A method for preparing concrete based on resource utilization of stone powder residue

Abstract

This invention belongs to the field of building materials technology, specifically relating to a method for preparing concrete based on the resource utilization of stone powder slag. This invention utilizes stone powder slag by selecting titanate-modified mineral powder, metakaolin, admixtures, water glass, sodium hydroxide, triethylamine, and quartz sand in combination with the stone powder slag, and modifies the components to effectively improve the compressive strength and fluidity of the concrete, achieving a good impermeability grade.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a method for preparing concrete based on the resource utilization of stone powder slag. Background Technology

[0002] Concrete is characterized by readily available raw materials, good economic efficiency, and ease of construction, and is widely used as a basic construction material in infrastructure construction such as transportation, buildings, municipal works, and bridges. With the increase in stone production, the amount of waste stone powder and slag generated is increasing year by year, and a large amount of this waste cannot be fully utilized. Utilizing solid waste in concrete can effectively save resources, protect the environment, and create an environmentally friendly society. Furthermore, using waste stone powder and slag as an admixture in concrete can achieve the reuse of waste resources.

[0003] Chinese patent (publication number CN116462484A) discloses a slag-waste marble powder-based alkali-activated high-strength concrete and its preparation method. The slag-waste marble powder-based alkali-activated high-strength concrete prepared by this invention possesses excellent physical and mechanical properties, exhibiting both early strength and high strength. In practical engineering, it can shorten the construction cycle and improve construction efficiency to a certain extent. Compared to the complex preparation process and harsh curing conditions of traditional high-strength concrete, this invention only requires uniform mixing of raw materials followed by room temperature or ambient temperature curing. Furthermore, the raw materials are inexpensive and readily available, making it highly valuable for application. However, existing technologies for preparing concrete using slag powder resources suffer from problems such as insufficient compressive strength, inadequate fluidity, and poor impermeability, severely impacting its practical use.

[0004] Therefore, how to utilize stone powder slag as a resource and use it in conjunction with other modified components to improve the compressive strength and fluidity of concrete and obtain a good impermeability grade has become a key area that needs to be addressed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing concrete based on the resource utilization of stone powder slag, which aims to solve the problems of insufficient compressive strength, insufficient fluidity, and poor impermeability of concrete prepared by the resource utilization of stone powder slag in the prior art.

[0006] This invention utilizes stone powder slag for resource recovery by using a combination of titanate-modified mineral powder, metakaolin, admixtures, water glass, sodium hydroxide, triethylamine, and quartz sand with the stone powder slag, and by modifying the components, effectively improving the compressive strength and fluidity of concrete, and achieving a good impermeability grade.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0008] This invention provides a method for preparing concrete based on the resource utilization of stone powder slag, comprising the following steps:

[0009] S1: By weight, add 2-4 parts of titanate coupling agent to 200-240 parts of anhydrous ethanol and stir evenly. Then add 80-100 parts of mineral powder for modification treatment to obtain titanate modified mineral powder.

[0010] S2: Mix 460-480 parts of titanate-modified mineral powder, 280-300 parts of metakaolin, 200-240 parts of stone powder slag and 6-8 parts of additives and stir evenly to obtain a mixture;

[0011] S3: Mix 180-200 parts of water glass, 30-40 parts of sodium hydroxide and 100-140 parts of water evenly to obtain an activator; then add the activator to the mixture, and add 10-20 parts of triethylamine and 900-1000 parts of quartz sand and stir at high speed to obtain concrete.

[0012] As a preferred technical solution of the present invention, the conditions for the modification treatment include: controlling the temperature at 70-80°C and stirring at a speed of 600-800 r / min for 50-70 min.

[0013] Titanate-modified mineral powder has better dispersibility, can be evenly distributed in concrete to reduce particle agglomeration, and effectively fill the pores in concrete. By reducing porosity, it increases the density of concrete, thereby improving the compressive strength of concrete.

[0014] As a preferred technical solution of the present invention, the metakaolin is a metakaolin composite material;

[0015] The preparation method of the metakaolin composite material includes: dissolving 10-20 parts by weight of chitosan in 400-500 parts by weight of 2-4% acetic acid solution, then adding 16-24 parts by weight of commercially available metakaolin for composite treatment to obtain an intermediate product; adding 1-3 parts by weight of γ-glycidyl etheroxypropyltrimethoxysilane to a mixture of 300-400 parts by weight of deionized water and 100-200 parts by weight of anhydrous ethanol and stirring evenly, then adding 40-60 parts by weight of the intermediate product for coupling treatment to obtain the metakaolin composite material.

[0016] As a preferred technical solution of the present invention, the conditions for the composite treatment include: stirring at a speed of 80-100 r / min for 2-4 h, filtering, washing with water, and freeze drying.

[0017] As a preferred technical solution of the present invention, the coupling treatment conditions include: stirring at a speed of 100-200 r / min for 2-4 hours at a temperature of 50-60°C, followed by washing with water and drying.

[0018] The chitosan introduced into metakaolin composites can form a thin lubricating film on the surface of metakaolin, reducing the frictional resistance between metakaolin particles and thus improving the flowability of concrete. At the same time, silane modification can effectively improve the dispersion of the chitosan composite in concrete paste, prevent particle aggregation, and effectively improve fluidity.

[0019] As a preferred embodiment of the present invention, the stone powder slag is modified stone powder slag;

[0020] The preparation method of modified stone powder slag includes: dispersing 10-20 parts by weight of aluminum tripolyphosphate in 200-300 parts by weight of deionized water, then adding 20-30 parts by weight of stone powder slag and grinding to obtain stone powder slag A; adding 20-30 parts by weight of the stone powder slag A to 40-50 parts by weight of methyl acrylate solution with a molar concentration of 0.1-0.2 mol / L and stirring to obtain modified stone powder slag.

[0021] As a preferred technical solution of the present invention, the grinding treatment conditions include: grinding in a closed sand mill for 60 to 80 minutes, drying, and pulverizing.

[0022] As a preferred technical solution of the present invention, the stirring treatment conditions include: stirring at 60-70°C for 2-4 hours, filtration, and drying at 100-110°C for 6-8 hours.

[0023] Methyl acrylate in modified stone powder slag has hydrophobic properties that reduce the water molecule penetration rate, delay the invasion of harmful ions, and effectively reduce the penetration path of water and other harmful substances; aluminum tripolyphosphate combines with calcium elements in stone powder slag through phosphate groups to achieve chemical passivation of concrete, thereby improving the impermeability level through hydrophobic barrier + chemical passivation.

[0024] As a preferred embodiment of the present invention, the admixture is a naphthalene-based water-reducing agent and sodium tetraborate decahydrate; the mass ratio of the naphthalene-based water-reducing agent and sodium tetraborate decahydrate in the admixture is (1-2):1.

[0025] As a preferred embodiment of the present invention, the conditions for high-speed stirring include: a rotation speed of 280-300 r / min and a time of 2-4 min.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) This invention introduces chitosan into the metakaolin composite material to form a lubricating film, and at the same time, it combines the flexible polymer chains such as the titanate of modified mineral powder and the methyl acrylate of modified stone powder slag to improve the fluidity of concrete. In addition, one end of the titanate modifier in the modified mineral powder forms a strong chemical bond with the mineral powder, and the long-chain organic groups extending to the outside end are entangled with the molecular chains of methyl acrylate in the modified stone powder slag. At the same time, the metakaolin composite material introduces epoxy groups through a coupling agent. Under the action of triethylamine, the epoxy groups undergo an addition reaction with the methyl acrylate of the modified stone powder slag, thereby constructing a high-density network structure. This network structure reduces the porosity and defects inside the concrete and makes the material more compact, improving the compressive strength while reducing the permeation channels.

[0028] (2) The mineral powder modified with titanate of the present invention has better dispersibility, can be evenly distributed in concrete to reduce particle agglomeration, and effectively fill the pores in concrete. By reducing the porosity, the density of concrete is increased, thereby improving the compressive strength of concrete.

[0029] (3) The chitosan introduced into the metakaolin composite material of the present invention can form a thin lubricating film on the surface of metakaolin, reduce the frictional resistance between metakaolin, and thus improve the flowability of concrete. At the same time, silane modification can effectively improve the dispersion of the chitosan composite material in the concrete paste, prevent the aggregation between particles, and effectively improve the fluidity.

[0030] (4) Methyl acrylate in the modified stone powder slag of the present invention has hydrophobic properties that can reduce the water molecule permeation rate, delay the invasion of harmful ions, and effectively reduce the permeation path of water and other harmful substances; aluminum tripolyphosphate combines with calcium elements in stone powder slag through phosphate groups to achieve chemical passivation of concrete, and improves the impermeability level through hydrophobic barrier + chemical passivation. Detailed Implementation

[0031] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0032] The sources of some components in the examples and comparative examples are as follows:

[0033] Mineral powder, 200 mesh, purchased from Yonghao Mineral Products Processing Plant in Pengzhou City;

[0034] Commercially available metakaolin, product number A00379, was purchased from Wuhan Jiyesheng Chemical Co., Ltd.

[0035] Stone powder residue is waste stone powder residue produced in the Hezhou marble mining area;

[0036] Water glass, product number CG225, purchased from Shandong Zhengxing New Materials Co., Ltd.

[0037] Sodium hydroxide, CAS No. 1310-73-2, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0038] Naphthalene-based water-reducing agent, product number SY-4, Anhui Shengyuan Chemical Co., Ltd.;

[0039] Sodium tetraborate decahydrate, CAS No. 1303-96-4, was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0040] Quartz sand, 120 mesh, purchased from Hubei Chengfeng Chemical Co., Ltd.

[0041] Titanate coupling agent 201, CAS No. 67691-13-8, was purchased from Tianmen Hengchang Chemical Co., Ltd.

[0042] Acetic acid, CAS No. 64-19-7, purchased from Sinopharm Chemical Reagent Co., Ltd.

[0043] Chitosan, CAS No. 9012-76-4, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0044] γ-glycidoxypropyltrimethoxysilane, CAS No. 2530-83-8, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0045] Aluminum tripolyphosphate, CAS No. 13939-25-8, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0046] Methyl acrylate, CAS 96-33-3, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0047] Example 1

[0048] This embodiment provides a method for preparing concrete based on the resource utilization of stone powder slag, including the following steps:

[0049] S1: By weight, add 4 parts of titanate coupling agent to 240 parts of anhydrous ethanol and stir evenly. Then add 100 parts of mineral powder for modification treatment. Control the temperature at 80℃ and stir at 800r / min for 50min to obtain titanate modified mineral powder.

[0050] S2: Mix 480 parts of titanate modified mineral powder, 300 parts of metakaolin composite material, 240 parts of modified stone powder slag and 8 parts of additives (4 parts of naphthalene-based water-reducing agent and 4 parts of sodium tetraborate decahydrate) and stir evenly to obtain a mixture.

[0051] S3: Mix 200 parts water glass, 40 parts sodium hydroxide and 140 parts water evenly to obtain an activator; then add the activator to the mixture, and add 20 parts triethylamine and 1000 parts quartz sand. Stir at high speed (300 r / min for 2 min) to obtain concrete.

[0052] Preparation of the metakaolin composite material: 20 parts by weight of chitosan were dissolved in 500 parts by weight of 4% acetic acid solution, and then 24 parts by weight of commercially available metakaolin were added for composite treatment. The mixture was stirred at 100 r / min for 2 h, filtered, washed with water, and freeze-dried to obtain an intermediate product. 3 parts by weight of γ-glycidoxypropyltrimethoxysilane were added to a mixture of 400 parts by weight of deionized water and 200 parts by weight of anhydrous ethanol and stirred evenly. Then 60 parts by weight of the intermediate product were added for coupling treatment. The mixture was stirred at 200 r / min for 2 h at 60 °C, washed with water, and dried to obtain the metakaolin composite material.

[0053] Preparation of the modified stone powder slag: By weight, 20 parts of aluminum tripolyphosphate are dispersed in 300 parts of deionized water, and then 30 parts of stone powder slag are added for grinding. The mixture is then ground in a closed sand mill for 80 minutes, dried, and pulverized to obtain stone powder slag A. 30 parts of the stone powder slag A are added to 50 parts of methyl acrylate solution with a molar concentration of 0.2 mol / L and stirred at 70°C for 2 hours. The mixture is then filtered and dried at 110°C for 6 hours to obtain the modified stone powder slag.

[0054] Example 2

[0055] This embodiment provides a method for preparing concrete based on the resource utilization of stone powder slag, including the following steps:

[0056] S1: By weight, add 2 parts of titanate coupling agent to 200 parts of anhydrous ethanol and stir evenly. Then add 80 parts of mineral powder for modification treatment. Control the temperature at 80℃ and stir at 800r / min for 50min to obtain titanate modified mineral powder.

[0057] S2: Mix 460 parts of titanate modified mineral powder, 280 parts of metakaolin composite material, 200 parts of modified stone powder slag and 6 parts of additives (4 parts of naphthalene-based water-reducing agent and 2 parts of sodium tetraborate decahydrate) and stir evenly to obtain a mixture;

[0058] S3: Mix 180 parts water glass, 30 parts sodium hydroxide and 100 parts water evenly to obtain an activator; then add the activator to the mixture, and add 10 parts triethylamine and 900 parts quartz sand. Stir at high speed (280 r / min for 4 min) to obtain concrete.

[0059] Preparation of the metakaolin composite material: 10 parts by weight of chitosan were dissolved in 400 parts by weight of 2% acetic acid solution, and then 16 parts by weight of commercially available metakaolin were added for composite treatment. The mixture was stirred at 80 r / min for 4 h, filtered, washed with water, and freeze-dried to obtain an intermediate product. 1 part by weight of γ-glycidoxypropyltrimethoxysilane was added to a mixture of 300 parts by weight of deionized water and 100 parts by weight of anhydrous ethanol and stirred evenly. Then, 40 parts by weight of the intermediate product were added for coupling treatment. The mixture was stirred at 100 r / min for 4 h at 50 °C, washed with water, and dried to obtain the metakaolin composite material.

[0060] Preparation of the modified stone powder slag: By weight, 10 parts of aluminum tripolyphosphate are dispersed in 200 parts of deionized water, and then 20 parts of stone powder slag are added for grinding. The mixture is ground in a closed sand mill for 6 minutes, dried, and pulverized to obtain stone powder slag A. 20 parts of the stone powder slag A are added to 40 parts of methyl acrylate solution with a molar concentration of 0.1 mol / L and stirred for 4 hours at 60°C. The mixture is then filtered and dried at 100°C for 8 hours to obtain the modified stone powder slag.

[0061] Example 3

[0062] This embodiment provides a method for preparing concrete based on the resource utilization of stone powder slag, including the following steps:

[0063] S1: By weight, 3 parts of titanate coupling agent were added to 220 parts of anhydrous ethanol and stirred evenly. Then, 90 parts of mineral powder were added for modification treatment. The temperature was controlled at 75℃ and stirred at 700r / min for 60min to obtain titanate modified mineral powder.

[0064] S2: Mix 470 parts of titanate modified mineral powder, 290 parts of metakaolin composite material, 220 parts of modified stone powder slag and 7 parts of additives (4 parts of naphthalene-based water-reducing agent and 3 parts of sodium tetraborate decahydrate) and stir evenly to obtain a mixture.

[0065] S3: Mix 190 parts water glass, 35 parts sodium hydroxide and 120 parts water evenly to obtain an activator; then add the activator to the mixture, and add 15 parts triethylamine and 950 parts quartz sand. Stir at high speed (290 r / min for 3 min) to obtain concrete.

[0066] Preparation of the metakaolin composite material: 15 parts by weight of chitosan were dissolved in 450 parts by weight of 3% acetic acid solution, and then 20 parts by weight of commercially available metakaolin were added for composite treatment. The mixture was stirred at 90 r / min for 3 h, filtered, washed with water, and freeze-dried to obtain an intermediate product. 2 parts by weight of γ-glycidyl etheroxypropyltrimethoxysilane were added to a mixture of 350 parts by weight of deionized water and 150 parts by weight of anhydrous ethanol and stirred evenly. Then, 50 parts by weight of the intermediate product were added for coupling treatment. The mixture was stirred at 150 r / min for 3 h at 55 °C, washed with water, and dried to obtain the metakaolin composite material.

[0067] Preparation of the modified stone powder slag: By weight, 15 parts of aluminum tripolyphosphate were dispersed in 250 parts of deionized water, and then 25 parts of stone powder slag were added for grinding. The mixture was ground in a closed sand mill for 70 minutes, dried, and pulverized to obtain stone powder slag A. 25 parts of the stone powder slag A were added to 45 parts of methyl acrylate solution with a molar concentration of 0.2 mol / L and stirred for 3 hours at 65°C. The mixture was then filtered and dried at 105°C for 7 hours to obtain the modified stone powder slag.

[0068] Example 4

[0069] The difference between this embodiment and Embodiment 1 is that commercially available mineral powder (200 mesh, purchased from Pengzhou Yonghao Mineral Products Processing Plant) is used instead of titanate-modified mineral powder.

[0070] Example 5

[0071] The difference between this embodiment and Embodiment 1 is that commercially available metakaolin (item number A00379) is used instead of metakaolin composite material.

[0072] Comparative Example 1

[0073] The difference between this comparative example and Example 1 is that 480 parts of titanate-modified mineral powder are not added to the components.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Example 1 is that 300 parts of metakaolin composite material are not added to the components.

[0076] Comparative Example 3

[0077] The difference between this comparative example and Example 1 is that 240 parts of modified stone powder slag are not added to the components.

[0078] The compressive strength, fluidity, and impermeability grade of the concrete provided in the above embodiments and comparative examples were tested using the following methods:

[0079] (1) Compressive strength

[0080] The compressive strength was tested in accordance with the requirements of GB / T 17671-2021 Cement Mortar Strength Test Method (ISO Method).

[0081] (2) Flowability

[0082] The fluidity was tested in accordance with the requirements of GB / T 2419-2005, "Determination of Flowability of Cement Mortar".

[0083] (3) Impermeability grade

[0084] The impermeability grade was tested in accordance with the requirements of GB / T 50082-2024 Standard for Test Methods of Long-Term Performance and Durability of Concrete.

[0085] The performance test data above are shown in Table 1.

[0086] Table 1 Performance Test Results

[0087] 28-day compressive strength (MPa) Flowability (mm) impermeability grade Example 1 102.1 224 P9 Example 2 101.5 221 P9 Example 3 102.8 223 P9 Example 4 95.7 196 P7 Example 5 96.2 199 P7 Comparative Example 1 89.4 188 P5 Comparative Example 2 90.5 180 P5 Comparative Example 3 90.3 191 P4

[0088] As can be seen from the above, this invention achieves resource utilization by modifying stone powder slag, and at the same time introduces a composite material of mineral powder and metakaolin modified with titanate, which effectively improves the compressive strength of concrete, enhances its fluidity, and obtains a good impermeability grade.

[0089] Compared with Example 1, replacing the titanate-modified mineral powder with commercially available mineral powder (200 mesh, purchased from Pengzhou Yonghao Mineral Products Processing Plant) resulted in decreased compressive strength, reduced fluidity, and worsened impermeability (Example 4); compared with Example 1, replacing the metakaolin composite material with commercially available metakaolin (item number A00379) resulted in decreased compressive strength, reduced fluidity, and worsened impermeability (Example 5); compared with Example 1, not adding 480 parts of titanate-modified mineral powder resulted in decreased compressive strength, reduced fluidity, and worsened impermeability (Comparative Example 1); compared with Example 1, not adding 300 parts of metakaolin composite material resulted in decreased compressive strength, reduced fluidity, and worsened impermeability (Comparative Example 2); compared with Example 1, not adding 240 parts of modified stone powder slag resulted in decreased compressive strength, reduced fluidity, and worsened impermeability (Comparative Example 3).

[0090] In summary, this invention utilizes stone powder slag for resource recovery by using a combination of titanate-modified mineral powder, metakaolin, admixtures, water glass, sodium hydroxide, triethylamine, and quartz sand with the stone powder slag, and by modifying the components, effectively improving the compressive strength and fluidity of concrete, and achieving a good impermeability grade.

Claims

1. A method for preparing concrete based on the resource utilization of stone powder slag, characterized in that, Includes the following steps: S1: By weight, add 2-4 parts of titanate coupling agent to 200-240 parts of anhydrous ethanol and stir evenly. Then add 80-100 parts of mineral powder for modification treatment to obtain titanate modified mineral powder. S2: Mix 460-480 parts of titanate modified mineral powder, 280-300 parts of metakaolin composite material, 200-240 parts of modified stone powder slag and 6-8 parts of additives and stir evenly to obtain a mixture; S3: Mix 180-200 parts of water glass, 30-40 parts of sodium hydroxide and 100-140 parts of water evenly to obtain an activator; then add the activator to the mixture, and add 10-20 parts of triethylamine and 900-1000 parts of quartz sand and stir at high speed to obtain concrete; The preparation method of the metakaolin composite material includes: dissolving 10-20 parts by weight of chitosan in 400-500 parts by weight of 2-4% acetic acid solution, then adding 16-24 parts by weight of commercially available metakaolin for composite treatment to obtain an intermediate product; adding 1-3 parts by weight of γ-glycidyl etheroxypropyltrimethoxysilane to a mixture of 300-400 parts by weight of deionized water and 100-200 parts by weight of anhydrous ethanol and stirring evenly, then adding 40-60 parts by weight of the intermediate product for coupling treatment to obtain the metakaolin composite material; The method for preparing the modified stone powder slag includes: dispersing 10-20 parts by weight of aluminum tripolyphosphate in 200-300 parts by weight of deionized water, then adding 20-30 parts by weight of stone powder slag and grinding to obtain stone powder slag A; adding 20-30 parts by weight of the stone powder slag A to 40-50 parts by weight of methyl acrylate solution with a molar concentration of 0.1-0.2 mol / L and stirring to obtain the modified stone powder slag.

2. The method for preparing concrete based on the resource utilization of stone powder slag according to claim 1, characterized in that, The conditions for the modification treatment include: controlling the temperature at 70-80℃ and stirring at a speed of 600-800 r / min for 50-70 min.

3. The method for preparing concrete based on the resource utilization of stone powder slag according to claim 1, characterized in that, The conditions for the composite treatment include: stirring at a speed of 80-100 r / min for 2-4 hours, filtration, washing with water, and freeze drying.

4. The method for preparing concrete based on the resource utilization of stone powder slag according to claim 1, characterized in that, The coupling treatment conditions include: stirring at 100-200 r / min for 2-4 hours at a temperature of 50-60℃, followed by washing with water and drying.

5. The method for preparing concrete based on the resource utilization of stone powder slag according to claim 1, characterized in that, The grinding process includes: grinding in a closed sand mill for 60-80 minutes, drying, and pulverizing.

6. The method for preparing concrete based on the resource utilization of stone powder slag according to claim 1, characterized in that, The conditions for the stirring treatment include: stirring at 60-70°C for 2-4 hours, filtration, and drying at 100-110°C for 6-8 hours.

7. The method for preparing concrete based on the resource utilization of stone powder slag according to claim 1, characterized in that, The admixture is a naphthalene-based water-reducing agent and sodium tetraborate decahydrate; the mass ratio of the naphthalene-based water-reducing agent and sodium tetraborate decahydrate in the admixture is (1-2):

1.

8. The method for preparing concrete based on the resource utilization of stone powder slag according to claim 1, characterized in that, The conditions for high-speed stirring include: a rotation speed of 280–300 r / min and a stirring time of 2–4 min.