A concrete anti-cracking agent and a preparation method thereof

Abstract

The application relates to the technical field of concrete, and discloses a concrete anti-cracking agent and a preparation method thereof. 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 are added into a stirrer, and stirred for 10-16 minutes; and the concrete anti-cracking agent is obtained after the stirring is finished. The concrete anti-cracking agent has good anti-cracking and anti-compression effects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete, in particular to a concrete anti-cracking agent and a preparation method thereof. BACKGROUND

[0002] Concrete is the most common building material at present, which is widely used in the fields of building, bridge and pavement. However, the cracking phenomenon occurs in the long-term use process, which affects the durability of concrete and reduces the service life and use performance of concrete. Therefore, how to avoid this phenomenon is the key to solve the problem. For example, the Chinese patent application with the publication number CN 104030635B discloses a kind of concrete and a preparation method thereof. The concrete provided by the application has excellent impact resistance, but its anti-cracking performance is not improved. SUMMARY

[0003] (I) Technical problems solved

[0004] In view of the deficiencies in the prior art, the present application provides a kind of concrete anti-cracking agent and a preparation method thereof, which has good anti-cracking effect and improves the strength of concrete.

[0005] (II) Technical solutions

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a kind of concrete anti-cracking 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, and 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 the nitrogen atmosphere, add trimesoyl chloride and 4-((dimethylamino) methyl) phenol to the acetonitrile solvent, ultrasonically disperse uniformly, continue to add pyridine catalyst to it, carry out substitution reaction, react at 80-90℃ for 7-9h, after the reaction is completed, cool to room temperature, remove the solvent by rotary evaporation, wash and dry to obtain intermediate 1;

[0009] (2) Add intermediate 1 and 3-chloro-1,2-propanediol to the N,N-dimethylformamide solvent, stir and mix, react at 70-86℃ for 4-5h, after the reaction is completed, distill under reduced pressure, wash and dry to obtain intermediate 2;

[0010] (3) to the mass fraction of 2-4 % of sodium hydroxide aqueous solution, 7-12 parts by weight of cellulose is added, then 9-13 parts by weight of epoxy chloropropane and ethanol solvent are added dropwise, and the reaction is stirred at 70-80 DEG C for 5-6 h to obtain epoxy cellulose, 7-10 parts by weight of intermediate 2 and 0.01-0.02 parts by weight of boron trifluoride ether catalyst are continuously added to carry out ring-opening reaction, and the reaction is carried out at 75-92 DEG C, after the reaction, filtration and washing are carried out to obtain a quaternary ammonium salt modified cellulose chain extender;

[0011] (4) toluene diisocyanate and polyether polyol are added into a reaction kettle, dibutyltin dilaurate is added, and pre-polymerization is carried out under a nitrogen atmosphere, the pre-polymerization temperature is 75-90 DEG C, and the pre-polymerization time is 3-4 h, then the quaternary ammonium salt modified cellulose chain extender is added, chain extension reaction is carried out under stirring, the reaction is carried out at 65-80 DEG C, after the reaction is completed, natural cooling is carried out to obtain a cellulose-based polyurethane.

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

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

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

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

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

[0017] Preferably, the preparation method of the concrete anti-cracking agent is as follows: zeolite powder, hard gypsum, polymethyl methacrylate microspheres, cellulose-based polyurethane and graphene oxide are added into a stirrer, stirring is carried out for 10-16 min, and the concrete anti-cracking agent is obtained after the stirring is completed.

[0018] (Three) beneficial technical effects

[0019] The concrete anti-cracking agent is obtained by adding the zeolite powder, hard gypsum, polymethyl methacrylate microspheres, cellulose-based polyurethane and graphene oxide into a stirrer and stirring.

[0020] The acyl chloride in the trimesoyl chloride reacts with the phenolic hydroxyl group in the 4-((dimethylamino)methyl)phenol to introduce a tertiary amine group, and the reaction with the chlorine in the 3-chloro-1,2-propanediol generates a quaternary ammonium salt group and introduces a hydroxyl group, and the ring-opening reaction with the epoxy group in the cellulose generates a hydroxyl group to obtain a quaternary ammonium salt modified cellulose chain extender.

[0021] The polyurethane in the cellulose-based polyurethane can form a good bond with the concrete surface, connecting various parts of the concrete into a whole, which helps to improve the internal structure stability of the concrete and has a good anti-cracking effect and mechanical properties; the cellulose fibers in it are distributed in three dimensions in the concrete, and when the concrete is subjected to external force, the presence of the cellulose fibers can make the stress more evenly distributed in the concrete, reducing the stress concentration phenomenon, thereby preventing the occurrence and expansion of micro-cracks, and having a good anti-cracking effect; the quaternary ammonium salt group can improve the durability of the concrete. DETAILED DESCRIPTION

[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 trimesoyl chloride and 3.22 g of 4-((dimethylamino)methyl)phenol were added to 30 mL of acetonitrile solvent and ultrasonically dispersed, then 0.01 g of pyridine catalyst was added for substitution reaction, and the reaction was carried out at 80°C for 7 h. After cooling 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 and stirred to mix, and the reaction was carried out at 70°C for 4 h. After distillation under reduced pressure, washing and drying, intermediate 2 was obtained;

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

[0027] (4) 0.6 g of toluene diisocyanate and 1.3 g of polyether polyol were added to a reaction kettle, 0.011 g of dibutyltin dilaurate was added, and pre-polymerization was carried out under a nitrogen atmosphere, the pre-polymerization temperature was 75°C, and the pre-polymerization time was 3 h, then 0.2 g of the quaternary ammonium salt modified cellulose chain extender was added, and chain extension was carried out under stirring, the chain extension was carried out at 65°C for 10 min, after the reaction was completed, natural cooling was carried out, and a cellulose-based polyurethane was obtained;

[0028] (5) 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 parts by weight of graphene oxide were added to a stirrer, stirring was carried out for 10 min, and after the stirring was completed, a concrete anti-cracking agent was obtained.

[0029] Example 2

[0030] (1) 1.3 g of trimesoyl chloride and 3.57 g of 4-((dimethylamino)methyl)phenol were added to 40 mL of acetonitrile solvent under a nitrogen atmosphere, and ultrasonic dispersion was carried out, then 0.02 g of pyridine catalyst was added, substitution reaction was carried out, the reaction was carried out at 90°C for 9 h, after the reaction was completed, the temperature was cooled to room temperature, and the solvent was removed by rotary evaporation, then washing and drying were carried out, and an intermediate 1 was obtained;

[0031] (2) 1 g of the intermediate 1 and 4.2 g of 3-chloro-1,2-propanediol were added to 35 mL of N,N-dimethylformamide solvent, and stirring and mixing were carried out, the reaction was carried out at 86°C for 5 h, after the reaction was completed, distillation was carried out under reduced pressure, and washing and drying were carried out, and an intermediate 2 was obtained;

[0032] (3) 12 parts by weight of cellulose was added to a 4% mass fraction sodium hydroxide aqueous solution, then 13 parts by weight of epichlorohydrin and 40 mL of ethanol solvent were added dropwise, and stirring reaction was carried out at 80°C for 6 h, and epoxide cellulose was obtained, then 10 parts by weight of the intermediate 2 and 0.02 parts by weight of boron trifluoride ether catalyst were added, ring-opening reaction was carried out, the reaction was carried out at 92°C for 7 h, after the reaction was completed, filtration was carried out, and washing was carried out, and a quaternary ammonium salt modified cellulose chain extender was obtained;

[0033] (4) 0.7 g of toluene diisocyanate and 1.5 g of polyether polyol were added to a reaction kettle, 0.012 g of dibutyltin dilaurate was added, and pre-polymerization was carried out under a nitrogen atmosphere, the pre-polymerization temperature was 90°C, and the pre-polymerization time was 4 h, then 0.3 g of the quaternary ammonium salt modified cellulose chain extender was added, and chain extension was carried out under stirring, the chain extension was carried out at 80°C for 15 min, after the reaction was completed, natural cooling was carried out, and a cellulose-based polyurethane was obtained;

[0034] (5) 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 parts by weight of graphene oxide were added to a stirrer, stirred for 16 min, and after the end, a concrete anti-cracking agent was obtained.

[0035] Example 3

[0036] (1) 1.2 g of trimesoyl chloride and 3.46 g of 4-((dimethylamino)methyl)phenol were added to 35 mL of acetonitrile solvent under a nitrogen atmosphere, and ultrasonic dispersion was performed. Then, 0.015 g of a pyridine catalyst was added, a substitution reaction was performed, and the reaction was performed at 85°C for 8 h. After the end, the reaction solution was cooled to room temperature, and the solvent was removed by rotary evaporation. Then, washing and drying were performed, and intermediate 1 was obtained.

[0037] (2) 1 g of intermediate 1 and 3.6 g of 3-chloro-1,2-propanediol were added to 30 mL of N,N-dimethylformamide solvent, and stirring was performed. Then, the reaction was performed at 82°C for 4 h. After the end, distillation was performed under reduced pressure, and washing and drying were performed, and intermediate 2 was obtained.

[0038] (3) 10 parts by weight of cellulose was added to a 3% by mass sodium hydroxide aqueous solution, and then 12 parts by weight of epichlorohydrin and 30 mL of ethanol solvent were added dropwise. Then, stirring was performed at 75°C for 6 h, and epoxy cellulose was obtained. Then, 8 parts by weight of intermediate 2 and 0.015 parts by weight of boron trifluoride diethyl ether catalyst were added, and ring-opening reaction was performed. Then, the reaction was performed at 85°C for 6 h, and after the reaction, filtration was performed, and washing was performed, and quaternary ammonium salt-modified cellulose chain extender was obtained.

[0039] (4) 0.65 g of toluene diisocyanate and 1.4 g of polyether polyol were added to a reaction kettle, and then 0.011 g of dibutyltin dilaurate was added. Then, prepolymerization was performed under a nitrogen atmosphere, and the prepolymerization temperature was 80°C, and the time was 3 h. Then, 0.25 g of quaternary ammonium salt-modified cellulose chain extender was added, and chain extension reaction was performed by stirring. Then, the reaction was performed at 75°C for 12 min, and after the end of the reaction, natural cooling was performed, and cellulose-based polyurethane was obtained.

[0040] (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 stirring was performed for 13 min, and after the end, a concrete anti-cracking agent was obtained.

[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 and uniformly dispersed by ultrasonic, 0.01 g of pyridine catalyst was further added to perform substitution reaction, and the reaction was performed at 80°C for 7 h, after which 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, mixed by stirring, and the reaction was performed at 70°C for 4 h, after which it was distilled under reduced pressure, washed and dried to obtain intermediate 2;

[0044] (3) 12 parts by weight of cellulose were added to a 4% by mass aqueous sodium hydroxide solution, and then 13 parts by weight of epichlorohydrin and 40 mL of ethanol solvent were added dropwise, and the reaction was performed by stirring at 80°C for 6 h to obtain epoxy cellulose, 10 parts by weight of intermediate 2 and 0.02 parts by weight of boron trifluoride diethyl ether catalyst were further added to perform ring-opening reaction, and the reaction was performed at 92°C for 7 h, after which 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, 0.012 g of dibutyltin dilaurate was further added, and pre-polymerization was performed under a nitrogen atmosphere, the pre-polymerization temperature was 90°C, and the pre-polymerization time was 4 h, 0.3 g of a quaternary ammonium salt-modified cellulose chain extender was further added, and chain extension reaction was performed by stirring, the reaction was performed at 80°C for 15 min, after which it was naturally cooled to obtain a 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, stirred for 13 min, and then a concrete anti-cracking agent 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 and uniformly dispersed by ultrasonic, 0.02 g of pyridine catalyst was further added to perform substitution reaction, and the reaction was performed at 90°C for 9 h, after which 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, mixed by stirring, and the reaction was performed at 86°C for 5 h, after which it was distilled under reduced pressure, washed and dried to obtain intermediate 2;

[0050] (3) 10 parts by weight of cellulose was added to a 3% by mass aqueous sodium hydroxide solution, then 12 parts by weight of epichlorohydrin and 30 mL of an ethanol solvent were added dropwise, and the reaction was stirred at 75°C for 6 h to obtain epoxide cellulose. Then 8 parts by weight of intermediate 2 and 0.015 parts by weight of boron trifluoride etherate catalyst were added to the epoxide cellulose, and ring-opening reaction was performed at 85°C for 6 h. After the reaction, the product was filtered and washed to obtain the quaternary ammonium salt modified cellulose chain extender;

[0051] (4) 0.65 g of toluene diisocyanate and 1.4 g of polyether polyol were added to a reaction kettle, and 0.011 g of dibutyltin dilaurate was added. Prepolymerization was performed under a nitrogen atmosphere at a temperature of 80°C for 3 h. Then 0.25 g of the quaternary ammonium salt modified cellulose chain extender was added, and chain extension reaction was performed by stirring at 75°C for 12 min. After the reaction, the product was naturally cooled to obtain the cellulose-based polyurethane;

[0052] (5) 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 the cellulose-based polyurethane, and 0.4 parts by weight of graphene oxide were added to a stirrer, and stirring was performed for 10 min. After the stirring was completed, a concrete anti-cracking agent was obtained.

[0053] Comparative Example 1

[0054] The present comparative example is different from Example 5 in that intermediate 2 is used instead of the cellulose-based polyurethane.

[0055] Comparative Example 2

[0056] The present comparative example is different from Example 5 in that the quaternary ammonium salt modified cellulose chain extender is used instead of the cellulose-based polyurethane.

[0057] The mechanical properties of the concrete were detected according to the provisions in GB / T50081-2002 “Standard for Testing Methods of Mechanical Properties of Ordinary Concrete”. The test results are shown in Table 1.

[0058] Table 1: Compression strength test.

[0059]

[0060]

[0061] As shown in Table 1, the compression strengths of Examples 1-5 of the present application are better than those of Comparative Examples 1-2.

[0062] Pour 140 parts by weight of medium sand, 300 parts by weight of stone 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, 0.4 parts by weight of anti-cracking agent to continue stirring for 8 min, after the end, cast into a mold, and maintain at room temperature for 22 h, demold, and then maintain in a standard curing chamber for 35 days to obtain a concrete test piece. The full-size model size is 3 m x 3 m x 3 m, the cracking condition of the model is observed periodically, and the cracking condition of the model after 180 d is shown in Table 2.

[0063] Table 2: Anti-cracking test.

[0064]

[0065]

[0066] As shown in Table 2, the anti-cracking effect of Examples 1-5 of the present application is better than that of Comparative Examples 1-2.

[0067] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details, and the present application is not limited to the specific embodiments described. Obviously, according to the content of the present application, many modifications and changes can be made. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited only by the claims and their full scope and equivalents.

Claims

1. A concrete crack-resistant agent, characterized in that, It includes the following components by weight: 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 parts by weight of graphene oxide. The preparation method of the cellulose-based polyurethane is as follows: (1) Under a nitrogen atmosphere, pyromellitic methyl chloride and 4-((dimethylamino)methyl)phenol were added to acetonitrile solvent and ultrasonically dispersed evenly. Pyridine catalyst was added to carry out the substitution reaction. The reaction was carried out at 80-90℃ for 7-9h. After the reaction was completed, the mixture was cooled to room temperature, the solvent was removed by rotary evaporation, and the mixture was washed and dried to obtain intermediate 1. (2) Add intermediate 1 and 3-chloro-1,2-propanediol to N,N-dimethylformamide solvent, stir and mix, react at 70-86℃ for 4-5h, after which distill under reduced pressure, wash and dry to obtain intermediate 2; (3) Add 7-12 parts by weight of cellulose to a 2-4% sodium hydroxide aqueous solution, then add 9-13 parts by weight of epichlorohydrin and ethanol solvent, stir and react at 70-80℃ for 5-6 hours to obtain epoxy cellulose, and continue to add 7-10 parts by weight of intermediate 2 and 0.01-0.02 parts by weight of boron trifluoride diethyl ether catalyst to carry out ring-opening reaction at 75-92℃. After the reaction, filter and wash to obtain quaternary ammonium salt modified cellulose chain extender. (4) Toluene diisocyanate and polyether polyol are added to the reactor, and then dibutyltin dilaurate is added. Prepolymerization is carried out under a nitrogen atmosphere at a temperature of 75-90℃ for 3-4 hours. Then, quaternary ammonium salt modified cellulose chain extender is added and stirred to carry out the chain extension reaction at 65-80℃. After the reaction is completed, the mixture is cooled naturally to obtain cellulose-based polyurethane.

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

02.

3. The concrete crack-resistant agent according to claim 1, characterized in that, The mass ratio of intermediate 1,3-chloro-1,2-propanediol in (2) is 1:3.14-4.

2.

4. The concrete crack-resistant agent according to claim 1, characterized in that, The cyclization reaction time in (3) is 5-7 hours.

5. The concrete crack-resistant agent according to claim 1, 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.

6. The concrete crack-resistant agent according to claim 1, characterized in that, The chain extension reaction time in (4) is 10-15 min.

7. A method for preparing a concrete crack-resistant agent as described in any one of claims 1-6, characterized in that, The concrete crack-resistant agent is prepared by adding zeolite powder, anhydrite, polymethyl methacrylate microspheres, cellulose-based polyurethane, and graphene oxide into a mixer and stirring for 10-16 minutes. The concrete crack-resistant agent is then obtained.

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