A wet spray UHPC device for orienting steel fibers

Abstract

The utility model discloses a kind of wet type injection UHPC devices for directional steel fiber, it is related to concrete construction equipment technical field.The device includes spray gun, magnetization tapering pipeline, raw material supply part, accelerator supply device, compressed air supply device and control system.The spray gun is sequentially connected by mixing section, shrinkage section and polymerization section, and the inner wall of mixing section is equipped with continuous spiral projection and is connected accelerator pipeline, and polymerization section is connected air delivery pipe.Magnetization tapering pipeline outer wall is wound electromagnetic coil, and its inner diameter is linear tapering along flow direction.The utility model carries out pre-orientation to steel fiber by magnetization tapering pipeline, realizes the full mixing of material and accelerator and stable injection using spray gun structure, and finally forms the UHPC layer of fiber directional arrangement in component, significantly improves its mechanical property and construction quality.

Description

Technical Field

[0001] This utility model relates to the field of concrete construction equipment technology, specifically to a wet spraying UHPC device for oriented steel fibers. Background Technology

[0002] Ultra-high performance concrete (UHPC) has been increasingly widely used in modern civil engineering due to its superior mechanical properties and durability, such as in the construction of important infrastructure projects like bridges and high-speed railways. In the construction of UHPC, spraying technology is a commonly used and efficient method that can quickly and effectively apply UHPC material to the surface of the target structure to form a robust protective or load-bearing layer.

[0003] Currently, traditional wet shotcrete equipment presents numerous problems when used in UHPC construction. Firstly, regarding the orientation of steel fibers, conventional equipment cannot effectively control the distribution and orientation of steel fibers within the UHPC. Random distribution of steel fibers in the concrete often fails to fully utilize their reinforcing effect, resulting in suboptimal mechanical properties of the concrete, particularly tensile and crack resistance. Secondly, existing shotcrete equipment has deficiencies in raw material mixing, transportation, and the timing and effectiveness of mixing with accelerators. For example, segregation may occur during raw material transportation, affecting the uniformity of the UHPC; uneven mixing of the accelerator and UHPC raw materials leads to inconsistent setting times of the shotcrete, impacting construction quality and efficiency. Furthermore, traditional shotcrete equipment has low efficiency in utilizing compressed air during spraying, resulting in unstable spraying pressure, which in turn affects the spraying distance and spraying effect. Utility Model Content

[0004] The purpose of this invention is to provide an integrated device that can achieve efficient directional arrangement of steel fibers and adapt to wet spraying processes, so as to improve the mechanical properties and construction reliability of UHPC components.

[0005] The technical solution adopted in this utility model is as follows: A wet spraying UHPC device for oriented steel fibers, comprising:

[0006] A spray gun, comprising a mixing section, a shrinking section, and a polymerization section connected in sequence; the inner wall of the mixing section is provided with a continuous spiral protrusion structure along the axial direction, and a quick-setting agent pipe is connected to the mixing section; the large end of the shrinking section is connected to the mixing section, and the small end is connected to the polymerization section; an air delivery pipe is connected to the polymerization section.

[0007] A magnetized tapering pipe, wherein the inner diameter of the magnetized tapering pipe is linearly tapered along the material flow direction, the large diameter end of which is connected to the raw material supply section, and the small diameter end is connected to the mixing section of the spray gun; an electromagnetic coil is wound around the outer wall of the magnetized tapering pipe.

[0008] Raw material supply department, used to transport UHPC material into magnetized tapered pipes;

[0009] A quick-setting agent supply device is connected to the mixing section of the spray gun through the quick-setting agent pipeline, and is used to deliver quick-setting agent to the mixing section;

[0010] A compressed air supply device is connected to the polymerization section of the spray gun via the air delivery pipe, and is used to supply compressed air to the polymerization section;

[0011] The control system is used to control the current magnitude and switching on / off of the electromagnetic coil, as well as to adjust the delivery parameters of UHPC raw materials, accelerators, and compressed air.

[0012] Furthermore, the spray gun is made of non-magnetic aluminum alloy material.

[0013] Furthermore, the magnetic field strength inside the magnetized converging pipe is greater than 80mT, and the relationship between the pipe length L (m) and the flow velocity V (m / s) of the magnetized converging pipe is L > 30V.

[0014] Furthermore, the electromagnetic coil is wrapped with an insulating jacket.

[0015] Furthermore, an insulated handle is attached to the spray gun.

[0016] Furthermore, the raw material supply unit is a wet shotcrete machine, used to transport the mixed UHPC material to the magnetized converging pipe.

[0017] The beneficial effects of this utility model are as follows:

[0018] (1) Significant effect of steel fiber orientation: The strong magnetic field generated by the magnetized tapered pipe effectively guides the steel fibers in the UHPC to arrange in an orderly manner along the material flow direction. This orientation distribution can give full play to the bridging and reinforcing role of steel fibers, significantly improving the overall tensile, bending and crack resistance of the sprayed layer, and is especially suitable for key structures with strict requirements for mechanical properties;

[0019] (2) Good uniformity of raw material mixing: The continuous spiral protrusion structure on the inner wall of the mixing section of the spray gun can guide the material to flow in a spiral manner after the UHPC raw material and the quick-setting agent enter the mixing section, increasing the chance of mutual friction and collision between materials, thereby achieving full mixing, effectively avoiding problems such as inconsistent concrete setting time and large strength dispersion caused by uneven mixing, and ensuring the quality stability of UHPC after spraying.

[0020] (3) Stable and efficient injection pressure: Through the combined design of the contraction section and the aggregation section, and the precise introduction of compressed air, the material flow is effectively aggregated and accelerated, forming a stable and concentrated injection beam, ensuring that the injection pressure is efficient and controllable, thereby meeting the construction requirements under different distances and working conditions, effectively improving construction efficiency and reducing rebound;

[0021] (4) Precise control and strong adaptability: The control system can precisely control the current and on / off state of the electromagnetic coil, thereby flexibly adjusting the magnetic field strength and action time in the magnetized converging pipe to adapt to the needs of different steel fiber contents and UHPC raw material characteristics; at the same time, it can also precisely adjust the conveying parameters of UHPC raw material, accelerator and compressed air to ensure the best spraying effect under different construction conditions, thus improving the versatility and adaptability of the device.

[0022] (5) High safety performance: The spray gun is made of non-magnetic aluminum alloy material, which effectively avoids the problem of the steel fiber orientation effect and safety hazards caused by the magnetism of the spray gun itself in a strong magnetic field environment; the electromagnetic coil is wrapped with an insulating jacket and the spray gun is connected to an insulating handle, which greatly improves the safety of operators, prevents electric shock accidents during equipment operation, and protects the personal safety of construction personnel. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0024] Figure 2 This is a schematic diagram of the structure of the spray gun of this utility model.

[0025] Figure 3 This is a schematic diagram of the structure of the magnetized tapered pipe of this utility model. Detailed Implementation

[0026] To facilitate understanding of this utility model, it will be described more comprehensively and in detail below with reference to the accompanying drawings and preferred embodiments. However, the scope of protection of this utility model is not limited to the following specific embodiments.

[0027] like Figures 1 to 3 As shown, the present invention provides a wet spraying UHPC device for oriented steel fibers, which mainly includes a spray gun 1, a magnetized tapered pipe 2, a raw material supply unit 3, a quick-setting agent supply device 4, a compressed air supply device 6, and a control system (not shown in the figure).

[0028] The spray gun 1 is the core component for material mixing and jet formation. It is made of non-magnetic aluminum alloy to avoid interference with the magnetic field. Along the material flow direction, the spray gun 1 includes a coaxially connected mixing section 11, a contraction section 12, and a polymerization section 13. The inner wall of the mixing section 11 has a continuous spiral protrusion structure 14, which guides the material to rotate, achieving thorough mixing of the UHPC material and the accelerator. An accelerator pipe 5 is connected to the side wall of the mixing section 11. The contraction section 12 is conical, with its larger end connected to the mixing section 11 and its smaller end connected to the polymerization section 13; its function is to converge the material flow. The polymerization section 13 is cylindrical, with an air delivery pipe 7 connected to its side wall for introducing compressed air to further accelerate the material and form a stable jet. Furthermore, an insulated handle 15 is installed on the outer wall of the spray gun 1 to ensure operator safety.

[0029] The magnetized tapered pipe 2 is a key component for achieving the directional alignment of steel fibers, and its inner diameter linearly tapers along the material flow direction. Its larger diameter end connects to the raw material supply section 3, and its smaller diameter end connects to the mixing section 11 of the spray gun 1. An electromagnetic coil 21 is tightly wound around the outer wall of the pipe, and the coil is wrapped with an insulating jacket. By energizing the electromagnetic coil 21 through the control system, a strong magnetic field with an intensity greater than 80 mT can be generated inside the pipe. To ensure sufficient magnetization and orientation time for the steel fibers, the length L (in meters) of the magnetized tapered pipe 2 and the flow velocity V (in meters per second) of the material inside the pipe satisfy the relationship: L > 30V.

[0030] The raw material supply unit 3 is specifically a wet shotcrete machine, which continuously pumps the pre-mixed UHPC material containing steel fibers to the magnetized converging pipe 2.

[0031] The accelerator supply device 4 is connected to the mixing section 11 of the spray gun 1 through the accelerator pipe 5, and is used to accurately deliver liquid accelerator into the mixing section.

[0032] The compressed air supply device 6 is connected to the aggregation section 13 of the spray gun 1 via the air delivery pipe 7, and is used to provide a stable, high-pressure air source.

[0033] The control system is electrically connected to the electromagnetic coil 21, the raw material supply unit 3, the accelerator supply device 4, and the compressed air supply device 6. It is used to coordinate the presence and strength of the magnetic field and to precisely adjust parameters such as the flow rate and pressure of the UHPC material, accelerator, and compressed air.

[0034] The specific working process of this utility model is as follows:

[0035] Step 1: Mix cement, silica fume, quartz sand, and steel fiber (preferably at a volumetric admixture of about 2%) to prepare UHPC material. Start the device, activate the electromagnetic coil 21 of the magnetized converging pipe 2 through the control system, and use a gaussmeter to calibrate and ensure that the magnetic field strength inside the pipe is stable above 80mT.

[0036] Step 2: Clean the spraying surface and install reinforcing mesh. Start the compressed air supply device 6 and the wet shotcrete machine (which serves as the raw material supply unit 3) sequentially, then open the valves of the quick-setting agent pipe 5 and the air delivery pipe 7 for a test spray. Formal spraying can only begin after the concrete flow from the spray gun 1 outlet has stabilized.

[0037] Step 3: The operator holds the insulated handle 15 and sprays. The spray angle of the spray gun 1 needs to be adjusted according to the expected force direction on the working surface, ensuring that the angle between the spray gun axis and the main force direction of the working surface is no greater than 30°. This operation, combined with the pre-orientation of the steel fibers by the magnetic field inside the pipeline, ensures that the vast majority of steel fibers are aligned along the main force direction within the molded matrix. During spraying, the spray gun 1 should be moved in a spiral motion to ensure that the sprayed layer evenly covers the entire working surface.

[0038] Step 4: After the sprayed UHPC layer has initially set, smooth its surface and immediately perform moisture curing according to specifications. During the curing period, it is strictly forbidden to apply any external load to the work surface.

[0039] With the aid of the teachings present in the foregoing description and related drawings, those skilled in the art will conceive of many modifications and other embodiments of the present invention. Therefore, it is to be understood that the present invention is not limited to the specific embodiments disclosed, and modifications and other embodiments are considered to be included within the scope of the appended claims. Although specific terms are used herein, they are used in a general and descriptive sense only and are not intended to be limiting.

Claims

1. A wet-jet UHPC device for oriented steel fibers, characterized in that, include: The spray gun (1) includes a mixing section (11), a shrinking section (12), and a polymerization section (13) connected in sequence; the inner wall of the mixing section (11) is provided with a continuous spiral protrusion structure (14) along the axial direction, and a quick-setting agent pipe (5) is connected to the mixing section (11); the large end of the shrinking section (12) is connected to the mixing section (11), and the small end is connected to the polymerization section (13); an air delivery pipe (7) is connected to the polymerization section (13). The magnetized tapering pipe (2) has an inner diameter that tapers linearly along the material flow direction. Its large diameter end is connected to the raw material supply section (3), and its small diameter end is connected to the mixing section (11) of the spray gun (1). The outer wall of the magnetized tapering pipe (2) is wound with an electromagnetic coil (21). Raw material supply unit (3) is used to transport UHPC material to the magnetized tapered pipe (2); The accelerator supply device (4) is connected to the mixing section (11) of the spray gun (1) through the accelerator pipe (5) and is used to supply accelerator to the mixing section (11); A compressed air supply device (6) is connected to the polymerization section (13) of the spray gun (1) via the air delivery pipe (7) and is used to supply compressed air to the polymerization section (13); The control system is used to control the current magnitude and on / off state of the electromagnetic coil (21), and to adjust the delivery parameters of UHPC raw materials, accelerators and compressed air.

2. The wet jetting UHPC device for oriented steel fibers as described in claim 1, characterized in that, The spray gun (1) is made of non-magnetic aluminum alloy material.

3. The wet jetting UHPC device for oriented steel fibers as described in claim 1, characterized in that, The magnetic field strength inside the magnetized converging pipe (2) is greater than 80mT, and the relationship between the pipe length L (m) and the flow velocity V (m / s) of the magnetized converging pipe (2) is L > 30V.

4. The wet jetting UHPC device for oriented steel fibers as described in claim 1, characterized in that, The electromagnetic coil (21) is wrapped with an insulating jacket.

5. A wet jetting UHPC device for oriented steel fibers as described in claim 1, characterized in that, An insulated handle (15) is attached to the spray gun (1).

6. The wet jetting UHPC device for oriented steel fibers as described in claim 1, characterized in that, The raw material supply unit (3) is a wet shotcrete machine, used to transport the mixed UHPC material to the magnetized tapering pipe (2).

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