Self-adhesive reinforced concrete beam composite reinforcement layer structure and its construction method
By combining precast shell plates and shear connectors with ECC and FRP materials, the problems of low construction efficiency and bond failure in ECC-FRP composite reinforcement technology are solved, achieving efficient and reliable reinforcement and improved durability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA CONSTR EIGHT ENG DIV CORP LTD
- Filing Date
- 2026-04-30
- Publication Date
- 2026-06-30
AI Technical Summary
Existing ECC-FRP composite reinforcement technology has low construction efficiency and quality assurance in old buildings. Furthermore, traditional reinforcement methods rely on a large amount of wet work, which cannot effectively solve the problem of bonding failure.
The structure combines precast shell plates and shear connectors, and integrates ultra-high toughness cementitious composite (ECC) and fiber-reinforced polymer (FRP) composites. By combining the precast reinforcement layer with on-site wet work, a self-bonding reinforced concrete beam composite reinforcement layer is formed, avoiding the use of additional cementitious materials.
It achieves efficient and reliable reinforcement, reduces construction procedures, shortens the construction period, improves construction quality and durability, and ensures effective bonding and joint operation between the reinforcement layer and the substrate.
Smart Images
Figure CN122304528A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building structure reinforcement technology, specifically to a self-adhesive reinforced concrete beam composite reinforcement layer structure and its construction method. Background Technology
[0002] my country still has a large number of buildings constructed in the last century. Due to limitations in economic and technological conditions, changes in building functions, and prolonged exposure to harsh environments, the strength, rigidity, and durability of these old buildings no longer meet current standards. The structural components of these old buildings also suffer varying degrees of damage, posing serious threats to people's lives and property. Therefore, the repair and reinforcement of these buildings with safety hazards is urgently needed.
[0003] Common reinforcement methods for reinforced concrete members include increasing the cross-section, replacing concrete, encasing in steel, and altering the structural force transmission path. Increasing the cross-section significantly increases the structure's self-weight, alters its natural frequency, reduces usable space, and impacts functionality. Replacing concrete involves patching, resulting in poor bonding between the old and new concrete, limitations in operational space, and complex processes. Encasing in steel is limited by the operating environment, requires consideration of steel plate durability, and is costly.
[0004] Fiber-reinforced composite materials are lightweight and high-strength, and are widely used in the repair and reinforcement of concrete structures. Currently, the most common method is external fiber-reinforced composite (FRP) reinforcement. This method uses epoxy resin organic cementitious materials (vitrification temperature 60~82℃) for bonding. However, the bond strength of the epoxy resin organic cementitious material decreases when it reaches its vitrification temperature, causing it to lose its foundation for transmitting inter-fiber shear force and working together with the concrete, leading to premature loss of load-bearing capacity of the reinforced system. While external fiber-reinforced composite (FRP) reinforcement utilizes modified cement mortar or high-performance concrete as inorganic cementitious materials, which have significantly better high-temperature resistance and fire resistance than organic adhesives, their lower elongation and poor compatibility with FRP still fail to fundamentally solve the bond failure problem.
[0005] Ultra-high toughness cementitious composite (ECC) is an inorganic cementitious material with high ductility, high durability, and multiple cracking behaviors and strain hardening characteristics. Using ECC and FRP (fiberglass reinforced polymer) materials simultaneously for composite reinforcement of structural members allows their advantages to complement each other, thereby improving the mechanical and deformation properties of the structural members. ECC exhibits significant crack resistance; in the early stages of crack initiation, the fibers effectively bridge the cracks, slowing their propagation and limiting their width. After cracking, ECC possesses excellent stress transfer capabilities and ultra-high ultimate tensile strain, enabling it to work in conjunction with FRP to fully utilize the superior properties of the materials and improve the failure mode of the reinforced specimens.
[0006] However, current ECC-FRP composite reinforcement mainly relies on manual labor, and the on-site reinforcement process involves a large amount of wet work. Under harsh environmental conditions and time constraints, traditional reinforcement methods are not conducive to improving construction efficiency and ensuring construction quality. Therefore, it is meaningful to explore an ECC-FRP composite reinforcement technology that is efficient, low-cost, and provides excellent reinforcement results. Summary of the Invention
[0007] To overcome the shortcomings of existing technologies, a self-adhesive reinforced concrete beam composite reinforcement layer structure and its construction method are provided to solve the problem of a large amount of wet work involved in the process of using ECC-FRP composite reinforcement for old building structures.
[0008] To achieve the above objectives, a self-adhesive reinforced concrete beam composite reinforcement layer structure is provided, comprising: A precast shell plate, comprising an FRP grid and a precast ECC covering the FRP grid, wherein the precast shell plate has multiple through holes; A shear connector is provided, wherein the reinforced concrete beam to be reinforced has a roughened surface, the precast shell plate is disposed opposite to the roughened surface, one end of the shear connector is inserted into the through hole, and the other end of the shear connector is inserted into the reinforced concrete beam, and a casting space is formed between the precast shell plate and the roughened surface. An adhesive layer is formed by injecting post-cast ECC into the casting space to solidify it.
[0009] Furthermore, the FRP mesh is a basalt fiber mesh, a carbon fiber mesh, or a glass fiber mesh.
[0010] Furthermore, the thickness of the adhesive layer is adapted to the thickness of the prefabricated shell plate.
[0011] Furthermore, the roughness of the chiseled surface is 5 mm.
[0012] Furthermore, the depth to which the shear connector is implanted in the reinforced concrete beam is greater than or equal to 10d.
[0013] This invention provides a construction method for a self-adhesive reinforced concrete beam composite reinforcement layer structure, comprising the following steps: The precast ECC is wrapped around the FRP grid to solidify and form a precast shell plate; The reinforced concrete beam to be reinforced is roughened to form a roughened surface; The other end of the shear connector is inserted into the reinforced concrete beam; ECC is then cast onto the roughened surface after coating. The precast shell plate is bonded to the post-cast ECC, and one end of the shear connector is inserted into the through hole of the precast shell plate, so that the post-cast ECC is solidified to form an adhesive layer.
[0014] The beneficial effects of this invention are that the self-adhesive reinforced concrete beam composite reinforcement layer structure adopts a "precast + cast-in-place" semi-precast reinforcement layer construction process. The lower half of the reinforcement layer is precast, while the upper half is constructed on-site using wet methods. The lower half of the reinforcement layer simultaneously serves as both a reinforcement function and a formwork function, achieving advantages such as saving construction procedures, shortening the construction period, reducing on-site work, increasing standardized work, and ensuring construction quality.
[0015] The self-bonding reinforced concrete beam composite reinforcement layer structure of this invention adopts a "self-bonding" reinforcement process. The upper composite reinforcement layer is applied wet on-site, bonding the lower reinforcement layer and the beam together. Once the upper layer reaches its design strength, it forms an ECC-FRP composite reinforcement layer with the lower reinforcement layer, jointly contributing to the load-bearing capacity. This reinforcement process combines reinforcement and bonding effects, avoiding the use of additional inorganic and organic cementitious materials between the substrate and the reinforcement layer. It achieves unity between the reinforcement layer and the bonding layer, ensuring reliable reinforcement results and improving the durability of the reinforced component. Attached Figure Description
[0016] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the self-adhesive reinforced concrete beam composite reinforcement layer structure according to an embodiment of the present invention.
[0017] Figure 2 This is an exploded structural diagram of the self-adhesive reinforced concrete beam composite reinforcement layer structure according to an embodiment of the present invention.
[0018] Figure 3 This is a schematic diagram of the cross-section of a reinforced concrete beam according to an embodiment of the present invention.
[0019] Figure 4 This is a schematic diagram of the structure of the prefabricated shell plate according to an embodiment of the present invention.
[0020] Figure label: Precast shell plate 1, through hole 10, FRP mesh 11, precast ECC 12; Shear connector 2; Adhesive layer 3; 4. Reinforced concrete beam. Detailed Implementation
[0021] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.
[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0023] Reference Figures 1 to 4 As shown, the present invention provides a self-adhesive reinforced concrete beam composite reinforcement layer structure, comprising: a precast shell plate 1, a shear connector 2, and an adhesive layer 3.
[0024] In this embodiment, the bottom of the reinforced concrete beam is the location to be reinforced.
[0025] The precast shell 1 includes an FRP mesh 11 and a precast ECC 12. The precast ECC 12 covers the FRP mesh 11 to solidify and form the precast shell 1.
[0026] As a preferred embodiment, the FRP mesh 11 is a basalt fiber mesh, a carbon fiber mesh, or a glass fiber mesh.
[0027] The precast shell plate 1 has multiple through holes 10.
[0028] The shape and size of the precast shell plate 1 are adapted to the shape and size of the reinforced concrete beam at the location to be reinforced.
[0029] The shear connector 2 consists of multiple pieces. The reinforced concrete beam 4 to be reinforced has a roughened surface. The roughness of the roughened surface is 5 mm.
[0030] The precast shell plate 1 is positioned opposite the roughened surface. One end of the shear connector 2 passes through the through hole 10. The other end of the shear connector 2 is embedded in the reinforced concrete beam 4. The depth of the shear connector 2 embedded in the reinforced concrete beam 4 is greater than or equal to 10d.
[0031] A casting space is formed between the precast shell plate 1 and the roughened surface. Post-cast ECC is poured into the casting space of the adhesive layer 3 to solidify and form the adhesive layer 3.
[0032] In this embodiment, the thickness of the adhesive layer 3 is adapted to the thickness of the prefabricated shell plate 1.
[0033] The self-bonding reinforced concrete beam composite reinforcement layer structure of the present invention is used to improve the flexural bearing capacity and ductility of existing reinforced concrete beams, improve the failure mode, and enhance the seismic performance of reinforced concrete beams. At the same time, it avoids the use of inorganic cementitious materials other than mortar, modified cement mortar, and high-ductility concrete, as well as organic cementitious materials such as epoxy resin, thus solving the problem that the reinforced concrete beam and the composite reinforcement layer cannot work effectively together, resulting in insufficient performance of the reinforcement layer.
[0034] The self-bonded reinforced concrete beam composite reinforcement layer structure of the present invention possesses excellent reinforcement effect, good overall workability of the reinforcement layer, lightweight and high strength, high ultimate tensile strain, multi-crack failure, and strain hardening properties. The composite reinforcement layer is prepared using ultra-high ductility cementitious composite (ECC) and fiber-reinforced polymer (FRP) meshes.
[0035] The self-adhesive reinforced concrete beam composite reinforcement layer structure of the present invention has the advantages of saving construction procedures, shortening construction period, reducing on-site work, and increasing standardized work.
[0036] The lower half of the self-adhesive reinforced concrete beam composite reinforcement layer structure of the present invention (precast half-shell) is precast, and its internal structure includes ECC and FRP mesh, which can achieve standardized assembly line preparation and also serve as a template. During the construction of the self-adhesive reinforced concrete beam composite reinforcement layer structure of the present invention, the on-site wet work only includes the pouring of the upper half of the composite reinforcement layer ECC (bonding layer) and interface treatment.
[0037] The self-adhesive reinforced concrete beam composite reinforcement layer structure of the present invention features reliable interfacial bonding, good durability, and full utilization of the reinforcement layer material performance. The upper composite reinforcement layer has both reinforcement and bonding effects, avoiding the use of additional inorganic and organic cementitious materials between the substrate and the reinforcement layer, thus achieving unity between the reinforcement layer and the bonding layer.
[0038] This invention provides a construction method for a self-adhesive reinforced concrete beam composite reinforcement layer structure, comprising the following steps: S1. The precast ECC is wrapped around the FRP grid to solidify and form a precast shell plate.
[0039] Specifically, the prefabricated shell plate preparation steps include: S11. Based on the width a, length b, and thickness of the reinforcement layer of the beam to be reinforced, prepare the lower half of the reinforcement layer mold with dimensions a×b×(h / 2). h is the thickness of the self-adhesive reinforced concrete beam composite reinforcement layer structure.
[0040] S12. Select an FRP mesh with appropriate spacing to ensure that the pre-cast ECC can evenly fill the FRP mesh. Cut the FRP mesh evenly to the required size, ensuring symmetry in the shape plane and good load-bearing capacity. Place the FRP mesh on the bottom side of the mold, ensuring that the FRP mesh is located in the center of the reinforcement layer after reinforcement.
[0041] S13. Based on project requirements and FRP mesh specifications, leave through holes with a diameter ≥10d+2 to ensure subsequent reinforcement layer anchorage. d is the diameter of the shear connector.
[0042] S14. Pour the ECC into the mold to ensure a uniform, full, and smooth pouring effect, and then cure it under standard curing conditions for 28 days.
[0043] S2. The reinforced concrete beam to be reinforced is roughened to form a roughened surface.
[0044] Specifically, the bottom surface of the reinforced concrete beam should be roughened and reinforced with rebar according to the project requirements to ensure good bonding between the bottom surface of the beam and the post-cast ECC. The roughness should be 5mm and the rebar depth should be ≥10d. After the interface treatment, remove floating dust, oil stains and other impurities.
[0045] S3. Insert the other end of the shear connector into the reinforced concrete beam.
[0046] S4. Apply ECC to the roughened surface and then cast it.
[0047] Clean and moisten the bottom of the beam, and then evenly and fully apply the ECC grout to the bottom of the beam to a thickness of h / 2.
[0048] S5. The precast shell plate is bonded to the post-cast ECC, and one end of the shear connector is inserted into the through hole of the precast shell plate, so that the post-cast ECC is solidified to form an adhesive layer.
[0049] The precast shell slab is accurately and securely fixed to the bottom of the beam to ensure a tight bond between the post-cast ECC and the precast shell slab.
[0050] The bonding layer should be fully cured so that the strength of the subsequent ECC grout reaches the design value.
[0051] The self-adhesive reinforced concrete beam composite reinforcement layer structure of this invention adopts a "precast + cast-in-place" semi-precast reinforcement layer construction process. The lower half of the reinforcement layer is precast, while the upper half of the reinforcement layer is constructed on-site with wet work. The lower half of the reinforcement layer simultaneously serves as both a reinforcement function and a formwork function, achieving advantages such as saving construction procedures, shortening the construction period, reducing on-site work, increasing standardized work, and ensuring construction quality.
[0052] The self-bonding reinforced concrete beam composite reinforcement layer structure of this invention adopts a "self-bonding" reinforcement process. The upper composite reinforcement layer is applied wet on-site, bonding the lower reinforcement layer and the beam together. Once the upper layer reaches its design strength, it forms an ECC-FRP composite reinforcement layer with the lower reinforcement layer, jointly contributing to the load-bearing capacity. This reinforcement process combines reinforcement and bonding effects, avoiding the use of additional inorganic and organic cementitious materials between the substrate and the reinforcement layer. It achieves unity between the reinforcement layer and the bonding layer, ensuring reliable reinforcement results and improving the durability of the reinforced component.
[0053] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.
Claims
1. A self-adhesive reinforced concrete beam composite reinforcement layer structure, characterized in that, include: A precast shell plate, comprising an FRP grid and a precast ECC covering the FRP grid, wherein the precast shell plate has multiple through holes; A shear connector is provided, wherein the reinforced concrete beam to be reinforced has a roughened surface, the precast shell plate is disposed opposite to the roughened surface, one end of the shear connector is inserted into the through hole, and the other end of the shear connector is inserted into the reinforced concrete beam, and a casting space is formed between the precast shell plate and the roughened surface. An adhesive layer is formed by injecting post-cast ECC into the casting space to solidify it.
2. The self-adhesive reinforced concrete beam composite reinforcement layer structure according to claim 1, characterized in that, The FRP mesh is a basalt fiber mesh, a carbon fiber mesh, or a glass fiber mesh.
3. The self-adhesive reinforced concrete beam composite reinforcement layer structure according to claim 1, characterized in that, The thickness of the adhesive layer is adapted to the thickness of the precast shell plate.
4. The self-adhesive reinforced concrete beam composite reinforcement layer structure according to claim 1, characterized in that, The roughness of the chiseled surface is 5 mm.
5. The self-adhesive reinforced concrete beam composite reinforcement layer structure according to claim 1, characterized in that, The depth to which the shear connector is implanted in the reinforced concrete beam is greater than or equal to 10d.
6. A construction method for a self-adhesive reinforced concrete beam composite reinforcement layer structure as described in any one of claims 1 to 5, characterized in that, Includes the following steps: The precast ECC is wrapped around the FRP grid to solidify and form a precast shell plate; The reinforced concrete beam to be reinforced is roughened to form a roughened surface; The other end of the shear connector is inserted into the reinforced concrete beam; ECC is then cast onto the roughened surface after coating. The precast shell plate is bonded to the post-cast ECC, and one end of the shear connector is inserted into the through hole of the precast shell plate, so that the post-cast ECC is solidified to form an adhesive layer.