Light UHPC-based logistics tray and preparation method thereof

Abstract

The invention relates to a light UHPC-based logistics tray and a preparation method thereof, and belongs to the technical field of logistics trays. The logistics tray comprises a light UHPC base body and a metal net. The light UHPC matrix is prepared from the following raw materials in parts by mass: 885 to 930 parts of ordinary Portland cement, 45 to 50 parts of solid waste-based sulfur aluminum iron series low-carbon cementing material, 380 to 570 parts of solid waste-based artificial sand, 0 to 150 parts of filler, 15 to 20 parts of fiber, 2 to 4 parts of HPMC, 20 to 49 parts of water reducing agent and 180 to 210 parts of water. The lightweight UHPC matrix adopts a composite cementing material, and the composite cementing material contained in the raw materials for preparing the added solid-waste-based artificial sand is similar to the cementing material of the lightweight UHPC matrix, so that a hydration product of the cementing material can be embedded into micropores in the solid-waste-based artificial sand; and the solid waste proportion in the solid waste-based artificial sand can reach 80% or above, so that the mechanical strength requirement of the logistics tray can still be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of logistics pallets, and in particular relates to a lightweight UHPC-based logistics pallet and a preparation method thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Logistics pallets are horizontal platforms used for the collection, stacking, handling, and transportation of goods and products as unit loads, and are compatible with forklifts. Logistics pallets are currently categorized by material, primarily including wooden, steel, plastic, composite, and paper pallets. Wooden and plastic pallets consume significant amounts of natural resources and have low durability, while steel and composite pallets are heavy, and paper pallets are easily broken. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the purpose of the present invention is to provide a lightweight UHPC-based logistics pallet and a preparation method thereof, which has a high solid waste utilization ratio, high product strength, can be applied to conventional logistics scenarios, and has good construction performance, short demoulding time, no need for steaming, and a short production cycle.

[0005] In order to achieve the above object, the technical solution of the present invention is: In a first aspect, a lightweight UHPC-based logistics pallet comprises a lightweight UHPC matrix and a metal mesh embedded in the lightweight UHPC matrix; the lightweight UHPC matrix is ​​prepared from the following raw materials in mass fractions: 885-930 parts of ordinary Portland cement, 45-50 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material, 380-570 parts of solid waste-based artificial sand, 0-150 parts of filler, 15-20 parts of fiber, 2-5 parts of hydroxypropyl methylcellulose (HPMC), 20-49 parts of a water reducer, and 180-210 parts of water; The solid waste-based artificial sand is prepared from the following components in percentage by mass: 10-20% composite cementitious material, 0-90% phosphogypsum or desulfurized gypsum, and 0-90% fly ash or gold tailings; wherein the composite cementitious material comprises ordinary Portland cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of (90-95):(5-10).

[0006] In a second aspect, the method for preparing the above-mentioned lightweight UHPC-based logistics pallet comprises the following steps: S1. Pre-wetting the solid waste-based artificial sand with water to make the saturated surface of the solid waste-based artificial sand dry; S2. Ordinary Portland cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, filler, fiber, and hydroxypropyl methylcellulose are mixed and stirred, and then the solid waste-based artificial sand, water reducer, and water obtained in S1 are added. After stirring, the mixture is poured into a forming mold, and then pressed onto a metal mesh surface and smoothed; S3. Let it stand for 3~6 hours before demoulding. Cover with plastic film after spraying water and cure for 1~3 days.

[0007] The beneficial effects of the present invention are: 1. The lightweight UHPC concrete logistics pallet provided by the present invention utilizes a composite cementitious material (ordinary Portland cement + solid waste-based sulfur-aluminum-iron low-carbon cementitious material) as the primary cementitious material in the lightweight UHPC matrix. This material exhibits fast setting and high strength. The composite cementitious material contained in the raw materials for preparing the solid waste-based artificial sand is similar to the cementitious material in the lightweight UHPC matrix. Therefore, when preparing the lightweight UHPC logistics pallet, the hydration products of the cementitious material are similar to those of the lightweight aggregate sand, allowing the cementitious material to embed into the micropores of the solid waste-based artificial sand. This results in a tight bond between the two, a dense interface transition zone, high overall strength, and improved impermeability and durability. Even when the solid waste ratio in the solid waste-based artificial sand exceeds 80%, the pallet still meets the mechanical strength requirements: the pallet's static load (flexural strength) can reach over 1000 kg, and its flexural rigidity can reach over 600 kg.

[0008] 2. The lightweight UHPC concrete-based logistics pallet of the present invention can be demolded within 3 to 6 hours after pouring. During the preparation process of the concrete pallet, the construction performance is good and the demolding time is short, which is more than 75% shorter than the demolding time of conventional concrete pallets. No steaming is required, energy consumption is low, and the product can be shipped quickly. It has the remarkable characteristics of low production cost and high production efficiency. DETAILED DESCRIPTION

[0009] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0010] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0011] One or more embodiments of the present invention provide a lightweight UHPC-based logistics pallet, comprising a lightweight UHPC matrix and a metal mesh embedded in the lightweight UHPC matrix; the lightweight UHPC matrix is ​​prepared from the following raw materials in mass fractions: 885-930 parts of ordinary Portland cement, 45-50 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material, 380-570 parts of solid waste-based artificial sand, 0-150 parts of filler, 15-20 parts of fiber, 2-5 parts of hydroxypropyl methylcellulose (HPMC), 20-49 parts of a water reducer, and 180-210 parts of water; The solid waste-based artificial sand is prepared from the following components in percentage by mass: 10-20% composite cementitious material, 0-90% phosphogypsum or desulfurized gypsum, and 0-90% fly ash or gold tailings; wherein the composite cementitious material comprises ordinary Portland cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of (90-95):(5-10).

[0012] Among the above components, the raw materials for preparing solid waste-based artificial sand include a composite cementitious material similar to the lightweight UHPC matrix. Therefore, the hydration products of the composite cementitious material in the lightweight UHPC matrix can embed into the micropores within the solid waste-based artificial sand, allowing it to tightly bond with the surrounding cementitious material, creating a dense interface transition zone and excellent overall mechanical properties. Even with a solid waste content exceeding 80%, the pallet static load (flexural strength) can still reach over 1000kg and flexural stiffness over 600kg, resulting in low production costs and high performance.

[0013] Optionally, the lightweight UHPC matrix is ​​prepared from the following raw materials in mass fractions: 885-900 parts of ordinary Portland cement, 45-50 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material, 380-430 parts of solid waste-based artificial sand, 130-150 parts of filler, 15-20 parts of fiber, 2-4 parts of hydroxypropyl methylcellulose, 20-49 parts of water reducer and 180-210 parts of water.

[0014] Optionally, the ordinary Portland cement is PO42.5 or PO42.5R grade cement.

[0015] Optionally, the solid waste-based sulfur-aluminum-iron low-carbon cementitious material meets the T / CCPA 42-2023 standard.

[0016] Optionally, the filler includes one or more of silica fume, slag powder and fly ash.

[0017] Optionally, the fibers include one or more of polypropylene fibers and polyethylene fibers, and are components of UHPC.

[0018] Optionally, the water reducer is a polycarboxylic acid water reducer, which is suitable for the gelling material used in the present invention.

[0019] Optionally, the metal mesh is a steel wire mesh with a steel wire diameter of 2-3 mm and a mesh size of (5-8) cm×(5-8) cm.

[0020] Optionally, the size range of the lightweight UHPC-based logistics tray is (1100~1200) mm× (1000~1100) mm, and the metal mesh covers the cross-section of the lightweight UHPC-based logistics tray in the thickness direction; 1~2 layers of metal mesh are embedded in the lightweight UHPC matrix.

[0021] Optionally, the solid waste-based artificial sand is made of the following components in percentage by mass: 10-20% of composite cementitious material, 80-90% of phosphogypsum, desulfurized gypsum, fly ash or gold tailings; the preparation method comprises: vigorously stirring the composite cementitious material and solid waste (phosphogypsum, desulfurized gypsum, fly ash or gold tailings), and obtaining the sand after granulation and screening; the properties of the solid waste-based artificial sand include: bulk density greater than 1100 kg / m 3 , the cylinder pressure strength is greater than 6MPa; specifically, the proportion of phosphogypsum or desulfurization gypsum is 0~90%, and the proportion of fly ash or gold tailings is 0~90%.

[0022] One or more embodiments of the present invention provide a method for preparing the above-mentioned lightweight UHPC-based logistics pallet, comprising the following steps: S1. Pre-wetting the solid waste-based artificial sand with water to make the saturated surface of the solid waste-based artificial sand dry; S2. Ordinary Portland cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, filler, fiber, and hydroxypropyl methylcellulose are mixed and stirred, and then the solid waste-based artificial sand, water reducer, and water obtained in S1 are added. After stirring, the mixture is poured into a forming mold, and then pressed onto a metal mesh surface and smoothed; S3. Let it stand for 3~6 hours before demoulding. Cover with plastic film after spraying water and cure for 1~3 days.

[0023] During the preparation process of the above concrete pallets, the demoulding can be done within 3 to 6 hours after pouring, which is more than 75% shorter than the demoulding time of conventional concrete pallets. It has good construction performance, does not require steaming, and has the remarkable characteristic of high production efficiency.

[0024] The inner wall of the tray forming mold of the present invention is covered with PVC film to facilitate the demoulding of the tray. The mold size depends on the specific needs.

[0025] The present invention does not impose any special restrictions on the stirring process, and stirring parameters commonly used in the art can be used.

[0026] Optionally, in S2, the depth of the metal mesh is pressed into the tray so that the thickness of the tray is evenly divided into multiple layers; when one layer of metal mesh is used, the depth of the metal mesh is 1 / 2 of the tray thickness; when two layers of metal mesh are used, the depth of the metal mesh is 1 / 3 and 2 / 3 of the tray thickness.

[0027] The present invention will be further described below with reference to the embodiments.

[0028] Example 1 A lightweight UHPC-based logistics pallet comprises a lightweight UHPC matrix and a metal mesh embedded in the lightweight UHPC matrix. The lightweight UHPC matrix is ​​prepared from the following raw materials in proportions by weight: 930 parts of PO 42.5 ordinary Portland cement, 45 parts of a solid waste-based sulfur-aluminum-iron low-carbon cementitious material that complies with T / CCPA 42-2023, 570 parts of solid waste-based artificial sand, 15 parts of polypropylene fiber, 5 parts of hydroxypropyl methylcellulose (HPMC), 20.25 parts of a polycarboxylic acid-based high-performance water reducer, and 210 parts of water. The solid waste-based artificial sand is prepared from the following components in percentage by mass: 18% composite cementitious material and 82% phosphogypsum; wherein the composite cementitious material includes ordinary Portland cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of 90:10.

[0029] The preparation method comprises: S0. Add phosphogypsum and composite cementitious materials into a granulator in several times. During the adding process, the granulator first rotates at a speed of 50 Hz, stirs for 5 minutes, and then adds water. Then, the granulator rotates at a speed of 30 Hz to convert the powder into a masterbatch; then, continue to rotate, add materials, and add water until some particles are larger than 1.18 mm to obtain a particle-containing material; the particle-containing material is put into a screening machine with a jacketed screen for screening; particles with a particle size of less than 1.18 mm are screened out, and the particles are returned to the granulator to repeat the granulation and screening process; particles with a particle size of 1.18 to 2.35 mm are screened out, and the particles are placed in a granulator, which rotates at a speed of 40 Hz to improve strength and sphericity to obtain a solid waste-based artificial sand product. The bulk density of the solid waste-based artificial sand product is measured to be 1100 kg / m 3 , cylinder pressure strength is greater than 6MPa; S1. Pre-wetting the solid waste-based artificial sand with water to make the saturated surface of the solid waste-based artificial sand dry; S2. After mixing ordinary Portland cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, fiber, and hydroxypropyl methylcellulose, add the saturated surface-dried solid waste-based artificial sand, water reducer, and water obtained in S1. Stir for 1.5 minutes, pour into a forming mold, and then press into a metal mesh surface and smooth it; S3. Mechanically vibrate the mold for 10 minutes, let it stand at room temperature (25±3℃), demould it after 5 hours, spray it with water, cover it with plastic film and cure it for 2 days.

[0030] The obtained pallet has a length of 1100 mm, a width of 1100 mm, and a surface wall thickness of 20 mm; a layer of wire mesh is buried at 1 / 2 of the thickness, the wire mesh is woven with steel wire with a diameter of 2 mm, and the mesh aperture is 5 cm × 5 cm.

[0031] Example 2 A lightweight UHPC-based logistics pallet comprises a lightweight UHPC matrix and a metal mesh embedded in the lightweight UHPC matrix; the lightweight UHPC matrix is ​​prepared from the following raw materials in proportions by weight: 885 parts of PO 42.5 grade ordinary Portland cement, 50 parts of a solid waste-based sulfur-aluminum-iron low-carbon cementitious material that complies with the T / CCPA 42-2023 standard, 430 parts of solid waste-based artificial sand, 118 parts of silica fume (filler), 32 parts of slag powder (filler), 20 parts of polypropylene fiber, 4 parts of hydroxypropyl methylcellulose (HPMC), 49 parts of a polycarboxylic acid-based high-performance water reducer, and 180 parts of water.

[0032] The solid waste-based artificial sand is prepared from the following components in percentage by mass: 18% composite cementitious material and 82% phosphogypsum; wherein the composite cementitious material includes ordinary Portland cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of 95:5.

[0033] The preparation method comprises: S0, preparing solid waste-based artificial sand according to the method of S0 in Example 1; S1. Pre-wetting the solid waste-based artificial sand with water to make the saturated surface of the solid waste-based artificial sand dry; S2. Ordinary Portland cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, slag powder, fiber, and hydroxypropyl methylcellulose were mixed and stirred for 0.5 min, and then the saturated surface-dried solid waste-based artificial sand, water reducer, and water obtained in S1 were added. After stirring for 1.5 min, the mixture was poured into a forming mold and then pressed onto a metal mesh surface and smoothed. S3. Mechanically vibrate the mold for 15 minutes, let it stand at room temperature (25±3℃), demould it after 3.3 hours, spray it with water, cover it with plastic film and cure it for 2 days.

[0034] The obtained pallet has a length of 1100 mm, a width of 1100 mm, and a surface wall thickness of 18 mm; a layer of steel wire mesh identical to that of Example 1 is embedded at 1 / 2 of the thickness.

[0035] Example 3 A lightweight UHPC-based logistics pallet comprises a lightweight UHPC matrix and a metal mesh embedded in the lightweight UHPC matrix. The lightweight UHPC matrix is ​​prepared from the following raw materials in mass fractions: 900 parts of PO 42.5 grade ordinary Portland cement, 45 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material that complies with the T / CCPA 42-2023 standard, 380 parts of solid waste-based artificial sand, 130 parts of silica fume (filler), 18 parts of polypropylene fiber, 2 parts of hydroxypropyl methylcellulose (HPMC), 26 parts of a polycarboxylic acid-based high-performance water reducer, and 195 parts of water.

[0036] The solid waste-based artificial sand is prepared from the following components in percentage by mass: 18% composite cementitious material and 82% phosphogypsum; wherein the composite cementitious material includes ordinary Portland cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of 93:7.

[0037] The preparation method comprises: S0, preparing solid waste-based artificial sand according to the method of S0 in Example 1; S1. Pre-wetting the solid waste-based artificial sand with water to make the saturated surface of the solid waste-based artificial sand dry; S2. Ordinary Portland cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, fiber, and hydroxypropyl methylcellulose were mixed and stirred for 0.5 min, and then the saturated surface-dried solid waste-based artificial sand, water reducer, and water obtained in S1 were added. After stirring for 1.5 min, the mixture was poured into a forming mold and then pressed onto a metal mesh surface and smoothed. S3. Mechanically vibrate the mold for 15 minutes, let it stand at room temperature (25±3℃), demould it after 3.5 hours, spray it with water, cover it with plastic film and cure it for 3 days.

[0038] The obtained pallet has a length of 1100 mm, a width of 1100 mm, and a surface wall thickness of 15 mm; a layer of steel wire mesh identical to that of Example 1 is embedded at 1 / 2 of the thickness.

[0039] Comparative Example 1 A UHPC-based logistics pallet includes a lightweight UHPC base. The lightweight UHPC base is prepared from the following raw materials in mass fractions: 882 parts of PO 42.5 ordinary Portland cement, 1100 parts of machine-made sand (conforming to GB175-2023 standard), 17 parts of polypropylene fiber, 3 parts of hydroxypropyl methylcellulose (HPMC), 22 parts of a polycarboxylic acid-based high-performance water reducer, and 190 parts of water.

[0040] The preparation method comprises: Step 1: Mix ordinary Portland cement machine-made sand, fiber, and hydroxypropyl methylcellulose and stir for 0.5 minutes, then add water reducer and water, stir for 1.5 minutes, and pour into the molding mold; Step 2: Mechanically vibrate the mold for 20 minutes, let it stand at room temperature (25±3℃), demould after 24 hours, steam cure for 1 day, and then naturally cure for 26 days.

[0041] The obtained pallet has a length of 1100 mm, a width of 1100 mm and a surface wall thickness of 40 mm.

[0042] The difference from Example 1 is that: no solid waste-based sulfur-aluminum-iron low-carbon cementitious material and no steel mesh are added to the preparation raw materials, and in the preparation method, demoulding is carried out within 24 hours, followed by steam curing and natural curing.

[0043] Comparative Example 2 A UHPC-based logistics pallet includes a lightweight UHPC matrix; the lightweight UHPC matrix is ​​prepared from the following raw materials in mass fractions: 1050 parts of PO 42.5 ordinary Portland cement, 1100 parts of machine-made sand (conforming to GB175-2023 standard), 18 parts of polypropylene fiber, 3 parts of hydroxypropyl methylcellulose (HPMC), 25 parts of a polycarboxylic acid-based high-performance water reducer, and 200 parts of water.

[0044] The preparation method comprises: Step 1: Mix ordinary Portland cement machine-made sand, fiber, and hydroxypropyl methylcellulose and stir for 0.6 minutes, then add water reducer and water, stir for 1.5 minutes, and pour into the molding mold; Step 2: Mechanically vibrate the mold for 20 minutes, let it stand at room temperature (25±3℃), demould after 24 hours, steam cure for 1 day, and then naturally cure for 26 days.

[0045] The obtained pallet has a length of 1100 mm, a width of 1100 mm and a surface wall thickness of 40 mm.

[0046] The difference from Example 1 is that: no solid waste-based sulfur-aluminum-iron low-carbon cementitious material is added to the preparation raw materials, no steel mesh is added, and the preparation method is demoulding for 24 hours, followed by steam curing and natural curing. The slump and diffusion of the lightweight aggregate concrete prepared in step S2 of Example 1, Example 2 and Example 3, and the ordinary concrete prepared in step 1 of Comparative Example 1 and Comparative Example 2 were tested, respectively. The data are shown in Table 1.

[0047] Table 1 Concrete performance data

[0048] From the data in Table 1, it can be seen that the fluidity and slump indicators of the lightweight aggregate concrete used to prepare the lightweight UHPC matrix in Examples 1, 2 and 3 are better than the fluidity and slump of the ordinary concrete in Comparative Examples 1 and 2, indicating that they have better construction performance.

[0049] The performance of the pallet is tested, and the requirements in the standard include: 1. According to GB / T3716-2000 standard, the specifications of logistics pallets are 1100 mm × 1100 mm flat pallets, and the turnover times are greater than 500 times.

[0050] 2. The normal load capacity is determined according to the industry standard value of 1.5 tons. Specific performance indicators include: static load of 1500kg; bending strength of 1800kg, bending stiffness of 800kg; fork-lift strength of 1800kg, fork-lift stiffness of 600kg; stacking strength of 2000kg, palletizing stiffness of 1000kg; corner drop: the diagonal change rate of the empty pallet at a drop height of h=800mm is ≤2%; no damage that may endanger the pallet's function and performance will occur.

[0051] 3. Design the ultimate load capacity of the pallet based on its actual usage requirements, as shown in Table 2.

[0052] Table 2 Ultimate load capacity

[0053] The lightweight UHPC-based logistics pallets after demolding in step S3 of Examples 1, 2, and 3, and the UHPC-based logistics pallets after demolding in step 2 of Comparative Examples 1 and 2 were subjected to performance tests, including bending strength and bending stiffness. After the curing step was completed, the pallets were subjected to performance tests, including ultimate bending strength, fork-lifting ultimate strength, and stacking ultimate strength. The results are shown in Table 3.

[0054] Table 3 Pallet performance data

[0055] It can be seen that the pallets of Examples 1-3 achieved a flexural strength of over 1000 kg within 6 hours of demolding, and no steam curing was required after demolding. All parameters met the pallet standard requirements of GB / T3716-2000. Ordinary Portland cement-based concrete logistics pallets require steam curing after demolding, using steam heating to accelerate the hardening process of the Portland cement-based concrete.

[0056] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A lightweight UHPC-based logistics pallet, characterized in that: The lightweight UHPC matrix comprises a lightweight UHPC matrix and a metal mesh embedded in the lightweight UHPC matrix; the lightweight UHPC matrix is ​​prepared from the following raw materials in mass fractions: 885-930 parts of ordinary Portland cement, 45-50 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material, 380-570 parts of solid waste-based artificial sand, 0-150 parts of filler, 15-20 parts of fiber, 2-4 parts of hydroxypropyl methylcellulose, 20-49 parts of water reducer, and 180-210 parts of water; The solid waste-based artificial sand is prepared from the following components in percentage by mass: 10-20% composite cementitious material, 0-90% phosphogypsum or desulfurized gypsum, and 0-90% fly ash or gold tailings; wherein the composite cementitious material comprises ordinary Portland cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of (90-95):(10-5).

2. The lightweight UHPC-based logistics pallet according to claim 1, characterized in that: The lightweight UHPC matrix is ​​prepared from the following raw materials in mass fractions: 885-900 parts of ordinary Portland cement, 45-50 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material, 380-430 parts of solid waste-based artificial sand, 130-150 parts of filler, 15-20 parts of fiber, 2-4 parts of hydroxypropyl methylcellulose, 20-49 parts of water reducer, and 180-210 parts of water.

3. The lightweight UHPC-based logistics pallet according to any one of claims 1-2, characterized in that: The ordinary Portland cement is PO42.5 or PO42.5R grade cement; Alternatively, the filler includes one or more of silica fume, slag powder and fly ash.

4. The lightweight UHPC-based logistics pallet according to any one of claims 1-2, characterized in that: The fibers include one or more of polypropylene fibers and polyethylene fibers.

5. The lightweight UHPC-based logistics pallet according to any one of claims 1-2, characterized in that: The water reducer is a polycarboxylic acid water reducer.

6. The lightweight UHPC-based logistics pallet according to any one of claims 1-2, characterized in that: The metal mesh is a steel mesh with a steel wire diameter of 2-3 mm and a mesh size of (5-8) cm×(5-8) cm.

7. The lightweight UHPC-based logistics pallet according to any one of claims 1-2, characterized in that: The size range is (1100~1200) mm×(1000~1100) mm, and the metal mesh covers the cross section of the lightweight UHPC-based logistics tray in the thickness direction; 1~2 layers of metal mesh are embedded in the lightweight UHPC matrix.

8. The lightweight UHPC-based logistics pallet according to claim 1, characterized in that: The solid waste-based artificial sand is prepared from the following components in percentage by mass: 10-20% of a composite cementitious material, and 80-90% of one or more of phosphogypsum, desulfurized gypsum, fly ash, and gold tailings.

9. A method for preparing a lightweight UHPC-based logistics pallet according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Pre-wetting the solid waste-based artificial sand with water to make the saturated surface of the solid waste-based artificial sand dry; S2. Ordinary Portland cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, filler, fiber, and hydroxypropyl methylcellulose are mixed and stirred, and then the solid waste-based artificial sand, water reducer, and water obtained in S1 are added. After stirring, the mixture is poured into a forming mold, and then pressed onto a metal mesh surface and smoothed; S3. Let it stand for 3~6 hours before demoulding. Cover with plastic film after spraying water and cure for 1~3 days.

10. The method for preparing a lightweight UHPC-based logistics pallet according to claim 7, wherein: In S2, the depth of the metal mesh is pressed into the tray so that the thickness of the tray is evenly divided into multiple layers.

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