Concrete anti-cracking agent and preparation method thereof

Abstract

The invention relates to the technical field of concrete, and discloses a concrete anti-cracking agent and a preparation method thereof.The preparation method comprises the steps that 10-15 parts by weight of zeolite powder, 12-16 parts by weight of anhydrite, 2-3 parts by weight of polymethyl methacrylate microspheres, 1-3 parts by weight of cellulose-based polyurethane and 0.4-0.7 part by weight of graphene oxide are added into a stirrer and stirred for 10-16 min, and a mixture is obtained; and finally, obtaining the concrete anti-cracking agent. The concrete anti-cracking agent disclosed by the invention has relatively good anti-cracking and compression-resistant effects.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and particularly to a concrete crack resistance agent and a preparation method thereof. Background Art

[0002] Concrete is one of the most common building materials at present, and is widely used in the fields of buildings, bridges, road surfaces, etc. However, during long-term use, cracking will occur, which will affect the durability of concrete and reduce the service performance and service life of concrete. Therefore, how to avoid this phenomenon is the key to solving the problem. For example, the Chinese invention patent application with the publication number CN 104030635B discloses a concrete and a preparation method thereof. The concrete provided by this invention has excellent impact resistance, but its crack resistance has not been improved. Summary of the Invention

[0003] (1) Technical Problem to be Solved

[0004] In view of the deficiencies of the prior art, the present invention provides a concrete crack resistance agent and a preparation method thereof, which have good crack resistance effect and at the same time improve the strength of concrete.

[0005] (2) Technical Solution

[0006] To achieve the above object, the present invention provides the following technical solution: A concrete crack resistance agent, comprising the following weight components: 10-15 parts by weight of zeolite powder, 12-16 parts by weight of anhydrite, 2-3 parts by weight of polymethyl methacrylate microspheres, 1-3 parts by weight of cellulose-based polyurethane, 0.4-0.7 parts by weight of graphene oxide.

[0007] Preferably, the preparation method of the cellulose-based polyurethane is as follows:

[0008] (1) Under a nitrogen atmosphere, add trimellitic acid chloride and 4-((dimethylamino)methyl)phenol to an acetonitrile solvent, ultrasonically disperse evenly, then continue to add a pyridine catalyst thereto, and carry out a substitution reaction, reacting at 80-90 °C for 7-9 h. After completion, cool to room temperature, rotary evaporate to remove the solvent, wash and dry to obtain Intermediate 1;

[0009] (2) Add Intermediate 1 and 3-chloro-1,2-propanediol to an N,N-dimethylformamide solvent, stir and mix, react at 70-86 °C for 4-5 h. After completion, carry out vacuum distillation, wash and dry to obtain Intermediate 2;

[0010] (3) Add 7-12 parts by weight of cellulose to an aqueous sodium hydroxide solution with a mass fraction of 2-4%, then dropwise add 9-13 parts by weight of epichlorohydrin and ethanol solvent, and stir and react at 70-80 °C for 5-6 h to obtain epoxy cellulose. Then continue to add 7-10 parts by weight of intermediate 2 and 0.01-0.02 parts by weight of boron trifluoride ethyl ether catalyst thereto for ring-opening reaction, react at 75-92 °C, and after the reaction, filter and wash to obtain a quaternary ammonium salt-modified cellulose chain extender;

[0011] (4) Add toluene diisocyanate and polyether polyol to a reaction kettle, then add dibutyltin dilaurate, and carry out prepolymerization under a nitrogen atmosphere at a prepolymerization temperature of 75-90 °C for 3-4 h. Then add the quaternary ammonium salt-modified cellulose chain extender and stir for chain extension reaction, react at 65-80 °C, and after the reaction ends, naturally cool to obtain cellulose-based polyurethane.

[0012] Preferably, in the step (1), the mass ratio of trimellitic acid chloride, 4-((dimethylamino)methyl)phenol, and pyridine catalyst is 1.1-1.3:3.22-3.57:0.01-0.02.

[0013] Preferably, in the step (2), the mass ratio of intermediate 1 and 3-chloro-1,2-propanediol is 1:3.14-4.2.

[0014] Preferably, in the step (3), the cyclization reaction time is 5-7 h.

[0015] Preferably, in the step (4), the mass ratio of toluene diisocyanate, polyether polyol, dibutyltin dilaurate, and quaternary ammonium salt-modified cellulose chain extender is 0.6-0.7:1.3-1.5:0.011-0.012:0.2-0.3.

[0016] Preferably, in the step (4), the chain extension reaction time is 10-15 min.

[0017] Preferably, the preparation method of the concrete crack resistance agent is: add zeolite powder, anhydrite, polymethyl methacrylate microspheres, cellulose-based polyurethane, and graphene oxide to a stirrer, stir for 10-16 min, and obtain the concrete crack resistance agent after completion.

[0018] (III) Beneficial technical effects

[0019] In the present invention, zeolite powder, anhydrite, polymethyl methacrylate microspheres, cellulose-based polyurethane, and graphene oxide are added to a stirrer and stirred, and the concrete crack resistance agent is obtained after completion.

[0020] The acyl chloride in trimellitic acid chloride will react with the phenolic hydroxyl group in 4-((dimethylamino)methyl)phenol to introduce a tertiary amino group, which will continue to react with the chlorine in 3-chloro-1,2-propanediol to form a quaternary ammonium salt group. Then, the hydroxyl group will continue to react with the epoxy group in cellulose through ring-opening reaction, and a quaternary ammonium salt-modified cellulose chain extender can be obtained with the formation of hydroxyl groups.

[0021] The polyurethane in the cellulose-based polyurethane can form a good bond with the concrete surface, connecting all parts of the concrete into a whole. This bonding effect helps to improve the internal structural stability of the concrete, achieving a good anti-cracking effect and mechanical properties. The cellulose fibers in it are distributed in a three-dimensional manner in the concrete. When the concrete is subjected to external forces, the presence of cellulose fibers can make the stress more evenly distributed inside the concrete, reducing the stress concentration phenomenon, thereby preventing the occurrence and expansion of microcracks and achieving a good anti-cracking effect. The quaternary ammonium salt group in it can improve the durability of the concrete. Specific implementation method

[0022] The zeolite powder is selected from clinoptilolite powder, and the median particle size of the zeolite powder is <80 μm. The particle size of the polymethyl methacrylate microspheres is 80 nm.

[0023] Example 1

[0024] (1) Under a nitrogen atmosphere, 1.1 g of trimellitic acid chloride and 3.22 g of 4-((dimethylamino)methyl)phenol were added to 30 mL of acetonitrile solvent, ultrasonically dispersed evenly, and then 0.01 g of pyridine catalyst was added thereto for a substitution reaction. The reaction was carried out at 80 °C for 7 h. After the reaction, it was cooled to room temperature, the solvent was removed by rotary evaporation, washed and dried to obtain Intermediate 1;

[0025] (2) 1 g of Intermediate 1 and 3.14 g of 3-chloro-1,2-propanediol were added to 25 mL of N,N-dimethylformamide solvent, stirred and mixed, and the reaction was carried out at 70 °C for 4 h. After the reaction, it was distilled under reduced pressure, washed and dried to obtain Intermediate 2;

[0026] (3) 7 parts by weight of cellulose was added to an aqueous sodium hydroxide solution with a mass fraction of 2%, then 9 parts by weight of epichlorohydrin and 20 mL of ethanol solvent were added dropwise, and the reaction was stirred at 70 °C for 5 h to obtain epoxy cellulose. Then 7 parts by weight of Intermediate 2 and 0.01 part by weight of boron trifluoride diethyl ether catalyst were added thereto for a ring-opening reaction, and the reaction was carried out at 75 °C for 5 h. After the reaction, it was filtered and washed to obtain the quaternary ammonium salt-modified cellulose chain extender;

[0027] (4) Add 0.6 g of toluene diisocyanate and 1.3 g of polyether polyol into a reaction kettle, then add 0.011 g of dibutyltin dilaurate, and carry out prepolymerization under a nitrogen atmosphere. The prepolymerization temperature is 75 °C and the time is 3 h. Then add 0.2 g of quaternary ammonium salt modified cellulose chain extender, and stir to carry out the chain extension reaction. React at 65 °C for 10 min. After the reaction is completed, cool naturally to obtain cellulose-based polyurethane;

[0028] (5) Add 10 parts by weight of zeolite powder, 12 parts by weight of anhydrite, 2 parts by weight of polymethyl methacrylate microspheres, 1 part by weight of cellulose-based polyurethane, and 0.4 part by weight of graphene oxide into a stirrer, and stir for 10 min. After completion, obtain a concrete crack resistance agent.

[0029] Example 2

[0030] (1) Under a nitrogen atmosphere, add 1.3 g of trimesoyl chloride and 3.57 g of 4-((dimethylamino)methyl)phenol to 40 mL of acetonitrile solvent, ultrasonically disperse evenly, continue to add 0.02 g of pyridine catalyst thereto, and carry out a substitution reaction. React at 90 °C for 9 h. After completion, cool to room temperature, rotary evaporate to remove the solvent, wash and dry to obtain Intermediate 1;

[0031] (2) Add 1 g of Intermediate 1 and 4.2 g of 3-chloro-1,2-propanediol to 35 mL of N,N-dimethylformamide solvent, stir and mix, and react at 86 °C for 5 h. After completion, carry out vacuum distillation, wash and dry to obtain Intermediate 2;

[0032] (3) Add 12 parts by weight of cellulose to an aqueous sodium hydroxide solution with a mass fraction of 4%, then dropwise add 13 parts by weight of epichlorohydrin and 40 mL of ethanol solvent, and stir and react at 80 °C for 6 h to obtain epoxy cellulose. Continue to add 10 parts by weight of Intermediate 2 and 0.02 part by weight of boron trifluoride diethyl ether catalyst thereto, and carry out a ring-opening reaction. React at 92 °C for 7 h. After the reaction, filter and wash to obtain a quaternary ammonium salt modified cellulose chain extender;

[0033] (4) Add 0.7 g of toluene diisocyanate and 1.5 g of polyether polyol into a reaction kettle, then add 0.012 g of dibutyltin dilaurate, and carry out prepolymerization under a nitrogen atmosphere. The prepolymerization temperature is 90 °C and the time is 4 h. Then add 0.3 g of quaternary ammonium salt modified cellulose chain extender, and stir to carry out the chain extension reaction. React at 80 °C for 15 min. After the reaction is completed, cool naturally to obtain cellulose-based polyurethane;

[0034] (5) Add 15 parts by weight of zeolite powder, 16 parts by weight of anhydrite, 3 parts by weight of polymethyl methacrylate microspheres, 3 parts by weight of cellulose-based polyurethane, and 0.7 part by weight of graphene oxide to a stirrer, stir for 16 min, and obtain a concrete crack inhibitor after completion.

[0035] Example 3

[0036] (1) Under a nitrogen atmosphere, add 1.2 g of trimesoyl chloride and 3.46 g of 4-((dimethylamino)methyl)phenol to 35 mL of acetonitrile solvent, ultrasonically disperse evenly, continue to add 0.015 g of pyridine catalyst thereto, carry out a substitution reaction, react at 85 °C for 8 h, cool to room temperature after completion, rotary evaporate to remove the solvent, wash and dry to obtain Intermediate 1;

[0037] (2) Add 1 g of Intermediate 1 and 3.6 g of 3-chloro-1,2-propanediol to 30 mL of N,N-dimethylformamide solvent, stir and mix, react at 82 °C for 4 h, carry out vacuum distillation after completion, wash and dry to obtain Intermediate 2;

[0038] (3) Add 10 parts by weight of cellulose to an aqueous sodium hydroxide solution with a mass fraction of 3%, then dropwise add 12 parts by weight of epichlorohydrin and 30 mL of ethanol solvent, stir and react at 75 °C for 6 h to obtain epoxy cellulose, continue to add 8 parts by weight of Intermediate 2 and 0.015 part by weight of boron trifluoride diethyl ether catalyst thereto, carry out a ring-opening reaction, react at 85 °C for 6 h, filter and wash after the reaction to obtain a quaternary ammonium salt-modified cellulose chain extender;

[0039] (4) Add 0.65 g of toluene diisocyanate and 1.4 g of polyether polyol to a reaction kettle, add 0.011 g of dibutyltin dilaurate again, carry out prepolymerization under a nitrogen atmosphere, the prepolymerization temperature is 80 °C and the time is 3 h, then add 0.25 g of quaternary ammonium salt-modified cellulose chain extender, stir to carry out a chain extension reaction, react at 75 °C for 12 min, and naturally cool after the reaction is completed to obtain cellulose-based polyurethane;

[0040] (5) Add 12 parts by weight of zeolite powder, 14 parts by weight of anhydrite, 3 parts by weight of polymethyl methacrylate microspheres, 2 parts by weight of cellulose-based polyurethane, and 0.5 part by weight of graphene oxide to a stirrer, stir for 13 min, and obtain a concrete crack inhibitor after completion.

[0041] Example 4

[0042] (1) Under a nitrogen atmosphere, 1.1 g of trimesoyl chloride and 3.22 g of 4-((dimethylamino)methyl)phenol were added to 30 mL of acetonitrile solvent, ultrasonically dispersed evenly, and then 0.01 g of pyridine catalyst was added thereto for a substitution reaction. The reaction was carried out at 80 °C for 7 h. After completion, it was cooled to room temperature, the solvent was removed by rotary evaporation, washed and dried to obtain Intermediate 1;

[0043] (2) 1 g of Intermediate 1 and 3.14 g of 3-chloro-1,2-propanediol were added to 25 mL of N,N-dimethylformamide solvent, stirred and mixed, and the reaction was carried out at 70 °C for 4 h. After completion, it was distilled under reduced pressure, washed and dried to obtain Intermediate 2;

[0044] (3) 12 parts by weight of cellulose was added to an aqueous sodium hydroxide solution with a mass fraction of 4%, and then 13 parts by weight of epichlorohydrin and 40 mL of ethanol solvent were added dropwise. The reaction was stirred at 80 °C for 6 h to obtain epoxy cellulose. Then 10 parts by weight of Intermediate 2 and 0.02 parts by weight of boron trifluoride diethyl ether catalyst were added thereto for a ring-opening reaction. The reaction was carried out at 92 °C for 7 h. After the reaction, it was filtered and washed to obtain a quaternary ammonium salt-modified cellulose chain extender;

[0045] (4) 0.7 g of toluene diisocyanate and 1.5 g of polyether polyol were added to a reaction kettle, and then 0.012 g of dibutyltin dilaurate was added. Under a nitrogen atmosphere, prepolymerization was carried out at a temperature of 90 °C for 4 h. Then 0.3 g of the quaternary ammonium salt-modified cellulose chain extender was added and stirred for a chain extension reaction. The reaction was carried out at 80 °C for 15 min. After the reaction was completed, it was naturally cooled to obtain cellulose-based polyurethane;

[0046] (5) 12 parts by weight of zeolite powder, 14 parts by weight of anhydrite, 3 parts by weight of polymethyl methacrylate microspheres, 2 parts by weight of cellulose-based polyurethane, and 0.5 parts by weight of graphene oxide were added to a stirrer and stirred for 13 min. After completion, a concrete crack inhibitor was obtained.

[0047] Example 5

[0048] (1) Under a nitrogen atmosphere, 1.3 g of trimesoyl chloride and 3.57 g of 4-((dimethylamino)methyl)phenol were added to 40 mL of acetonitrile solvent, ultrasonically dispersed evenly, and then 0.02 g of pyridine catalyst was added thereto for a substitution reaction. The reaction was carried out at 90 °C for 9 h. After completion, it was cooled to room temperature, the solvent was removed by rotary evaporation, washed and dried to obtain Intermediate 1;

[0049] (2) 1 g of Intermediate 1 and 4.2 g of 3-chloro-1,2-propanediol were added to 35 mL of N,N-dimethylformamide solvent, stirred and mixed, and the reaction was carried out at 86 °C for 5 h. After completion, it was distilled under reduced pressure, washed and dried to obtain Intermediate 2;

[0050] (3) Add 10 parts by weight of cellulose to an aqueous sodium hydroxide solution with a mass fraction of 3%, then dropwise add 12 parts by weight of epichlorohydrin and 30 mL of ethanol solvent, stir and react at 75 °C for 6 h to obtain epoxy cellulose. Continue to add 8 parts by weight of intermediate 2 and 0.015 parts by weight of boron trifluoride ethyl ether catalyst thereto for ring-opening reaction, react at 85 °C for 6 h, filter and wash after the reaction to obtain a quaternary ammonium salt-modified cellulose chain extender;

[0051] (4) Add 0.65 g of toluene diisocyanate and 1.4 g of polyether polyol to a reaction kettle, then add 0.011 g of dibutyltin dilaurate, and carry out prepolymerization under a nitrogen atmosphere at a temperature of 80 °C for 3 h. Then add 0.25 g of the quaternary ammonium salt-modified cellulose chain extender and stir for chain extension reaction, react at 75 °C for 12 min. After the reaction is completed, cool naturally to obtain cellulose-based polyurethane;

[0052] (5) Add 10 parts by weight of zeolite powder, 12 parts by weight of anhydrite, 2 parts by weight of polymethyl methacrylate microspheres, 1 part by weight of cellulose-based polyurethane, and 0.4 part by weight of graphene oxide to a stirrer, stir for 10 min, and obtain a concrete crack resistance agent after completion.

[0053] Comparative Example 1

[0054] Compared with Example 5, the difference in this comparative example is that intermediate 2 is used instead of cellulose-based polyurethane.

[0055] Comparative Example 2

[0056] Compared with Example 5, the difference in this comparative example is that the quaternary ammonium salt-modified cellulose chain extender is used instead of cellulose-based polyurethane.

[0057] According to the regulations in the "Standard Test Method for Mechanical Properties of Ordinary Concrete" GB / T50081-2002, the mechanical properties of the concrete were detected; the test results are shown in Table 1.

[0058] Table 1: Compressive strength test.

[0059]

[0060]

[0061] As can be seen from Table 1, Examples 1-5 of the present invention have better compressive strength compared with Comparative Examples 1-2.

[0062] Pour 140 parts by weight of medium sand and 300 parts by weight of gravel into a blender and stir for 1 min. Then add 80 parts by weight of fly ash, 100 parts by weight of cement, 40 parts by weight of water, and 0.4 parts by weight of crack inhibitor and continue stirring for 8 min. After that, cast it into a mold and cure it at room temperature for 22 h. Demold after forming, and then cure it in a standard curing room for 35 days to obtain concrete specimens. The full-scale model size is 3 m × 3 m × 3 m. Regularly observe the cracking situation of the model. The cracking situation of the model after 180 d is shown in Table 2.

[0063] Table 2: Crack resistance test.

[0064]

[0065]

[0066] As can be seen from Table 2, Examples 1-5 of the present invention have better crack resistance than Comparative Examples 1-2.

[0067] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A concrete anti-cracking agent, characterized in that: The invention comprises the following components by weight: 10-15 parts by weight of zeolite powder, 12-16 parts by weight of hard gypsum, 2-3 parts by weight of polymethyl methacrylate microspheres, 1-3 parts by weight of cellulose-based polyurethane, and 0.4-0.7 parts by weight of graphene oxide.

2. The concrete anti-cracking agent according to claim 1, characterized in that: The preparation method of the cellulose-based polyurethane is: (1) Under a nitrogen atmosphere, trimesoyl chloride and 4-((dimethylamino)methyl)phenol were added to an acetonitrile solvent, and ultrasonic dispersion was performed uniformly. A pyridine catalyst was added thereto to carry out a substitution reaction, and the reaction was carried out at 80-90° C. for 7-9 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, and the reaction was washed and dried to obtain an intermediate 1; (2) adding intermediate 1 and 3-chloro-1,2-propanediol to N,N-dimethylformamide solvent, stirring and mixing, reacting at 70-86° C. for 4-5 hours, and then distilling under reduced pressure, washing and drying to obtain intermediate 2; (3) adding 7-12 parts by weight of cellulose to a 2-4% sodium hydroxide aqueous solution, then dropwise adding 9-13 parts by weight of epichlorohydrin and ethanol solvent, stirring and reacting at 70-80° C. for 5-6 hours to obtain epoxy cellulose, and then adding 7-10 parts by weight of intermediate 2 and 0.01-0.02 parts by weight of boron trifluoride ether catalyst to the mixture to carry out a ring-opening reaction, reacting at 75-92° C., filtering after the reaction, washing, and obtaining a quaternary ammonium salt modified cellulose chain extender; (4) Toluene diisocyanate and polyether polyol are added to a reaction kettle, and then dibutyltin dilaurate is added to carry out prepolymerization under a nitrogen atmosphere. The prepolymerization temperature is 75-90°C and the time is 3-4 hours. Then, a quaternary ammonium salt-modified cellulose chain extender is added and stirred to carry out a chain extension reaction. The reaction is carried out at 65-80°C. After the reaction is completed, the mixture is cooled naturally to obtain a cellulose-based polyurethane.

3. The concrete anti-cracking agent according to claim 2, characterized in that: The mass ratio of trimesoyl chloride, 4-((dimethylamino)methyl)phenol and pyridine catalyst in (1) is 1.1-1.3:3.22-3.57:0.01-0.

02.

4. The concrete anti-cracking agent according to claim 2, characterized in that: The mass ratio of the intermediate 1:3-chloro-1,2-propylene glycol in (2) is 1:3.14-4.

2.

5. The concrete anti-cracking agent according to claim 2, characterized in that: The cyclization reaction time in (3) is 5-7h.

6. The concrete anti-cracking agent according to claim 2, characterized in that: The mass ratio of toluene diisocyanate, polyether polyol, dibutyltin dilaurate and quaternary ammonium salt modified cellulose chain extender in (4) is 0.6-0.7:1.3-1.5:0.011-0.012:0.2-0.

3.

7. The concrete anti-cracking agent according to claim 2, characterized in that: The time of the chain extension reaction in (4) is 10-15 minutes.

8. A method for preparing the concrete anti-cracking agent according to any one of claims 1 to 7, characterized in that: The preparation method of the concrete anti-cracking agent is as follows: zeolite powder, anhydrite, polymethyl methacrylate microspheres, cellulose-based polyurethane and graphene oxide are added into a stirrer, and stirred for 10-16 minutes, and then the concrete anti-cracking agent is obtained.

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