Crack-resistant concrete and preparation process thereof

Abstract

The present application discloses a crack-resistant concrete and a preparation process thereof. The concrete comprises the following raw materials in parts by mass: 303-398 parts of cement; 363-476 parts of sand; 636-830 parts of aggregate; 180-239 parts of water; 1.9-2.5 parts of a water reducer; and 61.3-72.4 parts of modified glass fiber. Sintered particles are fixed to the surface of the glass fiber by melting and semi-embedding, thereby improving the bonding strength between the glass fiber and the surrounding concrete substrate without damaging the glass fiber body. The concrete has a higher improvement effect on the crack resistance of the concrete than the existing chemically silane-modified glass fiber and chemically etched glass fiber, and does not suffer from the disadvantage of chemically etched glass fiber body strength reduction without efficiency enhancement. Therefore, when the concrete of the present application is subjected to high load, the bonding surface between the concrete substrate and the glass fiber is less likely to crack and separate, thereby further improving the crack resistance of the concrete.

Description

Technical Field

[0001] The present application relates to the field of concrete, and in particular to a crack-resistant concrete and a preparation process thereof. Background Art

[0002] Currently, most exterior walls of buildings are constructed of reinforced concrete. Due to concrete's low tensile strength, it is susceptible to thermal contraction deformation and cracking under load and thermal shrinkage stress, affecting the normal use and anti-leakage performance of the building. A common method for crack resistance in concrete structures is to increase the amount of reinforcement. While increasing the amount of reinforcement can enhance the concrete's crack resistance and reduce crack width, the increased amount of rebar increases costs and construction costs. Therefore, relying solely on the amount of rebar to improve concrete's crack resistance is not the optimal solution.

[0003] Currently, fiber-reinforced materials, such as glass fiber, are added to concrete. The addition of glass fiber can enhance the tensile strength and modulus of concrete, and prevent the concrete from cracking and breaking when subjected to external force impact. On the other hand, the addition of glass fiber can reduce the shrinkage and expansion of concrete, thereby maintaining the stability of concrete.

[0004] However, because the bond strength between glass fiber and the concrete substrate is weaker than the tensile strength of the glass fiber itself, cracking and separation of the glass fiber-concrete composite often begins at the interface, preventing the glass fiber from fully enhancing the concrete's crack resistance. Currently, some buildings, such as storage warehouses and power distribution stations, require walls with higher crack resistance than ordinary building walls. Therefore, the applicant hopes to further improve the crack resistance of glass fiber-reinforced concrete, thereby achieving even higher crack resistance in combination with reinforced reinforcement to achieve even more crack-resistant walls. Summary of the Invention

[0005] Provided are crack-resistant concrete and a preparation process thereof for a concrete wall with higher crack resistance.

[0006] The first object of the present invention is achieved through the following technical solutions:

[0007] A crack-resistant concrete comprising the following raw materials in parts by weight:

[0008] 303-398 parts of cement;

[0009] 363-476 parts of sand;

[0010] 636-830 parts of aggregate;

[0011] 180-239 parts water;

[0012] 1.9-2.5 parts of water reducer;

[0013] 61.3-72.4 parts of modified glass fiber;

[0014] The sand particle size distribution is 0.02~2mm,

[0015] Aggregate grading is 4 to 12 cm;

[0016] The surface of the modified glass is melted and semi-embedded with sintered particles with a particle size of 15 to 16 μm, and the sintered particles are a mixture of ceramic powder, metal, and metal oxide;

[0017] The modified glass fiber is 4 to 5 cm long and has a body diameter of 0.2±0.05 mm.

[0018] By adopting the above technical solution, the sintered particles are fixed to the modified glass fiber by melting and semi-embedding, which greatly improves the bonding strength between the modified glass fiber and the surrounding concrete substrate after the concrete is cured without damaging the glass fiber itself.

[0019] This improvement method is different from the current chemical silane-modified glass fiber and chemically etched glass fiber. Its improvement effect on the crack resistance of concrete is higher than that of chemical silane-modified glass fiber, and it does not have the disadvantage of chemically etched glass fiber that reduces the strength of the body without increasing the efficiency.

[0020] Therefore, when the concrete of the present application is subjected to high loads, the interface between the concrete base material and the glass fiber is less likely to crack and separate, thereby improving the crack resistance of the concrete.

[0021] Optionally, the sintered particles are obtained by sintering ceramic powder mixed with aluminum powder and aluminum hydroxide.

[0022] By adopting the above technical solution, the metal hydroxide acts as an intermediate binder to assist in mixing the ceramic powder and the metal powder before sintering, and the metal oxide formed during the sintering process conforms to the shape of the metal powder during the densification process and coats it, thereby ensuring a stable bond between the ceramic powder and the metal powder.

[0023] The function of the metal powder is to absorb heat and increase the temperature, thus promoting the sintering of the sintered particles and embedding them into the surface of the glass fiber, thus ensuring the bonding strength between the sintered particles and the surface of the glass fiber.

[0024] First, the aluminum oxide obtained by dehydrating aluminum hydroxide is prepared by sintering at a high temperature and can effectively infiltrate and bond aluminum powder, so that the bonding strength of the sintered particles and the molten part is high, and the bonding strength is high when sintering and embedding glass fibers;

[0025] Compared with other metals, aluminum is better at improving the toughness of sintered particles when subjected to tension, so that the resulting modified glass fiber is better than the modified glass fiber prepared from other metals and metal oxides.

[0026] Optionally, the sintered particles are obtained by sintering a mixture of ceramic powder, aluminum powder and aluminum hydroxide gel solution.

[0027] By adopting the above technical solution, aluminum powder and ceramic powder are mixed with aluminum hydroxide gel solution, so that the two can be mixed more evenly, the hydroxide acts better as a binder before sintering, the texture of the sintered particles is stronger, the bonding strength after the modified glass fiber surface is embedded is higher, and the resulting concrete has stronger crack resistance.

[0028] Optional: Sintered pellets are prepared as follows:

[0029] Aluminum powder with a particle size of 0.5 to 1 μm is added to an aluminum hydroxide gel solution and mixed evenly. Ceramic powder with a particle size of 4 to 5 μm is then added and mixed evenly. The mixture is heated to 60°C and stirred continuously to evaporate water until the moisture content of the material drops to 42wt%. Sintered particles are obtained by spray granulation. After drying, the mixture is sintered at 660°C to a density of 1.86 to 1.89 g / cm3, and then crushed to obtain sintered particles.

[0030] By adopting the above technical solution, the mixing is uniform and the granulation gap is large, the pore distribution during sintering is also more uniform, the sintered body is easier to crush, the crushed powder fineness distribution is concentrated, the unified crushing work is convenient, and the sintered particles with the required particle size are obtained at a high rate after screening.

[0031] Optional: The mass ratio of aluminum powder, aluminum hydroxide and ceramic powder is 0.3:0.2:1.

[0032] By adopting the above technical solution, the sintering embedding strength of the sintered particles is large, and the resulting concrete has better crack resistance.

[0033] Optional: The preparation method of modified glass fiber is as follows:

[0034] The sintered powder is dispersed in an ethanol aqueous solution and sprayed onto the surface of the initial glass fiber. The initial glass fiber surface is then sintered at 400-500° C. The sintered powder is sintered and semi-embedded into the initial glass fiber surface to obtain a modified glass fiber.

[0035] By adopting the above technical solution, water has good adhesion to the sintered particles and is easy to form a slurry, while ethanol is volatile and can dry quickly after spraying, and then stably attach to the surface of the glass fiber to form particles, thereby increasing the number of sintered particles embedded in the sintering, enhancing the bonding strength between the modified glass fiber and the concrete base material, and improving the crack resistance of the concrete.

[0036] Optionally, the surface of the initial glass fiber is first sprayed with a 0.08 mol / L copper sulfate aqueous solution, and then dried at 380-400° C. before spraying with slurry mist.

[0037] By adopting the above technical solution, copper ions are burned to form an oxide layer, which reduces the bonding interface energy during attachment, facilitates the attachment of sintered particles to the glass fiber, and improves the crack resistance of concrete.

[0038] The second object of the present invention is achieved through the following technical solutions:

[0039] The above-mentioned process for preparing crack-resistant concrete comprises the following steps:

[0040] Mix cement, sand, aggregate, water and water reducer evenly, then add modified glass fiber and mix evenly again.

[0041] By adopting the above technical solution, the damage of modified glass fiber during the concrete mixing and preparation process is reduced, and the maximum crack resistance improvement of concrete by glass fiber is retained.

[0042] In summary, this application has at least the following beneficial effects:

[0043] The sintered particles are fixed to the surface of the glass fiber by melting and semi-embedding, improving the bonding strength between the glass fiber and the surrounding concrete substrate without damaging the glass fiber itself. Unlike current chemically silane-modified glass fibers and chemically etched glass fibers, the sintered particles have a higher effect on improving the crack resistance of concrete than chemically silane-modified glass fibers, and do not suffer from the disadvantage of chemically etched glass fibers, which have a reduced strength without increased efficiency. Therefore, when the concrete of the present application is subjected to high loads, the bonding surface between the concrete substrate and the glass fiber is less likely to crack and separate, thereby improving the crack resistance of the concrete. DETAILED DESCRIPTION

[0044] Preparation Example 1

[0045] A modified glass fiber is prepared using glass fiber having a diameter of 0.2±0.05 mm as the initial glass fiber. The specific preparation method is as follows:

[0046] S1: Aluminum powder with a particle size of 0.5-1 μm is added to an aluminum hydroxide gel solution and mixed evenly. The aluminum hydroxide gel solution is prepared by mixing aluminum chloride solution and ammonia water. Ceramic powder with a particle size of 4-5 μm is then added, mixed evenly, and heated to 60°C. Water is evaporated by continuous stirring until the moisture content of the material drops to 42wt%. Sintered particles are obtained by spray granulation. After drying, the particles are sintered at 660°C to a density of 1.86-1.89 g / cm3. The particles are then crushed and sieved to obtain sintered particles with a particle size of 15.5±0.5 μm. The mass ratio of aluminum powder, aluminum hydroxide in the aluminum hydroxide gel solution, and ceramic powder is 0.3:0.2:1.

[0047] S2: mixing the sintered particles with a 50 wt% ethanol aqueous solution in a mass ratio of 1:0.8 to obtain a slurry;

[0048] S3: The initial fiber is used as the fiber to be attached and is pulled at 0.4 m / s. During the pulling process, the fiber to be attached is sprayed with slurry at a spray density of 38.4 g / cm2·h. After spraying, the fiber enters the burning chamber and is burned at high temperature under a nitrogen atmosphere. The burning temperature is determined according to the softening point of the initial glass fiber. In this embodiment, the softening point of the initial glass fiber is 475°C, the burning temperature is 476±0.5°C, and the burning time is 3 seconds.

[0049] S4: After burning, the mixture is naturally cooled to room temperature and then cut into short fibers of 4.5±0.5 to obtain modified glass fibers.

[0050] Preparation Example 2

[0051] A modified glass fiber is prepared using a glass fiber having a diameter of 0.2±0.05 mm as an initial glass fiber, similar to Preparation Example 1, except that step S1 of Preparation Example 2 is as follows:

[0052] S1: Iron powder with a particle size of 0.5 to 1 μm is added to a ferric hydroxide gel solution and mixed evenly. The ferric hydroxide gel solution is prepared by mixing aluminum chloride solution and ammonia water. Ceramic powder with a particle size of 4 to 5 μm is then added, mixed evenly, and heated to 60°C. Water is evaporated by continuous stirring until the moisture content of the material drops to 42wt%. Sintered particles are obtained by spray granulation. After drying, the particles are sintered at 660°C to a density of 1.86 to 1.89 g / cm3. The particles are then crushed and sieved to obtain sintered particles with a particle size of 15.5±0.5 μm. The mass ratio of iron powder, ferric hydroxide in the ferric hydroxide gel solution, and ceramic powder is 0.3:0.2:1.

[0053] Preparation Example 3

[0054] A modified glass fiber is prepared using a glass fiber having a diameter of 0.2±0.05 mm as an initial glass fiber, similar to Preparation Example 1, except that step S1 of Preparation Example 3 is as follows:

[0055] S1: Aluminum powder with a particle size of 0.5-1 μm, aluminum hydroxide powder with a particle size of 0.2-0.5 μm, ceramic powder with a particle size of 4-5 μm, and water are uniformly mixed in a mass ratio of 0.3:0.2:1:4, heated to 60°C, and continuously stirred to evaporate the water until the moisture content of the material drops to 42wt%. Sintered particles are obtained by spray granulation, dried, and then sintered at 660°C to a sintered material with a density of 1.86-1.89 g / cm3. The sintered particles are then crushed and sieved to obtain sintered particles with a particle size of 15.5±0.5 μm.

[0056] Preparation Example 4

[0057] A modified glass fiber is prepared using glass fiber with a diameter of 0.2±0.05 mm as the initial glass fiber, which is similar to Preparation Example 1, except that the mass ratio of aluminum powder in S1 of Preparation Example 4, aluminum hydroxide in the aluminum hydroxide gel solution, and ceramic powder is 0.8:0.2:1.

[0058] Preparation Example 5

[0059] A modified glass fiber is prepared using glass fiber with a diameter of 0.2±0.05 mm as the initial glass fiber, which is similar to Preparation Example 1, except that the mass ratio of aluminum powder in S1 of Preparation Example 5, aluminum hydroxide in the aluminum hydroxide gel solution, and ceramic powder is 0.3:0.5:1.

[0060] Preparation Example 6

[0061] A modified glass fiber is prepared using glass fiber with a diameter of 0.2±0.05 mm as an initial glass fiber, which is similar to Preparation Example 1, except that in S2 of Preparation Example 5, sintered particles and water are mixed in a mass ratio of 1:0.8 to obtain a slurry.

[0062] Preparation Example 7

[0063] A modified glass fiber is prepared using a glass fiber having a diameter of 0.2±0.05 mm as an initial glass fiber, similar to Preparation Example 1, except that step S3 is as follows:

[0064] The initial glass fiber is drawn at a speed of 0.2 m / s. During the drawing process, the initial glass fiber is sprayed with a 0.08 mol / L copper sulfate aqueous solution at a spraying density of 18 ml / cm2·h. After spraying, the initial glass fiber is placed in a heating chamber and dried at 380-400°C in an air environment to obtain the fiber to be attached;

[0065] The fiber to be attached is pulled at 0.4 m / s. During the pulling process, the fiber to be attached is sprayed with slurry at a spraying density of 38.4 g / cm2·h. After spraying, it enters the burning chamber and is burned at high temperature under a nitrogen atmosphere. The burning temperature is determined according to the softening point of the initial glass fiber. In this embodiment, the softening point of the initial glass fiber is 475°C, the burning temperature is 476±0.5°C, and the burning time is 3s.

[0066] Examples 1 to 9

[0067] A crack-resistant concrete is prepared using cement, sand, aggregate, water, a water-reducing agent, and modified glass fiber as raw materials. The preparation method is as follows:

[0068] Water and water reducing agent are mixed to form a preparation liquid;

[0069] Mix the preparation liquid with cement, sand and aggregate evenly;

[0070] The modified glass fiber prepared in the preparation example is then added and mixed evenly to obtain crack-resistant concrete.

[0071] The sand particle size distribution is 0.02-2 mm, of which 0.02-0.05 mm accounts for 45.2 wt% and 1.5-2 mm accounts for 54.8 wt%.

[0072] The aggregate grading is 4 to 12 cm, of which 4 to 6 cm accounts for 22.6 wt%, 8 to 10 cm accounts for 47.3 wt%, and the remaining particle size grading is greater than 10 cm and does not exceed 12 cm.

[0073] The water reducer is calcium lignin sulfonate.

[0074] The amounts of raw materials used in Examples 1 to 9 and the sources of the modified glass fibers are shown in Table 1 below.

[0075] Table 1. Amounts of raw materials used in Examples 1 to 9 and sources of modified glass fibers

[0076]

[0077]

[0078] Comparative Example 1

[0079] A crack-resistant concrete is similar to Example 1, except that 4.5±0.5 cm of original glass fiber of equal mass is used instead of the modified glass fiber.

[0080] Comparative Example 2

[0081] A crack-resistant concrete is similar to Example 2, except that 4.5±0.5 cm of original glass fiber of equal mass is used instead of the modified glass fiber.

[0082] Comparative Example 3

[0083] A crack-resistant concrete is similar to Example 3, except that 4.5±0.5 cm of original glass fiber of equal mass is used instead of the modified glass fiber.

[0084] Comparative Example 4

[0085] A crack-resistant concrete is similar to Example 2, except that the modified glass fiber is prepared by the following method: 4.5±0.5 cm of initial glass fiber is added to a 12.6 wt% methanol dispersion of a silane coupling agent KH-151, subjected to ultrasonic load treatment at 43 kHz for 1.4 h, and then removed and dried to obtain the modified glass fiber.

[0086] Comparative Example 4

[0087] A crack-resistant concrete is similar to Example 2, except that the modified glass fiber is prepared by the following method: initial glass fiber is pulled at a speed of 0.4 m / s through a hydrogen fluoride etching chamber, and hydrogen fluoride solution is sprayed in the hydrogen fluoride etching chamber at a spray rate (hydrogen fluoride) of 0.02 g / cm2·h and a spray zone length of 0.4 m;

[0088] The glass fiber passed through the hydrogen fluoride etching chamber for 2 seconds and then was introduced into a water tank for cleaning, drying, and then cut into modified glass fibers of 4.5±0.5 cm.

[0089] The concrete obtained in Examples 1 to 9 and Comparative Examples 1 to 3 was subjected to a splitting tensile strength test according to GB / T50081-2002. The test results are shown in Table 2 below.

[0090] Table 2. Test results of concrete splitting tensile strength obtained from Examples 1 to 9 and Comparative Examples 1 to 3

[0091] Splitting tensile strength / MPa Example 1 8.83 Example 2 8.97 Example 3 8.91 Comparative Example 1 6.64 Comparative Example 2 6.76 Comparative Example 3 6.7 Comparative Example 4 7.23 Comparative Example 5 6.69 Example 4 8.17 Example 5 8.08 Example 6 8.46 Example 7 8.65 Example 8 8.73 Example 9 9.22

[0092] Combined with the above table, it can be seen from the comparison of Examples 1 to 3 and Comparative Examples 1 to 3 that the sintered particles in the present application are fixed to the surface of the modified glass fiber by melting and semi-embedding, and the metal hydroxide serves as an intermediate binder to assist in mixing the ceramic powder and the metal powder before sintering, and the metal oxide formed during the sintering process conforms to the shape of the metal powder during the densification process and is coated, so that the ceramic powder and the metal powder are stably combined; and the role of the metal powder is to absorb heat and heat up, promote the sintering of the sintered particles and embed them on the surface of the glass fiber, and ensure the bonding strength between the sintered particles and the glass fiber surface. As a result, the bonding strength between the modified glass fiber and the surrounding concrete substrate is greatly improved after the concrete is cured. When the concrete of the present application is subjected to high loads, the bonding surface between the concrete substrate and the glass fiber is not prone to cracking and separation, thereby improving the crack resistance of the concrete.

[0093] Furthermore, in combination with Comparative Examples 4 and 5 and Example 2, it can be seen that the modified glass fiber in the present application achieves excellent improvement effects without damaging the glass fiber body. It is different from the current chemically silane-modified glass fiber and chemically etched glass fiber. Its improvement effect on the crack resistance of concrete is higher than that of chemically silane-modified glass fiber, and it does not have the disadvantage of reduced strength of the chemically etched glass fiber body without increased efficiency.

[0094] Comparing Examples 2 and 4, it can be seen that the metal and metal oxide in the sintered particles can also be iron and iron oxides. However, compared to iron and iron oxides, the sintered particles composed of aluminum, aluminum oxide, and ceramic powder are preferably prepared by first dehydrating aluminum hydroxide with aluminum oxide. This is prepared by sintering at high temperature and can effectively infiltrate and bond with aluminum powder, resulting in high bonding strength in the sintered molten portion of the sintered particles and high bonding strength when embedded in glass fibers. Furthermore, aluminum, compared to other metals, is more effective in enhancing the toughness of sintered particles under tension. Therefore, the tensile strength of the concrete in Example 2 is significantly improved compared to that in Example 4.

[0095] Comparing Example 2 and Example 5, it can be seen that Example 2 uses aluminum hydroxide gel solution to mix aluminum powder and ceramic powder. Therefore, mixing aluminum powder and ceramic powder with aluminum hydroxide gel solution can make the two mixed more uniformly, and the hydroxide has a better effect as a binder before sintering, and the texture of the sintered particles is stronger. Example 5 uses aluminum hydroxide powder and water to mix aluminum powder and ceramic powder.

[0096] The crack resistance of the concrete obtained in Example 2 is better than that in Example 5. Therefore, the aluminum hydroxide gel solution is mixed with aluminum powder and ceramic powder, and the bonding strength after the modified glass fiber surface is embedded is higher, and the crack resistance of the obtained concrete is stronger.

[0097] In addition, during the preparation process of Preparation Example 1 and Preparation Example 3, since the preparation method of Preparation Example 1 uses aluminum hydroxide gel solution to mix aluminum powder and ceramic powder to mix the materials uniformly, the pore distribution during sintering is also more uniform, the sintered body is easier to crush, and the fineness distribution of the crushed powder is concentrated, which facilitates unified crushing work and has a high yield rate of sintered particles with the required particle size after screening.

[0098] By comparing Example 2 with Example 6 and Example 7, it can be seen that the modified fibers obtained by different proportions of ceramic powder, aluminum powder and aluminum hydroxide have different improvement effects on the crack resistance of concrete, among which the concrete obtained by the modified fiber of Preparation Example 1 used in Example 2 has the best crack resistance.

[0099] In the present application, an ethanol-water solution is used as a dispersant to disperse the sintered particles to form a slurry, and the glass fiber being pulled is sprayed with particles. Water has good adhesion to the sintered particles and is easy to form a slurry, while ethanol is volatile and can dry quickly after spraying, and then stably attach to the surface of the glass fiber to form particles, thereby increasing the number of sintered particles embedded in the sintering and enhancing the bonding strength between the modified glass fiber and the concrete base material. Combining Example 2 and Example 8, the concrete crack resistance of Example 2 is better than that of Example 8.

[0100] In addition, during the research process of this application, based on the improved method of this application, a small amount of copper sulfate is attached to the surface of the initial glass fiber and then dried at 380-400°C to form metal oxide attachment on its surface, which can further improve the slurry particle hanging effect, increase the number of sintered particles embedded in the sintering, and enhance the bonding strength between the modified glass fiber and the concrete base material. As shown in the scheme of Example 9, the resulting concrete has better crack resistance than Example 2.

[0101] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A crack-resistant concrete, characterized in that: Including the following raw materials by weight: 303~398 parts of cement; 363~476 parts of sand; Aggregate 636~830 parts; 180-239 parts water; 1.9~2.5 parts of water reducer; Modified glass fiber 61.3~72.4 parts; The sand particle size distribution is 0.02~2mm, Aggregate grading is 4~12cm; The surface of the modified glass is melted and semi-embedded with sintered particles with a particle size of 15 to 16 μm, and the sintered particles are a mixture of ceramic powder, metal, and metal oxide; The modified glass fiber is 4~5cm long and has a body diameter of 0.2±0.05mm.

2. The crack-resistant concrete according to claim 1, characterized in that: The sintered particles are obtained by sintering ceramic powder, aluminum powder and aluminum hydroxide.

3. The crack-resistant concrete according to claim 1, characterized in that: The sintered particles are obtained by sintering a mixture of ceramic powder, aluminum powder and aluminum hydroxide gel solution.

4. The crack-resistant concrete according to claim 1, characterized in that: The preparation method of sintered particles is as follows: Aluminum powder with a particle size of 0.5~1μm is added to aluminum hydroxide gel solution and mixed evenly. Then ceramic powder with a particle size of 4~5μm is added. After mixing evenly, it is heated to 60℃ and stirred continuously to evaporate the water until the water content of the material drops to 42wt%. Sintered particles are obtained by spray granulation, dried, and then sintered at 660℃ to a density of 1.86~1.89g / cm 3 The sintered material is then crushed to obtain sintered particles.

5. The crack-resistant concrete according to claim 4, characterized in that: The mass ratio of aluminum powder, aluminum hydroxide and ceramic powder is 0.3:0.2:

1.

6. The crack-resistant concrete according to claim 4, characterized in that: The preparation method of modified glass fiber is as follows: The sintered powder is dispersed in an ethanol aqueous solution and sprayed onto the surface of the initial glass fiber. The initial glass fiber surface is then sintered at 400-500°C, and the sintered powder is sintered and semi-embedded into the initial glass fiber surface to obtain a modified glass fiber.

7. The crack-resistant concrete according to claim 6, characterized in that: The surface of the initial glass fiber is first sprayed with a 0.08 mol / L copper sulfate aqueous solution, and then dried at 380-400° C. before being sprayed with a slurry mist.

8. The process for preparing crack-resistant concrete according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing cement, sand, aggregate, water and water reducing agent evenly, adding modified glass fiber and mixing evenly again.

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