A quick-setting high-strength concrete and its preparation method

Abstract

This invention relates to a rapid-setting high-strength concrete and its preparation method. The rapid-setting high-strength concrete comprises the following raw materials in parts by weight: 100-200 parts cement, 80-100 parts coarse aggregate, 40-60 parts fine aggregate, 10-20 parts rubber powder, 20-30 parts modified straw-based carbon powder, 0.3-0.5 parts coupling agent, and 0.6-0.8 parts water-reducing agent. The modified straw-based carbon powder is obtained by first adding straw powder to an activation solution containing aluminum sulfate, carboxymethyl starch, and triethanolamine, followed by activation, ball milling, and freeze-drying to obtain a precursor. The precursor is then mixed with flake aluminum powder and heated under an inert atmosphere to obtain the final product. The mass fraction of aluminum sulfate is 5-10%, the mass fraction of carboxymethyl starch is 5-10%, and the mass fraction of triethanolamine is 3-5%. This invention improves the rapid setting effect, compressive strength, flexural strength, and crack resistance of concrete by incorporating modified straw-based carbon powder into the concrete components. This is of great significance for improving the overall performance of concrete and developing infrastructure construction.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a fast-setting high-strength concrete and its preparation method. Background Technology

[0002] As the most widely used and consumed building material, improving the quality of concrete is of significant research value for enhancing the service life and performance of engineering structures. High-strength concrete, in particular, has a much higher strength than ordinary concrete.

[0003] High-strength concrete is more durable than soil and deforms much less under the same stress conditions, thus significantly improving the load-bearing capacity of its structure. Therefore, high-strength concrete has been used more extensively in large-scale, special, and important projects.

[0004] Furthermore, some special construction projects may require concrete to set within a short time. This indicates that there is a certain application demand for quick-setting high-strength concrete. To solve the above-mentioned technical problems, this invention proposes a quick-setting high-strength concrete and its preparation method. Summary of the Invention

[0005] The purpose of this invention is to provide a fast-setting high-strength concrete and its preparation method in order to solve the above-mentioned problems.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] This invention provides a quick-setting high-strength concrete, comprising the following raw materials in parts by weight: 100-200 parts cement, 80-100 parts coarse aggregate, 40-60 parts fine aggregate, 10-20 parts rubber powder, 20-30 parts modified straw-based carbon powder, 0.3-0.5 parts coupling agent, and 0.6-0.8 parts water-reducing agent;

[0008] The modified straw-based carbon powder is obtained by first adding straw powder to an activation solution containing aluminum sulfate, carboxymethyl starch and triethanolamine, then activating, ball milling and freeze-drying to obtain a precursor, and then mixing the precursor with flake aluminum powder and heating it under an inert atmosphere. The mass fraction of aluminum sulfate is 5-10%, the mass fraction of carboxymethyl starch is 5-10%, and the mass fraction of triethanolamine is 3-5%.

[0009] As a further optimization of the present invention, the preparation method of the modified straw-based carbon powder specifically includes the following steps:

[0010] (1) Add aluminum sulfate, carboxymethyl starch and triethanolamine to deionized water and stir until homogeneous to obtain an activated solution;

[0011] (2) Add straw powder to the activation solution to form a mixture, ball mill the mixture to obtain a mixed slurry, freeze dry the mixed slurry at -60 ~ -80℃ for 4-6 hours to obtain the precursor;

[0012] (3) The precursor is mixed with flake aluminum powder and heated at 600-700℃ for 1-3 hours in an inert atmosphere to obtain the modified straw-based carbon powder.

[0013] As a further optimization of the present invention, the amount of the activation solution is 6-10 times the mass of the straw powder.

[0014] As a further optimization of the present invention, the mass ratio of the flake aluminum powder to the precursor is 1:10-15.

[0015] As a further optimization of the present invention, the rubber powder is rubber powder processed from waste tires, with a fineness of 80-100 mesh.

[0016] As a further optimization of the present invention, the coupling agent is a silane coupling agent, and the polycarboxylate superplasticizer has a solid content of 30-40% and a water reduction rate of ≥30%.

[0017] The present invention also provides a method for preparing rapid-setting high-strength concrete as described above, comprising the following steps:

[0018] (1) Heat the modified straw-based carbon powder and rubber powder to 130-150℃ and stir thoroughly until evenly mixed;

[0019] (2) Mix the cement, coarse aggregate, fine aggregate, coupling agent and water-reducing agent evenly;

[0020] (3) Mix the materials from steps (1) and (2) evenly to obtain the product.

[0021] As a further optimization of the present invention, both steps (1) and (2) are stirred at 800-1000 r / min for 20-30 min.

[0022] The beneficial effects of this invention are as follows:

[0023] The fast-setting high-strength concrete provided by this invention is prepared using cement, coarse aggregate, fine aggregate, rubber powder, modified straw-based carbon powder, coupling agent, and water-reducing agent as main raw materials. The modified straw-based carbon powder is obtained by first adding straw powder to an activation solution containing aluminum sulfate, carboxymethyl starch, and triethanolamine, followed by activation, ball milling, and freeze-drying to obtain a precursor. This precursor is then mixed with flake aluminum powder and heated under an inert atmosphere to obtain the final product. The incorporation of modified straw-based carbon powder significantly improves the rapid-setting effect, compressive strength, flexural strength, and crack resistance of concrete, which is of great significance for improving the overall performance of concrete and developing infrastructure construction. Detailed Implementation

[0024] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content. Example

[0025] This embodiment provides a component formulation for quick-setting high-strength concrete, comprising the following raw materials in parts by weight: 200 parts cement, 100 parts coarse aggregate, 60 parts fine aggregate, 10 parts rubber powder, 30 parts modified straw-based carbon powder, 0.5 parts coupling agent, and 0.6 parts water-reducing agent. The rubber powder is made from waste tires and has a fineness of 80-100 mesh. The coupling agent is a silane coupling agent. The polycarboxylate water-reducing agent has a solid content of 30-40% and a water reduction rate of ≥30%.

[0026] The modified straw-based carbon powder is obtained by first adding straw powder to an activation solution containing aluminum sulfate, carboxymethyl starch and triethanolamine, then activating, ball milling and freeze-drying to obtain a precursor, and then mixing the precursor with flake aluminum powder and heating it under an inert atmosphere. The mass fraction of aluminum sulfate is 5%, the mass fraction of carboxymethyl starch is 10%, and the mass fraction of triethanolamine is 5%.

[0027] The preparation method of rapid-setting high-strength concrete includes the following steps:

[0028] (1) Preparation of modified straw-based carbon powder: First, aluminum sulfate, carboxymethyl starch and triethanolamine are added to deionized water and stirred evenly to obtain an activation solution. Then, straw powder is added to the activation solution to form a mixture. The mixture is ball-milled to obtain a mixed slurry. The mixed slurry is freeze-dried at -60℃ for 6h to obtain a precursor. Finally, the precursor is mixed with flake aluminum powder and heated at 600℃ for 3h in an inert atmosphere to obtain the modified straw-based carbon powder. The amount of the activation solution is 6 times the mass of the straw powder, and the mass ratio of the flake aluminum powder to the precursor is 1:10.

[0029] (2) Heat the modified straw-based carbon powder and rubber powder to 150°C and mix them evenly at 800 r / min for 30 min;

[0030] (3) Mix cement, coarse aggregate, fine aggregate, coupling agent and water-reducing agent at 800 r / min for 30 min until homogeneous;

[0031] (4) Mix the materials from steps (2) and (3) evenly to obtain the product. Example

[0032] This embodiment provides a component formulation for quick-setting high-strength concrete, comprising the following raw materials in parts by weight: 100 parts cement, 80 parts coarse aggregate, 40 parts fine aggregate, 20 parts rubber powder, 20 parts modified straw-based carbon powder, 0.3 parts coupling agent, and 0.8 parts water-reducing agent. The rubber powder is rubber powder processed from waste tires, with a fineness of 80-100 mesh. The coupling agent is a silane coupling agent. The polycarboxylate water-reducing agent has a solid content of 30-40% and a water reduction rate of ≥30%.

[0033] The modified straw-based carbon powder is obtained by first adding straw powder to an activation solution containing aluminum sulfate, carboxymethyl starch and triethanolamine, then activating, ball milling and freeze-drying to obtain a precursor, and then mixing the precursor with flake aluminum powder and heating it under an inert atmosphere. The mass fraction of aluminum sulfate is 10%, the mass fraction of carboxymethyl starch is 5%, and the mass fraction of triethanolamine is 3%.

[0034] The preparation method of rapid-setting high-strength concrete includes the following steps:

[0035] (1) Preparation of modified straw-based carbon powder: First, aluminum sulfate, carboxymethyl starch and triethanolamine are added to deionized water and stirred evenly to obtain an activation solution. Then, straw powder is added to the activation solution to form a mixture. The mixture is ball-milled to obtain a mixed slurry. The mixed slurry is freeze-dried at -80℃ for 4h to obtain a precursor. Finally, the precursor is mixed with flake aluminum powder and heated at 800℃ for 1h in an inert atmosphere to obtain the modified straw-based carbon powder. The amount of the activation solution is 10 times the mass of the straw powder, and the mass ratio of the flake aluminum powder to the precursor is 1:15.

[0036] (2) Heat the modified straw-based carbon powder and rubber powder to 150°C and mix them evenly at 1000 r / min for 20 min;

[0037] (3) Mix cement, coarse aggregate, fine aggregate, coupling agent and water-reducing agent at 1000r / min for 20min until homogeneous;

[0038] (4) Mix the materials from steps (2) and (3) evenly to obtain the product. Example

[0039] This embodiment provides a component formulation for quick-setting high-strength concrete, comprising the following raw materials in parts by weight: 150 parts cement, 90 parts coarse aggregate, 50 parts fine aggregate, 15 parts rubber powder, 25 parts modified straw-based carbon powder, 0.4 parts coupling agent, and 0.7 parts water-reducing agent. The rubber powder is rubber powder processed from waste tires, with a fineness of 80-100 mesh. The coupling agent is a silane coupling agent. The polycarboxylate water-reducing agent has a solid content of 30-40% and a water reduction rate of ≥30%.

[0040] The modified straw-based carbon powder is obtained by first adding straw powder to an activation solution containing aluminum sulfate, carboxymethyl starch and triethanolamine, then activating, ball milling and freeze-drying to obtain a precursor, and then mixing the precursor with flake aluminum powder and heating it under an inert atmosphere. The mass fraction of aluminum sulfate is 7.5%, the mass fraction of carboxymethyl starch is 7.5%, and the mass fraction of triethanolamine is 4%.

[0041] The preparation method of rapid-setting high-strength concrete includes the following steps:

[0042] (1) Preparation of modified straw-based carbon powder: First, aluminum sulfate, carboxymethyl starch and triethanolamine are added to deionized water and stirred evenly to obtain an activation solution. Then, straw powder is added to the activation solution to form a mixture. The mixture is ball-milled to obtain a mixed slurry. The mixed slurry is freeze-dried at -70℃ for 5h to obtain a precursor. Finally, the precursor is mixed with flake aluminum powder and heated at 700℃ for 2h in an inert atmosphere to obtain the modified straw-based carbon powder. The amount of the activation solution is 8 times the mass of the straw powder, and the mass ratio of the flake aluminum powder to the precursor is 1:12.

[0043] (2) Heat the modified straw-based carbon powder and rubber powder to 130°C and mix them evenly at 1000r / min for 20min;

[0044] (3) Mix cement, coarse aggregate, fine aggregate, coupling agent and water-reducing agent at 1000r / min for 20min until homogeneous;

[0045] (4) Mix the materials from steps (2) and (3) evenly to obtain the product.

[0046] Verification test

[0047] 1. To verify the effect of the incorporation of modified straw-based carbon powder on rapid-setting high-strength concrete, modified straw-based carbon powder was incorporated into the composition disclosed in Example 3 at weight ratios of 20, 25, and 30 parts (corresponding to adjustments of cement weight ratios of 155, 150, and 145), resulting in samples 1-3. In addition, control group 1 was set up with unmodified straw-based carbon powder (straw powder is burned into carbon at 600°C and then pulverized into carbon powder) at a weight ratio of 25 parts; control group 2 was with straw powder at a weight ratio of 25 parts; and control group 3 was without the addition of rubber powder (corresponding to adjustments of cement weight ratio of 165).

[0048] During sample preparation, the concrete sample was mixed with mixing water at a rate of 50% of the cement content. The initial and final setting times were recorded. Subsequently, the prepared sample was subjected to performance testing.

[0049] (1) The compressive strength and flexural strength of the samples were determined according to GT / B50107-2010: the specimen size was 100.0mm×100.0mm×100.0mm. After the specimen was formed, it should be left to stand at (20±5)℃ for (24±2)h. The specimens were numbered and demolded. They were then cured under standard laboratory conditions for 28 days. The specimens were first observed for cracks and the length of the cracks was recorded. Then the compressive strength and flexural strength were tested. The surface of the specimens should be wiped clean before the test.

[0050] (2) Splitting strength: Tested in accordance with JTG3420-2020 "Test Procedures for Cement and Cement Concrete in Highway Engineering".

[0051] Table 1. Test Results

[0052] ;

[0053] Conclusion: As shown in Table 1, the comparison between samples 1-3 and control group 1-2 indicates that the incorporation of modified straw-based carbon powder has a certain promoting effect on shortening the initial and final setting times of concrete specimens. In addition, the compressive strength, flexural strength, and splitting strength of the concrete specimens are also improved to a certain extent. Furthermore, no cracks appeared in samples 1-3, while cracks appeared in control groups 1 and 2, indicating that the incorporation of modified straw-based carbon powder also improves the crack resistance of the concrete specimens to a certain extent.

[0054] In addition, comparing samples 1-3, it can be seen that the difference among the three lies in the amount of modified straw-based carbon powder added. Sample 1 is 20 parts by weight, sample 2 is 25 parts by weight, and sample 3 is 30 parts by weight. The data results show that when the amount of modified straw-based carbon powder added is 25 parts by weight, the concrete specimen has the best rapid setting effect, compressive strength, flexural strength, and crack resistance.

[0055] Finally, the amount of modified straw-based carbon powder added to both control group 3 and sample 2 was the same, 25 parts by weight. However, control group 3 did not contain rubber powder in its component formulation. The data results show that sample 2 performed better than control group 3 in terms of rapid setting effect, compressive strength, flexural strength and crack resistance. This indicates that the synergistic effect of rubber powder and modified straw-based carbon powder jointly promotes the improvement of rapid setting effect, compressive strength, flexural strength and crack resistance of concrete specimens.

[0056] 2. To verify the effect of the activation solution composition formulation used in the preparation of modified straw-based carbon powder on the performance of rapid-setting high-strength concrete, the composition of the activation solution was adjusted using the composition formulation disclosed in Example 3, while keeping the proportions of the other components constant, as shown in Table 2; in addition, no flake aluminum powder was added as control group 4.

[0057] Table 2. Test Results

[0058] ;

[0059] The above samples were tested for performance according to the verification items shown in Verification Test 1, and the results are shown in Table 3.

[0060] Table 3. Test Results

[0061] ;

[0062] As can be seen from the table, the difference between samples 4-7 lies in the adjustment of the components and proportions of the activation solution. The test results show that when the mass fraction of aluminum sulfate is 10%, the mass fraction of carboxymethyl starch is 5%, and the mass fraction of triethanolamine is 5%, the concrete specimen has the best rapid setting effect, compressive strength, flexural strength, and crack resistance. As the mass fraction of aluminum sulfate increases, the rapid setting effect of the concrete specimen is improved, and as the mass fraction of carboxymethyl starch increases, the compressive strength, flexural strength, and crack resistance of the concrete specimen are improved.

[0063] Compared to sample 6, samples 8-9 replaced aluminum sulfate with potassium sulfate and carboxymethyl starch with starch, respectively. The test results show that aluminum sulfate is better than other sulfates in improving the rapid setting effect of concrete specimens, and carboxymethyl starch is better than ordinary starch in improving the compressive, flexural and crack resistance of concrete specimens.

[0064] Finally, the difference between control group 4 and sample 6 is that control group 4 did not add flake aluminum powder. The test results show that the addition of flake aluminum powder helps to improve the compressive, flexural and crack resistance of concrete specimens, and has no significant adverse effect on the rapid setting effect of concrete specimens. Therefore, to improve the compressive, flexural and crack resistance of concrete specimens, a certain amount of flake aluminum powder can be added.

[0065] The foregoing description illustrates and describes several preferred embodiments of the invention. However, as previously stated, it should be understood that the invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A type of rapid-setting high-strength concrete, characterized in that, The raw materials include the following parts by weight: 100-200 parts cement, 80-100 parts coarse aggregate, 40-60 parts fine aggregate, 10-20 parts rubber powder, 20-30 parts modified straw-based carbon powder, 0.3-0.5 parts coupling agent, and 0.6-0.8 parts water-reducing agent. The modified straw-based carbon powder is obtained by first adding straw powder to an activation solution containing aluminum sulfate, carboxymethyl starch and triethanolamine, then activating, ball milling and freeze-drying to obtain a precursor, and then mixing the precursor with flake aluminum powder and heating it under an inert atmosphere. The mass fraction of aluminum sulfate is 5-10%, the mass fraction of carboxymethyl starch is 5-10%, and the mass fraction of triethanolamine is 3-5%.

2. The rapid-setting high-strength concrete according to claim 1, characterized in that, The preparation method of the modified straw-based carbon powder specifically includes the following steps: (1) Add aluminum sulfate, carboxymethyl starch and triethanolamine to deionized water and stir until homogeneous to obtain an activated solution; (2) Add straw powder to the activation solution to form a mixture, ball mill the mixture to obtain a mixed slurry, freeze dry the mixed slurry at -60 ~ -80℃ for 4-6 hours to obtain the precursor; (3) The precursor is mixed with flake aluminum powder and heated at 600-700℃ for 1-3 hours in an inert atmosphere to obtain the modified straw-based carbon powder.

3. The rapid-setting high-strength concrete according to claim 1, characterized in that, The amount of the activation solution used is 6-10 times the mass of the straw powder.

4. The rapid-setting high-strength concrete according to claim 1, characterized in that, The mass ratio of the flake aluminum powder to the precursor is 1:10-15.

5. The rapid-setting high-strength concrete according to claim 1, characterized in that, The rubber powder is made from waste tires and has a fineness of 80-100 mesh.

6. The rapid-setting high-strength concrete according to claim 1, characterized in that, The coupling agent is a silane coupling agent, and the water-reducing agent has a solid content of 30-40% and a water reduction rate of ≥30%.

7. A method for preparing rapid-setting high-strength concrete as described in any one of claims 1-6, characterized in that, Includes the following steps, (1) Heat the modified straw-based carbon powder and rubber powder to 130-150℃ and stir thoroughly until evenly mixed; (2) Mix the cement, coarse aggregate, fine aggregate, coupling agent and water-reducing agent evenly; (3) Mix the materials from steps (1) and (2) evenly to obtain the product.

8. The method for preparing rapid-setting high-strength concrete according to claim 7, characterized in that, Both steps (1) and (2) involve stirring at 800-1000 r / min for 20-30 min.