced with a UHPC thin layer and a processing method, so as to solve the technical problem of how to strengthen the original thin-walled structure more stably without destroying the original thin-walled structure, and is suitable for thin-walled reinforced concrete structures with roughened surfaces.

[0004] The present application provides a thin-walled structure reinforced with a UHPC thin layer, including a thin-walled structure, UHPC thin layers are arranged on both sides or one side of the thin-walled structure, and anchor holes are arranged side by side on the thin-walled structure. The anchor units used for resisting pull-out and arranged side by side are fixed in the anchor holes by epoxy glues with different elastic moduli, which can provide passive restraint force to the UHPC thin layer, improve the interface reinforcement effect, and will not cause damage to the thin-walled structure.

[0005] Preferably, the anchor bolt unit includes a T-bolt, one end of the T-bolt is an anchor end with a first pad, the other end of the T-bolt is provided with a fixing piece, the first pad of the anchor end is spaced apart from the surface of the thin-walled structure, and the first pad is embedded in the UHPC thin layer, the T-bolt is inserted into the anchor bolt hole and forms an annular gap with the anchor bolt hole, and the inside of the annular gap is injected with epoxy glue with a high elastic modulus and epoxy glue with a low elastic modulus.

[0006] Preferably, a steel mesh is provided on the UHPC thin layer, and the steel mesh is tied to the inner side of the first pad and the fixing member or the inner side of the first pad.

[0007] Preferably, the fixing member comprises a second washer / wide head nut, and the second washer / wide head nut is threadedly connected to one end of the T-bolt.

[0008] The present application provides a method for processing a thin-walled structure reinforced with a UHPC thin layer. When UHPC thin layers are arranged on both sides of the thin-walled structure, the method comprises the following steps:

[0009] 1) The surface of the thin-walled structure is roughened, and a reinforcing bar hole larger than the diameter of the T-bolt is drilled in the thin-walled structure;

[0010] 2) The T-bolt is passed through the reinforcement hole to form an annular gap with the reinforcement hole, and the first pad at the anchor end is spaced from the surface of the thin-walled structure, and the first pad is embedded in the UHPC thin layer;

[0011] 3) Inject high elastic modulus epoxy glue into the middle of the annular gap, and inject low elastic modulus epoxy glue near the UHPC thin layers on both sides;

[0012] 4) After fixing with epoxy glue, put the second pad on the threaded section of the T-bolt and keep a distance from the surface of the thin-walled concrete;

[0013] 5) Tie the steel mesh of the UHPC thin layer to the inner surface of the first pad and the second pad of the T-bolt;

[0014] 6) After fixing, pour UHPC thin layer on both sides of the thin-walled structure to complete the reinforcement.

[0015] Preferably, when a UHPC thin layer is provided on one side of the thin-walled structure, the following steps are included:

[0016] 1) The surface of the thin-walled structure is roughened, and a reinforcing bar hole larger than the diameter of the T-bolt is drilled in the thin-walled structure;

[0017] 2) The T-bolt is passed through the reinforcement hole to form an annular gap with the reinforcement hole, and the first pad at the anchor end is spaced from the surface of the thin-walled structure, and the first pad is embedded in the UHPC thin layer;

[0018] 3) Inject low elastic modulus epoxy glue into the annular gap near the UHPC thin layer, and inject high elastic modulus epoxy glue into the annular gap near the threaded section of the T-bolt;

[0019] 4) After fixing with epoxy glue, put the second pad on the threaded section of the T-bolt and fix the second pad with a nut;

[0020] 5) Tie the steel mesh of the UHPC thin layer to the inner surface of the first pad of the T-bolt;

[0021] 6) After fixing, pour a thin layer of UHPC on one side of the thin-walled structure to complete the reinforcement.

[0022] Therefore, the present application adopts the above-mentioned thin-walled structure reinforced with a UHPC thin layer and a processing method. After the UHPC thin layer is reinforced, the UHPC thin layer and the thin-walled structure are synergistically stressed through the friction and adhesion of the interface. When loaded, the epoxy glue with high elastic modulus and the epoxy glue with low elastic modulus are arranged in the annular gap. The epoxy glue with low elastic modulus can produce a large deformation so that the anchor unit does not directly bear the interface shear force, but only bears the pulling force, and at the same time, the anchor unit will not cause damage to the thin-walled structure. And the anchor unit can continue to maintain the reinforcement effect after the interface cracks. The shear force of the new and old interfaces is provided by the interface adhesion and interface friction. The bolts do not directly bear the shear force. The anchor unit only provides passive restraint force to the UHPC thin layer, which can significantly improve the interface shear performance, and at the same time will not cause damage to the thin-walled structure due to the force.

[0023] The annular gap adopts epoxy glue with low elastic modulus and high elastic modulus so that the embedded reinforcement unit is only subjected to pulling action, which improves the stress mode of the embedded reinforcement unit of the thin-walled structure and will not cause damage to the thin-walled structure; the bolts provide passive constraint force on the UHPC thin layer, and the passive constraint force has an improvement effect on the shear resistance of the rough interface that exceeds the shear bearing capacity of the bolts themselves. The interface shear force is only borne by the bonding force between the rough interface and UHPC, and the stress on the reinforced interface is more uniform; the reinforcement method of the present invention can significantly improve the interface shear resistance, and even after the reinforced interface cracks, the bolts can continue to provide passive constraint force to maintain the reinforcement effect of the interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural diagram of Example 1;

[0025] Figure 2 for Figure 1 A magnified image of

[0026] Figure 3 It is the structural diagram of T-bolt;

[0027] Figure 4 is a structural diagram of the second pad;

[0028] Figure 5 is the structural diagram of the nut;

[0029] Figure 6 is a structural diagram of Example 2;

[0030] Figure 7 The load-displacement curves for the commonly used interfaces in Example 1 are shown in Figure 1, where HWs is the interface treated by pure high-pressure water jet and HWs-N6 is the interface treated by High-pressure water jet treatment interface of the rebar unit, MR S -N6 is adopted Mechanical roughening interface of the rebar unit, MC S -N6 is adopted Mechanical cutting interface of the rebar unit, MC-HW S -N6 is adopted Mechanical cutting of the rebar unit + high-pressure water jet processing interface, MR-HW S -N6 is adopted Mechanical roughening + high-pressure water jet treatment interface of the rebar embedding unit.

[0031] Figure 8 is the effect of embedding ratio on interface strength, where a is the effect of high-strength bolts on interface strength in this test; b is the effect of conventional embedded reinforcement on interface strength.

[0032] Fig. 9 is the effect of interface roughness on interface strength;

[0033] Fig.10 This is the result diagram after the interface cracking of the φ12 new type of rebar unit, where a is the failure phenomenon of the UHPC side of the shear specimen, and b is the failure phenomenon of the ordinary concrete side of the shear specimen.

[0034] Reference numerals

[0035] 1. Thin-walled structure; 2. UHPC thin layer; 3. T-bolt; 4. Second pad; 5. Epoxy glue with high elastic modulus; 6. Epoxy glue with low elastic modulus; 7. Steel mesh; 8. Threaded section; 9. Threaded hole; 10. First pad; 11. Nut. DETAILED DESCRIPTION

[0036] Example 1

[0037] like Figure 1-4 As shown, the present application provides a thin-walled structure 1 reinforced with a UHPC thin layer, including a thin-walled structure 1, which is a conventional concrete structure. UHPC thin layers 2 are arranged on both sides of the thin-walled structure 1, and the UHPC thin layers 2 are ultra-high performance concrete materials. Rebar holes are arranged on the thin-walled structure 1, and the rebar units are fixed in the rebar holes by epoxy glues with different elastic moduli.

[0038] The reinforcement unit includes a T-bolt 3, which is made of stainless steel. The T-bolt 3 is an anchoring end with a first pad 10. The other end of the T-bolt 3 is threadedly provided with a fixing piece, which is a wide-head nut or a second pad 4. The other end of the T-bolt 3 is provided with a threaded section 8. The center position of the wide-head nut or the second pad 4 is provided with a threaded hole 9. The surface of the threaded section 8 is provided with a thread matching the threaded hole 9. The first pad 10 of the anchoring end is spaced apart from the surface of the thin-walled structure 1, and the first pad 10 is embedded in the UHPC thin layer 2. The T-bolt 3 is inserted into the reinforcement hole and forms an annular gap with the reinforcement hole. The inside of the annular gap is injected with high elastic modulus epoxy glue 5 and low elastic modulus epoxy glue 6. A steel mesh 7 is provided on the UHPC thin layer 2, and the steel mesh 7 is tied to the first pad 10 and the inner side of the fixing piece.

[0039] A method for processing a thin-walled structure reinforced with a UHPC thin layer comprises the following steps:

[0040] 1) The surface of the thin-walled structure 1 is roughened by high-pressure water jet according to the carbonization depth, and a reinforcing bar hole larger than the diameter of the T-bolt 3 is drilled in the concrete of the thin-walled structure 1;

[0041] 2) Pass the T-bolt 3 through the anchor hole to keep a certain distance between the first pad 10 at the anchor end and the concrete surface of the thin-walled structure 1. The size of the distance is determined according to the thickness of the UHPC thin layer 2. The first pad 10 needs to be buried in the UHPC thin layer 2 and have a certain protective layer thickness;

[0042] 3) Inject high elastic modulus carben epoxy glue into the middle of the annular gap formed by the T-bolt 3 and the anchor hole, and inject low elastic modulus carben epoxy glue near the UHPC thin layers 2 on both sides;

[0043] 4) After the epoxy adhesive has formed strength, the threaded hole 9 of the wide head nut or the second pad 4 is sleeved onto the threaded section 8 of the T-bolt 3, and a certain distance is kept from the concrete surface of the thin-walled structure 1;

[0044] 5) Tie the steel mesh 7 of the UHPC thin layer 2 to the inner surface of the first pad 10 of the T-bolt 3 and the wide head nut / second pad 4;

[0045] 6) After fixing, the thin-walled structure 1 is moistened and saturated with concrete, and after saturation, UHPC thin layers 2 are poured on both sides to complete the reinforcement.

[0046] A carben epoxy adhesive with a high elastic modulus is used to fix the anchor unit in the middle of the annular gap, and a carben epoxy adhesive with a low elastic modulus is used at both ends of the annular gap so that the anchor unit is only subjected to a pulling action, thereby improving the stress mode of the anchor unit of the thin-walled structure 1 and not causing damage to the thin-walled structure 1; the T-bolt 3 provides a passive constraint force on the UHPC thin layer, and the passive constraint force has an improvement effect on the shear resistance of the rough interface that exceeds the shear bearing capacity of the bolt itself, and the interface shear force is only borne by the bonding force between the rough interface and the UHPC, so that the stress on the reinforced interface is more uniform; the reinforcement method of the present invention can significantly improve the interface shear resistance, and even after the reinforced interface is cracked, the bolt can continue to provide a passive constraint force to maintain the reinforcement effect of the interface.

[0047] Example 2

[0048] like Figure 3-10 As shown, the present application provides a thin-walled structure reinforced with a UHPC thin layer, including a thin-walled structure 1, wherein the thin-walled structure 1 is a conventional concrete structure, a UHPC thin layer 2 is arranged on one side of the thin-walled structure 1, and the UHPC thin layer 2 is an ultra-high performance concrete material. Rebar holes are arranged on the thin-walled structure 1, and the rebar units are fixed in the rebar holes by epoxy glues with different elastic moduli.

[0049] The reinforcement unit includes a T-bolt 3, which is made of stainless steel. The T-bolt 3 is an anchoring end with a first pad 10. The other end of the T-bolt 3 is threadedly provided with a fixing part, which is a second pad 4 / wide-head nut and a nut 11. The other end of the T-bolt 3 is provided with a threaded section 8. The center positions of the nut 11 and the second pad 4 / wide-head nut are provided with threaded holes 9. The surface of the threaded section 8 is provided with threads matching the threaded holes 9. The first pad 10 of the anchoring end is spaced apart from the surface of the thin-walled structure 1, and the first pad 10 is embedded in the UHPC thin layer 2. The T-bolt 3 is inserted into the reinforcement hole and forms an annular gap with the reinforcement hole. The interior of the annular gap is injected with high elastic modulus carben epoxy glue and low elastic modulus carben epoxy glue. A steel mesh 7 is provided on the UHPC thin layer 2, and the steel mesh 7 is tied to the inner side of the first pad 10.

[0050] A method for processing a thin-walled structure 1 reinforced with a UHPC thin layer comprises the following steps:

[0051] 1) The surface of the thin-walled structure 1 is roughened by high-pressure water jet according to the carbonization depth, and a reinforcing bar hole larger than the diameter of the T-bolt 3 is drilled in the concrete of the thin-walled structure 1;

[0052] 2) Pass the T-bolt 3 through the anchor hole, and the first pad 10 of the anchor end of the T-bolt 3 is located in the UHP C thin layer 2 and has a certain distance from the concrete surface of the thin-walled structure 1;

[0053] 3) In the annular gap formed by the T-bolt 3 and the anchor hole, a carben epoxy adhesive with a low elastic modulus is injected into the annular gap close to the UHPC thin layer 2, and a carben epoxy adhesive with a high elastic modulus is implanted into the annular gap close to the threaded section 8;

[0054] 4) After the epoxy adhesive has formed strength, the threaded hole 9 of the second pad 4 / wide head nut is sleeved on the threaded section 8 of the T-bolt 3, and a nut 11 is provided on the threaded section 8. The nut 11 clamps the second pad 4 on the concrete surface of the thin-walled structure 1;

[0055] 5) Tie the steel mesh 7 of the UHPC thin layer 2 to the inner surface of the first pad 10 of the T-bolt 3;

[0056] 6) After fixing, the thin-walled structure 1 concrete is moistened and saturated, and after saturation, the UHPC thin layer 2 can be poured to complete the reinforcement.

[0057] like Figure 1 The figure shows the load-slip curve of the specimen during the whole loading process. It can be seen from the curve that before the specimen cracks, the specimen is shear-resistant as a whole, and the load-slip curve rises roughly linearly. When the specimen reaches the cracking load V c After that, tiny cracks will appear in the specimen, and a short "platform" will appear in the load-slip curve of the embedded steel bar specimen. As the external load increases, the ultimate failure load V b , the crack develops rapidly until the interface is suddenly damaged, and then the bearing capacity of the specimen drops sharply, with an obvious downward mutation process, but the law of the descending section after the damage of all specimens is not obvious. It is mainly because the sudden release of internal energy in the interface causes the specimen to vibrate violently, and the micrometer cannot capture the slip data at this stage. The HWs and MRs-N6 specimens enter the failure mode after the interface is damaged, and the interface is completely detached; when the other embedded steel bar specimens continue to be loaded, the load can continue to increase, and there is still a certain residual bearing capacity. The residual bearing capacity is provided by bolts, with an average of 43kN, while the shear bearing capacity of a single bolt is 13kN. For rough interfaces, the pull-out resistance provided by bolts has a higher improvement on the interface bearing capacity than the direct shear resistance.

[0058] Table 1 Effect of different interface roughness on strength

[0059]

[0060]

[0061] In Table 1, V c is the bearing capacity of various specimens when they crack, V b is the ultimate bearing capacity of various specimens; δ c is the slip amount of each specimen when cracking; δ b Indicates the slip amount of the specimen under the ultimate load state; τc is the bearing capacity V at cracking c The corresponding interface strength; τ ac is the bearing capacity V at cracking c The corresponding average interface strength; τ b is the ultimate bearing capacity V b The corresponding interface strength, τ ab is the bearing capacity V at cracking c The corresponding average interface strength; τ r is the residual strength of the interface after destruction.

[0062] Depend on Fig. 9 It can be seen that under the same reinforcement rate, roughness 2.638 (interface strength 5.95MPa) > roughness 2.052 (interface strength 5.79MPa) > roughness 1.651 (interface strength 5.34MPa) > roughness 1.53 (interface strength 4.64MPa) > roughness 0.941 (interface strength 3.30MPa), that is, the greater the interface roughness, the greater the interface shear strength. When the interface roughness exceeds 2.0mm, the effect of increasing the roughness on the interface shear strength decreases.

[0063] Under the same interface treatment method (mechanical cutting + high-pressure water jet interface), the diameters of the embedded bars are 6mm, 8mm, 10mm, and 12mm, respectively, and the corresponding embedded bar rates are 0.08%, 0.155%, 0.242%, and 0.348%, respectively. The test loading results are shown in Table 2.

[0064] Table 2 Effect of reinforcing bar embedding ratio on interface strength

[0065]

[0066] According to the experimental loading phenomenon and finite element analysis, the interface bearing capacity can be divided into three parts, namely, the UHPC-NC interface adhesion, the interface friction and the shear force provided by the anchor unit. The interface friction is related to the interface roughness and the pull-out force provided by the bolt. That is, the rougher the interface, the greater the pull-out force provided by the bolt, the greater the interface friction and the higher the interface bearing capacity.

[0067] It can be seen from Table 2 that the rebar implantation rates are 0.08%, 0.155%, 0.242%, and 0.348%, which are 30.1%, 65.2%, 77.2%, and 103.2% higher than those of the interface without rebar implantation, respectively. Figure 8As shown. Different embedding rates can be selected according to the interface strength requirements. Compared with the existing research results of the UHPC-NC interface using steel bars as embedding units, under the same embedding rate, the strength of the interface using T-type high-strength bolt embedding units (roughness 2.638mm) is more than 1.65 times the strength of the conventional steel bar embedding interface (roughness 5.5mm); compared with the interface with a conventional steel bar embedding roughness of less than 5.0mm, the strength of the T-type high-strength bolt embedding interface is more than 2.42 times its interface strength. Compared with conventional steel bar embedding methods, this application can achieve higher strength at a low embedding rate, reduce the embedding rate of the original structure, and achieve the purpose of low loss.

[0068] Fig.10 This is the state after the interface is damaged. It can be seen that after the interface shear failure, the rebar hole does not show local crushing due to the shear failure of the rebar unit, indicating that this rebar planting method can provide good protection for the original structure.

[0069] Therefore, the present application provides a thin-walled structure reinforced with a UHPC thin layer and a processing method. This solution will not cause damage to the original thin-walled structure when performing interface roughening and anchoring. The T-bolts are fixed by epoxies with different elastic moduli, which can provide passive restraint to the UHPC thin layer and improve the interface reinforcement effect. The shear force of the new and old interfaces will not be directly transmitted through the anchor unit, and the anchor unit only provides passive restraint to the UHPC thin layer. Moreover, when subjected to force, the low elastic modulus epoxy used at the end will not cause damage to the thin-walled structure by the anchor unit.

[0070] In the description of this specification, the description with reference to the terms "an experimental example", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the experimental example or example are included in at least one experimental example or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same experimental example or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more experimental examples or examples in a suitable manner.

[0071] Finally, it should be noted that the above experimental examples are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred experimental examples, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A thin-walled structure reinforced with a UHPC thin layer, characterized in that: The invention comprises a thin-walled structure, wherein UHPC thin layers are arranged on both sides or on one side of the thin-walled structure, and a reinforcement hole is arranged on the thin-walled structure, and a T-bolt is fixed in the reinforcement hole by epoxy glue with different elastic modulus; one end of the T-bolt is an anchoring end with a first pad, and the other end of the T-bolt is provided with a fixing piece, and a spacing is reserved between the first pad of the anchoring end and the surface of the thin-walled structure, and the first pad is embedded in the UHPC thin layer, the T-bolt is inserted into the reinforcement hole and forms an annular gap with the reinforcement hole, and when UHPC thin layers are arranged on both sides of the thin-walled structure, epoxy glue with high elastic modulus is injected into the middle of the annular gap, and epoxy glue with low elastic modulus is injected into the position close to the UHPC thin layers on both sides; when a UHPC thin layer is arranged on one side of the thin-walled structure, epoxy glue with low elastic modulus is injected into the annular gap close to the UHPC thin layer, and epoxy glue with high elastic modulus is implanted in the annular gap close to the threaded section of the T-bolt.

2. A thin-walled structure reinforced with a UHPC thin layer according to claim 1, characterized in that: A steel mesh is arranged on the UHPC thin layer, and the steel mesh is tied to the inner side of the first pad and the fixing member or the inner side of the first pad.

3. A thin-walled structure reinforced with a UHPC thin layer according to claim 2, characterized in that: The fixing member comprises a second washer or a wide head nut, and the second washer or the wide head nut is threadedly connected with one end of the T-bolt.

4. The method for processing a thin-walled structure reinforced with a UHPC thin layer according to claim 3, characterized in that: When UHPC thin layers are provided on both sides of the thin-walled structure, the following steps are included: 1) The surface of the thin-walled structure is roughened, and a reinforcing bar hole larger than the diameter of the T-bolt is drilled in the thin-walled structure; 2) Pass the T-bolt through the reinforcement hole and form an annular gap with the reinforcement hole. Keep a distance between the first pad at the anchor end and the surface of the thin-walled structure, and bury the first pad in the UHPC thin layer; 3) Inject high elastic modulus epoxy glue into the middle of the annular gap, and inject low elastic modulus epoxy glue near the UHPC thin layers on both sides; 4) After the epoxy glue is fixed, the second pad or wide head nut is put on the threaded section of the T-bolt and kept at a distance from the surface of the thin-walled structure concrete; 5) Tie the steel mesh of the UHPC thin layer to the first pad of the T-bolt and the inner surface of the second pad or wide-head nut; 6) After fixing, pour UHPC thin layer on both sides of the thin-walled structure to complete the reinforcement.

5. The method for processing a thin-walled structure reinforced with a UHPC thin layer according to claim 3, characterized in that: When a UHPC thin layer is provided on one side of the thin-walled structure, the following steps are included: 1) The surface of the thin-walled structure is roughened, and a reinforcing bar hole larger than the diameter of the T-bolt is drilled in the thin-walled structure; 2) Pass the T-bolt through the reinforcement hole and form an annular gap with the reinforcement hole. Keep a distance between the first pad at the anchor end and the surface of the thin-walled structure, and bury the first pad in the UHPC thin layer; 3) Inject low elastic modulus epoxy glue into the annular gap near the UHPC thin layer, and implant high elastic modulus epoxy glue into the annular gap near the threaded section of the T-bolt; 4) After the epoxy glue is fixed, the second pad or wide head nut is sleeved on the threaded section of the T-bolt, and the second pad or wide head nut is fixed with the nut; 5) Tie the steel mesh of the UHPC thin layer to the inner surface of the first pad of the T-bolt; 6) After fixing, pour a thin layer of UHPC on one side of the thin-walled structure to complete the reinforcement.

Images