A kind of anti-splitting concrete containing modified fiber and preparation method

Abstract

The invention relates to the technical field of concrete materials, in particular to a modified fiber-containing anti-splitting concrete and a preparation method thereof; the modified fiber-containing anti-splitting concrete is composed of the following raw materials in parts by weight: 100-120 parts of silicate cement, 10-14 parts of quartz sand, 20-30 parts of aggregate, 5-8 parts of modified fiber, 4-7 parts of hydrophobic agent, 6-10 parts of water reducer and 30-50 parts of water; silicate cement, quartz sand, aggregate and modified fiber are put into a mixing device for mixing and stirring to obtain a mixture, the hydrophobic agent, the water reducer and water are fully mixed, the mixture is added thereto, the mixing is continued, and the mixing is continued, and the material is discharged after the mixing is completed, so as to finally obtain a finished product of the modified fiber-containing anti-splitting concrete; the modified fiber-containing anti-splitting concrete prepared by the invention not only has good mechanical properties, but also has excellent anti-seepage performance, and its quality is effectively guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of concrete materials, in particular to modified fiber-containing anti-splitting concrete and a preparation method thereof. Background Art

[0002] Concrete is an artificial stone made by mixing and curing cementitious materials, aggregates, water, etc. in a certain proportion. It has become the most widely used building material in the construction industry because of its wide source of raw materials, low price, simple production process, and good mechanical properties and durability.

[0003] In the patent document with application number "CN202010911918.7" and titled "A C35 basalt fiber concrete for abutments and its preparation method", it is recorded that "It is characterized by: in parts by weight, comprising 430-450 parts of cementitious materials, 4 parts of basalt fibers, 1790-1800 parts of aggregates, 7-8 parts of water reducers, and 150-170 parts of water; wherein the cementitious materials are composed of 2803-00 parts of cement, 60-70 parts of fly ash and 70-90 parts of slag powder, and the aggregates are composed of coarse aggregates and fine aggregates. The C35 basalt fiber concrete for abutments prepared by the present invention has a 28d compressive strength ≥35.0MPa, a 28d flexural strength ≥5.0MPa, a 28d splitting strength ≥3.0MPa, a 28d elastic modulus ≥30GPa, and a crack resistance grade of L-Ⅲ".

[0004] Although the concrete produced by the above patent document has advantages such as excellent mechanical properties, its own anti-seepage performance and anti-splitting performance are relatively insufficient and still need to be further improved. Based on this, the present invention provides a modified fiber-containing anti-splitting concrete and a preparation method to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a modified fiber-containing splitting-resistant concrete and a preparation method. The prepared modified fiber-containing splitting-resistant concrete not only has good mechanical properties, but also has excellent anti-seepage performance, effectively ensuring its quality.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The first aspect of the present invention provides a modified fiber-containing splitting-resistant concrete, which is composed of the following raw materials in parts by weight: 100 to 120 parts of silicate cement, 10 to 14 parts of quartz sand, 20 to 30 parts of aggregate, 5 to 8 parts of modified fibers, 4 to 7 parts of hydrophobic agent, 6 to 10 parts of water reducer and 30 to 50 parts of water.

[0008] The present invention is further configured as follows: the aggregate is formed by mixing modified clay and limestone in a mass ratio of 1:1.8 to 2.1.

[0009] The present invention is further configured as follows: the silicate cement is ordinary silicate cement P·O 42.5.

[0010] The present invention is further configured as follows: the preparation process of the modified clay is as follows:

[0011] Place the clay in a resistance furnace, heat it to 650-700°C at a heating rate of 8-10°C / min, and keep it at this temperature for 240-260min;

[0012] Then, the temperature is raised to 760-780°C at a heating rate of 4-6°C / min, and kept at this temperature for 100-120 minutes. After natural cooling, the mixture is placed in a pulverizing device and pulverized to 0.2-2.2 mm to obtain a powder.

[0013] The nano-silicon dioxide is ultrasonically dispersed in deionized water at a dosage ratio of 0.12 to 0.45 g / mL for 20 to 30 minutes to obtain a prepared solution;

[0014] The powder is placed in the prepared solution at a dosage ratio of 0.05-0.25 g / mL, and treated at 120-140 r / min for 30-36 hours. After filtration, it is dried at 70-80° C. to constant weight to obtain modified clay.

[0015] The present invention is further configured as follows: the preparation process of the modified fiber is as follows:

[0016] Taking polytetrafluoroethylene fiber, and subjecting it to electron beam irradiation to obtain pretreated polytetrafluoroethylene fiber;

[0017] The silane coupling agent KH560 is placed in an ethanol aqueous solution with a concentration of 80-84% at a mass ratio of 0.65-0.75:1, stirred at 120-240 r / min for 10-14 min, and then nano-silicon dioxide is added thereto, and stirring is continued for 70-80 min;

[0018] Then, the pretreated polytetrafluoroethylene fiber is added thereto, and ultrasonic treatment is performed for 40 to 50 minutes. After filtration, the fiber is washed with anhydrous ethanol and deionized water for 2 to 4 times respectively, and dried at a temperature of 70 to 80° C. for 14 to 16 hours to obtain modified fiber.

[0019] The present invention is further configured as follows: the irradiation dose of the electron beam irradiation is 200 to 300 kGy, and the irradiation time is 10 to 12 s.

[0020] The present invention is further configured as follows: the addition amount of the nano silicon dioxide is 1.2-1.4% of the mass of the ethanol aqueous solution.

[0021] The present invention is further configured as follows: the addition amount of the pretreated polytetrafluoroethylene fiber is 4.3-6.3% of the mass of the ethanol aqueous solution.

[0022] The present invention is further configured as follows: the water reducer is selected from any one of a polycarboxylate water reducer and a sodium lignin sulfonate water reducer.

[0023] The second aspect of the present invention: also provides a method for preparing the above-mentioned modified fiber-containing anti-splitting concrete, comprising the following steps:

[0024] Step 1: accurately weigh silicate cement, quartz sand, aggregate, modified fiber, hydrophobic agent, water reducing agent and water, and put silicate cement, quartz sand, aggregate and modified fiber into a mixing device for mixing and stirring to obtain a mixture;

[0025] Step 2: After the hydrophobic agent, water reducing agent and water are fully mixed, the mixture is added thereto, and the stirring and mixing is continued for 10 to 15 minutes. After the mixing is completed, the material is discharged to finally obtain a finished product of modified fiber-containing anti-splitting concrete.

[0026] The present invention is further configured as follows: in step 1, the rotation speed of the mixing equipment is 120 to 320 r / min, and the mixing time is 20 to 30 min.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] In the present invention, silicate cement, quartz sand, aggregate, modified fiber, hydrophobic agent, water reducing agent and water are used as raw materials. The silicate cement, quartz sand, aggregate and modified fiber are put into a mixing device for mixing and stirring to obtain a mixture. The hydrophobic agent, water reducing agent and water are fully mixed, and then the mixture is added thereto, and the mixing is continued. After the mixing is completed, the material is discharged to finally obtain a finished product of modified fiber-containing anti-split concrete. The modified fiber-containing anti-split concrete prepared by the present invention not only has good mechanical properties, but also has excellent anti-seepage performance, which effectively guarantees its quality. The modified fiber-containing anti-split concrete and preparation method provided by the present invention have a broader market prospect and are more suitable for promotion. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] The present embodiment provides a modified fiber-containing splitting-resistant concrete, which is composed of the following raw materials in parts by weight: 100 parts of Portland cement, 10 parts of quartz sand, 20 parts of aggregate, 5 parts of modified fiber, 4 parts of hydrophobic agent, 6 parts of water reducing agent and 30 parts of water.

[0032] In this embodiment, it should be noted that the silicate cement is ordinary silicate cement P·O42.5, which is purchased from Hunan Xindingli New Material Technology Co., Ltd.

[0033] Among them, the aggregate is a mixture of modified clay and limestone in a mass ratio of 1:1.8.

[0034] Further, the preparation process of modified clay is as follows:

[0035] The clay was placed in a resistance furnace, heated to 650°C at a heating rate of 8°C / min, and kept at this temperature for 240 min;

[0036] Then the temperature was raised to 760°C at a heating rate of 4°C / min and kept at that temperature for 100 minutes. After natural cooling, the mixture was placed in a pulverizing device and pulverized to 0.2 mm to obtain a powder.

[0037] The nano-silicon dioxide was ultrasonically dispersed in deionized water at a dosage of 0.12 g / mL for 20 min to obtain a prepared solution;

[0038] The powder was placed in the prepared solution at a dosage ratio of 0.05 g / mL and treated at 120 r / min for 30 h. After filtration, it was dried at 70° C. to constant weight to obtain modified clay.

[0039] In this embodiment, it should be noted that limestone was purchased from Shenyang Elepox Chemical Co., Ltd., clay was purchased from Shijiazhuang Fengming Mineral Products Co., Ltd., and nano-silicon dioxide was purchased from Aladdin Reagent (Shanghai) Co., Ltd.

[0040] Among them, the preparation process of modified fiber is as follows:

[0041] Taking polytetrafluoroethylene fiber, and subjecting it to electron beam irradiation to obtain pretreated polytetrafluoroethylene fiber;

[0042] The silane coupling agent KH560 was placed in an 80% ethanol aqueous solution at a mass ratio of 0.65:1, stirred at 120 r / min for 10 min, and then nano-silicon dioxide was added thereto, and stirring was continued for 70 min;

[0043] Then, the pretreated polytetrafluoroethylene fiber was added thereto, and ultrasonic treatment was performed for 40 minutes. After filtration, the fiber was washed twice with anhydrous ethanol and deionized water respectively, and dried at 70° C. for 14 hours to obtain modified fiber.

[0044] Furthermore, the irradiation dose of the electron beam irradiation is 20 kGy, and the irradiation time is 10 s.

[0045] In addition, the added amount of nano-silica is 1.2% of the mass of the ethanol aqueous solution.

[0046] The addition amount of the pretreated polytetrafluoroethylene fiber is 4.3% of the mass of the ethanol aqueous solution.

[0047] Among them, the water reducer is polycarboxylic acid water reducer.

[0048] In this embodiment, it should be noted that the polycarboxylate water reducer was purchased from Wuhan Runxingyuan Technology Co., Ltd.

[0049] In addition, this embodiment also provides a method for preparing the above-mentioned modified fiber-containing anti-splitting concrete, comprising the following steps:

[0050] Step 1: Accurately weigh silicate cement, quartz sand, aggregate, modified fiber, hydrophobic agent, water reducing agent and water, and put the silicate cement, quartz sand, aggregate and modified fiber into a mixing device for mixing and stirring to obtain a mixture.

[0051] Among them, the rotation speed of the mixing equipment is 120r / min, and the mixing time is 20min.

[0052] Step 2: After the hydrophobic agent, water reducing agent and water are fully mixed, the mixture is added thereto, and the stirring and mixing is continued for 10 minutes. After the mixing is completed, the material is discharged, and finally a finished product of modified fiber-containing anti-splitting concrete is obtained.

[0053] Example 2

[0054] The preparation method of the modified fiber anti-splitting concrete provided in this embodiment is basically the same as that in Embodiment 1, except that: the specific raw material composition and the specific preparation method of the modified fiber anti-splitting concrete in this embodiment are different; the specific raw material composition and the specific preparation method of the modified fiber anti-splitting concrete in this embodiment are as follows:

[0055] A modified fiber-containing splitting-resistant concrete is composed of the following raw materials in parts by weight: 110 parts of silicate cement, 12 parts of quartz sand, 25 parts of aggregate, 6 parts of modified fiber, 6 parts of hydrophobic agent, 8 parts of water reducing agent and 40 parts of water.

[0056] In this embodiment, it should be noted that the silicate cement is ordinary silicate cement P·O42.5, which is purchased from Hunan Xindingli New Material Technology Co., Ltd.

[0057] Among them, the aggregate is a mixture of modified clay and limestone in a mass ratio of 1:1.9.

[0058] Further, the preparation process of modified clay is as follows:

[0059] The clay was placed in a resistance furnace, heated to 675°C at a heating rate of 9°C / min, and kept at this temperature for 250 min;

[0060] Then the temperature was raised to 770°C at a heating rate of 5°C / min and kept at that temperature for 110min. After natural cooling, the mixture was placed in a pulverizing device and pulverized to 1.2mm to obtain a powder.

[0061] The nano-silicon dioxide was ultrasonically dispersed in deionized water at a dosage of 0.32 g / mL for 25 min to obtain a prepared solution;

[0062] The powder was placed in the prepared solution at a dosage ratio of 0.15 g / mL and treated at 130 r / min for 33 h. After filtration, it was dried at 75° C. to constant weight to obtain modified clay.

[0063] In this embodiment, it should be noted that limestone was purchased from Shenyang Elepox Chemical Co., Ltd., clay was purchased from Shijiazhuang Fengming Mineral Products Co., Ltd., and nano-silicon dioxide was purchased from Aladdin Reagent (Shanghai) Co., Ltd.

[0064] Among them, the preparation process of modified fiber is as follows:

[0065] Taking polytetrafluoroethylene fiber, and subjecting it to electron beam irradiation to obtain pretreated polytetrafluoroethylene fiber;

[0066] The silane coupling agent KH560 was placed in an ethanol aqueous solution with a concentration of 82% at a mass ratio of 0.7:1, stirred at 180 r / min for 12 min, and then nano-silicon dioxide was added thereto, and stirring was continued for 75 min;

[0067] Then, the pretreated polytetrafluoroethylene fiber was added thereto, and ultrasonic treatment was performed for 45 minutes. After filtration, the fiber was washed three times with anhydrous ethanol and deionized water respectively, and dried at 75° C. for 15 hours to obtain modified fiber.

[0068] Furthermore, the irradiation dose of the electron beam irradiation is 250 kGy, and the irradiation time is 11 s.

[0069] In addition, the added amount of nano-silica is 1.3% of the mass of the ethanol aqueous solution.

[0070] The addition amount of the pretreated polytetrafluoroethylene fiber is 5.3% of the mass of the ethanol aqueous solution.

[0071] Among them, the water reducer is lignin sulfonate sodium salt water reducer.

[0072] In this embodiment, it should be noted that the sodium lignin sulfonate water reducer was purchased from Shandong Qiansheng Chemical Co., Ltd.

[0073] In addition, this embodiment also provides a method for preparing the above-mentioned modified fiber-containing anti-splitting concrete, comprising the following steps:

[0074] Step 1: Accurately weigh silicate cement, quartz sand, aggregate, modified fiber, hydrophobic agent, water reducing agent and water, and put the silicate cement, quartz sand, aggregate and modified fiber into a mixing device for mixing and stirring to obtain a mixture.

[0075] Among them, the rotation speed of the mixing equipment is 220r / min, and the mixing time is 25min.

[0076] Step 2: After the hydrophobic agent, water reducing agent and water are fully mixed, the mixture is added thereto, and the stirring and mixing is continued for 12 minutes. After the mixing is completed, the material is discharged, and finally a finished product of modified fiber-containing anti-splitting concrete is obtained.

[0077] Example 3

[0078] The preparation method of the modified fiber anti-splitting concrete provided in this embodiment is basically the same as that in Embodiment 1, except that: the specific raw material composition and the specific preparation method of the modified fiber anti-splitting concrete in this embodiment are different; the specific raw material composition and the specific preparation method of the modified fiber anti-splitting concrete in this embodiment are as follows:

[0079] A modified fiber-containing anti-splitting concrete is composed of the following raw materials in parts by weight: 120 parts of Portland cement, 14 parts of quartz sand, 30 parts of aggregate, 8 parts of modified fiber, 7 parts of hydrophobic agent, 10 parts of water reducing agent and 50 parts of water.

[0080] In this embodiment, it should be noted that the silicate cement is ordinary silicate cement P·O42.5, which is purchased from Hunan Xindingli New Material Technology Co., Ltd.

[0081] Among them, the aggregate is a mixture of modified clay and limestone in a mass ratio of 1:2.1.

[0082] Further, the preparation process of modified clay is as follows:

[0083] The clay was placed in a resistance furnace, heated to 700°C at a heating rate of 10°C / min, and kept at this temperature for 260 min;

[0084] Then the temperature was raised to 780°C at a heating rate of 6°C / min and kept at that temperature for 120min. After natural cooling, the mixture was placed in a pulverizing device and pulverized to 2.2mm to obtain a powder.

[0085] The nano-silicon dioxide was ultrasonically dispersed in deionized water at a dosage of 0.45 g / mL for 30 min to obtain a prepared solution;

[0086] The powder was placed in the prepared solution at a dosage ratio of 0.25 g / mL and treated at 140 r / min for 36 h. After filtration, it was dried at 80° C. to constant weight to obtain modified clay.

[0087] In this embodiment, it should be noted that limestone was purchased from Shenyang Elepox Chemical Co., Ltd., clay was purchased from Shijiazhuang Fengming Mineral Products Co., Ltd., and nano-silicon dioxide was purchased from Aladdin Reagent (Shanghai) Co., Ltd.

[0088] Among them, the preparation process of modified fiber is as follows:

[0089] Taking polytetrafluoroethylene fiber, and subjecting it to electron beam irradiation to obtain pretreated polytetrafluoroethylene fiber;

[0090] The silane coupling agent KH560 was placed in an ethanol aqueous solution with a concentration of 84% at a mass ratio of 0.75:1, stirred at 240 r / min for 14 min, and then nano-silicon dioxide was added thereto, and stirring was continued for 80 min;

[0091] Then, the pretreated polytetrafluoroethylene fiber was added thereto, and ultrasonic treatment was performed for 50 minutes. After filtration, the fiber was washed with anhydrous ethanol and deionized water for 4 times respectively, and dried at 80° C. for 16 hours to obtain modified fiber.

[0092] Furthermore, the irradiation dose of the electron beam irradiation is 300 kGy, and the irradiation time is 12 s.

[0093] In addition, the added amount of nano-silicon dioxide is 1.4% by mass of the ethanol aqueous solution.

[0094] The addition amount of the pretreated polytetrafluoroethylene fiber is 6.3% of the mass of the ethanol aqueous solution.

[0095] Among them, the water reducer is polycarboxylic acid water reducer.

[0096] In this embodiment, it should be noted that the polycarboxylate water reducer was purchased from Wuhan Runxingyuan Technology Co., Ltd.

[0097] In addition, this embodiment also provides a method for preparing the above-mentioned modified fiber-containing anti-splitting concrete, comprising the following steps:

[0098] Step 1: Accurately weigh silicate cement, quartz sand, aggregate, modified fiber, hydrophobic agent, water reducing agent and water, and put the silicate cement, quartz sand, aggregate and modified fiber into a mixing device for mixing and stirring to obtain a mixture.

[0099] Among them, the rotation speed of the mixing equipment is 320r / min, and the mixing time is 30min.

[0100] Step 2: After the hydrophobic agent, water reducing agent and water are fully mixed, the mixture is added thereto, and the stirring and mixing is continued for 15 minutes. After the mixing is completed, the material is discharged, and finally a finished product of modified fiber-containing anti-splitting concrete is obtained.

[0101] Comparative Example 1: The difference from Example 1 is that in this example, an equal amount of polytetrafluoroethylene fibers are used instead of modified fibers.

[0102] Comparative Example 2: The difference from Example 1 is that the aggregate in this example is a mixture of modified clay and limestone in a mass ratio of 1:1.

[0103] Comparative Example 3: The difference from Example 1 is that the aggregate in this example is a mixture of modified clay and limestone in a mass ratio of 2:1.

[0104] Comparative Example 4: The difference from Example 1 is that the aggregate in this example is a mixture of clay and limestone in a mass ratio of 1:2.1.

[0105] Performance test: The concrete samples provided in Examples 1 to 3 and Comparative Examples 1 to 4 are marked as Examples 1 to 3 and Comparative Examples 1 to 4, respectively; and the relevant properties of the concrete provided in Examples 1 to 3 and Comparative Examples 1 to 4 are tested as follows:

[0106] 1. Mechanical test: The test method is GBT50081-2019 to test the 28d splitting tensile strength and 28d compressive strength.

[0107] 2. Water absorption test: The test method is to use Appendix F of DB32 / T3696-2019 "Concrete Water Absorption Test Method" to determine the water absorption of concrete.

[0108] The obtained test data are recorded in Table 1 and Table 2 below:

[0109] Table 1 Mechanical properties test results of each group of concrete

[0110] Group Compressive strength(MPa) Splitting tensile strength (MPa) Example 1 Group 76.4 4.45 Example 2 Group 76.2 4.43 Example 3 Group 75.9 4.41 Comparison group 1 55.4 2.98 Comparison of 2 groups 68.2 3.38 Comparison of 3 groups 67.8 3.43 Comparison of 4 groups 59.9 3.16

[0111] Table 2 Absorption performance test results of each group of concrete

[0112]

[0113]

[0114] By comparing and analyzing the relevant data in Table 1 and Table 2, it can be seen that the modified fiber-containing splitting-resistant concrete prepared by the present invention not only has good mechanical properties, but also has excellent anti-seepage performance, effectively ensuring its quality. This shows that the modified fiber-containing splitting-resistant concrete and preparation method provided by the present invention have a broader market prospect and are more suitable for promotion.

[0115] In the present invention, silicate cement, quartz sand, aggregate, modified fiber, hydrophobic agent, water reducing agent and water are used as raw materials. The silicate cement, quartz sand, aggregate and modified fiber are put into a mixing device for mixing and stirring to obtain a mixture. The hydrophobic agent, water reducing agent and water are fully mixed, and then the mixture is added thereto, and the mixing is continued. After the mixing is completed, the material is discharged to finally obtain a finished product of modified fiber-containing anti-splitting concrete. The modified fiber-containing anti-splitting concrete prepared by the present invention not only has good mechanical properties, but also has excellent anti-seepage performance, and effectively guarantees its quality.

[0116] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0117] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A modified fiber-containing splitting-resistant concrete, characterized in that: The invention is composed of the following raw materials in parts by weight: 100-120 parts of silicate cement, 10-14 parts of quartz sand, 20-30 parts of aggregate, 5-8 parts of modified fiber, 4-7 parts of hydrophobic agent, 6-10 parts of water reducing agent and 30-50 parts of water; The aggregate is made of modified clay and limestone in a mass ratio of 1:1.8 to 2.1; The preparation process of the modified clay is as follows: Place the clay in a resistance furnace, heat it to 650-700°C at a heating rate of 8-10°C / min, and keep it at this temperature for 240-260min; Then, the temperature is raised to 760-780°C at a heating rate of 4-6°C / min, and kept at this temperature for 100-120 minutes. After natural cooling, the mixture is placed in a pulverizing device and pulverized to 0.2-2.2 mm to obtain a powder. The nano-silicon dioxide is ultrasonically dispersed in deionized water at a dosage ratio of 0.12 to 0.45 g / mL for 20 to 30 minutes to obtain a prepared solution; The powder is placed in the prepared solution at a dosage ratio of 0.05 to 0.25 g / mL, and treated at 120 to 140 r / min for 30 to 36 hours, and after suction filtration, dried at 70 to 80° C. to constant weight to obtain modified clay; The preparation process of the modified fiber is as follows: Taking polytetrafluoroethylene fiber, and subjecting it to electron beam irradiation to obtain pretreated polytetrafluoroethylene fiber; Place silane coupling agent KH560 in an ethanol aqueous solution with a concentration of 80-84% at a mass ratio of 0.65-0.75:1, stir at 120-240 r / min for 10-14 min, then add nano-silicon dioxide and continue stirring for 70-80 min; Then, pretreated polytetrafluoroethylene fiber is added thereto, and ultrasonic treatment is performed for 40 to 50 minutes. After filtration, the fiber is washed with anhydrous ethanol and deionized water for 2 to 4 times, respectively, and dried at a temperature of 70 to 80° C. for 14 to 16 hours to obtain modified fiber. The irradiation dose of the electron beam irradiation is 200 to 300 kGy, and the irradiation time is 10 to 12 seconds; The amount of nano silicon dioxide added is 1.2-1.4% of the mass of the ethanol aqueous solution; The addition amount of the pretreated polytetrafluoroethylene fiber is 4.3-6.3% of the mass of the ethanol aqueous solution.

2. The modified fiber-containing splitting-resistant concrete according to claim 1, characterized in that: The water reducer is selected from any one of polycarboxylic acid water reducer and sodium lignin sulfonate water reducer.

3. A method for preparing a modified fiber-containing splitting-resistant concrete according to any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1: accurately weigh silicate cement, quartz sand, aggregate, modified fiber, hydrophobic agent, water reducing agent and water, and put silicate cement, quartz sand, aggregate and modified fiber into a mixing device for mixing and stirring to obtain a mixture; Step 2: After the hydrophobic agent, water reducing agent and water are fully mixed, the mixture is added thereto, and the stirring and mixing is continued for 10 to 15 minutes. After the mixing is completed, the material is discharged to finally obtain a finished product of modified fiber-containing anti-splitting concrete.

4. The method for preparing a modified fiber-containing splitting-resistant concrete according to claim 3, characterized in that: In the step 1, the rotation speed of the mixing equipment is 120 to 320 r / min, and the mixing time is 20 to 30 min.

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