High-strength environment-friendly concrete with high adaptive viscosity and preparation method thereof

Abstract

The invention provides high-strength environment-friendly concrete with high adaptive viscosity and a preparation method thereof, and belongs to the technical field of concrete. The concrete comprises the following raw materials in parts by weight: 300-350 parts of cement; 43-58 parts of mineral powder; 20 to 35 parts of fly ash; 15-25 parts of rice hull ash; 800 to 855 parts of sand; 800 to 1000 parts of stone; 25-35 parts of an expanding agent; 180 to 220 parts of water; 8-10 parts of a water reducing agent; 7-12 parts of an air entraining agent; 24 to 36 parts of composite fiber; 20 to 30 parts of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules; the concrete provided by the invention has various advantages, and is excellent in strength, compressive strength, environmental protection performance and adaptive viscosity. And the composite fibers and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules cooperate with each other, so that the internal structure of the concrete is further optimized, and the overall performance is enhanced.

Description

Technical Field

[0001] The present application belongs to the technical field of concrete, and specifically relates to a high-strength environmentally friendly concrete with high adaptive viscosity and a preparation method thereof. Background Art

[0002] In the construction field, high-strength concrete, with its high density and strength, has greatly extended the service life of concrete structures and is widely used in high-rise structures and harsh environments. However, the high amount of cementitious materials and low water-cement ratio of high-strength concrete lead to high hydration heat, large shrinkage deformation, and significantly increased cracking risk. Once cracked, the concrete's impermeability decreases, and as the concrete continues to deteriorate, the compressive strength also decreases.

[0003] At present, the main technical means to improve the crack resistance of high-strength concrete focus on reducing concrete shrinkage and adiabatic temperature rise. In terms of reducing shrinkage, although there are methods such as adding highly absorbent resins and shrinkage reducers, the cost of highly absorbent resins and shrinkage reducers is relatively high, and they have not yet been promoted on a large scale. In addition, the existing technical means are relatively single and lack systematicity. In terms of reducing adiabatic temperature rise, the main methods include reducing the amount of cement, adding hydration heat inhibitors, and adding large amounts of mineral admixtures. However, the cost of hydration heat inhibitors is high. Although reducing the amount of cement and adding large amounts of mineral admixtures can reduce the adiabatic temperature rise, it will lose the early strength of concrete, and the quality stability of the admixtures is high. Therefore, it is urgent to develop a concrete that has crack resistance and high strength at the same time. Summary of the invention

[0004] In order to solve the problem that existing concrete is difficult to maintain high strength while having excellent crack resistance, compressive strength and pumping performance, the present application provides a high-strength environmentally friendly concrete with high adaptive viscosity and a preparation method thereof.

[0005] In the first aspect, the present application provides a high-strength environmentally friendly concrete with high adaptive viscosity, wherein the concrete comprises the following raw materials by weight: 300-350 parts of cement; 43-58 parts of mineral powder; 20-35 parts of fly ash; 15-25 parts of rice husk ash; 800-855 parts of sand; 800-1000 parts of gravel; 25-35 parts of expansion agent; 180-220 parts of water; 8-10 parts of water reducer; 7-12 parts of air entraining agent; 24-36 parts of composite fiber; 20-30 parts of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules; the composite fiber comprises polypropylene fiber and chitosan fiber in a weight ratio of 1.5-2:1.

[0006] By adopting the above technical scheme, the technical scheme provided by the present application solves the problem that the existing concrete is difficult to balance crack resistance, compressive strength and pumping performance while maintaining high strength. It can enhance the crack resistance, compressive strength and pumping performance of concrete through the synergistic effect of composite fiber and polyethylene glycol diacrylate-butyl rubber composite core microcapsules on the basis of improving the strength of concrete. In this technical scheme, the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core microcapsules cooperate with each other to have a positive impact on the overall performance of concrete. The polypropylene fiber and chitosan fiber in the composite fiber are combined in a specific proportion to exert a synergistic effect. Polypropylene fiber enhances the toughness of concrete, making it less likely to crack when the concrete is under pressure; chitosan fiber is rich in polar groups such as hydroxyl and amino groups, making it hydrophilic. When it is evenly dispersed in concrete, it will have a strong affinity with water molecules, and water molecules will adhere to the fiber surface instead of randomly gathering to form a continuous water flow channel, which can reduce the probability of leakage channels due to water accumulation and improve impermeability. In addition, during the preparation and mixing of concrete, there will be some fine impurity particles inside. Chitosan fiber absorbs these particles by virtue of its adsorption and fills the tiny pores that may have existed originally, making the internal microstructure of concrete more compact, and making it more difficult for external moisture, salt and other substances to penetrate, thereby effectively enhancing the anti-permeability of concrete. And it cooperates and synergizes with components such as cement, sand and gravel and other additives to jointly improve the anti-permeability of concrete. Polyethylene glycol diacrylate-butyl rubber composite core material microcapsules form a unique microstructure inside the concrete, which interacts with the composite fibers to further enhance the crack resistance of the concrete. The presence of microcapsules increases the elasticity and deformation capacity of concrete, enabling the concrete to better absorb energy and reduce the occurrence of cracks when subjected to external pressure or temperature changes. At the same time, the combined action of composite fibers and polyethylene glycol diacrylate-butyl rubber composite core material microcapsules also improves the compressive strength of concrete. They not only improve the anti-permeability of concrete, but also prevent chemical erosion inside the concrete to a certain extent, extending the service life of concrete. At the same time, in the construction field, the production process of traditional concrete is often accompanied by a large amount of resource consumption and environmental pollution. With the increasing global attention to sustainable development, the development of environmentally friendly building materials has become an important trend in the industry. Therefore, in order to meet these environmental challenges, this application uses rice husk ash in this application. The use of rice husk ash can reduce the environmental pollution caused by incineration and realize the recycling of resources. In addition, this application optimizes the ratio and performance of raw materials so that the concrete can meet the fluidity requirements during the pumping process while maintaining a high adaptive viscosity, ensuring that the concrete can be smoothly transported to the designated location during the construction process.In summary, the technical solution provided in this application achieves a comprehensive improvement in the high strength, crack resistance, compressive strength and pumping performance of concrete through the synergistic effect of various components, providing a concrete material with more advantages and practical value for construction projects.

[0007] Optionally, the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule is prepared by the following method; S1. Adding polyethylene glycol diacrylate and butyl rubber particles in a weight ratio of 1-3:1 to an emulsifier solution of sodium lauryl sulfate, stirring evenly, to prepare a mixed emulsion; S2, adding sodium metabisulfite and ammonium persulfate to the mixed emulsion in step S1, and reacting at 75° C.-80° C. for 2-3 hours to obtain a core material emulsion; the weight ratio of the mixed emulsion, sodium metabisulfite and ammonium persulfate in step S2 is 100:1-1.5:1; S3, mixing gelatin and gum arabic in water, heating to 65°C-70°C, stirring for 20-30 minutes to dissolve, and then adding glutaraldehyde and stirring to obtain a wall material solution; in step S3, the weight ratio of gelatin, gum arabic and glutaraldehyde is 10-15:8-10:2-3; S4, mixing the core material emulsion and the wall material solution in a weight ratio of 3:2, stirring evenly, and then using a spray drying method to allow the wall material to wrap the core material to form the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule.

[0008] By adopting the above technical scheme, the present application successfully solves the problem that the existing high-strength concrete is difficult to take into account crack resistance and compressive strength while maintaining high strength. The preparation process of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules allows polyethylene glycol diacrylate and butyl rubber particles to be fully mixed and cross-linked to form a stable core material structure. The sodium dodecyl sulfate emulsifier solution ensures that the core material is evenly dispersed, and the wall material formed by gelatin, gum arabic and glutaraldehyde wraps the core material, giving the microcapsules good stability and structure. The microcapsules absorb energy, reduce cracks, and improve the impermeability of concrete inside the concrete, and work together with the composite fibers to enhance the crack resistance and compressive strength of the concrete. The wall material of the microcapsule effectively blocks moisture and foreign substances, further improving the impermeability of the concrete. At the same time, its elastic structure can buffer stress when the concrete is subjected to external pressure or temperature changes, reducing the formation of cracks. Under the synergistic effect with the composite fiber, the microcapsule and the composite fiber jointly optimize the internal humidity environment and density of the concrete, improve the overall performance of the concrete, and extend the service life of the concrete.

[0009] Optionally, the stirring speed in step S1 is 300-500 r / min, and the stirring time is 30-45 min.

[0010] Optionally, the percentage of sodium dodecyl sulfate in the sodium dodecyl sulfate emulsifier solution in step S1 is 2%-5%.

[0011] Optionally, the spray drying parameters in step S4 are as follows: spray pressure is 0.5-1MPa, air inlet temperature is 120-150°C, air outlet temperature is 80-100°C, and feed rate is 5-10 ml / min; the average particle size of the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 25μm.

[0012] Optionally, the weight ratio of the composite fiber to the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule is 1-1.5:1.

[0013] By adopting the above technical solution, in the concrete system, the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules act together on the concrete. With its high strength and toughness, the composite fiber forms a tightly interwoven network structure inside the concrete, enhancing the overall strength and toughness of the concrete. The polyethylene glycol diacrylate-butyl rubber composite core material microcapsules form a tiny elastic structure inside the concrete, absorbing energy, relieving stress concentration, and reducing the generation of cracks. At the same time, its wall material effectively blocks moisture and foreign substances, improving the impermeability of the concrete. The two cooperate with each other, and the network structure of the composite fiber and the elastic structure of the microcapsule complement each other. The energy absorbed by the microcapsule is transferred to the composite fiber, so that the composite fiber can better play a reinforcing role; the composite fiber helps the microcapsule to be better dispersed in the concrete, further optimizing the humidity environment and density inside the concrete. This joint action allows the concrete to significantly improve the crack resistance and compressive strength while maintaining high strength.

[0014] Preferably, the weight ratio of the composite fiber to the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule is 1.2:1.

[0015] Optionally, the expansion agent is a calcium sulphoaluminate expansion agent; the water reducer is a polycarboxylic acid-based water reducer; and the air entraining agent is a rosin-based air entraining agent.

[0016] Optionally, the composite fiber is a coupling agent modified composite fiber.

[0017] By adopting the above technical scheme, the interaction between the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules can be further enhanced. The coupling agent can form a special interface layer on the surface of the composite fiber. On the one hand, this interface layer can chemically react with the surface of the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules to enhance the binding force between the microcapsules and the composite fiber; on the other hand, it can improve the compatibility between the composite fiber and the concrete matrix, so that the composite fiber can be better dispersed and play a role in the concrete. This modified composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules act together on the concrete, which helps to improve the overall performance of the concrete. The high strength and toughness of the composite fiber cooperate with the elastic structure of the microcapsules to further enhance the crack resistance and compressive strength of the concrete. The microcapsules optimize the humidity environment and density inside the concrete by absorbing energy, reducing the generation of cracks, and improving the impermeability of the concrete. At the same time, the coupling agent-modified composite fiber can also improve the processability and stability of the concrete, making the concrete easier to operate and shape during the construction process, providing a more reliable guarantee for the application of concrete in construction projects.

[0018] In a second aspect, the present application provides a method for preparing concrete, the preparation method comprising the following steps: A1. Add cement, mineral powder, fly ash, rice husk ash, sand, gravel, expansion agent, composite fiber, polyethylene glycol diacrylate-butyl rubber composite core material into a mixing device in sequence and mix evenly; A2, adding water, water reducing agent and air entraining agent to the mixture in step A1, and stirring evenly; A3, pouring the stirred mixture into a mold, vibrating and molding, and curing to obtain the concrete.

[0019] By adopting the above technical solution, the preparation method provided by this application is simple and efficient. The raw materials are mixed and stirred evenly according to the steps, so that the concrete can be fully integrated and ensure that each component plays a role. Vibration molding makes the concrete dense, and the strength and compressive strength after curing are improved. The overall performance is good, which meets the various requirements of construction projects for concrete.

[0020] In summary, the present application has at least one of the following beneficial effects: 1. The technical solution provided by the present application solves the problem that the existing concrete is difficult to balance crack resistance, compressive strength and pumping performance while maintaining high strength. On the basis of improving the strength of concrete, the crack resistance, compressive strength and pumping performance of concrete can be enhanced through the synergistic effect of composite fibers and polyethylene glycol diacrylate-butyl rubber composite core material microcapsules. In this technical solution, the composite fibers and polyethylene glycol diacrylate-butyl rubber composite core material microcapsules cooperate with each other to have a positive impact on the overall performance of concrete. The polypropylene fiber and chitosan fiber in the composite fiber are combined in a specific proportion to exert a synergistic effect. Polypropylene fiber enhances the toughness of concrete, making it less likely to crack when the concrete is under pressure; chitosan fiber is rich in polar groups such as hydroxyl and amino groups, making it hydrophilic. When it is evenly dispersed in concrete, it will have a strong affinity with water molecules, and water molecules will adhere to the fiber surface instead of randomly gathering to form a continuous water flow channel, which can reduce the probability of leakage channels due to water accumulation and improve impermeability. In addition, during the preparation and mixing of concrete, there will be some fine impurity particles inside. Chitosan fiber absorbs these particles by virtue of its adsorption and fills the tiny pores that may have existed originally, making the internal microstructure of concrete more compact, and making it more difficult for external moisture, salt and other substances to penetrate, thereby effectively enhancing the anti-permeability of concrete. And it cooperates and synergizes with components such as cement, sand and gravel and other additives to jointly improve the anti-permeability of concrete. Polyethylene glycol diacrylate-butyl rubber composite core material microcapsules form a unique microstructure inside the concrete, which interacts with the composite fibers to further enhance the crack resistance of the concrete. The presence of microcapsules increases the elasticity and deformation capacity of concrete, enabling the concrete to better absorb energy and reduce the occurrence of cracks when subjected to external pressure or temperature changes. At the same time, the combined action of composite fibers and polyethylene glycol diacrylate-butyl rubber composite core material microcapsules also improves the compressive strength of concrete. They not only improve the anti-permeability of concrete, but also prevent chemical erosion inside the concrete to a certain extent, extending the service life of concrete. In addition, this application optimizes the ratio and performance of raw materials so that the concrete can meet the fluidity requirements during the pumping process while maintaining a high adaptive viscosity, ensuring that the concrete can be smoothly transported to the designated location during the construction process.

[0021] 2. Composite fibers and polyethylene glycol diacrylate-butyl rubber composite core material microcapsules work together on concrete. With its high strength and toughness, the composite fibers form a tightly interwoven network structure inside the concrete, enhancing the overall strength and toughness of the concrete. Polyethylene glycol diacrylate-butyl rubber composite core material microcapsules form tiny elastic structures inside the concrete, absorbing energy, relieving stress concentration, and reducing cracks. At the same time, its wall material effectively blocks moisture and foreign substances, improving the impermeability of concrete. The two work together, and the network structure of the composite fibers and the elastic structure of the microcapsules complement each other. The energy absorbed by the microcapsules is transferred to the composite fibers, allowing the composite fibers to better play a reinforcing role; the composite fibers help the microcapsules to be better dispersed in the concrete, further optimizing the humidity environment and density inside the concrete. This combined effect allows the concrete to significantly improve its crack resistance and compressive strength while maintaining high strength.

[0022] 3. The preparation process of polyethylene glycol diacrylate-butyl rubber composite core microcapsules allows polyethylene glycol diacrylate and butyl rubber particles to be fully mixed and cross-linked to form a stable core material structure. The sodium dodecyl sulfate emulsifier solution ensures the uniform dispersion of the core material, and the wall material formed by gelatin, gum arabic and glutaraldehyde wraps the core material, giving the microcapsules good stability and structure. The microcapsules absorb energy, reduce cracks, and improve the impermeability of concrete inside the concrete, and work together with the composite fibers to enhance the crack resistance and compressive strength of the concrete. The wall material of the microcapsule effectively blocks moisture and foreign substances, further improving the impermeability of the concrete. At the same time, its elastic structure can buffer stress when the concrete is subjected to external pressure or temperature changes, reducing the formation of cracks. Under the synergistic effect of the composite fiber, the microcapsule and the composite fiber jointly optimize the internal humidity environment and density of the concrete, improve the overall performance of the concrete, and extend the service life of the concrete.

[0023] 4. The concrete provided by this application has many advantages, and performs well in strength, compressive strength, environmental performance and adaptive viscosity. The use of materials such as rice husk ash effectively reduces the environmental load, not only reducing the consumption of natural resources, but also reducing waste emissions. The composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules work together to further optimize the internal structure of the concrete and enhance the overall performance. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0025] In the field of construction, high-strength concrete, with its high density and strength, has greatly extended the service life of concrete structures and is widely used in high-rise structures and harsh environments. However, the high amount of cementitious materials and low water-cement ratio of high-strength concrete lead to high hydration heat, large shrinkage deformation, and significantly increased cracking risk. Once cracked, the impermeability of concrete decreases, and as the concrete deteriorates continuously, the compressive strength also decreases. At present, the main technical means to improve the crack resistance of high-strength concrete focus on reducing concrete shrinkage and adiabatic temperature rise. In terms of reducing shrinkage, although there are methods such as adding highly absorbent resins and shrinkage reducers, the cost of highly absorbent resins and shrinkage reducers is relatively high and has not yet been promoted on a large scale. In addition, the existing technical means are relatively single and lack of systematicity. In terms of reducing adiabatic temperature rise, the main methods include reducing the amount of cement, adding hydration heat inhibitors, and adding large amounts of mineral admixtures. However, the cost of hydration heat inhibitors is high. Although reducing the amount of cement and adding large amounts of mineral admixtures can reduce the adiabatic temperature rise, it will lose the early strength of concrete and require high stability of admixture quality. Therefore, there is an urgent need to develop a concrete that has crack resistance and high strength.

[0026] Therefore, in order to solve the problem that the existing concrete is difficult to maintain high strength while having excellent crack resistance, compressive strength and pumping performance, the present application provides a high-strength environmentally friendly concrete with high adaptive viscosity, which includes the following raw materials by weight: 300-350 parts of cement; 43-58 parts of mineral powder; 20-35 parts of fly ash; 15-25 parts of rice husk ash; 800-855 parts of sand; 800-1000 parts of gravel; 25-35 parts of expansion agent; 180-220 parts of water; 8-10 parts of water reducer; 7-12 parts of air entraining agent; 24-36 parts of composite fiber; 20-30 parts of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules; the composite fiber includes polypropylene fiber and chitosan fiber with a weight ratio of 1.5-2:1. Based on this technical solution, the technical solution provided by the present application solves the problem that the existing concrete is difficult to take into account crack resistance, compressive strength and pumping performance while maintaining high strength. On the basis of improving the strength of concrete, the synergistic effect of composite fibers and polyethylene glycol diacrylate-butyl rubber composite core microcapsules can enhance the crack resistance, compressive strength and pumping performance of concrete. In this technical solution, the composite fibers and polyethylene glycol diacrylate-butyl rubber composite core microcapsules cooperate with each other to have a positive impact on the overall performance of concrete. The polypropylene fiber and chitosan fiber in the composite fiber are combined in a specific proportion to exert a synergistic effect. Polypropylene fiber enhances the toughness of concrete, making it less likely to crack when under pressure; chitosan fiber is rich in polar groups such as hydroxyl and amino groups, making it hydrophilic. When it is evenly dispersed in concrete, it will have a strong affinity with water molecules, and water molecules will adhere to the fiber surface instead of randomly gathering to form a continuous water flow channel, which can reduce the probability of leakage channels due to water accumulation and improve impermeability. In addition, during the preparation and mixing of concrete, there will be some fine impurity particles inside. Chitosan fiber absorbs these particles by virtue of its adsorption and fills the tiny pores that may have existed originally, making the internal microstructure of concrete more compact, and making it more difficult for external moisture, salt and other substances to penetrate, thereby effectively enhancing the anti-permeability of concrete. And it cooperates and synergizes with components such as cement, sand and gravel and other additives to jointly improve the anti-permeability of concrete. Polyethylene glycol diacrylate-butyl rubber composite core material microcapsules form a unique microstructure inside the concrete, which interacts with the composite fibers to further enhance the crack resistance of the concrete. The presence of microcapsules increases the elasticity and deformation capacity of concrete, enabling the concrete to better absorb energy and reduce the occurrence of cracks when subjected to external pressure or temperature changes. At the same time, the combined action of composite fibers and polyethylene glycol diacrylate-butyl rubber composite core material microcapsules also improves the compressive strength of concrete. They not only improve the anti-permeability of concrete, but also prevent chemical erosion inside the concrete to a certain extent, extending the service life of concrete.In addition, this application optimizes the ratio and performance of raw materials so that the concrete can meet the fluidity requirements during pumping while maintaining a high adaptive viscosity, ensuring that the concrete can be smoothly transported to the designated location during the construction process. In summary, the technical solution provided by this application achieves a comprehensive improvement in the high strength, crack resistance, compressive strength and pumping performance of concrete through the synergistic effect of various components, providing a concrete material with more advantages and practical value for construction projects.

[0027] In some embodiments, polyethylene glycol diacrylate-butyl rubber composite core material microcapsules are prepared by the following method; S1. Adding polyethylene glycol diacrylate and butyl rubber particles in a weight ratio of 1-3:1 to an emulsifier solution of sodium lauryl sulfate, stirring evenly, to prepare a mixed emulsion; S2, adding sodium metabisulfite and ammonium persulfate to the mixed emulsion in step S1, and reacting at 75° C.-80° C. for 2-3 hours to obtain a core material emulsion; the weight ratio of the mixed emulsion, sodium metabisulfite and ammonium persulfate in step S2 is 100:1-1.5:1; S3, mixing gelatin and gum arabic in water, heating to 65°C-70°C, stirring for 20-30 minutes to dissolve, and then adding glutaraldehyde and stirring to obtain a wall material solution; in step S3, the weight ratio of gelatin, gum arabic and glutaraldehyde is 10-15:8-10:2-3; S4. The core material emulsion and the wall material solution are mixed in a weight ratio of 3:2, stirred evenly, and then spray-dried to allow the wall material to wrap the core material to form polyethylene glycol diacrylate-butyl rubber composite core material microcapsules.

[0028] Based on the above technical solutions, this application successfully solves the problem that the existing high-strength concrete is difficult to take into account crack resistance and compressive strength while maintaining high strength. The preparation process of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules allows polyethylene glycol diacrylate and butyl rubber particles to be fully mixed and cross-linked to form a stable core material structure. The sodium dodecyl sulfate emulsifier solution ensures that the core material is evenly dispersed, and the wall material formed by gelatin, gum arabic and glutaraldehyde wraps the core material, giving the microcapsules good stability and structure. The microcapsules absorb energy, reduce cracks, and improve the impermeability of concrete inside the concrete, and work together with the composite fibers to enhance the crack resistance and compressive strength of the concrete. The wall material of the microcapsule effectively blocks moisture and foreign substances, further improving the impermeability of the concrete. At the same time, its elastic structure can buffer stress when the concrete is subjected to external pressure or temperature changes, reducing the formation of cracks. Under the synergistic effect with the composite fiber, the microcapsule and the composite fiber jointly optimize the internal humidity environment and density of the concrete, improve the overall performance of the concrete, and extend the service life of the concrete.

[0029] The scheme of the present application is described below in conjunction with the following specific examples. Unless otherwise specified, the raw materials used in the following examples are all from common commercial products, and the devices or equipment used are all purchased from conventional market sales channels.

[0030] Preparation Example 1 This preparation example provides polyethylene glycol diacrylate-butyl rubber composite core material microcapsules, and the preparation method comprises the following steps: S1. Add polyethylene glycol diacrylate and butyl rubber particles in a weight ratio of 1:1 (100 g of polyethylene glycol diacrylate and 100 g of butyl rubber particles) to an emulsifier solution of sodium dodecyl sulfate (300 ml), and stir evenly (stirring speed 300 rpm, stirring time 45 min) to obtain a mixed emulsion; the percentage of sodium dodecyl sulfate in the emulsifier solution of sodium dodecyl sulfate is 4%.

[0031] S2, adding sodium metabisulfite (1 g) and ammonium persulfate (1 g) to the mixed emulsion of step S1, reacting at 75° C. for 2 hours to obtain a core material emulsion; S3, gelatin (10 g) and gum arabic (8 g) were mixed evenly in water, heated to 65° C., stirred for 20 minutes to dissolve, and glutaraldehyde (2 g) was added and stirred evenly to obtain a wall material solution; S4, the core material emulsion and the wall material solution are mixed in a weight ratio of 3:2 (300 g of the core material emulsion and 200 g of the wall material solution), stirred evenly (stirring speed 300 rpm), and then spray dried (inlet air temperature 150°C, outlet air temperature 80°C, spray pressure 0.2 MPa) to make the wall material wrap the core material to form polyethylene glycol diacrylate-butyl rubber composite core material microcapsules. The average particle size of the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 25 μm.

[0032] Preparation Example 2 This preparation example provides polyethylene glycol diacrylate-butyl rubber composite core material microcapsules, and the preparation method comprises the following steps: S1. Add polyethylene glycol diacrylate and butyl rubber particles in a weight ratio of 3:1 (300 g polyethylene glycol diacrylate, 100 g butyl rubber particles) to an emulsifier solution of sodium dodecyl sulfate (500 ml, 4% content), and stir evenly (stirring speed 500 rpm, stirring time 30 min) to obtain a mixed emulsion; S2, adding sodium metabisulfite (1.5 g) and ammonium persulfate (1 g) to the mixed emulsion in step S1, and reacting at 80° C. for 3 hours to obtain a core material emulsion; S3, mix 15 g of gelatin and 10 g of gum arabic in water, heat to 70°C, stir for 30 min to dissolve, then add 3 g of glutaraldehyde and stir to obtain a wall material solution; S4, the core material emulsion and the wall material solution are mixed in a weight ratio of 3:2 (core material emulsion 450g, wall material solution 300g), stirred evenly (stirring speed 500 rpm), and then spray dried (inlet air temperature 180°C, outlet air temperature 100°C, spray pressure 0.3MPa) to make the wall material wrap the core material to form polyethylene glycol diacrylate-butyl rubber composite core material microcapsules. The average particle size of the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 25μm Preparation Example 3 This preparation example provides a polyethylene glycol diacrylate-butyl rubber composite core material microcapsule, and the preparation method comprises the following steps: S1. Add polyethylene glycol diacrylate and butyl rubber particles in a weight ratio of 2.3:1 (230 g polyethylene glycol diacrylate, 100 g butyl rubber particles) to an emulsifier solution of sodium dodecyl sulfate (450 ml, 4% content), and stir evenly (stirring speed 420 rpm, stirring time 35 min) to obtain a mixed emulsion; S2, adding sodium metabisulfite (1.3 g) and ammonium persulfate (1 g) to the mixed emulsion in step S1, and reacting at 77° C. for 2.2 hours to obtain a core material emulsion; S3, gelatin (13 g) and gum arabic (9 g) were mixed evenly in water, heated to 66°C, stirred for 23 min to dissolve, and glutaraldehyde (2.2 g) was added and stirred evenly to obtain a wall material solution; S4, the core material emulsion and the wall material solution are mixed in a weight ratio of 3:2 (345 g of the core material emulsion and 230 g of the wall material solution), stirred evenly (stirring speed 420 rpm), and then spray dried (inlet air temperature 168°C, outlet air temperature 92°C, spray pressure 0.23 MPa) to make the wall material wrap the core material to form polyethylene glycol diacrylate-butyl rubber composite core material microcapsules. The average particle size of the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 25 μm.

[0033] Example 1 The present embodiment provides a concrete, which includes the following raw materials by weight: 330 parts of cement; 50 parts of mineral powder; 28 parts of fly ash; 20 parts of rice husk ash; 825 parts of sand; 932 parts of gravel; 30 parts of expansion agent; 195 parts of water; 8.5 parts of water reducer; 10 parts of air entraining agent; 30 parts of composite fiber; 25 parts of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules; The composite fiber is made by mixing polypropylene fiber and chitosan fiber in a weight ratio of 1.5:1. The length of the polypropylene fiber is 18 mm, and the length of the chitosan fiber is 12 mm); The polyethylene glycol diacrylate-butyl rubber composite core material microcapsules in this embodiment are prepared by Preparation Example 1. The expansion agent in this embodiment is calcium sulfoaluminate expansion agent; The water reducing agent in this embodiment is a polycarboxylic acid water reducing agent; the water reduction rate is 25%. The air-entraining agent in this embodiment is a rosin-based air-entraining agent with an air content of 3.5%.

[0034] The cement in this embodiment is ordinary Portland cement, with a strength grade of 42.5 and a specific surface area of ​​350 m2 / kg; The mineral powder in this embodiment is granulated blast furnace slag powder, with an activity index of 95% and a specific surface area of ​​400 m2 / kg; the fly ash in this embodiment is Class I fly ash, with a fineness of 12% and a water requirement ratio of 95%; The rice husk ash in this embodiment was calcined at 500°C, with an average particle size of 30 μm and a silicon dioxide content of 85%; The sand in this embodiment is medium sand, with a fineness modulus of 2.6 and a mud content of 1%; The stone in this embodiment is a continuously graded crushed stone with a particle size of 5-20 mm and a crushing index of 8%; The method for preparing concrete comprises the following steps: A1: Add cement, mineral powder, fly ash, rice husk ash, sand, gravel, expansion agent, composite fiber, polyethylene glycol diacrylate-butyl rubber composite core material into the forced mixing equipment in sequence, and stir at a speed of 200r / min for 5 minutes to make it uniform; A2: Add water, water reducing agent and air entraining agent to the mixture in step A1, and continue stirring at a speed of 200 r / min for 3 minutes to stir evenly; A3: Pour the stirred mixture into a mold and vibrate it for 3 minutes at a vibration table frequency of 50 Hz and an amplitude of 0.5 mm. Then, cure it in a standard curing room with a temperature of 20±2°C and a relative humidity of more than 95% for 28 days to obtain concrete.

[0035] Example 2 The difference between this embodiment and embodiment 1 is that, in this embodiment, when preparing concrete, the total weight of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 55 parts, wherein the weight ratio of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 1:1.

[0036] Example 3 The difference between this embodiment and embodiment 1 is that, in this embodiment, when preparing concrete, the total weight of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 55 parts, wherein the weight ratio of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 1.4:1.

[0037] Example 4 The difference between this embodiment and embodiment 1 is that, in this embodiment, when preparing concrete, the total weight of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 98 parts, wherein the weight ratio of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 1.5:1.

[0038] Comparative Examples 1-4 Comparative Example 1 The difference between this comparative example and Example 1 is that when preparing concrete, an equal amount of composite fibers is used to replace the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules.

[0039] Comparative Example 2 The difference between this comparative example and Example 1 is that when preparing concrete, an equal amount of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules are used to replace the composite fibers.

[0040] Comparative Example 3 The difference between this comparative example and Example 1 is that when preparing concrete, an equal amount of polypropylene fibers are used instead of composite fibers.

[0041] Comparative Example 4 The difference between this comparative example and Example 1 is that, when preparing concrete, an equal amount of chitosan fibers are used instead of composite fibers.

[0042] Experimental testing: 1. Compressive strength: refer to GB / T50081-2016 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete", and the test environment temperature is -15℃.

[0043] 2. Early crack resistance: Standard test blocks were made in accordance with GB / T50081-2016 "Standard Test Methods for Mechanical Properties of Ordinary Concrete". The test blocks were cured at 5°C for 2 hours and then at -15°C for 24 hours to measure the number of cracks per unit area and the total crack area per unit area.

[0044] 3. Viscosity test: The experimental test results of Examples 1-4 and Comparative Examples 1-4 are shown in Table 1.

[0045] Table 1 - Experimental test results of Examples 1-4 and Comparative Examples 1-4 Result analysis: The difference between Example 2-4 and Example 1 is that when preparing concrete, the total weight of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core microcapsule remains unchanged, but the weight ratio between the two changes. Combined with the experimental test results in Table 1, it can be seen that when the weight ratio of the composite fiber to the polyethylene glycol diacrylate-butyl rubber composite core microcapsule is 1.2:1, the prepared concrete exhibits higher compressive strength and better crack resistance.

[0046] The difference between Comparative Example 1 and Example 1 is that when preparing concrete, an equal amount of composite fibers is used to replace the polyethylene glycol diacrylate-butyl rubber composite core microcapsules. Combined with the experimental test results in Table 1, it can be seen that the compressive strength of Comparative Example 1 is reduced to 35.4 MPa, and the number of cracks per unit area increases to 15.3 / m 2 The total cracking area per unit area is 169.2mm 2 / m 2 This shows that the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules have a significant effect on improving the compressive strength and crack resistance of concrete. The lack of this material will lead to a significant decrease in concrete performance.

[0047] The difference between Comparative Example 2 and Example 1 is that when preparing concrete, an equal amount of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules are used to replace the composite fibers. Combined with the experimental test results in Table 1, it can be seen that the compressive strength of Comparative Example 2 is 36.2 MPa, and the number of cracks per unit area is 14.2 / m 2 The total cracking area per unit area is 173.5mm 2 / m 2 , which are significantly deteriorated compared with Example 1, indicating that composite fibers are indispensable in enhancing the compression and crack resistance of concrete, and that only relying on polyethylene glycol diacrylate-butyl rubber composite core microcapsules cannot maintain good performance of concrete.

[0048] The difference between Comparative Example 3 and Example 1 is that when preparing concrete, an equal amount of polypropylene fibers is used instead of composite fibers. Combined with the experimental test results in Table 1, it can be seen that the compressive strength of Comparative Example 3 is 39.8 MPa, and the number of cracks per unit area is 13.1 / m 2 The total cracking area per unit area is 146.9 mm 2 / m 2 Although it has a certain strength, its crack resistance is still far behind that of Example 1, indicating that the composite fiber composed of chitosan fiber and polypropylene fiber is of great significance to improving the crack resistance of concrete, and single polypropylene fiber is difficult to achieve the reinforcing effect of the composite fiber.

[0049] The difference between Comparative Example 4 and Example 1 is that, in preparing concrete, an equal amount of chitosan fibers are used instead of composite fibers. Combining the experimental test results in Table 1, it can be seen that the compressive strength of Comparative Example 4 is 40.1 MPa, and the number of cracks per unit area is 13.5 / m 2 The total cracking area per unit area is 142.7 mm 2 / m 2 Although it has a certain compressive resistance, its crack resistance is significantly weakened compared with Example 1. This shows that the composite fiber formed by the joint action of polypropylene fiber and chitosan fiber is better than single chitosan fiber in enhancing the comprehensive performance of concrete. The two work together to better improve the performance of concrete.

[0050] In summary, through the analysis of the experimental test results of Examples 1-4 and Comparative Examples 1-4, it can be seen that the composite fiber and polyethylene glycol diacrylate-butyl rubber composite core microcapsules play a key and synergistic role in improving the performance of concrete. Examples 2-4 show that when the total weight of the two remains unchanged and the weight ratio is 1.2:1, the concrete can exhibit higher compressive strength and better crack resistance. Comparative Example 1 uses an equal amount of composite fiber to replace the polyethylene glycol diacrylate-butyl rubber composite core microcapsules, and Comparative Example 2 uses an equal amount of polyethylene glycol diacrylate-butyl rubber composite core microcapsules to replace the composite fiber, both of which lead to significant deterioration of concrete performance. It can be seen that both are indispensable for improving concrete performance. Comparative Examples 3 and Comparative Examples 4 use a single polypropylene fiber or chitosan fiber to replace the composite fiber, respectively. Although they can maintain a certain strength, the crack resistance is significantly weakened compared with Example 1. It can be seen that the synergistic effect of the two fibers in the composite fiber plays an indispensable role in improving the comprehensive performance of concrete.

[0051] Embodiment 5-6 The difference between Example 5-6 and Example 1 is that, when preparing concrete, the weight proportions of some components are different. The difference is shown in Table 2.

[0052] Table 2 - Differences between Examples 5-6 and Example 2 The experimental test results of Examples 5-6 are shown in Table 3.

[0053] Table 3 - Experimental test results of Examples 5-6 Result analysis: The difference between Example 5-6 and Example 1 is that when preparing concrete, the weight proportions of some components are different. Combined with the experimental test results in Table 3, it can be seen that the comprehensive performance of the concrete prepared by Example 1 is better.

[0054] Example 7 The difference between Example 7-11 and Example 1 is that when preparing concrete, based on the premise that the weight ratio of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule is 1.2:1, the total weight ratio of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule in the concrete is changed, and a better weight ratio is selected.

[0055] In Example 1, the total weight of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 55 parts, and the total weight of the concrete is 2483.5 parts.

[0056] Therefore, it is not difficult to conclude that in Example 1, the proportion of the composite fiber (referred to as variable 1) and the polyethylene glycol diacrylate-butyl rubber composite core microcapsule (referred to as variable 2) in the concrete (referred to as the matrix) is 2.21%.

[0057] The differences between Examples 7-11 and Example 1 are shown in Table 4.

[0058] Proportion = (variable 1 + variable 2) / total weight of matrix * 100%.

[0059] Table 4 - Differences between Examples 7-11 and Example 1 The experimental test results of Examples 7-11 are shown in Table 5.

[0060] Table 5 - Experimental test results of Examples 7-11 Results analysis: The difference between Examples 7-11 and Example 5 is that when preparing concrete, the total weight of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core microcapsules in the concrete is different. Combined with the experimental test results in Table 5, it can be seen that when the total weight of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core microcapsules in the concrete accounts for 2-2.5%, the comprehensive performance of the prepared concrete is better, and when the total weight of the composite fiber and the polyethylene glycol diacrylate-butyl rubber composite core microcapsules in the concrete accounts for 2.49%, the comprehensive performance of the prepared concrete is the best. When the proportion is too high or too low, the comprehensive performance will decrease.

[0061] Examples 12-13 Example 12 The difference between this embodiment and embodiment 10 is that when preparing concrete, the preparation parameters of the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules used are different. The polyethylene glycol diacrylate-butyl rubber composite core material microcapsules in this embodiment are prepared by Preparation Example 2.

[0062] Example 13 The difference between this embodiment and embodiment 10 is that when preparing concrete, the preparation parameters of the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules used are different, and the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules in this embodiment are prepared by Preparation Example 3. The experimental test results of embodiments 12-13 are shown in Table 6.

[0063] Embodiment 14 The difference between this embodiment and embodiment 12 is that in this embodiment, a coupling agent-modified composite fiber is used instead of the composite fiber; specifically, the silane coupling agent KH-560 is added to the ethanol solution at a ratio of 5% by mass, stirred evenly, to prepare a silane coupling agent solution, and the composite fiber is immersed in the solution.

[0064] The soaking time is 3 hours. After the soaking is completed, the fiber is fished out and rinsed with deionized water for several times to remove the silane coupling agent solution remaining on the surface. After the rinsing is completed, the fiber is placed in an oven at 60°C for 2 hours to obtain a modified composite fiber. The preparation method of concrete in this embodiment includes the following steps: A1: Add cement, mineral powder, fly ash, rice husk ash, sand, gravel, expansion agent, composite fiber, polyethylene glycol diacrylate-butyl rubber composite core material into the forced mixing equipment in sequence, and stir at a speed of 200r / min for 5 minutes to make it uniform; A2: Add water, water reducing agent and air entraining agent to the mixture in step A1, and continue stirring at a speed of 200 r / min for 3 minutes to stir evenly; A3: Pour the stirred mixture into a mold and vibrate it for 3 minutes at a vibration table frequency of 50 Hz and an amplitude of 0.5 mm. Then, cure it in a standard curing room with a temperature of 20±2°C and a relative humidity of more than 95% for 28 days to obtain concrete.

[0065] Table 6 - Experimental test results of Examples 12-14 Result analysis: The difference between Example 12-13 and Example 10 is that different preparation parameters of the polyethylene glycol diacrylate-butyl rubber composite core microcapsules are used in preparing concrete. Combined with the experimental test results in Table 6, it can be seen that the concrete prepared by Example 12 has better comprehensive performance.

[0066] The difference between Example 14 and Example 12 is that in this example, the coupling agent-modified composite fiber is used instead of the composite fiber. Combined with the experimental test results in Table 6, it can be seen that Example 14 has a significant improvement in compressive strength, reaching 46.8MPa, which is higher than 44.7MPa in Example 12; the early crack number is reduced to 6.5 / m 2 The total cracking area per unit area is also reduced to 95.2mm 2 / m 2 This shows that the coupling agent modified composite fiber has a positive effect on improving the crack resistance of concrete; the reason may be that the silane coupling agent KH-560 forms an organic silicon layer on the fiber surface, which enhances the interfacial bonding between the fiber and the polyethylene glycol diacrylate-butyl rubber composite core microcapsules. This strong interfacial bonding makes the microcapsules more stable and evenly dispersed in the concrete. When the concrete is subjected to external forces, the microcapsules can better exert their elasticity and toughness, absorb stress, and effectively inhibit the generation and expansion of cracks, thereby improving the crack resistance of the concrete. At the same time, the synergistic effect of the modified composite fiber and the microcapsules further enhances the compactness of the internal structure of the concrete, which also improves the compressive strength of the concrete.

[0067] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the principles of the present application should be included in the protection scope of the present application.

Claims

1. A high-strength environmentally friendly concrete with high adaptive viscosity, characterized in that: The concrete comprises the following raw materials by weight: 300-350 parts of cement; 43-58 parts of mineral powder; 20-35 parts of fly ash; 15-25 parts of rice husk ash; 800-855 parts of sand. 1-30 parts; 800-1000 parts of stone; 25-35 parts of expansion agent; 180-220 parts of water; 8-10 parts of water reducing agent; 7-12 parts of air entraining agent; 24-36 parts of composite fiber; 20-30 parts of polyethylene glycol diacrylate-butyl rubber composite core material microcapsules; The composite fiber comprises polypropylene fiber and chitosan fiber in a weight ratio of 1.5-2:

1.

2. The concrete according to claim 1, characterized in that The polyethylene glycol diacrylate-butyl rubber composite core material microcapsule is prepared by the following method: S1. Adding polyethylene glycol diacrylate and butyl rubber particles in a weight ratio of 1-3:1 to an emulsifier solution of sodium lauryl sulfate, stirring evenly, to prepare a mixed emulsion; S2, adding sodium metabisulfite and ammonium persulfate to the mixed emulsion in step S1, and reacting at 75° C.-80° C. for 2-3 hours to obtain a core material emulsion; the weight ratio of the mixed emulsion, sodium metabisulfite and ammonium persulfate in step S2 is 100:1-1.5:1; S3, mixing gelatin and gum arabic in water, heating to 65°C-70°C, stirring for 20-30 minutes to dissolve, and then adding glutaraldehyde and stirring to obtain a wall material solution; in step S3, the weight ratio of gelatin, gum arabic and glutaraldehyde is 10-15:8-10:2-3; S4, mixing the core material emulsion and the wall material solution in a weight ratio of 3:2, stirring evenly, and then using a spray drying method to allow the wall material to wrap the core material to form the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule.

3. The concrete according to claim 2, characterized in that: The stirring speed in step S1 is 300-500 r / min, and the stirring time is 30-45 min.

4. The concrete according to claim 2, characterized in that The percentage of sodium dodecyl sulfate in the sodium dodecyl sulfate emulsifier solution in step S1 is 2%-5%.

5. The concrete according to claim 2, characterized in that: The spray drying parameters in step S4 are as follows: spray pressure is 0.5-1MPa, air inlet temperature is 120-150°C, air outlet temperature is 80-100°C, and feed rate is 5-10 ml / min; the average particle size of the polyethylene glycol diacrylate-butyl rubber composite core material microcapsules is 25 μm.

6. The concrete according to claim 1, characterized in that The weight ratio of the composite fiber to the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule is 1-1.5:

1.

7. The concrete according to claim 6, characterized in that The weight ratio of the composite fiber to the polyethylene glycol diacrylate-butyl rubber composite core material microcapsule is 1.2:

1.

8. The concrete according to claim 1, characterized in that The expansion agent is a calcium sulphoaluminate expansion agent; the water reducing agent is a polycarboxylic acid-based water reducing agent; and the air entraining agent is a rosin-based air entraining agent.

9. The concrete according to claim 1, characterized in that The composite fiber is a coupling agent modified composite fiber.

10. A method for preparing concrete according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: A1. Add cement, mineral powder, fly ash, rice husk ash, sand, gravel, expansion agent, composite fiber, polyethylene glycol diacrylate-butyl rubber composite core material into a mixing device in sequence and mix evenly; A2, adding water, water reducing agent and air entraining agent to the mixture in step A1, and stirring evenly; A3, pouring the stirred mixture into a mold, vibrating and molding, and curing to obtain the concrete.

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