A reinforced and toughened panel concrete and a method of making the same

Abstract

The application discloses a kind of reinforced toughened panel concrete and preparation method thereof, belong to panel concrete preparation technical field.The reinforced toughened panel concrete of the application includes the following components: low-heat portland cement, fly ash, slag powder, silica fume, fly ash microbeads, sand, water, copper-plated steel fiber, polyethylene fiber, high-performance water reducing agent, hydration temperature rise inhibitor and calcium-magnesium composite expansive agent.The reinforced toughened panel concrete of the application can realize the whole process performance optimization of panel concrete from micro defect inhibition to macro toughening and crack control, significantly improve the compressive strength and axial tensile strength and crack resistance of panel concrete, effectively solve the intrinsic brittleness and early shrinkage cracking risk of ultra-high strength concrete.

Description

Technical Field

[0001] This invention relates to the field of panel concrete preparation technology, specifically to a reinforced and toughened panel concrete and its preparation method. Background Technology

[0002] With the rapid development of my country's water conservancy and hydropower industry, the construction scale of concrete-faced rockfill dams (CFRD) is constantly advancing towards ultra-high dams of 200 meters and even 300 meters. As the most critical seepage prevention structure of rockfill dams, the face panel is subjected to extremely harsh service environments such as high altitude, large temperature differences, low humidity, and strong ultraviolet radiation. To meet the high compressive strength and durability requirements of the face panel, ultra-high-strength concrete with an extremely low water-cement ratio is commonly used in engineering projects. However, while this type of concrete increases compressive strength reserves, it also brings serious risks of brittleness and early cracking. Especially in cold, high-altitude regions, due to the intense accumulation of hydration heat, significant autogenous shrinkage, and the coupling effect of complex stress fields, the face panel is highly susceptible to penetrating cracks or localized compression failure. This invention aims to address the current imbalance in the physical and mechanical properties of concrete panels in high-face rockfill dams. By constructing a multi-component synergistic hydration kinetic regulation, a volumetric self-compensating stress field, and a cross-scale energy dissipation mechanism, it achieves full-process performance optimization of the concrete panels, from microscopic defect suppression to macroscopic toughening and crack control, thereby improving their long-term volumetric stability and structural durability under harsh environments.

[0003] Currently, existing technologies for improving concrete performance often suffer from the following defects: (1) The toughening scale is limited. Existing single-admixture macro-fiber schemes cannot suppress the initiation of early microcracks at the micro-nano scale, and are prone to inducing irreversible micro-damage at the fiber interface. (2) High strength characteristics bring about a contradiction between brittleness and shrinkage. Existing single-admixture expansion agent technology lacks effective three-dimensional physical constraints. Non-uniform expansion deformation is more likely to cause secondary damage to the matrix microstructure. (3) Insufficient tensile strength reserve and full-cycle energy dissipation capacity. Existing schemes have failed to solve the problem of time matching between rigid and flexible fibers and matrix hydration process, resulting in low intrinsic tensile strength of the material. It is impossible to achieve cross-scale energy dissipation throughout the entire cycle of crack initiation, propagation and penetration, which is difficult to meet the requirements of ultra-high dam panels for large deformation ductility and high fracture energy. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the existing technology, the purpose of this invention is to provide an enhanced and toughened concrete panel and its preparation method, so as to solve the problems of imbalance of physical and mechanical properties, insufficient tensile strength reserve, high risk of early shrinkage cracking and high intrinsic brittleness of high-face rockfill dam concrete in complex environments.

[0005] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A reinforced and toughened panel concrete is provided, comprising the following components in parts by weight: 1 part low-heat silicate cement, 0.16-0.17 parts fly ash, 0.16-0.17 parts slag powder, 0.16-0.17 parts silica fume, 0.16-0.17 parts fly ash microspheres, 1.17-1.18 parts sand, 0.33-0.34 parts water, 0.11-0.12 parts copper-plated steel fiber, 0.01-0.015 parts polyethylene fiber, 0.02-0.03 parts high-performance water-reducing agent, 0.015-0.018 parts hydration temperature rise inhibitor, and 0.13-0.14 parts calcium-magnesium composite expansion agent; wherein the high-performance water-reducing agent is a liquid polycarboxylate-based water-reducing agent.

[0006] Furthermore, the 28-day compressive strength of the reinforced and toughened concrete panel is ≥80MPa, the 28-day tensile strength is ≥5MPa, and the 28-day flexural fracture energy is ≥10000J / m².

[0007] Furthermore, the 3-day heat of hydration of low-heat silicate cement is ≤230kJ / kg, and the 7-day heat of hydration is ≤260kJ / kg; the SiO2 content of silica fume is ≥95%, and the particle size is 0.1μm~0.3μm; the particle size of fly ash microspheres is 0.5~5μm.

[0008] Furthermore, the sand has a fineness modulus of 2.6 to 3.0, a mud content of ≤1.0%, a clay lump content of ≤0.5%, and an apparent density of 2600 kg / m³ to 2700 kg / m³. 3 .

[0009] Furthermore, the copper-plated steel fibers have a length of 12~15mm, a diameter of 0.18~0.25mm, a tensile strength ≥2000MPa, and a copper plating layer thickness of 0.1μm~0.5μm; the polyethylene fibers have a length of 10~12mm, a diameter of 20~30μm, a tensile strength ≥2500MPa, an elastic modulus ≥100GPa, and an elongation of 2%~4%.

[0010] Furthermore, the high-performance water-reducing agent has a water reduction rate of ≥25% and an air content of 2%~4%.

[0011] Furthermore, the calcium-magnesium composite expansion agent contains ≥25% magnesium oxide and 15%~20% calcium oxide, and its restricted expansion rate in water for 14 days is ≥0.025%.

[0012] This invention provides a method for preparing the above-mentioned reinforced and toughened panel concrete, comprising the following steps: S1. Low-heat silicate cement, fly ash, slag powder, silica fume, fly ash microspheres, sand and calcium-magnesium composite expansion agent are added in sequence and mixed evenly to obtain dry mixture. S2. Mix water, high-performance water-reducing agent and hydration temperature rise inhibitor, then add to the dry mixture in step S1, mix well and obtain the adhesive paste. S3. At a rotation speed of 90~120r / min, copper-plated steel fibers and polyethylene fibers are added sequentially to the slurry from step S2, and the mixture is stirred to obtain the final product.

[0013] Furthermore, in step S3, both the copper-plated steel fiber and the polyethylene fiber are added in a multi-stage batch manner, with an interval of 30s to 45s between each batch.

[0014] The present invention has the following beneficial effects: (1) This invention constructs a multi-level energy dissipation and synergistic toughening mechanism for cross-scale rigid-flexible fibers. It fully utilizes the complementary advantages of high-modulus copper-plated steel fibers and high-ductility polyethylene fibers in terms of physical dimensions and mechanical response. In the initial stage of stress, the copper-plated steel fibers, with their high tensile strength and elastic modulus, effectively bear the stress concentration at the tip of the microcrack, significantly delaying the arrival of the initial cracking time; when the crack enters the macroscopic propagation stage, the polyethylene fibers, through their excellent elongation and long-range bridging ability, generate continuous frictional slip energy dissipation on both sides of the crack. Combined with the analysis of the evolution law of RA and AF values ​​in acoustic emission (AE) technology theory, it can be seen that this synergistic system significantly changes the microscopic fracture mechanism inside the material, successfully transforming the sudden brittle shear failure that is prone to occur in ultra-high strength matrices into ductile tensile failure with high energy dissipation characteristics. This results in the final concrete panel exhibiting a very full post-peak softening segment in the load-displacement curve, significantly increasing the flexural fracture energy to 15000J / m²~18000J / m², and enabling the axial tensile strength to reach over 5MPa, effectively solving the technical bottleneck of insufficient strain coordination ability in low water-cement ratio concrete.

[0015] (2) This invention achieves in-depth regulation of matrix volume stability and thermodynamics throughout the entire process. Addressing the challenge of early self-shrinkage and hydration heat accumulation in low water-cement ratio systems, which easily lead to internal microstructural damage, this invention innovatively introduces a dual-effect synergistic mechanism of "heat reduction-shrinkage compensation." By combining low-heat silicate cement with polymer polyol hydration temperature rise inhibitors, the early hydration heat release peak is significantly reduced, avoiding initial damage to the fiber-matrix interface caused by thermal stress. Simultaneously, the calcium-magnesium composite expansion agent, in a moisture-limited, extremely low water-cement ratio environment, can provide gradient expansion highly matched to the matrix shrinkage process. In a 90-day restricted shrinkage test system, this invention successfully controlled the early shrinkage value (negative values ​​representing shrinkage) of the material at a low level and smoothly transformed it into a micro-expansion state (positive values ​​representing expansion) as the age progresses. This precisely matched volume deformation establishes a uniform chemical prestress field within the concrete, effectively offsetting the drying shrinkage stress caused by harsh environments such as high altitude and low humidity, significantly improving the overall long-term crack resistance and durability of the structure.

[0016] (3) The microstructure was deeply optimized and the fiber-matrix interface transition zone (ITZ) performance was enhanced. This invention scientifically compounded silica fume with fly ash microspheres with a ball-bead effect, which not only significantly improved the rheological properties and workability of the slurry under extremely low water-cement ratio, but also eliminated harmful capillary pores inside the matrix through the dense filling effect of multi-level micro-nano powders. In a controlled low-heat environment, the precipitation process of cement hydration products (CSH gel) was slower and more dense and uniform, avoiding the coarsening and directional arrangement defects of crystals in traditional high-heat systems. This high-density interface transition zone greatly enhanced the interfacial adhesion and mechanical interlocking force between steel fibers and polyethylene fibers during the pull-out process. Experimental results show that the optimization of the matrix microstructure not only multiplied the frictional energy dissipation effect of the fibers, but also ensured that the compressive strength of the concrete reached 80 MPa at 28 days, achieving a good balance between high load bearing capacity and large deformation energy absorption capacity of ultra-high strength panel concrete. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the preparation method of the present invention. Detailed Implementation

[0018] The examples given below are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified, conditions in the examples are performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0019] A schematic diagram of the preparation method of the present invention is shown below. Figure 1 .

[0020] Example 1: A reinforced and toughened concrete panel comprises the following components in parts by weight: 1 part of P.LH 42.5 grade low-heat silicate cement (density 3.15 g / cm³). 3 Specific surface area 340m² 2 / kg), 0.165 parts of Grade I fly ash (particle size 12μm), 0.165 parts of S95 grade slag powder, 0.165 parts of silica fume (particle size 2μm, SiO2 content ≥98%), 0.165 parts of fly ash microspheres (particle size 1μm), 1.175 parts of manufactured sand (fineness modulus 2.7, mud content ≤1.0%, mud lump content ≤0.5%, apparent density 2600kg / m³), 0.335 parts of water, 0.115 parts of copper-plated steel fiber (length 13mm, diameter 0.22mm, copper plating thickness 0.2μm). The following components are used: tensile strength ≥2500MPa), 0.0125 parts of polyethylene fiber (length 12mm, diameter 25μm, tensile strength ≥3100MPa, elastic modulus ≥122GPa, elongation 3.5%), 0.025 parts of PCE liquid polycarboxylate superplasticizer (Beijing Institute of Architectural Design, water reduction rate ≥25%, air content 2%~4%), 0.0165 parts of SY-TS hydration temperature rise inhibitor (Wuhan Sanyuan Special Building Materials Co., Ltd.), and 0.135 parts of CMEA calcium magnesium composite expansion agent for concrete (Wuhan Sanyuan Special Building Materials Co., Ltd.).

[0021] Its preparation method is as follows: S1. Add P.LH 42.5 grade low heat silicate cement, grade I fly ash, S95 grade slag powder, silica fume, fly ash microspheres, manufactured sand and CMEA calcium magnesium composite expansion agent for concrete into a twin-shaft forced mixer and mix at a speed of 50 r / min for 120 s to obtain dry mix. S2. Add a premix consisting of water, PCE liquid polycarboxylate superplasticizer and SY-TS hydration temperature rise inhibitor to the dry mix in step S1, increase the speed to 100 r / min, and stir for 180 s to obtain the adhesive paste. S3. At a speed of 100 r / min, copper-plated steel fibers are added to the slurry from step S2 in three batches, with a time interval of 40 s between each batch, and a total stirring time of 120 s; then polyethylene fibers are added in four batches, with a time interval of 35 s between each batch, and a total stirring time of 150 s. The mixture is then thoroughly mixed to obtain the final product.

[0022] Example 2: The only difference between Example 2 and Example 1 is that the component ratio is adjusted to: 1 part of P.LH 42.5 grade low-heat silicate cement (density 3.15 g / cm³). 3 Specific surface area 340m² 2 / kg), 0.16 parts of Grade I fly ash (particle size 12μm), 0.16 parts of S95 grade slag powder, 0.16 parts of silica fume (particle size 2μm, SiO2 content ≥98%), 0.16 parts of fly ash microspheres (particle size 1μm), 1.17 parts of manufactured sand (fineness modulus 2.7, mud content ≤1.0%, mud lump content ≤0.5%, apparent density 2600kg / m³), 0.33 parts of water, 0.11 parts of copper-plated steel fiber (length 13mm, diameter 0.22mm, copper plating thickness 0.2μm, anti-aging properties). The following components are used: tensile strength ≥2500MPa), 0.01 parts of polyethylene fiber (length 12mm, diameter 25μm, tensile strength ≥3100MPa, elastic modulus ≥122GPa, elongation 3.5%), 0.02 parts of PCE liquid polycarboxylate superplasticizer (Beijing Institute of Architectural Design, water reduction rate ≥25%, air content 2%~4%), 0.015 parts of SY-TS hydration temperature rise inhibitor (Wuhan Sanyuan Special Building Materials Co., Ltd.), and 0.13 parts of CMEA calcium magnesium composite expansion agent for concrete (Wuhan Sanyuan Special Building Materials Co., Ltd.).

[0023] The preparation method is the same as in Example 1.

[0024] Example 3: The only difference between Example 3 and Example 1 is that the component ratio is adjusted to: 1 part of P.LH 42.5 grade low-heat silicate cement (density 3.15 g / cm³). 3 Specific surface area 340m² 2 / kg), 0.17 parts of Grade I fly ash (particle size 12μm), 0.17 parts of S95 grade slag powder, 0.17 parts of silica fume (particle size 2μm, SiO2 content ≥98%), 0.17 parts of fly ash microspheres (particle size 1μm), 1.18 parts of manufactured sand (fineness modulus 2.7, mud content ≤1.0%, mud lump content ≤0.5%, apparent density 2600kg / m³), 0.34 parts of water, 0.12 parts of copper-plated steel fiber (length 13mm, diameter 0.22mm, copper plating thickness 0.2μm, anti-aging properties). The following components are used: tensile strength ≥2500MPa), 0.015 parts of polyethylene fiber (length 12mm, diameter 25μm, tensile strength ≥3100MPa, elastic modulus ≥122GPa, elongation 3.5%), 0.03 parts of PCE liquid polycarboxylate superplasticizer (Beijing Institute of Architectural Design, water reduction rate ≥25%, air content 2%~4%), 0.018 parts of SY-TS hydration temperature rise inhibitor (Wuhan Sanyuan Special Building Materials Co., Ltd.), and 0.14 parts of CMEA calcium magnesium composite expansion agent for concrete (Wuhan Sanyuan Special Building Materials Co., Ltd.).

[0025] The preparation method is the same as in Example 1.

[0026] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is as follows: (1) No SY-TS hydration temperature rise inhibitor, CMEA calcium-magnesium composite expansion agent for concrete, copper-plated steel fiber and polyethylene fiber are added; (2) Use ordinary silicate cement instead of low-heat silicate cement; The remaining components and preparation methods are the same as in Example 2.

[0027] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is as follows: (1) No CMEA calcium-magnesium composite expansion agent, copper-plated steel fiber and polyethylene fiber are added to concrete; (2) Use ordinary silicate cement instead of low-heat silicate cement; The remaining components and preparation methods are the same as in Example 2.

[0028] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is as follows: (1) No SY-TS hydration temperature rise inhibitor, copper-plated steel fiber and polyethylene fiber are added; (2) Use ordinary silicate cement instead of low-heat silicate cement; The remaining components and preparation methods are the same as in Example 2.

[0029] Comparative Example 4: The difference between Comparative Example 4 and Example 3 is as follows: (1) No polyethylene fiber is added; (2) Adjust the ratio of copper-plated steel fiber to 0.23 parts; (3) Use ordinary silicate cement instead of low-heat silicate cement; The remaining components and preparation methods are the same as in Example 3.

[0030] Comparative Example 5: The difference between Comparative Example 5 and Example 3 is as follows: (1) No copper-plated steel fiber is added; (2) Adjust the polyethylene fiber ratio to 0.025 parts; (3) Use ordinary silicate cement instead of low-heat silicate cement; The remaining components and preparation methods are the same as in Example 3.

[0031] Comparative Example 6: The difference between Comparative Example 6 and Example 1 is as follows: (1) No polyethylene fiber is added; (2) Adjust the ratio of copper-plated steel fiber to 0.23 parts; The remaining components and preparation methods are the same as in Example 1.

[0032] Comparative Example 7: The difference between Comparative Example 7 and Example 1 is as follows: (1) No copper-plated steel fiber is added; (2) Adjust the polyethylene fiber ratio to 0.025 parts; The remaining components and preparation methods are the same as in Example 1.

[0033] Comparative Example 8: The difference between Comparative Example 8 and Example 1 is that copper-plated steel fibers and polyethylene fibers are not added, while the remaining components and preparation methods are the same as in Example 1.

[0034] Comparative Example 9: The difference between Comparative Example 9 and Example 1 is as follows: (1) No copper-plated steel fiber or polyethylene fiber is added; (2) Use ordinary silicate cement instead of low-heat silicate cement; The remaining components and preparation methods are the same as in Example 1.

[0035] Comparative Example 10: The difference between Comparative Example 10 and Example 1 is that ordinary silicate cement is used instead of low-heat silicate cement, while the other components and preparation methods are the same as in Example 1.

[0036] Experimental Example 1: Mortar Mechanical Property Testing The mechanical properties of the mortars prepared in Example 2 and Comparative Examples 1, 2, 3 and 9 were determined according to the "Method for Determination of Flowability of Cement Mortar" (GB / T 2419-2005). The test indicators included 7-day compressive strength, 28-day compressive strength, 7-day flexural strength and 28-day flexural strength. The test results are shown in Table 1.

[0037] Table 1 Mechanical properties of the mortars prepared in Example 2 and Comparative Examples 1-3

[0038] Experimental Example 2: Concrete Shrinkage Test Shrinkage performance tests were conducted on the concrete prepared in Example 3 and Comparative Examples 1, 4, 5, 8, and 10. According to the "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete" (GB / T 50082-2009), the test indicators included the maximum shrinkage value and the 90-day expansion value of the specimens. The test results are shown in Table 2.

[0039] Table 2. Shrinkage test results of concrete prepared in Example 3 and Comparative Examples 1, 4, 5, and 8.

[0040] Experimental Example 3: Concrete Fracture Energy and Strength Testing Four-point bending tests, compressive strength tests, and tensile strength tests were conducted on the concrete prepared in Examples 1 and 3, and Comparative Examples 1 and 4-8, according to the "Ultra-High Performance Concrete" (GB / T 31387-2025). The test results are shown in Table 3.

[0041] Table 3. Test results of fracture energy and strength of concrete prepared in Examples 1 and 3 and Comparative Examples 1, 4-8

[0042] As shown in Table 1-3: (1) Regarding the synergistic effect of chemically regulated components, the 7-day and 28-day compressive strengths of Comparative Example 1 were 60.2 MPa and 71.1 MPa, respectively, and its 7-day and 28-day flexural strengths were 16.5 MPa and 16.9 MPa, respectively. The 7-day compressive and flexural strengths of Comparative Example 2 decreased to 57.8 MPa and 15.9 MPa, respectively; the 28-day flexural strength of Comparative Example 3 was 19.2 MPa. The 28-day compressive strength of Example 2 was 87.1 MPa, and its 7-day and 28-day flexural strengths were significantly increased to 21.6 MPa and 32.0 MPa, respectively. The data show that the hydration temperature rise inhibitor effectively delayed the early hydration kinetic process, provided sufficient physical space for the formation of expansion products, reduced the early damage of expansion pressure to the matrix microstructure, and thus successfully achieved synergistic toughening among chemical components.

[0043] (2) Regarding the constraint coordination of volumetric deformation, the maximum shrinkage of Comparative Example 8 was 101.9 με, and its 90-day expansion reached 1558.8 με; the maximum shrinkage of Comparative Example 5 was 323.6 με, and its 90-day expansion was 36.6 με; the maximum shrinkage of Comparative Example 4 was 245.0 με, and its 90-day expansion was 321.2 με. In contrast, the maximum shrinkage of Example 3 was controlled at 89.2 με, and its 90-day micro-expansion stabilized at 1224.5 με. The test results show that the hybrid fiber network effectively constrained the free expansion of the calcium-magnesium composite expansion agent, successfully converting volumetric expansion into internal chemical pre-stress, and achieving self-balancing deformation.

[0044] (3) Regarding the coupling toughening at the matrix-fiber interface, the bending fracture energy of Comparative Example 1 is only 135 J / m², the maximum load is 10.91 kN, and its 28-day tensile strength is 2.74 MPa; the fracture energy of Comparative Example 8 is 111 J / m². 2The tensile strength was 3.51 MPa. The fracture energy of Example 3 was 14171 J / m², and the maximum load was 40.2 kN. Under the same fiber content, the maximum load of Example 1 increased to 47.51 kN, corresponding to a displacement of 1.42 mm, and the bending fracture energy was further significantly increased to 16811 J / m². Its 28-day compressive strength was 81.5 MPa, and its 28-day tensile strength also increased to 5.13 MPa. Furthermore, Comparative Example 6 had a fracture energy of 14925 J / m², a maximum load of 49.5 kN, and a tensile strength of 5.74 MPa; Comparative Example 7 had a fracture energy of 22357 J / m², a maximum load of 37.5 kN, and a tensile strength of 3.62 MPa. This fully demonstrates that Example 1, by delaying the heat release of hydration with low-heat silicate cement, improves the density of the fiber interface transition zone (ITZ), effectively increases the frictional energy dissipation of fibers during the pull-out process, thereby achieving a comprehensive balance of higher bending load, higher fracture energy, and excellent tensile strength.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A reinforced and toughened concrete panel, characterized in that, The composition includes the following components in parts by weight: 1 part low-heat silicate cement, 0.16-0.17 parts fly ash, 0.16-0.17 parts slag powder, 0.16-0.17 parts silica fume, 0.16-0.17 parts fly ash microspheres, 1.17-1.18 parts sand, 0.33-0.34 parts water, 0.11-0.12 parts copper-plated steel fiber, 0.01-0.015 parts polyethylene fiber, 0.02-0.03 parts high-performance water-reducing agent, 0.015-0.018 parts hydration temperature rise inhibitor, and 0.13-0.14 parts calcium-magnesium composite expansion agent; The high-performance water-reducing agent is a liquid polycarboxylate-based water-reducing agent.

2. The reinforced and toughened concrete panel according to claim 1, characterized in that, The reinforced and toughened panel concrete has a 28-day compressive strength ≥80MPa, a 28-day tensile strength ≥5MPa, and a 28-day flexural fracture energy ≥10000J / m².

3. The reinforced and toughened concrete panel according to claim 1, characterized in that, The low-heat silicate cement has a 3-day heat of hydration ≤230kJ / kg and a 7-day heat of hydration ≤260kJ / kg; the silica fume has a SiO2 content ≥95% and a particle size of 0.1μm~0.3μm; the fly ash microspheres have a particle size of 0.5~5μm.

4. The reinforced and toughened concrete panel according to claim 1, characterized in that, The sand has a fineness modulus of 2.6 to 3.0, a mud content of ≤1.0%, a clay lump content of ≤0.5%, and an apparent density of 2600 kg / m³ to 2700 kg / m³. 3 .

5. The reinforced and toughened concrete panel according to claim 1, characterized in that, The copper-plated steel fiber has a length of 12-15 mm, a diameter of 0.18-0.25 mm, a tensile strength ≥2000 MPa, and a copper plating layer thickness of 0.1 μm-0.5 μm; the polyethylene fiber has a length of 10-12 mm, a diameter of 20-30 μm, a tensile strength ≥2500 MPa, an elastic modulus ≥100 GPa, and an elongation of 2%-4%.

6. The reinforced and toughened concrete panel according to claim 1, characterized in that, The high-performance water-reducing agent has a water reduction rate of ≥25% and an air content of 2%~4%.

7. The reinforced and toughened concrete panel according to claim 1, characterized in that, The calcium-magnesium composite expanding agent contains ≥25% magnesium oxide and 15%~20% calcium oxide, and its restricted expansion rate in water for 14 days is ≥0.025%.

8. The method for preparing reinforced and toughened panel concrete according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Low-heat silicate cement, fly ash, slag powder, silica fume, fly ash microspheres, sand and calcium-magnesium composite expansion agent are added in sequence and mixed evenly to obtain dry mixture. S2. Mix water, high-performance water-reducing agent and hydration temperature rise inhibitor, and then add them to the dry mixture in step S1. Mix well to obtain the adhesive paste. S3. At a rotation speed of 90~120r / min, copper-plated steel fibers and polyethylene fibers are added sequentially to the slurry from step S2, and the mixture is stirred to obtain the final product.

9. The preparation method according to claim 8, characterized in that, In step S3, both the copper-plated steel fiber and the polyethylene fiber are added in a multi-stage batch manner, with an interval of 30s to 45s between each batch.

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