Method for manufacturing high-strength concrete cover plate

Abstract

The application belongs to the technical field of building materials, and particularly relates to a preparation method of a high-strength concrete cover plate, which comprises the following steps: S1, fully stirring cement, silica powder, sand and polypropylene fibers to obtain a mixture; S2, adding water, a water reducing agent and a retarder into the mixture and fully stirring to obtain a concrete slurry; S3, horizontally placing basalt bars in a cover plate mold, pouring the concrete slurry into the cover plate mold until the liquid level reaches 4 / 5 of the thickness of the mold; S4, twisting a basalt fiber bundle to obtain a twisted basalt fiber bundle; S5, inserting the twisted basalt fiber bundle into the concrete slurry in the mold along the vertical direction; and S6, continuously pouring the concrete slurry into the mold until the mold is filled, laying a layer of a fiber net on the surface of the slurry, and obtaining the cover plate after curing and demolding when the slurry is solidified; the scheme can improve the mechanical properties of the cover plate in all aspects.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of building materials, and particularly relates to a preparation method of high-strength concrete cover plate. BACKGROUND

[0002] The concrete cover plate is an engineering material poured by cement concrete, and is widely used in different places such as municipal roads, garden facilities, residential areas, schools and stadiums. The use of the cover plate determines that it must have excellent mechanical properties, especially compression resistance, crack resistance, tensile resistance and the like.

[0003] In the field of fiber reinforced concrete, a lot of research has been done. It is known in the art that the tensile resistance, toughness and other mechanical properties and durability of the fiber concrete can be improved to different degrees compared with ordinary concrete by putting fibers as reinforcing materials into the concrete. However, different studies have drawn different conclusions about the compression resistance, but it is generally believed that the compression resistance of the concrete is affected by the diameter, length and dosage of the fiber. Generally, the compression resistance of the concrete increases first and then decreases with the increase of the dosage of the fiber.

[0004] The fibers can be mixed into the concrete singly or mixedly. If a single fiber is used, the effect of improvement is very limited, while the mixed fibers can play the respective advantages of different fibers, and the effect of improvement is obvious.

[0005] However, the document “Study on Mechanical Properties, Permeability and Pore Structure of Basalt-Polypropylene Fiber Reinforced Concrete, Huang Daguan, et al.” has concluded that in the polypropylene-basalt hybrid fiber system, when the dosage of basalt fiber is fixed, the compression strength of the concrete gradually decreases with the increase of the dosage of polypropylene fiber; when the dosage of polypropylene fiber is fixed, the compression strength of the concrete changes little with the increase of the dosage of basalt fiber.

[0006] Therefore, it is not ideal to enhance the compression resistance of the concrete cover plate by mixing hybrid fibers by the traditional method, and it is necessary to propose a new preparation method of the cover plate, which can effectively improve the compression resistance of the cover plate without affecting other mechanical properties of the cover plate. SUMMARY

[0007] The present application aims to overcome the above-mentioned deficiencies, and provides a preparation method of high-strength concrete cover plate, which adds polypropylene fibers in the components, inserts twisted basalt fiber bundles in the vertical direction, and lays a layer of fiber mesh on the top of the cover plate, thereby effectively improving the mechanical properties of the cover plate including the compression resistance.

[0008] The purpose of the present application is achieved by the following technical solutions:

[0009] A preparation method of high-strength concrete cover plate, comprising the following steps:

[0010] S1. Cement, silica fume, sand, polypropylene fiber are fully stirred to reach a uniformly distributed state to obtain a mixture;

[0011] S2. Water, water reducing agent and retarder are added to the mixture and fully stirred to reach a uniformly mixed state to obtain a concrete slurry;

[0012] S3. After placing basalt bars horizontally in the cover plate mold, pour the concrete slurry into the mold until the liquid level reaches 4 / 5 of the thickness of the mold;

[0013] S4. Twist a single basalt fiber bundle, and then twist 2-3 twisted basalt fiber bundles again, the twisting directions are the same, and the total twist is the same, to obtain a twisted basalt fiber bundle;

[0014] S5. Quickly insert the twisted basalt fiber bundle into the concrete slurry in the mold along the vertical direction until the fiber bundle is immersed in the concrete slurry, or rotate the fiber bundle along the twisting direction while inserting to prevent the twisted fiber bundle from spreading out;

[0015] S6. Continue to pour the concrete slurry into the mold until the mold is filled, lay a layer of fiber mesh on the surface of the slurry, and gently vibrate and press to make the fiber mesh immersed in the slurry by 1-2 cm. After the slurry solidifies, the cover plate is obtained after curing and demolding.

[0016] Further, in steps S1-S2, the cement is 100-130 parts by weight, the silica fume is 20-40 parts by weight, the sand is 70-90 parts by weight, the polypropylene fiber is 20-40 parts by weight, the water is 30-40 parts by weight, the water reducing agent is 25 parts by weight, and the retarder is 1.5-2 parts by weight.

[0017] Further, in steps S1-S2, the cement is 110 parts by weight, the silica fume is 25 parts by weight, the sand is 80 parts by weight, the polypropylene fiber is 30 parts by weight, the water is 33 parts by weight, the water reducing agent is 25 parts by weight, and the retarder is 1.5-2 parts by weight.

[0018] The water reducing agent and the retarder are known to those skilled in the art, and the present application does not make other limitations.

[0019] Further, in step S1, the polypropylene fiber is a monofilament fiber, the length is 12-20 mm, the diameter is 40-50 μm, the density is 900-920 kg / m 3 , the elastic modulus is 5-8 GPa, the tensile strength is 500-600 MPa, and the elongation at break is 30-40%.

[0020] Further, in step S3, the thickness of the cover plate mold is 10-12 cm.

[0021] Further, in step S3, the basalt rib has a diameter of 4-10 mm, a bending strength of 650-680 MPa, a tensile strength of 900-1000 MPa, a shear strength of 250-270 MPa, an elastic modulus of 40-45 GPa, a magnetic susceptibility of less than 5*10-7 CGSM, and a bonding strength with concrete of no less than 35 MPa.

[0022] Further, in step S3, the basalt rib has a diameter of 4-10 mm, a bending strength of 650-680 MPa, a tensile strength of 900-1000 MPa, a shear strength of 250-270 MPa, an elastic modulus of 40-45 GPa, a magnetic susceptibility of less than 5*10-7 CGSM, and a bonding strength with concrete of no less than 35 MPa.

[0023] Further, in step S4, the twisted basalt fiber bundle has a diameter of 1 mm, a length of 7-9 cm, and a twist of 30 / 100.

[0024] Further, in step S5, the twisted basalt fiber bundle has an insertion density of 30-40 roots / ㎡.

[0025] Further, in step S6, the fiber net includes a polypropylene fiber net or a basalt fiber net, has a mesh size of 20 mm*20 mm, and a thickness of 0.5-1 mm.

[0026] The concrete is a non-homogeneous material, and has micro-cracks, pores and defects of different sizes inside. A certain amount of fibers added into the concrete can bear load together with the matrix. When stress is transmitted from the matrix to the fibers, the deformation or fracture of the fibers can consume energy, so that the compressive strength of the concrete is improved. However, when the fiber content is too high, the average spacing of the fibers in the matrix is reduced, and when it is reduced to a certain extent, the fibers are overlapped and bunched, so that the adhesion effect of the fibers and the concrete is poor, and the density and continuity of the concrete are reduced, thereby causing certain crack defects. In addition, the uneven dispersion of the high fiber content in the concrete can produce many weak interfaces, which can reduce the compressive strength of the concrete.

[0027] In the preparation of the cover plate, in order to improve the crack resistance or tensile performance of the product, a high content of polypropylene fiber is usually added, which has an adverse effect on the compressive performance of the cover plate.

[0028] The beneficial effects of the present application are:

[0029] 1.The application inserts the twisted basalt fiber bundle when pouring the concrete cover plate, the basalt fiber bundle after insertion slowly spreads out, increases the contact area of the concrete and the basalt fiber bundle, thereby reducing the fiber usage and improving the bonding force between the fiber bundle and the concrete matrix; the basalt fiber bundle after spreading out is in a spring shape, when the cover plate bears a load, the spring-shaped basalt fiber bundle can deform together with the concrete, plays a buffering role, improves the compressive strength of the cover plate, and compared with the untwisted fiber, since it is difficult to control the direction of the fiber during the processing process and the direction of the pressure during the use process, the untwisted fiber is difficult to increase the compressive strength.

[0030] 2.The fiber net has a certain blocking effect, after laying and vibrating, the phenomenon of agglomeration and knotting of the polypropylene fiber at the top can be avoided to a certain extent, the concrete matrix forms a more perfect microstructure, reduces internal defects, and obtains a concrete structure with better continuity, which helps to enhance the mechanical properties of the cover plate; the fiber net itself has a good reinforcing effect and does not adversely affect the tensile and bending properties of the cover plate. DETAILED DESCRIPTION

[0031] The technical solutions of the application will be further described in detail below in combination with examples, but the protection scope of the application is not limited to the following description.

[0032] In each of the following examples and comparative examples, the polypropylene fiber is monofilament fiber, the length of which is 18-20mm, the diameter of which is 40-50μm, the density of which is 920kg / m 3 , the elastic modulus of which is 6GPa, the tensile strength of which is 600MPa, and the elongation at break of which is 35%; the diameter of the basalt rod is 8-10mm, the bending strength of which is 650MPa, the tensile strength of which is 1000MPa, the shear strength of which is 270MPa, the elastic modulus of which is 40GPa, and the magnetic susceptibility of which is less than 5×10 -7 CGSM, the bonding strength with the concrete is ≥35MPa; the fiber net, the water reducing agent and the retarder are all purchased from the market.

[0033] Example 1

[0034] A preparation method of a high-strength concrete cover plate, comprising the following steps:

[0035] S1. According to the weight parts, the cement 110 parts, the silicon powder 25 parts, the sand 80 parts and the polypropylene fiber 30 parts are fully stirred to reach a uniformly distributed state, and a mixture is obtained;

[0036] S2. To the mixture, water 33 parts, water reducing agent 25 parts and retarder 1.5 parts are added, and fully stirred to reach a uniformly mixed state, and a concrete slurry is obtained;

[0037] S3. Prepare a pre-prepared cover plate mold with a length of 1 m, a width of 0.5 m, and a thickness of 12 cm, and evenly place 2 basalt bars with a length of 1 m in the cover plate mold in the length direction, and the basalt bars are located at the middle position of the mold in the vertical direction; after placement, pour the concrete slurry gently until the liquid level reaches 4 / 5 (9.6 cm) of the thickness of the mold;

[0038] S4. Twist a single basalt fiber bundle, and then twist 3 twisted basalt fiber bundles again, the twisting directions are the same, and the total twist is 30 / 100 flowers / mode, to obtain a twisted basalt fiber bundle with a diameter of 1 mm and a length of 9 cm.

[0039] S5. Quickly insert the twisted basalt fiber bundle into the concrete slurry in the mold in the vertical direction until the fiber bundle is immersed in the concrete slurry, and rotate the fiber bundle along the twisting direction while inserting to prevent the twisted fiber bundle from spreading;

[0040] S6. Continue to pour the concrete slurry into the mold until the mold is filled, lay a layer of fiber mesh on the surface of the slurry, and gently vibrate, press, and immerse the fiber mesh in the slurry by 1-2 cm. After the slurry solidifies, the cover plate is obtained after curing and demolding.

[0041] The curing method is well known to those skilled in the art, the basalt fiber mesh has a mesh size of 20 mm x 20 mm and a thickness of 1 mm, and 15 twisted basalt fiber bundles are uniformly inserted into the cover plate in this embodiment.

[0042] Example 2

[0043] A preparation method of a high-strength concrete cover plate, comprising the following steps:

[0044] S1. Fully stir cement 125 parts, silica powder 40 parts, sand 90 parts, and polypropylene fiber 40 parts to achieve uniform distribution, to obtain a mixture;

[0045] S2. Add water 40 parts, water reducing agent 25 parts, and retarder 1.5 parts to the mixture, and fully stir to achieve uniform mixing, to obtain a concrete slurry;

[0046] S3. Prepare a pre-prepared cover plate mold with a length of 1.5 m, a width of 1 m, and a thickness of 10 cm, and evenly place 3 basalt bars with a length of 1.5 m in the cover plate mold in the length direction, and the basalt bars are located at the middle position of the mold in the vertical direction; after placement, pour the concrete slurry gently until the liquid level reaches 4 / 5 (8 cm) of the thickness of the mold;

[0047] S4. Twisting a single basalt fiber bundle, and then twisting two twisted basalt fiber bundles again, the twisting directions are the same, and the total twist is 40 / 100 turns per module, to obtain a twisted basalt fiber bundle with a diameter of 1 mm and a length of 7 cm.

[0048] S5. Quickly inserting the twisted basalt fiber bundle into the concrete slurry in the mold along the vertical direction until the fiber bundle is immersed in the concrete slurry, and rotating the fiber bundle along the twisting direction while inserting to prevent the twisted fiber bundle from spreading out;

[0049] S6. Continue pouring the concrete slurry into the mold until the mold is filled, lay a layer of basalt fiber mesh on the surface of the slurry, and gently vibrate and press so that the fiber mesh is immersed in the slurry by 1-2 cm. After the slurry solidifies, the cover plate is obtained after curing and demolding.

[0050] The curing method is known to those skilled in the art, the basalt fiber mesh has a mesh size of 20 mm x 20 mm and a thickness of 0.5 mm, and 60 twisted basalt fiber bundles are uniformly inserted into the cover plate in this embodiment.

[0051] Comparative Example 1

[0052] A method for preparing a high-strength concrete cover plate, comprising the following steps:

[0053] S1. Fully stirring cement 110 parts, silica powder 25 parts, and sand 80 parts to achieve uniform distribution, to obtain a mixture;

[0054] S2. Adding water 33 parts, water reducing agent 25 parts, and retarder 1.5 parts to the mixture, and fully stirring to achieve uniform mixing, to obtain a concrete slurry;

[0055] S3. Preparing a pre-prepared cover plate mold, the mold is 1 m long, 0.5 m wide, and 12 cm thick, and 2 basalt bars each 1 m long are uniformly placed in the mold along the length direction, and the basalt bars are located at the middle position of the mold in the vertical direction. After placement, the concrete slurry is gently poured into the mold until the mold is filled with the slurry. After the slurry solidifies, the cover plate is obtained after curing and demolding.

[0056] The difference between Comparative Example 1 and Example 1 is that no polypropylene fiber is added in the cover plate components of Comparative Example 1, no twisted basalt fiber bundle is inserted, and no fiber mesh is laid during pouring.

[0057] Comparative Example 2

[0058] A method for preparing a high-strength concrete cover plate, comprising the following steps:

[0059] S1. Cement 110 parts, silica fume 25 parts, sand 80 parts, polypropylene fiber 30 parts are fully stirred to reach a uniformly distributed state to obtain a mixture;

[0060] S2. To the mixture, add water 33 parts, water reducing agent 25 parts and retarder 1.5 parts, fully stir to reach a uniformly mixed state to obtain a concrete slurry;

[0061] S3. Prepare an advance-prepared cover plate mold, the mold is 1m long, 0.5m wide and 12cm thick, place 2 basalt bars each 1m long evenly in the length direction in the cover plate mold, the basalt bars are located at the middle position of the mold in the vertical direction; after placement, gently pour in the concrete slurry until the mold is filled with the slurry; after the slurry solidifies, the cover plate is obtained after curing and demolding.

[0062] The cover plate of Comparative Example 2 and Example 1 is the same in components, except that twisted basalt fiber bundles are not inserted and a fiber net is not laid during pouring.

[0063] Comparative Example 3

[0064] A preparation method of a high-strength concrete cover plate, comprising the following steps:

[0065] S1. Cement 110 parts, silica fume 25 parts, sand 80 parts, polypropylene fiber 30 parts are fully stirred to reach a uniformly distributed state to obtain a mixture;

[0066] S2. To the mixture, add water 33 parts, water reducing agent 25 parts and retarder 1.5 parts, fully stir to reach a uniformly mixed state to obtain a concrete slurry;

[0067] S3. Prepare an advance-prepared cover plate mold, the mold is 1m long, 0.5m wide and 12cm thick, place 2 basalt bars each 1m long evenly in the length direction in the cover plate mold, the basalt bars are located at the middle position of the mold in the vertical direction; after placement, gently pour in the concrete slurry until the mold is filled with the slurry; S4. Lay a layer of basalt fiber net on the surface of the slurry, gently vibrate, press and make the fiber net sink into the slurry 1-2cm, after the slurry solidifies, the cover plate is obtained after curing and demolding.

[0068] The cover plate of Comparative Example 3 and Example 1 is the same in components, except that twisted basalt fiber bundles are not inserted during pouring in Comparative Example 3.

[0069] Comparative Example 4

[0070] A preparation method of a high-strength concrete cover plate, comprising the following steps:

[0071] S1. Mix cement 110 parts by weight, silica fume 25 parts, sand 80 parts, polypropylene fiber 30 parts to obtain a mixture;

[0072] S2. Add water 33 parts, water reducing agent 25 parts and retarder 1.5 parts to the mixture, and fully stir to obtain a concrete slurry;

[0073] S3. Prepare a pre-prepared cover plate mold, the mold is 1m long, 0.5m wide and 12cm thick, 2 1m long basalt bars are evenly placed in the cover plate mold along the length direction, and the basalt bars are located at the middle position of the mold in the vertical direction; after placement, the concrete slurry is gently poured until the liquid level reaches 4 / 5 (9.6cm) of the thickness of the mold;

[0074] S4. Insert a basalt fiber bundle with a diameter of 1mm and a length of 9cm into the concrete slurry in the mold along the vertical direction until the fiber bundle is immersed in the concrete slurry;

[0075] S5. Continue to pour the concrete slurry into the mold until the mold is filled, and a layer of basalt fiber mesh is laid on the surface of the slurry, and the fiber mesh is gently vibrated and pressed to immerse the fiber mesh in the slurry by 1-2cm; after the slurry is solidified, the cover plate is obtained after curing and demolding.

[0076] Comparative Example 4 and Example 1 have the same components of the cover plate, the difference is that the fiber bundle is not twisted in Comparative Example 4.

[0077] Comparative Example 5

[0078] A preparation method of a high-strength concrete cover plate, comprising the following steps:

[0079] S1. Mix cement 110 parts by weight, silica fume 25 parts, sand 80 parts, polypropylene fiber 30 parts to obtain a mixture;

[0080] S2. Add water 33 parts, water reducing agent 25 parts and retarder 1.5 parts to the mixture, and fully stir to obtain a concrete slurry;

[0081] S3. Prepare a pre-prepared cover plate mold, the mold is 1m long, 0.5m wide and 12cm thick, 2 1m long basalt bars are evenly placed in the cover plate mold along the length direction, and the basalt bars are located at the middle position of the mold in the vertical direction; after placement, the concrete slurry is gently poured until the liquid level reaches 4 / 5 (9.6cm) of the thickness of the mold;

[0082] S4. Twisting a single steel fiber bundle, and twisting three twisted steel fiber bundles again, the same direction and the same total twist degree, 30 / 100 flowers per module, to obtain a twisted steel fiber bundle, the diameter is 1 mm, the length is 9 cm.

[0083] S5. Quickly inserting the steel fiber bundle into the concrete slurry in the mold in the vertical direction until the fiber bundle is immersed in the concrete slurry, and rotating it along the twisting direction while inserting to prevent the twisted fiber bundle from spreading out;

[0084] S6. Continue to pour the concrete slurry into the mold until it is filled, and lay a layer of basalt fiber mesh on the surface of the slurry, and gently vibrate and press so that the fiber mesh is immersed in the slurry by 1-2 cm. After the slurry solidifies, the cover plate is obtained after curing and demolding.

[0085] The comparative example 5 and the cover plate of the example 1 have the same components, except that the basalt fiber bundle is replaced by a steel fiber bundle in the comparative example 5.

[0086] According to the method specified in the standard GB 50081—2002 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete", the compressive strength, splitting tensile strength, flexural strength and crack resistance of the concrete cover plates prepared in the above examples and comparative examples are tested. The test results are shown in Table 1.

[0087] Table 1

[0088]

[0089] According to Table 1, it can be seen from comparative example 1 and comparative example 2 that after adding polypropylene fibers in the cover plate components, the flexural, splitting tensile and crack resistance are improved to a certain extent, but the compressive strength is significantly reduced, indicating that the dosage of polypropylene fibers exceeds a certain limit, which weakens the compressive strength of the cover plate; comparative example 3 lays a layer of fiber mesh on the basis of comparative example 2, which has little effect on the compressive strength of the cover plate, but the flexural, splitting tensile and crack resistance are greatly improved; comparative example 4, compared with example 1, does not twist the basalt fiber bundle, and the compressive strength is slightly improved compared with comparative example 3, but the amplitude is much smaller than example 1, and cracks appear, which may be because the untwisted fiber bundle deviates after insertion, and cannot bear the vertical pressure, so the improvement of the compressive strength is not obvious. In addition, the surface of the untwisted fiber bundle is smooth, and the adhesion to the matrix is low, which leads to the easy occurrence of cracks in the cover plate; comparative example 5 replaces the basalt fiber of example 1 with steel fiber, although the compressive strength is further improved, but the crack length reaches 3 cm, and the crack resistance does not meet the product requirements.

[0090] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and operation described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the claims below and their equivalents.

Claims

1. A method of manufacturing a high-strength concrete cover plate, characterized by, The method comprises the following steps: S1. Cement, silica powder, sand, and polypropylene fibers are fully stirred to achieve a uniformly distributed state, obtaining a mixture; S2. Water, a water reducing agent, and a retarder are added to the mixture, and the mixture is fully stirred to achieve a uniformly mixed state, obtaining a concrete slurry; S3. After a basalt rod is horizontally placed in a cover plate mold, the concrete slurry is poured into the mold until the liquid level reaches 4 / 5 of the thickness of the mold; S4. A single basalt fiber bundle is twisted, and 2-3 twisted basalt fiber bundles are twisted again. The twisting directions are the same, and the total twist is the same, obtaining a twisted basalt fiber bundle; S5. The twisted basalt fiber bundle is quickly inserted into the concrete slurry in the mold in a vertical direction, and the twisted basalt fiber bundle is rotated along the twisting direction to prevent the twisted fiber bundle from spreading out; S6. The concrete slurry is continuously poured into the mold until the mold is filled, and a fiber mesh is laid on the surface of the slurry. The fiber mesh is gently vibrated, pressed, and immersed in the slurry by 1-2 cm. After the slurry is solidified, the cover plate is obtained after curing and demolding.

2. The method of claim 1, wherein the high-strength concrete cover plate is prepared by mixing cement, sand, and aggregate in a ratio of 1:2:3, respectively, and then adding water to the mixture in an amount of 40% of the total weight of the mixture. In steps S1-S2, the cement is 100-130 parts by weight, the silica powder is 20-40 parts by weight, the sand is 70-90 parts by weight, the polypropylene fiber is 20-40 parts by weight, the water is 30-40 parts by weight, the water reducing agent is 25 parts by weight, and the retarder is 1.5-2 parts by weight.

3. The method of claim 1, wherein the high-strength concrete cover plate is prepared by mixing cement, sand, and aggregate in a ratio of 1:2:3, respectively, and then adding water to the mixture in an amount of 40% of the total weight of the mixture. In steps S1-S2, the cement is 110 parts by weight, the silica powder is 25 parts by weight, the sand is 80 parts by weight, the polypropylene fiber is 30 parts by weight, the water is 33 parts by weight, the water reducing agent is 25 parts by weight, and the retarder is 1.5-2 parts by weight.

4. The method of claim 1, wherein the high-strength concrete cover plate is prepared by mixing cement, sand, and aggregate in a ratio of 1:2:3, respectively, and then adding water to the mixture in an amount of 40% of the total weight of the mixture. In step S1, the polypropylene fibers are monofilament fibers having a length of 12-20 mm, a diameter of 40-50 μm, a density of 900-920 kg / m 3 , an elastic modulus of 5-8 GPa, a tensile strength of 500-600 MPa, and an elongation at break of 30-40%.

5. The method of claim 1, wherein the high-strength concrete cover plate is prepared by mixing cement, sand, and aggregate in a ratio of 1:2:3, respectively, and then adding water to the mixture in an amount of 40% of the total weight of the mixture. In step S3, the thickness of the cover plate mold is 10-12 cm.

6. The method of claim 1, wherein the high-strength concrete cover plate is prepared by mixing cement, sand, and aggregate in a ratio of 1:2:3, respectively, and then adding water to the mixture in an amount of 40% of the total weight of the mixture. In step S3, the basalt rod has a diameter of 4-10 mm, a bending strength of 650-680 MPa, a tensile strength of 900-1000 MPa, a shear strength of 250-270 MPa, an elastic modulus of 40-45 GPa, and a magnetic susceptibility of less than 5x10 -7 CGSM, and the bonding strength with concrete is ≥ 35 MPa.

7. The method for preparing a high-strength concrete cover plate according to claim 1, characterized in that, In step S3, the length of the basalt rod is the same as the length of the mold and is placed horizontally along the length direction of the mold.

8. The method for preparing a high-strength concrete cover plate according to claim 1, characterized in that, In step S4, the diameter of the twisted basalt fiber bundle is 1 mm, the length is 7-9 cm, and the twist is 30-40 / 100.

9. The method for preparing a high-strength concrete cover plate according to claim 1, characterized in that, In step S5, the insertion density of the twisted basalt fiber bundle is 30-40 roots / ㎡.

10. The method for preparing a high-strength concrete cover plate according to claim 1, characterized in that, In step S6, the fiber mesh includes a polypropylene fiber mesh or a basalt fiber mesh, the mesh size is 20 mm x 20 mm, and the thickness is 0.5-1 mm.

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