A method for preparing high-performance concrete using artificial sand

Abstract

This invention relates to the field of manufactured sand utilization technology, and in particular to a method for preparing high-performance concrete using manufactured sand, comprising the following steps: (1) pretreatment of manufactured sand, (2) batching, (3) mixing and blending the adhesive system, and (4) preparing concrete. This invention enhances contact through surface treatment of manufactured sand and utilizes targeted modification of natural fibers, enabling the cement in the concrete to adhere well to each component under the promotion of fibers, resulting in a compact and dense structure, ensuring the stability of its performance, and reducing performance degradation during use. Simultaneously, by utilizing a combination of multiple fibers and various ingredients, the concrete has a complex configuration, reducing its temperature transmission efficiency and resulting in good thermal insulation properties.

Description

Technical Field

[0001] This invention relates to the field of manufactured sand utilization technology, and in particular to a method for preparing high-performance concrete using manufactured sand. Background Technology

[0002] All manufactured sand and mixed sand that have undergone soil removal treatment are collectively referred to as artificial sand. Compared with natural sand under the same conditions, under the same mix design, molding and curing conditions, concrete made with artificial sand has the following characteristics: reduced slump and increased 28-day standard strength; if the slump remains unchanged, the water requirement increases; however, under normal circumstances, the measured strength of the concrete does not decrease after increasing the water-cement ratio without increasing cement. When designing concrete mix proportions according to the characteristics of natural sand, artificial sand has a high water requirement, slightly poorer workability, and is prone to bleeding, especially in low-strength concrete with low cement content. However, if the concrete mix proportions are designed according to the characteristics of artificial sand, by rationally utilizing the stone powder in the artificial sand and adjusting the sand ratio, it is entirely possible to prepare concrete with excellent workability.

[0003] Current technologies for the use of manufactured sand in concrete mainly focus on the concrete mix proportions. Further research is needed to explore how to improve concrete performance by taking advantage of the structural characteristics of manufactured sand. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for preparing high-performance concrete using manufactured sand. By optimizing the surface treatment and batching of the manufactured sand, concrete parameters are improved, thereby enhancing its performance. The specific solution is as follows:

[0005] A method for preparing high-performance concrete using manufactured sand includes the following steps:

[0006] (1) Pretreatment of artificial sand

[0007] Add sulfuric acid to water to make the sulfuric acid content of the aqueous solution 0.33-0.42% to obtain a dilute sulfuric acid solution. Then add artificial sand and soak for 20-30 minutes. Add quicklime to the mixture to make the pH of the solution 6.8-7.1 and continue soaking for 3-4 hours.

[0008] (2) Ingredients

[0009] Add coal gangue, river sand, and silica to the mixing system from the previous step and mix thoroughly.

[0010] (3) Blending the mixed adhesive system

[0011] Mix sawdust and bagasse, soak them in sodium hydroxide solution, raise the temperature to 50-60℃ and keep it at that temperature for 60-80 minutes; filter, rinse with water until neutral, soak the resulting fiber system in dilute hydrochloric acid solution for 30-50 minutes, add calcium hydroxide solution dropwise to make the pH of the mixture 7-7.3; filter, rinse the filter residue with water 2-3 times and dry for later use;

[0012] Under nitrogen protection, the above-mentioned fibers are mixed with distilled water at a mass ratio of 1:8-9. Potassium sulfate of 7-8% of the fiber mass is added to the aqueous solution. Acrylamide is added dropwise while stirring at high speed, followed by N,N'-methylenebisacrylamide. After the addition is complete, the temperature is raised to 50-60℃ and stirring is continued for 3-4 hours. After filtration, the obtained fibers are washed with distilled water 3-5 times to obtain modified natural fibers.

[0013] (4) Preparation of concrete

[0014] Take 120-130 parts of cement for later use; mix 35-48 parts of water and 4-5 parts of the above modified natural fiber evenly, add cement and stir for 10-15 minutes, add 6-8 parts of ceramic fiber, 4-5 parts of polypropylene fiber, 160-170 parts of the mixture in step (2), and 2-3 parts of water-reducing agent and mix evenly.

[0015] Furthermore, in step (1), the amount of sulfuric acid solution used is 3-3.7 times the mass of the artificial sand.

[0016] Furthermore, in step (2), the amount of coal gangue used is 13-16% of the mass of artificial sand.

[0017] Furthermore, in step (2), the amount of river sand used is 24-28% of the mass of artificial sand.

[0018] Furthermore, in step (2), the amount of silica used is 33-39% of the mass of the artificial sand.

[0019] Furthermore, in step (3), the mass ratio of the sawdust to bagasse is 8:1-3.

[0020] Furthermore, in step (3), the concentration of the dilute hydrochloric acid is 0.3-0.46 mol / L.

[0021] Furthermore, in step (3), the calcium hydroxide solution is a saturated solution.

[0022] Furthermore, in step (3), the amount of acrylamide used is 11-13% of the fiber mass.

[0023] Furthermore, in step (3), the amount of N,N'-methylenebisacrylamide used is 0.2-0.35% of the fiber mass.

[0024] Compared with the prior art, the technical effects of the present invention are reflected in:

[0025] This invention enhances contact through surface treatment of artificial sand and utilizes targeted modification of natural fibers to ensure good adhesion between cement and other components in concrete, resulting in a dense and compact structure that guarantees performance stability and reduces performance degradation during use. Simultaneously, by combining multiple fibers and ingredients, the concrete achieves a complex configuration, reducing its temperature transfer efficiency and providing excellent thermal insulation. Detailed Implementation

[0026] The technical solution of the present invention will be further defined below with reference to specific embodiments, but the scope of protection is not limited to the description.

[0027] Example 1

[0028] A method for preparing high-performance concrete using manufactured sand includes the following steps:

[0029] (1) Pretreatment of artificial sand

[0030] Add sulfuric acid to water to make the sulfuric acid content of the aqueous solution 0.33%, and then add artificial sand to soak for 20 minutes. Add quicklime to the mixture to make the pH of the solution 6.8, and continue soaking for 3 hours.

[0031] The amount of sulfuric acid solution used is three times the mass of the artificial sand;

[0032] (2) Ingredients

[0033] Add coal gangue, river sand, and silica to the mixing system from the previous step and mix thoroughly; the amount of coal gangue is 13% of the mass of the manufactured sand; the amount of river sand is 24% of the mass of the manufactured sand; and the amount of silica is 33% of the mass of the manufactured sand.

[0034] (3) Blending the mixed adhesive system

[0035] Mix sawdust and bagasse, soak them in sodium hydroxide solution, raise the temperature to 50°C and keep it at that temperature for 60 minutes; filter, rinse with water until neutral, soak the resulting fiber system in dilute hydrochloric acid solution for 30 minutes, add calcium hydroxide solution dropwise to make the pH of the mixture 7; filter, rinse the filter residue twice with water and dry for later use.

[0036] Under nitrogen protection, the above fibers were mixed with distilled water at a mass ratio of 1:8. Potassium sulfate at 7% of the fiber mass was added to the aqueous solution. Acrylamide was added dropwise while stirring at high speed, followed by N,N'-methylenebisacrylamide. After the addition was completed, the temperature was raised to 50°C and stirring was continued for 3 hours. The mixture was then filtered, and the resulting fibers were washed three times with distilled water to obtain the modified natural fibers.

[0037] The mass ratio of sawdust to bagasse is 8:1; the concentration of the dilute hydrochloric acid is 0.3 mol / L; the calcium hydroxide solution is a saturated solution; the amount of acrylamide used is 11% of the fiber mass; and the amount of N,N'-methylenebisacrylamide used is 0.2% of the fiber mass.

[0038] (4) Preparation of concrete

[0039] Take 120 parts of cement for later use; mix 35 parts of water and 4 parts of the above modified natural fiber evenly, add cement and stir for 10 minutes, add 6 parts of ceramic fiber, 4 parts of polypropylene fiber, 160 parts of the mixture in step (2) and 2 parts of water-reducing agent and mix evenly.

[0040] Example 2

[0041] A method for preparing high-performance concrete using manufactured sand includes the following steps:

[0042] (1) Pretreatment of artificial sand

[0043] Add sulfuric acid to water to make the sulfuric acid content of the aqueous solution 0.42% to obtain a dilute sulfuric acid solution. Then add artificial sand and soak for 30 minutes. Add quicklime to the mixture to make the pH of the solution 7.1 and continue soaking for 4 hours.

[0044] The amount of sulfuric acid solution used is 3.7 times the mass of the artificial sand;

[0045] (2) Ingredients

[0046] Add coal gangue, river sand, and silica to the mixing system from the previous step and mix thoroughly; the amount of coal gangue is 16% of the mass of the manufactured sand; the amount of river sand is 28% of the mass of the manufactured sand; and the amount of silica is 39% of the mass of the manufactured sand.

[0047] (3) Blending the mixed adhesive system

[0048] Mix sawdust and bagasse, soak in sodium hydroxide solution, raise the temperature to 60℃ and keep warm for 80 minutes; filter, rinse with water until neutral, soak the resulting fiber system in dilute hydrochloric acid solution for 50 minutes, add calcium hydroxide solution dropwise to make the pH of the mixture 7.3; filter, rinse the filter residue with water 3 times and dry for later use.

[0049] Under nitrogen protection, the above fibers were mixed with distilled water at a mass ratio of 1:9. Potassium sulfate at 8% of the fiber mass was added to the aqueous solution. Acrylamide was added dropwise while stirring at high speed, followed by N,N'-methylenebisacrylamide. After the addition was completed, the temperature was raised to 60°C and stirring was continued for 4 hours. The mixture was filtered, and the resulting fibers were washed with distilled water 5 times to obtain the modified natural fibers.

[0050] The mass ratio of sawdust to bagasse is 8:3; the concentration of the dilute hydrochloric acid is 0.46 mol / L; the calcium hydroxide solution is a saturated solution; the amount of acrylamide used is 13% of the fiber mass; and the amount of N,N'-methylenebisacrylamide used is 0.35% of the fiber mass.

[0051] (4) Preparation of concrete

[0052] Take 130 parts of cement for later use; mix 48 parts of water and 5 parts of the above modified natural fiber evenly, add cement and stir for 15 minutes, add 8 parts of ceramic fiber, 5 parts of polypropylene fiber, 170 parts of the mixture in step (2) and 3 parts of water-reducing agent and mix evenly.

[0053] Example 3

[0054] A method for preparing high-performance concrete using manufactured sand includes the following steps:

[0055] (1) Pretreatment of artificial sand

[0056] Add sulfuric acid to water to make the sulfuric acid content of the aqueous solution 0.39%, and then add artificial sand to soak for 25 minutes. Add quicklime to the mixture to make the pH of the solution 6.8, and continue soaking for 4 hours.

[0057] The amount of sulfuric acid solution used is 3.7 times the mass of the artificial sand;

[0058] (2) Ingredients

[0059] Add coal gangue, river sand, and silica to the mixing system from the previous step and mix thoroughly; the amount of coal gangue is 16% of the mass of the manufactured sand; the amount of river sand is 24% of the mass of the manufactured sand; and the amount of silica is 39% of the mass of the manufactured sand.

[0060] (3) Blending the mixed adhesive system

[0061] Mix sawdust and bagasse, soak them in sodium hydroxide solution, raise the temperature to 60°C and keep it at that temperature for 60 minutes; filter, rinse with water until neutral, soak the resulting fiber system in dilute hydrochloric acid solution for 50 minutes, add calcium hydroxide solution dropwise to make the pH of the mixture 7; filter, rinse the filter residue with water 3 times and dry for later use.

[0062] Under nitrogen protection, the above fibers were mixed with distilled water at a mass ratio of 1:9. Potassium sulfate at 7% of the fiber mass was added to the aqueous solution. Acrylamide was added dropwise while stirring at high speed, followed by N,N'-methylenebisacrylamide. After the addition was completed, the temperature was raised to 60°C and stirring was continued for 4 hours. The mixture was filtered, and the resulting fibers were washed three times with distilled water to obtain the modified natural fibers.

[0063] The mass ratio of sawdust to bagasse is 8:3; the concentration of the dilute hydrochloric acid is 0.3 mol / L; the calcium hydroxide solution is a saturated solution; the amount of acrylamide used is 13% of the fiber mass; and the amount of N,N'-methylenebisacrylamide used is 0.2% of the fiber mass.

[0064] (4) Preparation of concrete

[0065] Take 130 parts of cement for later use; mix 35 parts of water and 5 parts of the above modified natural fiber evenly, add cement and stir for 15 minutes, add 6 parts of ceramic fiber, 5 parts of polypropylene fiber, 160 parts of the mixture in step (2) and 3 parts of water-reducing agent and mix evenly.

[0066] Scale settings:

[0067]

[0068] Test Example 1

[0069] Concrete was prepared according to Examples 1-3 and Comparative Examples 1-3 respectively, and its properties were tested. The results are as follows:

[0070]

[0071] As can be seen from the table, the concrete produced according to Examples 1-3 of the present invention has high tensile strength and low thermal conductivity, exhibiting excellent heat insulation properties. After the concrete was used outdoors for 8 months, its indicators were tested again as follows:

[0072]

[0073] As can be seen from the table, after 8 months of use, the compressive strength and thermal conductivity of the concrete in the comparative examples were not ideal. In particular, the thermal conductivity of comparative examples 1-3 increased rapidly, indicating that the thermal insulation performance of comparative examples 1-3 was rapidly declining. This shows that the concrete of the present invention not only has good mechanical properties, but also stable thermal insulation performance.

Claims

1. A method for preparing high-performance concrete using manufactured sand, characterized in that, The following steps are involved: (1) Pretreatment of artificial sand Add sulfuric acid to water to make the sulfuric acid content of the aqueous solution 0.33-0.42% to obtain a dilute sulfuric acid solution. Then add artificial sand and soak for 20-30 minutes. Add quicklime to the mixture to make the pH of the solution 6.8-7.1 and continue soaking for 3-4 hours. (2) Ingredients Add coal gangue, river sand, and silica to the mixing system from the previous step and mix thoroughly. Mixing adhesive systems Mix sawdust and bagasse, soak them in sodium hydroxide solution, raise the temperature to 50-60℃ and keep it at that temperature for 60-80 minutes; filter, rinse with water until neutral, soak the resulting fiber system in dilute hydrochloric acid solution for 30-50 minutes, add calcium hydroxide solution dropwise to make the pH of the mixture 7-7.3; filter, rinse the filter residue with water 2-3 times and dry for later use; Under nitrogen protection, the above-mentioned fibers are mixed with distilled water at a mass ratio of 1:8-9. Potassium sulfate of 7-8% of the fiber mass is added to the aqueous solution. Acrylamide is added dropwise while stirring at high speed, followed by N,N'-methylenebisacrylamide. After the addition is complete, the temperature is raised to 50-60℃ and stirring is continued for 3-4 hours. After filtration, the obtained fibers are washed with distilled water 3-5 times to obtain modified natural fibers. The mass ratio of sawdust to bagasse is 8:1-3; the concentration of the dilute hydrochloric acid is 0.3-0.46 mol / L; the calcium hydroxide solution is a saturated solution; the amount of acrylamide used is 11-13% of the fiber mass; the amount of N,N'-methylenebisacrylamide used is 0.2-0.35% of the fiber mass. (4) Preparation of concrete Take 120-130 parts of cement for later use; mix 35-48 parts of water and 4-5 parts of the above modified natural fiber evenly, add cement and stir for 10-15 minutes, add 6-8 parts of ceramic fiber, 4-5 parts of polypropylene fiber, 160-170 parts of the mixture in step (2), and 2-3 parts of water-reducing agent and mix evenly.

2. The method for preparing high-performance concrete using manufactured sand according to claim 1, characterized in that, In step (1), the amount of sulfuric acid solution used is 3-3.7 times the mass of artificial sand.

3. The method for preparing high-performance concrete using manufactured sand according to claim 1, characterized in that, In step (2), the amount of coal gangue used is 13-16% of the mass of artificial sand.

4. The method for preparing high-performance concrete using manufactured sand according to claim 1, characterized in that, In step (2), the amount of river sand used is 24-28% of the mass of artificial sand.

5. The method for preparing high-performance concrete using manufactured sand according to claim 1, characterized in that, In step (2), the amount of silica used is 33-39% of the mass of the artificial sand.

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