Fiber grid rib constraint UHPC (Ultra High Performance Concrete) thin layer for reinforcing underwater structure of bridge

Abstract

The utility model provides a fiber grid rib constraint UHPC (Ultra High Performance Concrete) thin layer for reinforcing an underwater structure of a bridge. The fiber grid rib constraint UHPC thin layer comprises a jet UHPC thin layer, FRP (Fiber Reinforce Plastic) grid ribs and FRP embedded steel bars for positioning the FRP grid ribs, the UHPC thin layer is arranged on the outer layer of the existing damaged bridge underwater structure, the FRP grid ribs are arranged in the UHPC thin layer, the FRP embedded steel bars are partially embedded in the existing damaged bridge underwater structure, and the FRP embedded steel bars are partially embedded in the spraying UHPC thin layer. According to the utility model, common concrete which damages the underwater structure of the bridge can be effectively isolated from water, so that the common concrete is prevented from being directly scoured and permeated by the water; meanwhile, the UHPC prepared on the basis of the maximum compactness theory can form a compact interface with excellent bonding performance with the existing common concrete; due to the existence of the FRP embedded steel bars and the FRP grid steel bars, the bonding performance of the sprayed UHPC thin layer-existing concrete interface can be further improved, and then the cooperative work capacity of the sprayed UHPC thin layer and an existing damaged bridge underwater structure is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of reinforcement of underwater bridge structures, in particular to a fiber grid reinforcement-constrained UHPC thin layer for reinforcing underwater bridge structures. Background Art

[0002] Compared to bridge structures above water, underwater bridge structures operate in harsher conditions and environments. Underwater reinforced concrete structures are subject to high hydrostatic pressure, scouring, scouring, and freeze-thaw cycles in extremely cold regions. Due to their low strength, poor durability, large internal porosity, and low water resistance, these structures are prone to concrete cover shedding, exposed rebar, and weakened cross-sections. Exposed rebar is more susceptible to corrosion and expansion, further exacerbating underwater problems such as concrete shedding, reduced cross-sectional dimensions, pile necking, and riverbed incision, seriously threatening the overall safety of the bridge structure.

[0003] To this end, a Chinese patent application with publication number CN101503881BA discloses a method for reinforcing underwater structures with fiber-reinforced composite mesh bars. This method uses at least one layer of fiber-reinforced composite mesh bars to cover the surface of the underwater structure to be reinforced, and then combines the fiber-reinforced composite mesh bars with the underwater structure to be reinforced into a whole by pouring underwater epoxy resin or underwater non-dispersible mortar or underwater non-dispersible concrete. The method has the advantages of rapid reinforcement, short construction period, and no need for water abandonment or waterproofing. However, this method still has the following problems: (1) In a water environment, it is impossible to effectively treat the surface of the structure to be reinforced, resulting in poor bonding performance of the old concrete-reinforcement material interface, which in turn leads to poor durability of the reinforced underwater bridge structure; (2) It is difficult for divers to install steel casing or underwater fiberglass sleeve underwater; (3) In essence, it is still a reinforcement method that increases the cross-section.

[0004] A Chinese patent application, publication number CN114808763A, discloses a technology for reinforcing underwater pier columns using a combination of ultra-high performance concrete formwork and steel-fiber composite reinforcement. High-durability, low-damage steel-fiber composite reinforcement is added longitudinally to the pier cap to create a continuous, flexural structure. High-strength, high-ductility ultra-high performance concrete formwork is used circumferentially to form a cylindrical structure and restraint system surrounding the pier. Finally, underwater non-dispersible mortar is used to grout the joints, connecting the steel-fiber composite reinforcement, ultra-high performance concrete formwork, and the original structure into a load-bearing whole. This improves the durability and overall seismic resistance of the underwater pier columns. This solution utilizes ultra-high performance concrete formwork as a permanent formwork, significantly improving the lateral stiffness, strength, ductility, and energy dissipation capacity of the piers without the need for drainage construction. However, this method results in a significant increase in the cross-sectional dimensions of the reinforced piers and a significant increase in costs. Utility Model Content

[0005] The purpose of the present invention is to provide a solution combining FRP mesh reinforcement and sprayed UHPC technology to improve the above-mentioned shortcomings in the background technology.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a fiber mesh bar constrained UHPC thin layer for reinforcing the underwater structure of a bridge, which is used to reinforce the underwater structure of an existing damaged bridge, including a sprayed UHPC thin layer, FRP mesh bars, and FRP embedded bars for positioning the FRP mesh bars; the sprayed UHPC thin layer is arranged on the outer layer of the existing damaged underwater structure of the bridge, the FRP mesh bars are arranged inside the sprayed UHPC thin layer, and the FRP embedded bars are partially embedded in the underwater structure of the existing damaged bridge and partially pre-buried in the sprayed UHPC thin layer.

[0007] Furthermore, the FRP mesh reinforcement is arranged to fit the surface of the existing damaged underwater structure of the bridge.

[0008] Furthermore, the mesh of the FRP mesh reinforcement is square or diamond-shaped.

[0009] Furthermore, the FRP mesh reinforcement includes a plurality of modules.

[0010] Furthermore, when the underwater structure of the existing damaged bridge is cylindrical, the FRP mesh bars are distributed in a cylindrical shape; when the underwater structure of the existing damaged bridge is rectangular, the FRP mesh bars are distributed in a rectangular shape.

[0011] The above solution of the utility model has the following beneficial effects:

[0012] The fiber mesh reinforcement provided by the utility model constrains the UHPC thin layer for reinforcing the underwater structure of the bridge. The sprayed UHPC thin layer has excellent anti-seepage performance and can effectively isolate the ordinary concrete of the existing damaged underwater structure of the bridge from water, preventing the ordinary concrete from being directly eroded and penetrated by water. At the same time, the UHPC formulated based on the maximum density theory can form a tight interface with the existing ordinary concrete with excellent bonding performance. The presence of FRP embedded bars and FRP mesh bars can further enhance the bonding performance of the sprayed UHPC thin layer-existing concrete interface, thereby effectively improving the collaborative working ability of the sprayed UHPC thin layer and the existing damaged underwater structure of the bridge.

[0013] The utility model is suitable for thin layer reinforcement and has little effect on the cross-sectional dimensions of the reinforced bridge underwater structure, which is perfectly adapted to the engineering background requiring thin layer reinforcement.

[0014] The corresponding process of the utility model is simple, no formwork is required for pouring UHPC, construction is convenient in a narrow space, and the widening of the underwater structure of the bridge is small, which minimizes the impact on the passage of ships.

[0015] Other beneficial effects of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 This is a cross-sectional view of the overall structure of the utility model;

[0018] Figure 3 This is a schematic diagram of the overall structure of the utility model (rectangular bridge underwater structure);

[0019] Figure 4 These are the construction steps in the embodiment of the present utility model.

[0020] [Description of Reference Numerals]

[0021] 1-Existing damaged underwater structure of the bridge; 2-FRP embedded reinforcement; 3-Sprayed UHPC thin layer; 4-FRP mesh reinforcement; 5-Steel cofferdam. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to a locking connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0025] like Figure 1 、 Figure 2 As shown, an embodiment of the present invention provides a fiber mesh bar-constrained UHPC layer for reinforcing an underwater bridge structure. The structure is used to reinforce an existing damaged underwater bridge structure 1. The structure comprises a sprayed UHPC layer 3, FRP mesh bars 4, and FRP anchor bars 2 for positioning the FRP mesh bars 4. The sprayed UHPC layer 3 is applied to the exterior of the damaged underwater bridge structure 1, while the FRP mesh bars 4 are positioned within the sprayed UHPC layer 3. The FRP anchor bars 2 are partially embedded within the damaged underwater bridge structure 1 and partially pre-buried within the sprayed UHPC layer 3, thereby firmly connecting the sprayed UHPC layer 3 to the damaged underwater bridge structure 1. As a preferred embodiment, the FRP mesh bar 4 in this embodiment may have a square, diamond, or other shape, although this is not a specific limitation. The FRP mesh bar 4 is typically prefabricated in multiple modules. During operation, a steel cofferdam 5 is set up to isolate the damaged underwater bridge structure 1 to form a drainage area. The FRP mesh bars 4 of each module are then assembled in the drainage area.

[0026] It should be noted that for the cylindrical existing damaged bridge underwater structure, the FRP mesh reinforcement 4 is also distributed in a cylindrical shape, that is, the outer layer is a cylindrical surface. Figure 3 As shown, for the rectangular existing damaged bridge underwater structure, the FRP mesh reinforcement 3 is also distributed in a rectangular shape, that is, the outer layer is a rectangular surface.

[0027] When the solution provided in this embodiment is adopted, Figure 4 As shown, the following steps are specifically included: installing a steel cofferdam 5, draining the steel cofferdam 5 and performing bottom sealing treatment; cleaning the concrete surface of the existing damaged underwater structure 1 of the bridge; embedding FRP embedded steel bars 2 inside the existing damaged underwater structure 1 of the bridge, and at the same time covering the surface of the existing damaged underwater structure 1 with FRP mesh bars 4; spraying UHPC at the annular position where the FRP mesh bars 4 are located; forming a sprayed UHPC thin layer 3 after the UHPC hardens; and dismantling temporary facilities.

[0028] The solution provided by this embodiment has the following advantages: the sprayed UHPC thin layer 3 has good anti-seepage performance, which can effectively isolate the ordinary concrete of the existing damaged bridge underwater structure 1 from water, and prevent the ordinary concrete from being directly eroded and penetrated by water; at the same time, the UHPC formulated based on the maximum density theory can form a tight interface with the existing ordinary concrete with excellent bonding performance; the presence of FRP embedded bars 2 and FRP mesh bars 4 can further improve the bonding performance of the sprayed UHPC thin layer 3-existing concrete interface, thereby effectively improving the collaborative working ability of the sprayed UHPC thin layer 3 and the existing damaged bridge underwater structure 1; it is suitable for thin layer reinforcement, and the cross-sectional dimensions of the reinforced bridge underwater structure are slightly changed, which is perfectly adapted to the engineering background that requires thin layer reinforcement; the corresponding process of this solution is simple, no formwork for pouring UHPC is required, and it is convenient for construction in a narrow space, and the widening of the bridge underwater structure is small, which minimizes the impact on the passage of ships.

[0029] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0030] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A fiber grid reinforcement UHPC thin layer for reinforcing underwater bridge structures, used to reinforce existing damaged underwater bridge structures, characterized in that: It includes a sprayed UHPC thin layer, FRP mesh bars, and FRP embedded bars for positioning the FRP mesh bars; the sprayed UHPC thin layer is arranged on the outer layer of the existing damaged underwater structure of the bridge, the FRP mesh bars are arranged inside the sprayed UHPC thin layer, and the FRP embedded bars are partially embedded in the existing damaged underwater structure of the bridge and partially pre-buried in the sprayed UHPC thin layer.

2. The fiber grid reinforcement-constrained UHPC thin layer for reinforcing underwater bridge structures according to claim 1, characterized in that: The FRP grid reinforcement is arranged to fit the surface of the existing damaged underwater structure of the bridge.

3. The fiber grid reinforcement-constrained UHPC thin layer for reinforcing underwater bridge structures according to claim 1, characterized in that: The mesh of the FRP mesh reinforcement is square or diamond-shaped.

4. The fiber grid reinforcement-constrained UHPC thin layer for reinforcing underwater bridge structures according to claim 1, characterized in that: The FRP mesh reinforcement includes a plurality of modules.

5. The fiber grid reinforcement-constrained UHPC thin layer for reinforcing underwater bridge structures according to claim 1, characterized in that: When the underwater structure of the existing damaged bridge is cylindrical, the FRP mesh bars are distributed in a cylindrical shape; when the underwater structure of the existing damaged bridge is rectangular, the FRP mesh bars are distributed in a rectangular shape.

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