A self-setting metal slag fiber-reinforced concrete

Abstract

The present invention provides a self-setting metal slag fiber-reinforced concrete, which is composed of water, cement, sand, gravel, isobutene, benzoyl peroxide, maleic anhydride, N,N-dimethylformamide, metal slag fibers, and silicate. Among them, the alternating copolymer of isobutene and maleic anhydride is used to accelerate the setting speed of the self-setting metal slag fiber-reinforced concrete, and it contains a large number of -COO- groups, which can make the surface of the metal slag fibers carry negative charges, enhance the dispersibility of the self-setting metal slag fiber-reinforced concrete, and make the structural components of each part of the prepared self-setting metal slag fiber-reinforced concrete uniform and stable; metal fibers are used to make them uniformly dispersed in the concrete to enhance the impact resistance of the concrete; the preparation process of the present invention is simple and has strong versatility, suitable for mass production in factories; the self-setting metal slag fiber-reinforced concrete prepared by this method has the effects of fast drying speed and high strength.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and in particular to a self-setting metal slag fiber reinforced concrete. Background Art

[0002] Concrete is commonly used in construction and road construction. The initial setting time of the existing concrete is about 2 - 4 hours, and it takes 24 - 48 hours to completely solidify; the distance between rural houses is small, and often a 1-meter-wide road leads to dozens of households. If there is road damage or due to pipeline renovation needs, it is obviously unrealistic to require villagers to wait for 48 hours without passing through this section after laying concrete; therefore, it is necessary to solve the problem of how to shorten the repair time; furthermore, the existing concrete often shows depressions after being used for 1 month. The reason is that the strength is not enough, resulting in depressions after being pressed by heavy objects in the initial stage.

[0003] Therefore, it is necessary to provide a concrete material that can solidify quickly and improve the strength. Summary of the Invention

[0004] In order to solve the technical problems of slow drying speed and low strength of concrete in the prior art, the present invention provides a self-setting metal slag fiber reinforced concrete that can solidify quickly and improve the strength.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A self-setting metal slag fiber reinforced concrete, by weight, consists of 170 - 200 parts of water, 300 - 500 parts of cement, 200 - 300 parts of sand, 1200 - 1300 parts of gravel, 40 - 500 parts of isobutene, 2.5 - 10 parts of benzoyl peroxide, 80 - 100 parts of maleic anhydride, 2.5 - 10 parts of N,N-dimethylformamide, 200 - 300 parts of metal slag fiber, and 80 - 120 parts of silicate; the particle size of the metal slag fiber is 45 - 150 μm;

[0007] Among them, the preparation method of the self-setting metal slag fiber reinforced concrete is as follows: [[ID=,]]

[0008] S1. In a 2L high-pressure reactor, dissolve benzoyl peroxide and N,N-dimethylformamide in 1 / 4 volume of water, and then add them to isobutene in batches through a dropping pump for mixing reaction to obtain a pre-mixture A;

[0009] S2. Add maleic anhydride to the pre-mixture A1, replace the gas with nitrogen 3 times, then pressurize to 0.3 - 0.5 MPa, raise the temperature to 60 - 80 °C, and stir evenly at 80 - 120 r / min to obtain a pre-mixture B;

[0010] S3. Slowly add metal slag fibers to premix B while stirring to obtain premix C;

[0011] S4. Mix the remaining 3 / 4 of water, cement, sand, gravel, and silicate evenly, and then add them to premix C obtained in S3 and stir evenly to obtain self-setting metal slag fiber-reinforced concrete.

[0012] The self-setting metal slag fiber-reinforced concrete prepared by this method has the effects of fast drying speed and high strength.

[0013] Metal slag fibers can effectively enhance the strength and performance of concrete. Specifically, they enhance the impact resistance and fatigue resistance of concrete, thereby increasing its strength. Metal fibers can effectively absorb and disperse impact energy, prevent the crushing and spalling of concrete, and enable concrete to better maintain integrity and stability under impact loads. Moreover, by evenly distributing metal fibers in concrete, the toughness and durability of concrete are enhanced, enabling it to have better fatigue resistance under long-term cyclic loads.

[0014] Similarly, silicate also has the role of assisting in enhancing the strength of self-setting metal slag fiber-reinforced concrete. Specifically, the calcium-silicate ratio of the calcium silicate is 0.8 - 0.85, and the content of silicon is higher than that of oxygen, resulting in a more rigid finished product.

[0015] To accelerate the setting speed of the concrete protected by the present invention, an alternating copolymer of isobutene and maleic anhydride is prepared as a dispersant.

[0016] The alternating copolymer of isobutene and maleic anhydride prepared using the formula of the present invention has a molecular weight of 5000 - 6000. The molecular structure of the alternating copolymer of isobutene and maleic anhydride contains a large number of -COO- groups, which can make the surface of metal slag fibers carry negative charges, so it has strong dispersibility. Therefore, the self-setting metal slag fiber-reinforced concrete system of the present invention has good dispersibility and can support the uniform distribution of metal fibers in the system.

[0017] Further, the metal slag fiber is one or more of aluminum slag fiber, nickel slag fiber, or aluminum-nickel alloy fiber;

[0018] Further, the particle size of the metal slag fiber is 45 - 150 μm.

[0019] It can be seen from Examples 1 - 2 that when the particle size of the metal fiber is 45 - 150 μm, it has a significant impact on the hardness of the prepared self-setting metal slag fiber-reinforced concrete.

[0020] Further, the silicate is calcium silicate. In the present invention, calcium silicate is used as a filler to further increase the strength of the self-setting metal slag fiber-reinforced concrete. Specifically, the particle size of the calcium silicate is 1500 - 1250 mesh.

[0021] Further, the cement is grade II fly ash cement.

[0022] Fly ash cement sets and hardens slowly, has low early strength, but high late strength, and can even catch up with or significantly exceed Portland cement in the later stage; and its specific surface area is 300 - 350 cm² / g, which helps to start the hydration reaction faster, thus forming higher strength in the early stage. Therefore, the self-setting metal slag fiber-reinforced concrete prepared has a small water absorption capacity, small dry shrinkage, strong crack resistance, and high strength.

[0023] Further, the specific surface area of the silicate is 400 - 450 m² / kg.

[0024] Specifically, the heating method in S2 is the segmented heating method. Starting from 40°C, for every 1°C increase in temperature, this section of temperature is maintained and heated for 3 - 4 minutes.

[0025] Segmented heating can better control the reaction rate and reaction uniformity of maleic anhydride, nitrogen, and other components in the system, thereby improving the reaction efficiency and obtaining a more ideal finished product.

[0026] The present invention has the following advantages over the prior art:

[0027] 1. A self-setting metal slag fiber-reinforced concrete provided by the present application uses an isobutene and maleic anhydride alternating copolymer to accelerate the setting speed of the self-setting metal slag fiber-reinforced concrete, and contains a large number of -COO- groups, which can make the surface of the metal slag fiber carry negative charges, enhancing the dispersibility of the self-setting metal slag fiber-reinforced concrete, making the structure components of each part of the prepared self-setting metal slag fiber-reinforced concrete uniform and stable; using metal fibers to uniformly disperse them in the concrete to enhance the impact resistance and fatigue resistance of the concrete, thereby improving the strength of the concrete, so that the self-setting metal slag fiber-reinforced concrete has better fatigue resistance under long-term cyclic loading.

[0028] In a high-pressure reactor, first dissolve benzoyl peroxide and N,N-dimethylformamide in water, then add them to isobutene in batches, then add maleic anhydride, and after the nitrogen replacement procedure, add the remaining materials and mix them evenly; the preparation process is simple, has strong versatility, and is suitable for factory batch production; the self-setting metal slag fiber-reinforced concrete prepared by this method has the effects of fast drying speed and high strength. Specific embodiments

[0029] The specific technical solutions of the present invention will be described below in conjunction with specific Examples 1-5:

[0030] The following is the raw material information used in the embodiments of the present invention:

[0031] Cement (grade classification: PO42.5R, brand: China Resources Cement);

[0032] Fly ash cement (P.C 32.5R, brand: Sanhu Cement);

[0033] Sand (particle size in Zone II, strength less than C30);

[0034] Gravel (basalt produced by Shijiazhuang Hongshuo Mineral Products Co., Ltd.);

[0035] Maleic anhydride (purity ≥ 99.5%, industrial product, brand: Jieao);

[0036] Isobutene (purity ≥ 99.5%, industrial product, brand: Huibao);

[0037] Benzoyl peroxide (content: 74 - 76%, analytical pure, produced by Jinan Guochen Taifu Chemical Co., Ltd.);

[0038] N,N-Dimethylformamide (purity ≥ 99.5%, produced by Wuhan Jixin Yibang Biotechnology Co., Ltd.);

[0039] Calcium silicate (purity ≥ 97%, industrial product, produced by Shijiazhuang Lishang Mineral Products Processing Co., Ltd.).

[0040] Example 1:

[0041] S1. In a 2L high-pressure reactor, 2.5 parts of benzoyl peroxide and 2.5 parts of N,N-dimethylformamide are dissolved in 42.5 parts of water and then added to 40 parts of isobutene in batches through a dropping pump for mixing reaction to obtain a premix A1;

[0042] S2. 90 parts of maleic anhydride are added to the premix A1. After purging with nitrogen 3 times, the pressure is increased to 0.3 MPa, the temperature is raised to 60 °C, and stirring is carried out at 80 r / min for 19 minutes to obtain a premix B1;

[0043] S3. While stirring, 200 parts of aluminum slag fibers with a particle size of 45 μm are slowly added to the premix B1 until the aluminum slag fibers are evenly distributed in the premix B1 to obtain a premix C1;

[0044] S4. Mix 127.5 parts of the remaining water, 300 parts of cement, 200 parts of sand, 1200 parts of gravel, and 90 parts of calcium silicate with a specific surface area of 450 m² / kg evenly, and then add them to the pre-mixture C1 prepared in S3 and stir evenly to obtain self-setting metal slag fiber-reinforced concrete D1.

[0045] Example 2:

[0046] S1. In a 2-L high-pressure reactor, dissolve 2.5 parts of benzoyl peroxide and 2.5 parts of N,N-dimethylformamide in 42.5 parts of water, and then add them to 40 parts of isobutene in batches through a dropping pump for mixing reaction to obtain pre-mixture A2;

[0047] S2. Add 90 parts of maleic anhydride to the pre-mixture A2. After displacing with nitrogen 3 times, pressurize to 0.3 MPa, raise the temperature to 60 °C, and stir at 100 r / min for 15 minutes to obtain pre-mixture B2;

[0048] S3. Slowly add 200 parts of aluminum slag fibers with a particle size of 30 μm to the pre-mixture B2 while stirring until the aluminum slag fibers are evenly distributed in the pre-mixture B2 to obtain pre-mixture C2;

[0049] S4. Mix 127.5 parts of the remaining water, 300 parts of cement, 200 parts of sand, 1200 parts of gravel, and 90 parts of calcium silicate with a specific surface area of 450 m² / kg evenly, and then add them to the pre-mixture C2 prepared in S3 and stir evenly to obtain self-setting metal slag fiber-reinforced concrete D2.

[0050] Example 3:

[0051] S1. In a 2-L high-pressure reactor, dissolve 10 parts of benzoyl peroxide and 10 parts of N,N-dimethylformamide in 50 parts of water, and then add them to 300 parts of isobutene in batches through a dropping pump for mixing reaction to obtain pre-mixture A3;

[0052] S2. Add 80 parts of maleic anhydride to the pre-mixture A3. After displacing with nitrogen 3 times, pressurize to 0.5 MPa, raise the temperature to 80 °C, and maintain this temperature for 4 minutes every time the temperature is raised by 10 °C starting from 40 °C, and stir at 80 r / min for 20 minutes to obtain pre-mixture B3;

[0053] S3. Slowly add 200 parts of nickel slag fibers with a particle size of 75 μm to the pre-mixture B3 while stirring until the nickel slag fibers are evenly distributed in the pre-mixture B3 to obtain pre-mixture C3;

[0054] S4. After uniformly mixing the remaining 150 parts of water, 400 parts of cement, 300 parts of sand, 1200 parts of gravel, and 120 parts of calcium silicate with a specific surface area of 400 m² / kg, add them to the pre-mixture C3 prepared in S3 and stir evenly to obtain self-setting metal slag fiber-reinforced concrete D3.

[0055] Example 4:

[0056] S1. In a 2-L high-pressure reactor, dissolve 7.5 parts of benzoyl peroxide and 7.5 parts of N,N-dimethylformamide in 50 parts of water, and then add them to 500 parts of isobutene in batches through a dropping pump for mixing reaction to obtain pre-mixture A4.

[0057] S2. Add 100 parts of maleic anhydride to the pre-mixture A4. After displacing with nitrogen 3 times, pressurize to 0.5 MPa, raise the temperature to 60 °C, start heating at 40 °C and maintain this temperature for 3 minutes every time the temperature is raised by 10 °C, and stir at 120 r / min for 25 minutes to obtain pre-mixture B4.

[0058] S3. While stirring, slowly add 300 parts of a mixture of nickel slag fibers and aluminum-nickel alloy fibers with a particle size of 150 μm to the pre-mixture B4 until the mixture of nickel slag fibers and aluminum-nickel alloy fibers is evenly distributed in the pre-mixture B4 to obtain pre-mixture C4.

[0059] S4. After uniformly mixing the 150 parts of water, 500 parts of cement, 300 parts of sand, 1300 parts of gravel, and 120 parts of aluminum silicate with a specific surface area of 450 m² / kg, add them to the pre-mixture C4 prepared in S3 and stir evenly to obtain self-setting metal slag fiber-reinforced concrete D4.

[0060] Example 5:

[0061] S1. In a 2-L high-pressure reactor, dissolve 7.5 parts of benzoyl peroxide and 7.5 parts of N,N-dimethylformamide in 50 parts of water, and then add them to 500 parts of isobutene in batches through a dropping pump for mixing reaction to obtain pre-mixture A5.

[0062] S2. Add 100 parts of maleic anhydride to the pre-mixture A5. After displacing with nitrogen 3 times, pressurize to 0.5 MPa, raise the temperature to 60 °C, and stir evenly at 120 r / min to obtain pre-mixture B5.

[0063] S3. While stirring, slowly add 300 parts of a mixture of nickel slag fibers and aluminum-nickel alloy fibers with a particle size of 150 μm to the pre-mixture B5 until the mixture of nickel slag fibers and aluminum-nickel alloy fibers is evenly distributed in the pre-mixture B5 to obtain pre-mixture C5.

[0064] S4. Mix 150 parts of water, 500 parts of cement, 300 parts of sand, 1300 parts of gravel, and 120 parts of aluminum silicate with a specific surface area of 300 m² / kg evenly, and then add the mixture to the pre-mixture C5 obtained in S3 and stir evenly to obtain self-setting metal slag fiber-reinforced concrete D5.

[0065] The present invention adopts the following method to test the technical effects of Examples 1-5:

[0066] Conduct a crack resistance test on the self-setting metal slag fiber-reinforced concrete required to be protected in Examples 1-5. The size of all specimens is 700 mm × 700 mm × 50 mm. Refer to the standard GB / T50081-2002 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" to conduct concrete strength tests.

[0067] Determine the setting effect of the present invention by measuring the final setting time of the self-setting metal slag fiber-reinforced concrete required to be protected in the present invention. The judgment method for the setting time cut-off point is: use a steel needle to press a mark on the surface of the concrete of the present invention. When the steel needle no longer leaves a mark on the concrete surface, this is the final setting time.

[0068] The experimental data for concrete strength and setting effect are as follows:

[0069]

[0070] Table 1

[0071] As can be seen from the above table in Examples 1-5, in the self-setting metal slag fiber-reinforced concrete required to be protected in the present invention, the hardness is high, the impact resistance is strong, and the setting time is significantly reduced compared to the setting time required for ordinary cement (which requires 24-48 hours of setting). By comparing Examples 1-4 and Example 5 of the present invention, it can be concluded that when the specific surface area range of silicate falls within 400-450 m² / kg, the obtained self-setting metal slag fiber-reinforced concrete has good strength, strong compressive resistance and impact resistance.

[0072] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A self-setting metal slag fiber-reinforced concrete, characterized in that, By weight, it consists of 170 - 200 parts of water, 300 - 500 parts of cement, 200 - 300 parts of sand, 1200 - 1300 parts of stone, 40 - 500 parts of isobutene, 2.5 - 10 parts of benzoyl peroxide, 80 - 100 parts of maleic anhydride, 2.5 - 10 parts of N,N-dimethylformamide, 200 - 300 parts of metal slag fiber, and 80 - 120 parts of silicate; The particle size of the metal slag fiber is 45 - 150 μm; Among them, the preparation method of self-setting metal slag fiber reinforced concrete is as follows: S1. Add benzoyl peroxide and N,N-dimethylformamide to isobutene in batches, mix and react to obtain premix A; S2. Add maleic anhydride to the premix A, replace with nitrogen, then pressurize at 0.3 - 0.5 MPa, stir at 80 - 120 r / min at 60 - 80 °C for 15 - 25 minutes to obtain premix B; S3. Slowly add metal slag fiber to the premix B while stirring to obtain premix C; S4. Mix the water, cement, sand, stone, and silicate evenly, and then add them to the premix C prepared in S3 and stir evenly to obtain a finished product of self-setting metal slag fiber reinforced concrete.

2. The self-setting metal slag fiber reinforced concrete according to claim 1, characterized in that: The metal slag fiber is one or more of aluminum slag fiber, nickel slag fiber, or aluminum-nickel alloy fiber.

3. The self-setting metal slag fiber-reinforced concrete according to claim 1, characterized in that: The sand is river sand with a particle size of 1 - 4 mm.

4. The self-setting metal slag fiber reinforced concrete according to claim 1, wherein: The silicate is calcium silicate, and the calcium-silicon ratio of the calcium silicate is 0.8 - 0.

85.

5. The self-setting metal slag fiber-reinforced concrete according to claim 1, wherein: The cement is grade II fly ash cement with an internal specific surface area of 300 - 350 cm² / g.

6. The self-curing metal slag fiber-reinforced concrete according to claim 4, characterized in that: The specific surface area of the silicate is 400 - 450 m² / kg.

7. The self-curing metal slag fiber-reinforced concrete according to claim 1, wherein: The stirring rate in S3 is 80 - 100 r / min.

8. The self-curing metal slag fiber-reinforced concrete according to claim 1, wherein: The heating method for temperature increase in S2 is the stepwise heating method, starting from 40 °C, maintaining the temperature of each 10 °C increase for 3 - 4 minutes.

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