High-performance concrete and preparation method thereof

Abstract

The invention relates to the technical field of building materials, and discloses high-performance concrete and a preparation method thereof.The high-performance concrete is prepared from, by mass, 9% of water, 10% of coarse aggregate, 10% of fine aggregate, 10% of a cementing material, 10% of an admixture, 10% of a water reducing agent, 10% of a retarder and 10% of an early strength agent. 38% of stones; 18% of fine sand; 13.5% of cement; 2% of asphalt; 4% of tire slag; 5% of rice hull ash; 3% of coal cinder; 3% of sulfonated coumarone resin; according to the high-performance concrete, solid waste coal slag and tire slag are adopted as raw materials, so that land occupation is reduced, and pollution to the environment is also reduced; meanwhile, concrete strength can be improved, cost is saved, durability is improved, and pollution is reduced; and the sulfonated coumarone resin, the tricalcium phosphate and the gypsum are matched, so that the problems of high brittleness, low tensile strength, high cost and cracks of the traditional concrete are solved.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to high performance concrete and a preparation method thereof. Background Art

[0002] Concrete is a material made of cement, sand, aggregate and water. It is widely used in construction, roads, bridges and other projects. The history of concrete can be traced back to the ancient Greek and Roman periods in the 7th century BC, when people used lime and clay to make building materials. However, real concrete was invented by British engineer John Smeaton in the early 19th century. He first used a mixture of hydraulic cement, aggregate and water when designing the third Eddystone Lighthouse. This is considered the starting point of modern concrete. Although concrete is a brittle material with low tensile strength, how to improve its crack resistance has always been a key problem, but concrete is still one of the most widely used building materials in the world. Whether it is the ancient pyramids thousands of years ago or the high-rise buildings in modern cities, in order to improve the quality of concrete, we can also adopt some advanced technical means, such as using high-performance admixtures or admixtures to improve the strength and durability of concrete. Through the comprehensive application of these measures, we can effectively improve the quality of concrete and ensure that it can achieve the expected effect during use. Ultra-High Performance Concrete (UHPC) is a new generation of ultra-high performance concrete (UHPC) is a new generation of cement-based civil engineering materials with low water-cement ratio, high cementitious material content, and high particle packing density. Excellent mechanical and durability properties make it suitable for important infrastructure such as bridges, railways, and special structures. UHPC is one of the most innovative cement-based engineering materials in the past thirty years, achieving a major leap in the performance of engineering materials. It has ultra-high mechanical properties and ultra-high durability, and is considered to be one of the best cement-based composite materials in the past thirty years. It can better adapt to the current trend of large-scale and complex civil engineering structures, and can also meet the requirements of social sustainable development for the development of high-performance materials. Although ultra-high performance concrete (UHPC) is an innovative cement-based engineering material with many advantages, it also has some disadvantages. First, the preparation cost of UHPC is relatively high, which may increase the total cost of the project. Second, the structural design and construction process of UHPC are relatively complex and require professional knowledge and technology, which will also increase the difficulty and complexity of the project. In addition, the hydration heat of UHPC is usually large, which may cause the temperature inside and on the surface of the concrete to rise, causing quality problems such as cracks. Finally, the current maturity of UHPC application technology is still relatively low, which means that some unknown problems may arise during use. Therefore, high-performance concrete with high cost performance that has similar advantages to ultra-high performance concrete and makes up for its shortcomings is urgently needed. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a high-performance concrete and a preparation method thereof. The new high-performance concrete has the advantages of low cost, simple construction, high strength, durability and crack resistance, and solves the problems of traditional concrete such as high brittleness, low tensile strength, high cost and cracks.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: the high-performance concrete is composed of water, coarse aggregate, fine aggregate, cementitious material, admixture, water reducer, retarder and early strength agent, and the mass percentage of the constituent raw materials is: water 9%; gravel 38%; fine sand 18%; cement 13.5%; asphalt 2%; tire residue 4%; rice husk ash 5%; coal slag 3%; sulfonated coumarone resin 3%; tricalcium phosphate 1.5% and gypsum 3%.

[0005] Preferably, in the high-performance concrete, water is the medium for all raw materials; coarse aggregate is composed of tire residue and gravel, and fine aggregate is composed of fine sand and asphalt; cement is used as a setting material, and rice husk ash and coal slag are both admixtures; sulfonated coumarone resin acts as a water reducer; tricalcium phosphate and gypsum are used as a retarder and an early strength agent, respectively.

[0006] Preferably, the preparation process of the high performance concrete raw material - rice husk ash: S1.1. Collection: Recover rice husks produced after rice is refined from farmland; S1.2, acidification: The collected rice husks were acidified with 15% H2SO4 and stirred and soaked for 4.5 hours, and the rice husks were washed with water until the pH value was between 5-5.5; S1.3, dehydration: drain the washed rice husks and put them into an electric hot air drying oven at 115°C for 3 hours to dry out excess water; S1.4, Calcination: First burn at a low temperature of 500-600℃ for 2-2.5 hours, and then burn at a high temperature of 800-820℃ for 3-3.5 hours. This two-combustion system can obtain high-quality rice husk ash, which can be used as a raw material for admixture after cooling.

[0007] Preferably, the preparation process of the high performance concrete raw material - gypsum: S2.1, Material selection: Use small pieces of natural gypsum ore; S2.2, Grinding: Gypsum ore is initially crushed by a jaw crusher, and the crushed gypsum is ground by a gypsum grinding machine; S2.3, Calcination: Calcine the natural gypsum ore at a temperature of 150-165°C in a calcination device for 1 hour to obtain β-hemihydrate gypsum, also known as building gypsum, which is used as a spare raw material for the early strength agent.

[0008] Preferably, the preparation process of the high performance concrete is: Step 1. Preparation of raw materials: Use electronic scales and electronic balances to accurately measure the mass percentage of various raw materials for later use; Step 2: Mixing step: The raw materials that have been precisely measured enter the self-falling mixer for mixing in a certain order. To ensure that the concrete is mixed evenly and reduce bubbles in the concrete, the time and speed of the mixer are adjusted according to the different functions of the raw materials.

[0009] Preferably, the order of adding the concrete raw materials in step 2 and their corresponding time and speed are as follows: (1) During the mixing process of the self-falling mixer, tire residue, gravel, fine sand and asphalt are first added. The speed is 20 revolutions per minute and the mixing time is 4 minutes. (2) Add cement and water, the speed is 15 rpm, and the mixing time is 3 minutes; (3) Finally, add rice husk ash, coal slag, sulfonated coumarone resin, tricalcium phosphate and gypsum. The speed is 20 rpm and the stirring time is 8 minutes.

[0010] Preferably, the mixing time of the self-falling mixer in the concrete (1) to (3) of step 2 is changed according to the volume of the concrete. In this step, the mixing time of (3) is 8 minutes, corresponding to a concrete volume of 48L.

[0011] Preferably, the raw materials of the high performance concrete have the following mass percentages: water 9%, gravel 35%, fine sand 18%, cement 13.5%, asphalt 9%, rice husk ash 5%, coal slag 3%, sulfonated coumarone resin 3%, tricalcium phosphate 1.5% and gypsum 3%.

[0012] Preferably, the raw materials of the high performance concrete have the following mass percentages: water 9%, gravel 43%, fine sand 18%, cement 13.5%, asphalt 2%, tire residue 4%, coal slag 3%, sulfonated coumarone resin 3%, tricalcium phosphate 1.5% and gypsum 3%.

[0013] Preferably, the raw materials of the high performance concrete have the following mass percentages: water 9%; gravel 41%; fine sand 18%; cement 13.5%; asphalt 2%, tire residue 4%; rice husk ash 5%; coal slag 3%; tricalcium phosphate 1.5% and gypsum 3%.

[0014] Compared with the prior art, the present invention provides a high performance concrete and a preparation method thereof, which has the following beneficial effects: 1. The present invention uses tire residue, rice husk ash and coal slag in a mixed manner. The application of tire residue in concrete has strength and firmness, can resist freeze-thaw cycles, sunlight and natural physical weathering corrosion, thereby ensuring the durability of concrete. In addition, the discarded tire residue can be reused in road construction to replace the elasticity and recovery ability of a small amount of asphalt, thereby reducing the production cost of concrete and improving the early strength and durability of concrete. Rice husk ash is prepared by low-temperature and high-temperature calcination, and its properties after calcination have volcanic ash activity. Adding it to concrete can improve the compressive strength. Rice husk has a large reserve in farmland and can be continuously supplied at a low price. When its usage does not exceed a certain proportion, it can replace part of the cement. Using rice husk ash as a raw material component can reduce the cost of concrete preparation. Coal slag is crushed and used as an admixture of concrete to fill the pores in concrete to reduce the density of concrete and improve the thermal insulation performance of concrete. Using solid waste such as coal slag and tire residue in concrete production not only reduces land occupation, but also reduces pollution to the environment, achieving the beneficial effects of improving concrete strength, saving costs and improving durability.

[0015] 2. The present invention uses sulfonated coumarone resin, tricalcium phosphate and gypsum as raw materials. Sulfonated coumarone resin is a high-efficiency water reducer. It uses the principle of intermolecular adsorption based on van der Waals force, which is similar to the principle of activated carbon adsorption. It can reduce the attraction between cement particles, thereby reducing the water consumption of concrete to increase the strength of concrete; tricalcium phosphate is an early strength agent, which can improve the durability of concrete, extend the service life of concrete, and improve the early strength of concrete; gypsum mainly plays the role of a retarder in concrete. It can quickly dissolve with tricalcium aluminate in cement to form calcium aluminate, thereby delaying the setting time of cement and effectively shortening the construction time of concrete. The three raw materials are used in a reasonable proportion to achieve the beneficial effects of early strength, durability and simple construction of concrete.

[0016] 3. The present invention has found through research that when there are too many or too large bubbles in concrete, the cross-sectional volume of the concrete will be reduced, resulting in the concrete being loose inside, thereby reducing the strength of the concrete. In order to solve this problem, a method for reducing bubbles is found in the novel concrete preparation process: during the concrete mixing process, the raw materials are added to the self-falling mixer for mixing in a certain order; the time and speed of the mixer are adjusted according to the different functions of the raw materials; by controlling the mixing time, the bubbles in the concrete can be effectively discharged, because the concrete has an optimal mixing time, before this time, the mixing time corresponding to the raw materials of different measurements can effectively discharge the bubbles in the concrete; this method not only improves the frost resistance and durability of the concrete, but also does not affect the strength of the concrete, thereby achieving the beneficial effects of frost resistance and quality improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a method for preparing high performance concrete according to the present invention; DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example 1 Specifically, the high-performance concrete is composed of water, coarse aggregate, fine aggregate, cementitious material, admixture, water reducer, retarder and early strength agent, and the mass percentage of the constituent raw materials is: water 9%; gravel 38%; fine sand 18%; cement 13.5%; asphalt 2%; tire residue 4%; rice husk ash 5%; coal slag 3%; sulfonated coumarone resin 3%; tricalcium phosphate 1.5% and gypsum 3%.

[0020] The invention has the advantages that tire residue, rice husk ash and coal slag are mixed and used, and the application of tire residue in concrete has strength and firmness, can resist freeze-thaw cycles, sunlight and natural physical weathering corrosion, thereby ensuring the durability of concrete. In addition, the discarded tire residue can be reused in road construction to replace the elasticity and recovery ability of a small amount of asphalt, thereby reducing the production cost of concrete and improving the early strength and durability of concrete; rice husk ash is prepared by low-temperature and high-temperature calcination, and its properties after calcination have volcanic ash activity, and adding it to concrete can improve the compressive strength, and rice husk has a large reserve in farmland, can be continuously supplied, and is inexpensive; when its usage does not exceed a certain proportion, it can replace part of the cement, and using rice husk ash as a raw material component can reduce the cost of concrete preparation; coal slag is crushed and used as an admixture of concrete to fill the pores in concrete to reduce the density of concrete and improve the thermal insulation performance of concrete. Using solid waste such as coal slag and tire residue in concrete production not only reduces land occupation, but also reduces pollution to the environment, achieving the beneficial effects of improving concrete strength, saving costs and improving durability.

[0021] Specifically, in the high-performance concrete, water is the medium for all raw materials; coarse aggregate is composed of tire residue and gravel, and fine aggregate is composed of fine sand and asphalt; cement is used as a setting material, while rice husk ash and coal slag are both admixtures; sulfonated coumarone resin acts as a water reducer; tricalcium phosphate and gypsum are used as a retarder and an early strength agent, respectively.

[0022] Specifically, the preparation process of the high performance concrete raw material - rice husk ash: S1.1. Collection: Recover rice husks produced after rice is refined from farmland; S1.2, acidification: The collected rice husks were acidified with 15% H2SO4 and stirred and soaked for 4.5 hours, and the rice husks were washed with water until the pH value was between 5-5.5; S1.3, dehydration: drain the washed rice husks and put them into an electric hot air drying oven at 115°C for 3 hours to dry out excess water; S1.4, Calcination: First burn at a low temperature of 500-600℃ for 2-2.5 hours, and then burn at a high temperature of 800-820℃ for 3-3.5 hours. This two-combustion system can obtain high-quality rice husk ash, which can be used as a raw material for admixture after cooling.

[0023] The invention has the advantages that the raw materials of the invention are sulfonated coumarone resin, tricalcium phosphate and gypsum, wherein the sulfonated coumarone resin is a high-efficiency water reducing agent, and the principle of intermolecular adsorption based on van der Waals force is similar to the principle of activated carbon adsorption, and can reduce the attraction between cement particles, thereby reducing the water consumption of concrete to increase the strength of concrete; tricalcium phosphate is an early strength agent, which can improve the durability of concrete, extend the service life of concrete, and improve the early strength of concrete; gypsum mainly plays the role of a retarder in concrete, and can quickly dissolve with tricalcium aluminate in cement to generate calcium aluminate, thereby delaying the setting time of cement, effectively shortening the construction time of concrete, and achieving the beneficial effects of early strength, durability and simple construction of concrete by using the three raw materials in a reasonable proportion.

[0024] Specifically, the preparation process of the high performance concrete raw material - gypsum: S2.1, Material selection: Use small pieces of natural gypsum ore; S2.2, Grinding: Gypsum ore is initially crushed by a jaw crusher, and the crushed gypsum is ground by a gypsum grinding machine; S2.3, Calcination: Calcine the natural gypsum ore at a temperature of 150-165°C in a calcination equipment for 1 hour to obtain β-hemihydrate gypsum, that is, building gypsum, which is used as a spare raw material for the early strength agent.

[0025] Specifically, the preparation process of the high performance concrete is as follows: Step 1. Preparation of raw materials: Use electronic scales and electronic balances to accurately measure the mass percentage of various raw materials for later use; Step 2: Mixing step: The raw materials that have been precisely measured enter the self-falling mixer for mixing in a certain order. To ensure that the concrete is mixed evenly and reduce bubbles in the concrete, the time and speed of the mixer are adjusted according to the different functions of the raw materials.

[0026] Specifically, the order of adding the concrete raw materials in step 2 and their corresponding time and speed are as follows: (1) During the mixing process of the self-falling mixer, tire residue, gravel, fine sand and asphalt are first added. The speed is 20 revolutions per minute and the mixing time is 4 minutes. (2) Add cement and water, the speed is 15 rpm, and the mixing time is 3 minutes; (3) Finally, add rice husk ash, coal slag, sulfonated coumarone resin, tricalcium phosphate and gypsum. The speed is 20 rpm and the stirring time is 8 minutes.

[0027] Specifically, the mixing time of the self-falling mixer in step 2 (1) to (3) of the concrete is changed according to the volume of the concrete. In this step, the mixing time of (3) is 8 minutes, corresponding to a concrete volume of 48L.

[0028] The advantage is that the present invention has found through research that when there are too many or too large bubbles in concrete, the cross-sectional volume of the concrete will be reduced, resulting in the concrete being loose inside, thereby reducing the strength of the concrete; in order to solve this problem, a method for reducing bubbles is found in the novel concrete preparation process: during the concrete mixing process, the raw materials are added to the self-falling mixer for mixing in a certain order; the time and speed of the mixer are adjusted according to the different functions of the raw materials; by controlling the mixing time, the bubbles in the concrete can be effectively discharged, because the concrete has an optimal mixing time, before this time, the mixing time corresponding to the raw materials of different measurements can effectively discharge the bubbles in the concrete; this method not only improves the frost resistance and durability of the concrete, but also does not affect the strength of the concrete, thereby achieving the beneficial effects of frost resistance and quality improvement.

[0029] The performance parameters of the finished product prepared in Example 1 are as follows: Table 1

[0030] Example 2 Specifically, the mass percentages of the raw materials of the high-performance concrete are: 9% water; 35% gravel; 18% fine sand; 13.5% cement; 9% asphalt, 5% rice husk ash, 3% coal slag, 3% sulfonated coumarone resin, 1.5% tricalcium phosphate, and 3% gypsum.

[0031] Example 3 Specifically, the raw materials of the high-performance concrete are as follows by weight: 9% water; 43% gravel; 18% fine sand; 13.5% cement; 2% asphalt; 4% tire residue; 3% coal slag; 3% sulfonated coumarone resin; 1.5% tricalcium phosphate and 3% gypsum.

[0032] Example 4 Specifically, the raw materials of the high-performance concrete have the following mass percentages: water 9%, gravel 41%, fine sand 18%, cement 13.5%, asphalt 2%, tire residue 4%, rice husk ash 5%, coal slag 3%, tricalcium phosphate 1.5% and gypsum 3%.

[0033] The compressive strength and frost resistance statistics of the finished concrete prepared in Example 1-4 are shown in Table 1-2: 1. Compressive strength test results Table 2 Table 2

[0034] Table 3: Freeze resistance test results Table 3

[0035] Note: In Example 1, the relative dynamic elastic modulus of the concrete specimen after two freeze-thaw cycles decreased by 15% and 16% respectively. The smaller this value is, the better the anti-freeze performance of the concrete is.

[0036] By comparing Tables 1-3 with Examples 1-4, it is known that the compressive strength and frost resistance tests of the formula ratio of Example 1 have the best performance.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high performance concrete, It is characterized in that The high performance concrete is composed of water, coarse aggregate, fine aggregate, cementitious material, admixture, water reducing agent, retarder and early strength agent, and the mass percentage of the constituent raw materials is: water 9%; gravel 38%; fine sand 18%; cement 13.5%; asphalt 2%; tire residue 4%; rice husk ash 5%; coal slag 3%; sulfonated coumarone resin 3%; tricalcium phosphate 1.5% and gypsum 3%.

2. A high performance concrete according to claim 1, Features: In the high-performance concrete, water is the medium for all raw materials; coarse aggregate is composed of tire residue and gravel, and fine aggregate is composed of fine sand and asphalt; cement is used as a setting material, while rice husk ash and coal slag are both admixtures; sulfonated coumarone resin acts as a water reducer; tricalcium phosphate and gypsum are used as a retarder and an early strength agent, respectively.

3. A high performance concrete according to claim 1, Features: The preparation process of the high performance concrete raw material - rice husk ash: S1.

1. Collection: Recover rice husks produced after rice is refined from farmland; S1.2, Acidification: The collected rice husks were treated with 15% H 2 SO 4 Acidification, stirring and soaking for 4.5 hours, washing the rice husks with water until the pH value is between 5 and 5.5; S1.3, dehydration: drain the washed rice husks and put them into an electric hot air drying oven at 115°C for 3 hours to dry out excess water; S1.4, Calcination: First burn at a low temperature of 500-600℃ for 2-2.5 hours, and then burn at a high temperature of 800-820℃ for 3-3.5 hours. This two-combustion system can obtain high-quality rice husk ash, which can be used as a raw material for admixture after cooling.

4. A high performance concrete according to claim 1, Features: The preparation process of the high performance concrete raw material - gypsum: S2.1, Material selection: Use small pieces of natural gypsum ore; S2.2, Grinding: Gypsum ore is initially crushed by a jaw crusher, and the crushed gypsum is ground by a gypsum grinding machine; S2.3, Calcination: Calcine the natural gypsum ore at a temperature of 150-165°C in a calcination equipment for 1 hour to obtain β-hemihydrate gypsum, that is, building gypsum, which is used as a spare raw material for the early strength agent.

5. A method for preparing high performance concrete, It is characterized in that The preparation process of the high performance concrete: Step 1. Preparation of raw materials: Use electronic scales and electronic balances to accurately measure the mass percentage of various raw materials for later use; Step 2: Mixing step: The raw materials that have been precisely measured enter the self-falling mixer for mixing in a certain order. To ensure that the concrete is mixed evenly and reduce bubbles in the concrete, the time and speed of the mixer are adjusted according to the different functions of the raw materials.

6. A method for preparing high performance concrete according to claim 5, Features: The order of adding the concrete raw materials in step 2 and their corresponding time and speed are as follows: (1) During the mixing process of the self-falling mixer, tire residue, gravel, fine sand and asphalt are first added. The speed is 20 revolutions per minute and the mixing time is 4 minutes. (2) Add cement and water, the speed is 15 rpm, and the mixing time is 3 minutes; (3) Finally, add rice husk ash, coal slag, sulfonated coumarone resin, tricalcium phosphate and gypsum. The speed is 20 rpm and the stirring time is 8 minutes.

7. A method for preparing high performance concrete according to claim 6, Features: The mixing time of the self-falling mixer in step 2 (1) to (3) of the concrete varies according to the volume of the concrete. In this step, the mixing time of (3) is 8 minutes, corresponding to a concrete volume of 48L.

8. The high performance concrete according to claim 1, Features: The raw materials of the high performance concrete are as follows by weight: 9% water; 35% gravel; 18% fine sand; 13.5% cement; 9% asphalt; 5% rice husk ash; 3% coal slag; 3% sulfonated coumarone resin; 1.5% tricalcium phosphate and 3% gypsum.

9. The high performance concrete according to claim 1, Features: The raw materials of the high performance concrete are as follows by weight: 9% water; 43% gravel; 18% fine sand; 13.5% cement; 2% asphalt; 4% tire residue; 3% coal slag; 3% sulfonated coumarone resin; 1.5% tricalcium phosphate and 3% gypsum.

10. The high performance concrete according to claim 1, Features: The raw materials of the high performance concrete are as follows by weight: 9% water; 41% gravel; 18% fine sand; 13.5% cement; 2% asphalt; 4% tire residue; 5% rice husk ash; 3% coal slag; 1.5% tricalcium phosphate and 3% gypsum.

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