A composite door panel based on uhpc panels

Abstract

The application discloses a composite door panel based on UHPC panels, comprising a door body, the door body is composed of UHPC panels, the UHPC panels are composite sandwich structures, the door panel adopts a three-layer composite structure, the outer panel and the inner panel are UHPC panels, and the core panel is a flame-retardant thermal insulation material, an interface strengthening layer is formed between the layers through pre-embedded sawtooth glass fiber mesh cloth and sprayed inorganic adhesive, the door panel has high strength and high weather resistance of UHPC, and the core panel has excellent heat insulation and fire resistance, the interlayer bonding strength is ensured through unique interface treatment, the product has the excellent performances of light weight, high strength, fireproofing, heat preservation, durability and maintenance-free, and is particularly suitable for building outer doors and industrial doors with strict performance requirements.

Description

Technical Field

[0001] This invention belongs to the field of building door and window technology, and particularly relates to a composite door panel based on a UHPC panel. Background Technology

[0002] In the construction and industrial sectors, door panels, as a key component of building envelopes, directly affect the safety, energy consumption, and lifespan of buildings. Currently, common door panel materials on the market mainly include:

[0003] 1. Metal door panels (such as steel and aluminum alloy door panels): Although they have high strength, they are prone to corrosion, have significant thermal bridging effects, poor thermal insulation performance, and require complex insulation layers to fill for fire resistance. In addition, the surface coating is prone to aging and peeling in harsh outdoor environments and requires regular maintenance.

[0004] 2. Wood and PVC door panels: Although their thermal insulation performance is acceptable, they have inherent defects such as low strength, poor weather resistance, easy deformation, flammability or low fire resistance rating, which make it difficult to meet the needs of high-performance buildings.

[0005] 3. Ordinary concrete or cement fiberboard: have problems such as heavy weight, high brittleness, easy cracking, and limited decorative options.

[0006] Ultra-high performance concrete (UHPC), as an emerging cement-based material, possesses characteristics such as high compressive strength (compressive strength > 150 MPa), excellent durability, and high temperature resistance, offering a potential solution to the aforementioned problems. However, using UHPC as a single material to manufacture door panels would result in excessively heavy products, making transportation and installation difficult. Furthermore, its relatively high thermal conductivity leads to insufficient thermal insulation performance, failing to meet the energy-saving requirements of modern buildings. Summary of the Invention

[0007] The purpose of this invention is to solve the above-mentioned technical problems existing in the prior art and to provide a composite door panel based on UHPC panel. This invention solves the problems of poor weather resistance, insufficient fire resistance, and need for regular maintenance of traditional door panel materials. At the same time, this invention combines UHPC material as the panel with flame-retardant insulation material, which reduces the weight of the door panel and provides better insulation performance, and is easy to process and form.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A composite door panel based on a UHPC panel includes a door body, characterized in that: the door body is composed of UHPC sheets, the UHPC sheets are composite sandwich structures, the UHPC sheets include an outer panel, a core panel and an inner panel that are sequentially laminated, and the outer panel and the inner panel are bonded to the core panel through an interface reinforcement layer to form the UHPC sheet.

[0010] Furthermore, the door body is made of UHPC panels spliced ​​together or cast in one piece.

[0011] Furthermore, the outer panel is made of UHPC material.

[0012] Furthermore, the outer panel contains 1-5% steel fiber or glass fiber, and the length of the steel fiber or glass fiber is 5-20 mm;

[0013] The outer panel contains 0.5% to 2% nano-modifier.

[0014] Furthermore, the core board is filled with flame-retardant and heat-insulating materials.

[0015] Furthermore, the flame-retardant insulation material is one or more of aerogel felt, rock wool, polyurethane, and ceramic fiberboard.

[0016] Furthermore, the inner panel is one or more of UHPC board, glass fiber polymer board and cement fiber board.

[0017] Furthermore, the thickness of the outer panel is 3–100 mm, and the thickness of the inner panel is 3–100 mm.

[0018] Furthermore, a protective coating is provided on the outer side of the outer panel.

[0019] Furthermore, the interface reinforcement layer includes a fiberglass mesh embedded in the outer panel and an inorganic adhesive sprayed on the inner side of the outer panel. The outer panel and the core board are bonded by the inorganic adhesive. The fiberglass mesh is serrated and extends 3-10 mm into the core board.

[0020] The present invention, by adopting the above-described technical solution, has the following beneficial effects:

[0021] This invention combines the high strength and durability of UHPC with the high thermal insulation and fire resistance of thermal insulation materials through a composite structure design of outer panel, inner panel and core panel. This allows a single door panel product to simultaneously meet the requirements of structural load-bearing, fire safety, building energy conservation and long-term durability, solving the problem of the single performance of traditional materials.

[0022] This invention employs an interface strengthening technology that combines pre-embedded serrated glass fiber mesh with sprayed inorganic adhesive. This technology creates a synergistic effect of mechanical interlocking and chemical bonding between the rigid UHPC outer and inner panels and the flexible flame-retardant insulation core board. This significantly enhances the interlayer shear strength, preventing the risk of delamination and detachment under external forces such as wind pressure and temperature changes. This ensures the structural integrity and safety of the composite door panel during long-term use. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the structure of a composite door panel based on a UHPC panel according to the present invention;

[0025] Figure 2 For the present invention Figure 1 A schematic diagram of the structure in the AA direction.

[0026] In the diagram: 10 - door body; +

[0027] 11-UHPC sheet; 111-Outer panel; 112-Core panel; 113-Inner panel;

[0028] 12-UHPC frame; 121-Crossbeam; 122-Sealing strip; 123-Steel hinge; 124-Steel door lock; Detailed Implementation

[0029] like Figures 1 to 2 As shown, this invention provides a composite door panel based on a UHPC panel, including a door body 10. The door body 10 is composed of UHPC sheets 11, which can be assembled by splicing or integral casting. The UHPC sheets 11 have a composite sandwich structure, which can be formed by one-time molding or segmented bonding to achieve the integration of structure, temperature and fire resistance.

[0030] UHPC sheet 11 includes an outer panel 111, a core panel 112, and an inner panel 113, which are composited from the outside to the inside. The outer panel 111 and the inner panel 113 are bonded to the core panel 112 through an interface reinforcement layer to form UHPC sheet 11.

[0031] The outer panel 111 is made of UHPC material. Utilizing the ultra-high strength and durability of UHPC material, the outer panel 111 of UHPC board 11 can directly withstand external impact, wind load and climate erosion, which greatly improves the overall service life and reliability of the door panel.

[0032] Furthermore, the outer panel 111 contains 1 to 5% steel fiber or glass fiber, with a length of 5 to 20 mm. The steel fiber and glass fiber are reinforcing materials, and their inclusion in the outer panel 111 can enhance the strength of the outer panel 111.

[0033] Furthermore, to enhance the bending resistance of the outer panel 111, reinforcing ribs with reasonable spacing can be set during the casting of the outer panel 111.

[0034] The outer panel 111 also contains 0.5-2% nano-modifiers to optimize the microstructure of UHPC, fill micropores, and further improve the density of the panel.

[0035] The thickness of the outer panel 111 is 3-100mm, and the thickness of the inner panel 113 is 3-100mm, which allows the door panel to be flexibly designed and optimized according to different performance requirements such as wind pressure resistance and impact resistance, realizing the diversification and customization of the product series.

[0036] The outer side of the outer panel 111 is provided with a protective coating. The protective coating is co-cured with the outer panel 111 to improve the weather resistance of the outer panel 111 surface and achieve better gloss and maintenance-free performance.

[0037] The outer panel 111 can be shaped, polished, have exposed aggregate, or be treated with fair-faced concrete. The protective coating can be made of fluorocarbon resin to improve the weather resistance, stain resistance, and self-cleaning ability of the door panel surface.

[0038] The core board 112 is filled with flame-retardant insulation material, which provides excellent thermal insulation performance for the door 10 and reduces building energy consumption.

[0039] Flame-retardant insulation materials are one or more of aerogel felt, rock wool, polyurethane and ceramic fiberboard.

[0040] The inner panel 113 is one or more of UHPC board, glass fiber polymer board and cement fiber board.

[0041] In this invention, the interface reinforcement layer includes a glass fiber mesh embedded in the outer panel 111 and an inorganic adhesive sprayed on the inner side of the outer panel 111. The inorganic adhesive can be silicate-based. The outer panel 111 and the core board 112 are bonded together by the inorganic adhesive. The glass fiber mesh is serrated and extends 3-10 mm into the core board 112. The interface reinforcement layer enhances the interfacial adhesion between the outer panel 111, the inner panel 113 and the core board 112, effectively preventing interlayer debonding and shear failure, and ensuring the integrity and stability of the composite structure under long-term use.

[0042] In this invention, the door body 10 includes a UHPC board 11 and a UHPC frame 12. The UHPC frame 12 is spliced ​​to form a regular shape, and the board body is fixedly connected within the regular shape. The regular shape can be rectangular or polygonal.

[0043] The door body 10 includes a UHPC sheet 11, a UHPC frame 12, a crossbeam 121, and a sealing strip 122. The crossbeam 121 is connected to the inner side of the UHPC frame 12. The UHPC sheet 11 is disposed within the space enclosed by the crossbeam 121 and the UHPC frame 12. The sealing strip 122 is disposed on the outer side of the UHPC frame 12. The sealing strip 122 can be made of EPDM rubber. A steel hinge 123 is provided on the UHPC frame 12, through which the door body 10 is installed.

[0044] A method for preparing a composite door panel based on a UHPC panel includes the following steps:

[0045] S1. Weigh the raw materials according to the design ratio, and put the dry materials into a high-speed shear mixer after premixing. Mix at low speed for 2-5 minutes until the color is uniform, ensuring that the micro powder material is fully dispersed and there are no lumps. Add the liquid material and mix at high speed for 3-5 minutes to fully mix the materials. Add the fiber and disperse it to obtain the UHPC mixture. Pour the UHPC mixture into a mold under low-frequency vibration and vacuum assistance. After curing at room temperature and humidity for 24-48 hours, demold it. Then, heat cure it at 80-95℃ for 48-72 hours to finally form the UHPC board.

[0046] Furthermore, in step S1, a TiO2 photocatalyst can be added during the preparation of the UHPC board to enhance the weather resistance of the UHPC board. The addition of the TiO2 photocatalyst can enable the surface of the door panel to have a photocatalytic self-cleaning function, which can decompose organic pollutants on the surface under light, keep the appearance clean, and reduce maintenance needs.

[0047] In this embodiment, the raw material ratio is: cement 750-850 kg / m³ 3 Silica fume 150-250 kg / m³ 3 Quartz powder 100-200 kg / m 3 The steel fiber content is 2% to 4%, and the length of the steel fiber is 5 to 20 mm.

[0048] In step S1 of this embodiment, the liquid material is a mixture of water and water-reducing agent; after adding fiber dispersion, the UHPC mixture is discharged. After discharge, a flowability test is performed, and a slump flowability test is used to obtain a target flowability diameter of 600-800 mm.

[0049] S2. Pre-embed fiberglass mesh in the outer panel 111, spray inorganic adhesive on the inner side of the cured outer panel 111. The inorganic adhesive is silicate-based and the spray thickness is 1mm. Lay flame-retardant insulation material with a thickness of 20-100mm. After covering the inner panel 113, hot press for 2 hours at 0.5MPa and 80℃ to finally form UHPC board 11.

[0050] S3. Test the wind pressure resistance of UHPC panels: First, calculate the section modulus of the UHPC panel, then calculate the ultimate bending moment of the UHPC panel based on the section modulus, and finally calculate the maximum pressure that the UHPC panel can withstand.

[0051] The formula for calculating the section modulus of a UHPC board is as follows:

[0052]

[0053] In the formula, W is the section modulus of the UHPC board; b is the width of the UHPC board; and h is the thickness of the UHPC board.

[0054] The formula for calculating the ultimate bending moment of a UHPC board is as follows:

[0055] M ult =f tf ×W (2)

[0056] In the formula, M ult f is the ultimate bending moment of the UHPC board. tf The value is 20 MPa; W is the section modulus of the UHPC plate;

[0057] The formula for calculating the maximum pressure that a UHPC board can withstand is:

[0058]

[0059] In the formula, q is the maximum pressure that the UHPC board can withstand, and M is... ult is the ultimate bending moment of the UHPC slab; l is the span of the UHPC slab; k is a coefficient, taken as 0.0479.

[0060] S4. Detect the overall thermal conductivity of UHPC sheet 11: Calculate the thermal resistance based on the thickness of UHPC sheet 11 and the thermal conductivity of the material, and calculate the final overall heat transfer coefficient based on the thermal resistance.

[0061] The formula for calculating thermal resistance is:

[0062]

[0063] In the formula, R is the thermal resistance; h is the thickness of the UHPC board 11; λ is the thermal conductivity.

[0064] The formula for calculating the heat transfer coefficient is:

[0065]

[0066] In this embodiment, a UHPC board 11 with dimensions of 1m×1m×8mm (length×width×thickness) is selected as an example. The wind pressure resistance of the UHPC board 11 is ≥4.475Kpa.

[0067] The specific calculation process for wind pressure resistance is as follows:

[0068] First, calculate the section modulus per unit width (1m) of the UHPC board, according to the formula...

[0069]

[0070] Then calculate the ultimate bending moment M of the UHPC plate. ult The ultimate bending moment is determined by the bending strength f. tfControl, f tf The value is taken as 20 MPa, according to the formula.

[0071] M ult =f tf ×W=20N / mm 2 ×10666.67mm 3 = 0.213 kN·m / m

[0072] The above figures represent the bending moments that a UHPC panel can withstand per meter of width.

[0073] The maximum pressure that a 1m×1m×8mm UHPC board can withstand is:

[0074]

[0075] K is a coefficient that depends on the side length ratio and boundary conditions of the UHPC board. For a 1m × 1m square UHPC board, the value of k is 0.0479. l is the span of the UHPC board, which is 1m.

[0076] Without considering the film effect, the minimum wind pressure resistance of UHPC panels is ≥4.475 kPa.

[0077] The overall thermal conductivity of UHPC sheet 11 is measured to be 0.675 W / (m·K).

[0078] Taking a UHPC board with an outer panel thickness of 1118mm, a rock wool core board thickness of 11250mm, and a UHPC board with an inner panel thickness of 1135mm as an example, the thermal conductivity of the composite UHPC board 11 is calculated as shown in Table 1:

[0079]

[0080] Table 1. Thermal conductivity data for UHPC sheet material.

[0081] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A composite door panel based on a UHPC panel, comprising a door body; characterized in that: The door is composed of UHPC sheets, which have a composite sandwich structure. The UHPC sheets include an outer panel, a core panel, and an inner panel that are sequentially laminated. The outer panel and the inner panel are bonded to the core panel through an interface reinforcement layer to form the UHPC sheets.

2. A composite door panel based on a UHPC panel according to claim 1, characterized in that: The door is constructed by splicing or integrally casting the UHPC sheet.

3. A composite door panel based on a UHPC panel according to claim 1, characterized in that: The outer panel is made of UHPC material.

4. A composite door panel based on a UHPC panel according to claim 1, characterized in that: The core board is filled with flame-retardant and heat-insulating material.

5. A composite door panel based on a UHPC panel according to claim 4, characterized in that: The flame-retardant insulation material is one or more of aerogel felt, rock wool, polyurethane, and ceramic fiberboard.

6. A composite door panel based on a UHPC panel according to claim 1, characterized in that: The inner panel is one or more of UHPC board, glass fiber polymer board and cement fiber board.

7. A composite door panel based on a UHPC panel according to claim 1, characterized in that: The thickness of the outer panel is 3-100mm, and the thickness of the inner panel is 3-100mm.

8. A composite door panel based on a UHPC panel according to claim 1, characterized in that: The outer panel has a protective coating on its outer side.

9. A composite door panel based on a UHPC panel according to claim 1, characterized in that: The interface reinforcement layer includes a fiberglass mesh embedded in the outer panel and an inorganic adhesive sprayed on the inner side of the outer panel. The outer panel is bonded to the core board by the inorganic adhesive. The fiberglass mesh is serrated and extends 3-10 mm into the core board.

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