A lightweight UHPC-based logistics pallet and its preparation method

Abstract

This invention relates to a lightweight UHPC-based logistics pallet and its preparation method, belonging to the technical field of logistics pallets. The logistics pallet comprises a lightweight UHPC matrix and a metal mesh. The lightweight UHPC matrix is ​​prepared from the following raw materials in the indicated mass fractions: 885-930 parts ordinary silicate cement, 45-50 parts solid waste-based sulfur-aluminum-iron low-carbon cementitious material, 380-570 parts solid waste-based artificial sand, 0-150 parts filler, 15-20 parts fiber, 2-4 parts HPMC, 20-49 parts water-reducing agent, and 180-210 parts water. The lightweight UHPC matrix utilizes a composite cementitious material. The composite cementitious material contained in the raw materials for preparing the solid waste-based artificial sand is similar to that of the lightweight UHPC matrix, allowing the hydration products of the cementitious material to embed into the micropores within the solid waste-based artificial sand. The solid waste content in the solid waste-based artificial sand can reach over 80%, still meeting the mechanical strength requirements of the logistics pallet.

Description

Technical Field

[0001] This invention belongs to the field of logistics pallet technology, specifically relating to a lightweight UHPC-based logistics pallet and its preparation method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Logistics pallets are horizontal platform devices used for the assembly, stacking, handling, and transportation of goods and products as unit loads, and can be used in conjunction with forklifts. Currently, logistics pallets are mainly classified by material into wooden pallets, steel pallets, plastic pallets, composite material pallets, and paper pallets. Wooden and plastic flat pallets consume large amounts of natural resources and have relatively low durability; steel and composite material pallets are heavy; and paper pallets are easily broken. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a lightweight UHPC-based logistics pallet and its preparation method, which has a high solid waste utilization rate, high product strength, is suitable for conventional logistics scenarios, has good construction performance, short demolding time, does not require steam curing, and has a short production cycle.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] In a first aspect, a lightweight UHPC-based logistics pallet includes 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 the indicated mass fractions: 885-930 parts of ordinary silicate 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 water-reducing agent, and 180-210 parts of water;

[0007] The solid waste-based artificial sand is made from the following components by mass percentage: 10-20% composite cementitious material, 0-90% phosphogypsum or desulfurized gypsum, and 0-90% fly ash or gold tailings; wherein the composite cementitious material includes ordinary silicate cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of (90-95):(5-10).

[0008] Secondly, the preparation method of the aforementioned lightweight UHPC-based logistics pallet includes the following steps:

[0009] S1. Pre-wet the solid waste-based artificial sand with water until the surface of the solid waste-based artificial sand is saturated and dry;

[0010] S2. Mix ordinary silicate cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, filler, fiber, and hydroxypropyl methylcellulose. Then add solid waste-based artificial sand, water-reducing agent, and water obtained in S1. After mixing, pour into a molding mold and press into a metal mesh and smooth the surface.

[0011] S3. Let stand for 3~6 hours to demold, spray with water and cover with plastic film for 1~3 days to cure.

[0012] The beneficial effects of this invention are as follows:

[0013] 1. The lightweight UHPC concrete logistics pallet provided by this invention uses a composite cementitious material (ordinary silicate cement + solid waste-based sulfur-aluminum-iron low-carbon cementitious material) as the main cementitious material in the lightweight UHPC matrix, which has the characteristics of rapid setting and high strength. The composite cementitious material contained in the raw materials for preparing the added solid waste-based artificial sand is similar to the cementitious material of 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 hydration products of the cementitious material to be embedded in the micropores of the solid waste-based artificial sand. As a result, the two are tightly bonded, the interface transition zone is dense, the overall strength is high, and the impermeability and durability are better. Even when the solid waste ratio in the solid waste-based artificial sand reaches more than 80%, the mechanical strength requirements of the logistics pallet can still be met: the static load (bending strength) of the pallet can reach more than 1000 kg, and the bending stiffness can reach more than 600 kg.

[0014] 2. The lightweight UHPC concrete-based logistics pallet of the present invention can be demolded within 3-6 hours after pouring. During the preparation of the concrete pallet, it has good construction performance, short demolding time (more than 75% shorter than conventional concrete pallets), no need for steam curing, low energy consumption, and fast product delivery. It has the significant characteristics of low production cost and high production efficiency. Detailed Implementation

[0015] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0016] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0017] 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 the indicated mass fractions: 885-930 parts of ordinary silicate 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 water-reducing agent, and 180-210 parts of water;

[0018] The solid waste-based artificial sand is made from the following components by mass percentage: 10-20% composite cementitious material, 0-90% phosphogypsum or desulfurized gypsum, and 0-90% fly ash or gold tailings; wherein the composite cementitious material includes ordinary silicate cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of (90-95):(5-10).

[0019] Among the above components, the raw materials for preparing solid waste-based artificial sand include composite cementitious materials similar to those in a lightweight UHPC matrix. Therefore, the hydration products of the composite cementitious materials in the lightweight UHPC matrix can be embedded into the micropores within the solid waste-based artificial sand, allowing it to bond tightly with the surrounding cementitious materials, resulting in a dense interfacial 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 1000 kg, and the flexural stiffness can reach over 600 kg; it exhibits significant advantages in terms of low production cost and high performance.

[0020] Optionally, the lightweight UHPC matrix is ​​prepared from the following raw materials in the indicated mass fractions: 885-900 parts of ordinary silicate 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-reducing agent, and 180-210 parts of water.

[0021] Optionally, the ordinary silicate cement is PO42.5 or PO42.5R grade cement.

[0022] Optionally, the solid waste-based sulfur-aluminum-iron low-carbon cementitious material meets the T / CCPA 42—2023 standard.

[0023] Optionally, the filler includes one or more of silica fume, slag powder, and fly ash.

[0024] Optionally, the fibers include one or more of polypropylene fibers and polyethylene fibers, which are components of UHPC.

[0025] Optionally, the water-reducing agent is a polycarboxylate-based water-reducing agent, suitable for the cementitious materials used in this invention.

[0026] Optionally, the metal mesh is a wire mesh with a wire diameter of 2~3mm and a mesh size of (5~8)cm×(5~8)cm.

[0027] Optionally, the lightweight UHPC-based logistics pallet has a size range of (1100~1200) mm × (1000~1100) mm, and the metal mesh covers the cross-section of the lightweight UHPC-based logistics pallet in the thickness direction; 1~2 layers of metal mesh are embedded in the lightweight UHPC matrix.

[0028] Optionally, the solid waste-based artificial sand is prepared from the following components by mass percentage: 10-20% composite cementitious material, and 80-90% phosphogypsum, desulfurized gypsum, fly ash, or gold tailings; the preparation method includes: vigorously mixing the composite cementitious material with solid waste (phosphogypsum, desulfurized gypsum, fly ash, or gold tailings), granulating, and sieving; the properties of the solid waste-based artificial sand include: a bulk density greater than 1100 kg / m³. 3 The compressive strength of the cylinder is greater than 6MPa; specifically, the proportion of phosphogypsum or desulfurized gypsum is 0~90%, and the proportion of fly ash or gold tailings is 0~90%.

[0029] 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:

[0030] S1. Pre-wet the solid waste-based artificial sand with water until the surface of the solid waste-based artificial sand is saturated and dry;

[0031] S2. Mix ordinary silicate cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, filler, fiber, and hydroxypropyl methylcellulose. Then add solid waste-based artificial sand, water-reducing agent, and water obtained in S1. After mixing, pour into a molding mold and press into a metal mesh and smooth the surface.

[0032] S3. Let stand for 3~6 hours to demold, spray with water and cover with plastic film for 1~3 days to cure.

[0033] During the preparation of the above concrete pallets, the membrane can be removed within 3 to 6 hours after pouring, which is more than 75% shorter than the removal time of conventional concrete pallets. It has good construction performance, does not require steam curing, and has the significant characteristics of high production efficiency.

[0034] The inner wall of the pallet forming mold of this invention is lined with a PVC film to facilitate pallet demolding. The mold size depends on specific requirements.

[0035] This invention does not impose any special restrictions on the stirring process; commonly used stirring parameters in the field can be used.

[0036] Optionally, in S2, the depth of the metal mesh pressing makes the pallet thickness dimension evenly divided into multiple layers; when using one layer of metal mesh, the pressing depth is 1 / 2 of the pallet thickness; when using two layers of metal mesh, the pressing depth is 1 / 3 and 2 / 3 of the pallet thickness.

[0037] The present invention will be further described below with reference to the embodiments.

[0038] Example 1

[0039] A lightweight UHPC-based logistics pallet includes 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 the indicated mass fractions: 930 parts of PO 42.5 ordinary silicate cement, 45 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material conforming to T / CCPA 42—2023 standard, 570 parts of solid waste-based artificial sand, 15 parts of polypropylene fiber, 5 parts of hydroxypropyl methylcellulose (HPMC), 20.25 parts of polycarboxylate-based high-performance water-reducing agent, and 210 parts of water;

[0040] The solid waste-based artificial sand is made from the following components by mass percentage: 18% composite cementitious material and 82% phosphogypsum; wherein the composite cementitious material includes ordinary silicate cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of 90:10.

[0041] Preparation methods include:

[0042] S0. Phosphogypsum and composite cementitious material are added to the granulator in multiple batches. During the addition process, the granulator first rotates at 50 Hz and stirs for 5 minutes before adding water. Then, the granulator rotates at 30 Hz to turn the powder into masterbatch. The process of rotation, addition, and water continues until some particles are larger than 1.18 mm, resulting in a material containing particles. This material is then screened in a sieve with a sleeve. Particles smaller than 1.18 mm are screened out and returned to the granulator for repeated granulation and screening. Particles with a diameter of 1.18–2.35 mm are screened out and placed back into the granulator at 40 Hz to improve strength and sphericity, yielding a solid waste-based artificial sand product. The bulk density of the solid waste-based artificial sand product is measured to be 1100 kg / m³. 3 The cylinder compressive strength is greater than 6 MPa;

[0043] S1. Pre-wet the solid waste-based artificial sand with water until the surface of the solid waste-based artificial sand is saturated and dry;

[0044] S2. Mix ordinary silicate cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, fiber, and hydroxypropyl methylcellulose. Then add the saturated surface-dry solid waste-based artificial sand, water-reducing agent, and water obtained in S1. Stir for 1.5 minutes and pour into a molding mold. Then press into a metal mesh and smooth the surface.

[0045] S3. Vibrate the mold mechanically for 10 minutes, let it stand at room temperature (25±3℃) for 5 hours, demold, spray with water and cover with plastic film for 2 days to cure.

[0046] The obtained pallet is 1100mm long, 1100mm wide, and has a surface wall thickness of 20mm; a layer of wire mesh is embedded at 1 / 2 of the thickness. The wire mesh is woven from 2mm diameter steel wire and has a mesh size of 5cm×5cm.

[0047] Example 2

[0048] A lightweight UHPC-based logistics pallet includes 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 the indicated mass fractions: 885 parts of PO 42.5 grade ordinary silicate cement, 50 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material conforming to 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 polycarboxylate-based high-performance water-reducing agent, and 180 parts of water.

[0049] The solid waste-based artificial sand is made from the following components by mass percentage: 18% composite cementitious material and 82% phosphogypsum; wherein the composite cementitious material includes ordinary silicate cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of 95:5.

[0050] Preparation methods include:

[0051] S0. Prepare solid waste-based artificial sand according to the method in S0 of Example 1;

[0052] S1. Pre-wet the solid waste-based artificial sand with water until the surface of the solid waste-based artificial sand is saturated and dry;

[0053] S2. Mix ordinary silicate cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, slag powder, fiber, and hydroxypropyl methylcellulose for 0.5 min. Then add the saturated surface-dry solid waste-based artificial sand, water-reducing agent, and water obtained in S1. Mix for 1.5 min and pour into a molding mold. Then press into a metal mesh and smooth the surface.

[0054] S3. Vibrate the mold mechanically for 15 minutes, let it stand at room temperature (25±3℃), demold for 3.3 hours, spray water and cover with plastic film for 2 days for curing.

[0055] The obtained pallet has a length of 1100mm, a width of 1100mm, and a surface wall thickness of 18mm; a layer of wire mesh, the same as in Example 1, is embedded at 1 / 2 of the thickness.

[0056] Example 3

[0057] A lightweight UHPC-based logistics pallet includes 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 the indicated mass fractions: 900 parts of PO 42.5 grade ordinary silicate cement, 45 parts of solid waste-based sulfur-aluminum-iron low-carbon cementitious material conforming to 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 polycarboxylate-based high-performance water-reducing agent, and 195 parts of water.

[0058] The solid waste-based artificial sand is made from the following components by mass percentage: 18% composite cementitious material and 82% phosphogypsum; wherein the composite cementitious material includes ordinary silicate cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of 93:7.

[0059] Preparation methods include:

[0060] S0. Prepare solid waste-based artificial sand according to the method in S0 of Example 1;

[0061] S1. Pre-wet the solid waste-based artificial sand with water until the surface of the solid waste-based artificial sand is saturated and dry;

[0062] S2. Mix ordinary silicate cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, fiber, and hydroxypropyl methylcellulose for 0.5 min. Then add the saturated surface-dry solid waste-based artificial sand, water-reducing agent, and water obtained in S1. Mix for 1.5 min and pour into a molding mold. Then press into a metal mesh and smooth the surface.

[0063] S3. Vibrate the mold mechanically for 15 minutes, let it stand at room temperature (25±3℃), demold for 3.5 hours, spray water and cover with plastic film for 3 days to cure.

[0064] The obtained pallet has a length of 1100mm, a width of 1100mm, and a surface wall thickness of 15mm; a layer of wire mesh, the same as in Example 1, is embedded at 1 / 2 of the thickness.

[0065] Comparative Example 1

[0066] A UHPC-based logistics pallet includes a lightweight UHPC matrix; the lightweight UHPC matrix is ​​prepared from the following raw materials in the indicated mass fractions: 882 parts of PO 42.5 ordinary silicate cement, 1100 parts of manufactured sand (compliant with GB175-2023 standard), 17 parts of polypropylene fiber, 3 parts of hydroxypropyl methylcellulose (HPMC), 22 parts of polycarboxylate-based high-performance water-reducing agent, and 190 parts of water.

[0067] Preparation methods include:

[0068] Step 1: Mix ordinary silicate cement, manufactured sand, fiber, and hydroxypropyl methylcellulose for 0.5 minutes, then add water-reducing agent and water, mix for 1.5 minutes, and pour into a molding mold.

[0069] Step 2: Vibrate the mold mechanically for 20 minutes, let it stand at room temperature (25±3℃), demold after 24 hours, steam cure for 1 day, and then naturally cure for 26 days.

[0070] The obtained pallet has a length of 1100mm, a width of 1100mm, and a surface wall thickness of 40mm.

[0071] The difference from Example 1 is that no solid waste-based sulfur-aluminum-iron low-carbon cementitious material or steel wire mesh is added to the raw materials. In the preparation method, the material is demolded after 24 hours, followed by steam curing and natural curing.

[0072] Comparative Example 2

[0073] A UHPC-based logistics pallet includes a lightweight UHPC matrix; the lightweight UHPC matrix is ​​prepared from the following raw materials in the indicated mass fractions: 1050 parts of PO 42.5 ordinary silicate cement, 1100 parts of manufactured sand (compliant with GB175-2023 standard), 18 parts of polypropylene fiber, 3 parts of hydroxypropyl methylcellulose (HPMC), 25 parts of polycarboxylate-based high-performance water-reducing agent, and 200 parts of water.

[0074] Preparation methods include:

[0075] Step 1: Mix ordinary silicate cement, manufactured sand, fiber, and hydroxypropyl methylcellulose for 0.6 minutes, then add water-reducing agent and water, mix for 1.5 minutes, and pour into a molding mold.

[0076] Step 2: Vibrate the mold mechanically for 20 minutes, let it stand at room temperature (25±3℃), demold after 24 hours, steam cure for 1 day, and then naturally cure for 26 days.

[0077] The obtained pallet has a length of 1100mm, a width of 1100mm, and a surface wall thickness of 40mm.

[0078] The difference from Example 1 is that no solid waste-based sulfur-aluminum-iron low-carbon cementitious material or steel wire mesh is added to the raw materials. The preparation method involves demolding after 24 hours, followed by steam curing and natural curing.

[0079] The slump and spread of the lightweight aggregate concrete prepared in step S2 of Examples 1, 2 and 3, and the ordinary concrete prepared in step one of Comparative Examples 1 and 2 were tested respectively. The data are shown in Table 1.

[0080] Table 1 Concrete Performance Data

[0081]

[0082] As can be seen from the data in Table 1, the flowability and slump of the lightweight aggregate concrete used to prepare the lightweight UHPC matrix in Examples 1, 2 and 3 are better than those of the ordinary concrete in Comparative Examples 1 and 2, indicating that it has better construction performance.

[0083] The standard requires testing pallet performance, including the following:

[0084] 1. According to GB / T3716—2000 standard, the specifications of logistics pallets are 1100 mm × 1100 mm flat pallets, and the number of turnovers is greater than 500 times.

[0085] 2. The normal load-bearing capacity is determined according to the industry standard of 1.5 tons. Specific performance includes: static load 1500kg; bending strength 1800kg, bending stiffness 800kg; forklift strength 1800kg, forklift stiffness 600kg; stacking strength 2000kg, stacking stiffness 1000kg; corner drop, the diagonal change rate of the empty pallet at a drop height h=800mm is ≤2%; no damage that endangers the function and performance of the pallet will occur.

[0086] 3. Design the ultimate load-bearing capacity of the pallet according to its actual usage requirements, as shown in Table 2.

[0087] Table 2 Ultimate bearing capacity

[0088]

[0089] Performance tests were conducted on the lightweight UHPC-based logistics pallets after demolding in step S3 of Examples 1, 2, and 3, and on the UHPC-based logistics pallets after demolding in step two of Comparative Examples 1 and 2. The tests included bending strength and bending stiffness. After the curing steps were completed, the pallets were then subjected to performance tests, including bending limit strength, forklift limit strength, and stacking limit strength. The results are shown in Table 3.

[0090] Table 3 Pallet Performance Data

[0091]

[0092] It can be seen that the pallets in Examples 1-3 can achieve a flexural strength of over 1000 kg within 6 hours of demolding, and do not require steam curing after demolding. All parameters meet the pallet standard requirements of GB / T3716-2000. Ordinary silicate cement-based concrete logistics pallets require steam curing after demolding, using steam heating to accelerate the hardening process of silicate cement-based concrete.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lightweight UHPC-based logistics pallet, characterized in that, It includes 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 parts by weight: 885-930 parts of ordinary silicate 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-reducing agent and 180-210 parts of water; The solid waste-based artificial sand is made from the following components by mass percentage: 10-20% composite cementitious material, 0-90% phosphogypsum or desulfurized gypsum, and 0-90% fly ash or gold tailings; wherein, the composite cementitious material includes ordinary silicate cement and solid waste-based sulfur-aluminum-iron low-carbon cementitious material in a mass ratio of (90-95):(10-5). The ordinary Portland cement is PO42.5 or PO42.5R grade cement; The bulk density of the solid waste-based artificial sand is greater than 1100 kg / m³. 3 The compressive strength of the cylinder is greater than 6MPa, and the particle size is 1.18~2.35mm.

2. The lightweight UHPC-based logistics pallet as described in claim 1, characterized in that, The lightweight UHPC matrix is ​​prepared from the following raw materials in parts by weight: 885-900 parts of ordinary silicate 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-reducing agent, and 180-210 parts of water.

3. The lightweight UHPC-based logistics pallet as described in any one of claims 1-2, characterized in that, The filler material includes one or more of silica fume, slag powder, and fly ash.

4. The lightweight UHPC-based logistics pallet as described in 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 as described in any one of claims 1-2, characterized in that, The water-reducing agent is a polycarboxylate-based water-reducing agent.

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

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

8. A method for preparing a lightweight UHPC-based logistics pallet as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Pre-wet the solid waste-based artificial sand with water until the surface of the solid waste-based artificial sand is saturated and dry; S2. Mix ordinary silicate cement, solid waste-based sulfur-aluminum-iron low-carbon cementitious material, filler, fiber, and hydroxypropyl methylcellulose. Then add solid waste-based artificial sand, water-reducing agent, and water obtained in S1. After mixing, pour into a molding mold and press into a metal mesh and smooth the surface. S3. Let stand for 3~6 hours to demold, spray with water and cover with plastic film for 1~3 days to cure.

9. The method for preparing the lightweight UHPC-based logistics pallet as described in claim 8, characterized in that, In S2, the depth to which the metal mesh is pressed in divides the tray thickness into multiple layers on an average basis.

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