Efficient concrete accelerator and preparation method thereof

Abstract

The invention relates to the field of accelerators, and particularly discloses an efficient concrete accelerator and a preparation method thereof. Comprising the following steps: S1, taking an initiator and water, and uniformly stirring to obtain a solution A; taking acrylic acid, sodium methallyl sulfonate and water, and uniformly stirring to obtain a solution B; a graphene modifier and water are taken, stirred and heated, the solution A and the solution B are dropwise added at the same time, stirring is conducted, pH is adjusted, and an additive is obtained; s2, aluminum sulfate, an additive, zinc sulfate, ferric sulfate, aluminum nitrate, hydroxypropyl methyl cellulose and water are taken and evenly mixed, and the efficient concrete accelerator is obtained; wherein the preparation of the graphene modifier comprises the following steps: dispersing aminated graphene in acetonitrile, adding modified polyethylene glycol ether, potassium carbonate and potassium iodide, reacting, adding a complexing agent and a defoaming agent, and reacting to obtain modified graphene; taking the modified graphene, adding potassium carbonate, dropwise adding an acryloyl chloride solution, stirring, reacting, carrying out suction filtration, and carrying out rotary evaporation to obtain the graphene modifier.

Description

Technical Field

[0001] The invention relates to the field of quick-setting agents, and specifically discloses a high-efficiency quick-setting agent for concrete and a preparation method thereof. Background Art

[0002] In tunnel construction, shotcrete is often mixed with a certain amount of accelerating agent to promote rapid coagulation and hardening of concrete, forming sufficient strength in a very short time to meet the requirements of special construction. Accelerating agents are divided into two categories: alkali accelerating agents and alkali-free accelerating agents. Alkali accelerating agents have a high alkali content, resulting in a low strength retention rate in the later stage, and there is a lot of dust during construction, which threatens the health of construction workers. Therefore, alkali-free accelerating agents are used more.

[0003] However, alkali-free quick-setting agents also have the problems of high dosage, poor stability, low early strength, and the later strength retention rate needs to be improved. With the increase in the amount of support engineering, the demand for shotcrete is increasing, and the performance requirements are also getting higher and higher. As the core admixture of shotcrete, quick-setting agents also need higher performance. Therefore, it is of great significance to study an alkali-free high-efficiency quick-setting agent that can achieve good results at a lower dosage, has good stability, good early strength, and high later strength retention rate, and its preparation method. Summary of the invention

[0004] The object of the present invention is to provide a high-efficiency concrete accelerating agent and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A method for preparing a high-efficiency concrete accelerating setting agent, characterized in that it comprises the following steps: S1: taking an initiator and water, stirring evenly to obtain a solution A; taking acrylic acid, sodium methacrylate sulfonate, and water, stirring evenly to obtain a solution B; taking a graphene modifier and water, stirring and heating, and simultaneously dripping solution A and solution B, after the dripping is completed, heating and stirring, adjusting the pH to neutral, and obtaining an additive;

[0006] S2: Take aluminum sulfate, additives, zinc sulfate, iron sulfate, aluminum nitrate, hydroxypropyl methylcellulose and water, stir at high speed to mix well, and obtain a high-efficiency concrete accelerating agent.

[0007] Preferably, the concrete high-efficiency accelerated setting agent includes the following raw materials, calculated by mass: 20 to 30 parts of aluminum sulfate, 5 to 10 parts of additives, 2 to 5 parts of zinc sulfate, 3 to 6 parts of iron sulfate, 3 to 6 parts of aluminum nitrate, 1 to 3 parts of hydroxypropyl methylcellulose, and 30 to 40 parts of water.

[0008] Preferably, the additive comprises the following raw materials, calculated by weight: 1 to 3 parts of initiator, 600 to 1200 parts of water, 20 to 40 parts of acrylic acid, 60 to 80 parts of sodium methyl methacrylate sulfonate, and 50 to 60 parts of graphene modifier.

[0009] Preferably, the preparation of the graphene modifier comprises the following steps: S1: dispersing the amino graphene in acetonitrile uniformly to obtain a dispersion with a concentration of 1 mol / L, adding modified polyethylene glycol ether, stirring uniformly, adding potassium carbonate and potassium iodide, reacting at 80-90° C. in a light-shielded state under nitrogen protection, condensing and refluxing for 20-25 hours, adding a complexing agent and a defoaming agent, reacting at 80-90° C. in a light-shielded state under nitrogen protection, condensing and refluxing for 10-15 hours, and obtaining modified graphene;

[0010] S2: Take acryloyl chloride and acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add potassium carbonate, dropwise add acryloyl chloride solution in an ice bath, stir in an ice bath for 1 to 2 hours, introduce nitrogen gas at 0°C in the dark to react for 20 to 25 hours, filter, and rotary evaporate to obtain a graphene modifier.

[0011] Preferably, the modified graphene includes the following raw materials, calculated by mass: 5 to 10 parts of amino graphene, 60 to 80 parts of modified polyethylene glycol ether, 15 to 30 parts of potassium carbonate, 0.5 to 2 parts of potassium iodide, 20 to 30 parts of complexing agent, and 5 to 10 parts of defoaming agent; the graphene modifier includes the following raw materials, calculated by mass: 5 to 15 parts of acryloyl chloride, 20 to 30 parts of acetonitrile, and 10 to 20 parts of potassium carbonate.

[0012] Preferably, the complexing agent includes hydroxyethyldiethylenetriamine, and the defoaming agent includes defoaming agent GP330; the mass ratio of the complexing agent to the defoaming agent is (3-4):1.

[0013] Preferably, the preparation of the modified polyethylene glycol ether comprises the following steps: taking thionyl chloride and dichloromethane, stirring evenly to obtain a mixed solution; taking polyethylene glycol ether and dichloromethane, stirring to dissolve, adding potassium carbonate, heating the oil bath to 40-45° C., stirring and dripping the mixed solution, after the dripping is completed for 40-60 minutes, heating to 45-50° C., condensing and reflux for 20-25 hours, cooling, filtering, and evaporating the solvent to obtain the modified polyethylene glycol ether.

[0014] Preferably, the modified polyethylene glycol ether comprises the following raw materials, calculated by mass: 40-60 parts of thionyl chloride, 60-80 parts of dichloromethane, 50-80 parts of polyethylene glycol ether, 100-150 parts of dichloromethane, and 10-20 parts of potassium carbonate.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: aluminum sulfate, additives, zinc sulfate, ferric sulfate, aluminum nitrate, hydroxypropyl methylcellulose and water are used as raw materials to prepare an accelerating setting agent, which has the characteristics of being alkali-free and highly efficient; wherein the preparation method of the additive comprises the following steps: polyethylene glycol ether is modified with thionyl chloride to obtain a modified polyethylene glycol ether with -Cl at both ends, the polyethylene glycol ether itself can provide steric hindrance to separate cement particles, and improve dispersibility and fluidity; after modification, it is reacted with amino graphene, and when the amount of the modified polyethylene glycol ether added is large, both hydrogen atoms on the amino group of the amino graphene are replaced to obtain a hyperbranched structure, which can significantly enhance the dispersibility and has good adaptability to various cements, and the oxygen-containing functional groups and wrinkles on the surface of the graphene serve as nucleation sites for hydration products, accelerate the hydration process, and arrange the morphology of the hydration products regularly, and at the same time, it has a pore filling effect on the cement matrix, and bridges the hydration products to make the water The product is more compact, which is helpful to improve the strength; then the complexing agent hydroxyethyl diethylene triamine and the defoaming agent GP330 are introduced to react with the -Cl at the other end of the modified polyethylene glycol ether to obtain modified graphene; the complexing agent promotes the hydration of mineral clinker in cement, reduces the setting time, and has a positive effect on the early and late strengths of cement; the defoaming agent is added to suppress bubbles generated during the mixing process of concrete. Since the modified graphene of the present invention has a hyperbranched structure, when added to concrete for mixing, it reacts quickly and easily generates a large number of bubbles, which affects the strength of the concrete. Therefore, the defoaming agent needs to be introduced. The defoaming agent has good defoaming ability and stability at the end of the hyperbranched structure; acryloyl chloride is introduced to obtain a graphene modifier with double bonds, which is then reacted with acrylic acid and sodium methacrylic acid to obtain an additive; after the additive is added, the quick-setting agent prepared by the present invention has good effect and stability, and has a positive effect on the early and late strengths of concrete. DETAILED DESCRIPTION

[0016] The following is a preferred implementation of the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. For ordinary technicians in this technical field, all other embodiments obtained by ordinary technicians in this field without creative work without departing from the principle of the embodiment of the present invention are within the scope of protection of the present invention.

[0017] Example 1: S1: Take 50 parts of thionyl chloride and 70 parts of dichloromethane, stir evenly to obtain a mixed solution; take 60 parts of polyethylene glycol ether and 140 parts of dichloromethane, stir to dissolve, add 15 parts of potassium carbonate, heat the oil bath to 42°C, stir and dropwise add the mixed solution, after 50 minutes of dropwise addition, heat to 50°C, condense and reflux for 24 hours, cool, filter, and evaporate the solvent to obtain modified polyethylene glycol ether;

[0018] S2: Disperse 8 parts of amino graphene in acetonitrile to obtain a dispersion with a concentration of 1 mol / L, add 70 parts of modified polyethylene glycol ether, stir evenly, add 25 parts of potassium carbonate and 1.5 parts of potassium iodide, react under nitrogen protection at 85°C in a dark environment, condense and reflux for 24 hours, add 24 parts of complexing agent hydroxyethyldiethylenetriamine and 7 parts of defoaming agent, react under nitrogen protection at 85°C in a dark environment, condense and reflux for 14 hours to obtain modified graphene;

[0019] S3: Take 12 parts of acryloyl chloride and 25 parts of acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add 15 parts of potassium carbonate, add acryloyl chloride solution dropwise for 35 minutes under ice bath, stir for 2 hours under ice bath, introduce nitrogen gas at 0℃ in the dark for 24 hours, filter, and evaporate to obtain graphene modifier;

[0020] S4: Take 2 parts of initiator and 25 parts of water, stir evenly to obtain solution A; take 30 parts of acrylic acid, 70 parts of sodium methyl propylene sulfonate and 400 parts of water, stir evenly to obtain solution B; take 55 parts of graphene modifier and 500 parts of water, stir, and heat to 65°C; add solution A and solution B dropwise at the same time, reflux at normal pressure, stir mechanically, add dropwise for 3 hours, heat to 75°C and stir for 4 hours, adjust pH to neutral, and obtain additive;

[0021] S5: Take 25 parts of aluminum sulfate, 8 parts of additives, 4 parts of zinc sulfate, 4 parts of iron sulfate, 4 parts of aluminum nitrate, 2 parts of hydroxypropyl methylcellulose, and 35 parts of water, and stir at a high speed of 2000 rpm for 30 minutes to obtain a high-efficiency concrete accelerating agent.

[0022] Example 2: S1: Take 50 parts of thionyl chloride and 70 parts of dichloromethane, stir evenly to obtain a mixed solution; take 50 parts of polyethylene glycol ether and 140 parts of dichloromethane, stir to dissolve, add 15 parts of potassium carbonate, heat the oil bath to 42°C, stir and dropwise add the mixed solution, after 50 minutes of dropwise addition, heat to 50°C, condense and reflux for 24 hours, cool, filter, and evaporate the solvent to obtain modified polyethylene glycol ether;

[0023] S2: Disperse 5 parts of amino graphene in acetonitrile to obtain a dispersion with a concentration of 1 mol / L, add 60 parts of modified polyethylene glycol ether, stir evenly, add 25 parts of potassium carbonate and 1.5 parts of potassium iodide, react at 85°C in a dark place under nitrogen protection, condense and reflux for 24 hours, add 20 parts of complexing agent hydroxyethyldiethylenetriamine and 5 parts of defoaming agent, react at 85°C in a dark place under nitrogen protection, condense and reflux for 14 hours to obtain modified graphene;

[0024] S3: Take 5 parts of acryloyl chloride and 25 parts of acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add 15 parts of potassium carbonate, add acryloyl chloride solution dropwise for 35 minutes under ice bath, stir for 2 hours under ice bath, introduce nitrogen gas at 0℃ in the dark for 24 hours, filter, and evaporate to obtain graphene modifier;

[0025] S4: Take 2 parts of initiator and 25 parts of water, stir evenly to obtain solution A; take 20 parts of acrylic acid, 60 parts of sodium methyl propylene sulfonate and 400 parts of water, stir evenly to obtain solution B; take 50 parts of graphene modifier and 500 parts of water, stir, and heat to 65°C; add solution A and solution B dropwise at the same time, reflux at normal pressure, stir mechanically, add dropwise for 3 hours, heat to 75°C and stir for 4 hours, adjust pH to neutral, and obtain additive;

[0026] S5: Take 25 parts of aluminum sulfate, 7 parts of additives, 4 parts of zinc sulfate, 4 parts of iron sulfate, 4 parts of aluminum nitrate, 2 parts of hydroxypropyl methylcellulose, and 40 parts of water, and stir at a high speed of 2000 rpm for 30 minutes to obtain a high-efficiency concrete accelerating agent.

[0027] Example 3: S1: Take 50 parts of thionyl chloride and 70 parts of dichloromethane, stir evenly to obtain a mixed solution; take 80 parts of polyethylene glycol ether and 140 parts of dichloromethane, stir to dissolve, add 15 parts of potassium carbonate, heat the oil bath to 42°C, stir and drop the mixed solution, after 50 minutes of dropwise addition, heat to 50°C, condense and reflux for 24 hours, cool, filter, and evaporate the solvent to obtain modified polyethylene glycol ether;

[0028] S2: Disperse 5 parts of amino graphene in acetonitrile to obtain a dispersion with a concentration of 1 mol / L, add 80 parts of modified polyethylene glycol ether, stir evenly, add 25 parts of potassium carbonate and 1.5 parts of potassium iodide, react under nitrogen protection at 85°C in a dark environment, condense and reflux for 24 hours, add 30 parts of complexing agent hydroxyethyldiethylenetriamine and 10 parts of defoaming agent, react under nitrogen protection at 85°C in a dark environment, condense and reflux for 14 hours to obtain modified graphene;

[0029] S3: Take 15 parts of acryloyl chloride and 25 parts of acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add 15 parts of potassium carbonate, add acryloyl chloride solution dropwise for 35 minutes under ice bath, stir for 2 hours under ice bath, introduce nitrogen gas at 0℃ in the dark for 24 hours, filter, and evaporate to obtain graphene modifier;

[0030] S4: Take 2 parts of initiator and 25 parts of water, stir evenly to obtain solution A; take 40 parts of acrylic acid, 80 parts of sodium methyl propylene sulfonate and 400 parts of water, stir evenly to obtain solution B; take 60 parts of graphene modifier and 500 parts of water, stir, and heat to 65°C; add solution A and solution B dropwise at the same time, reflux at normal pressure, stir mechanically, add dropwise for 3 hours, heat to 75°C and stir for 4 hours, adjust pH to neutral, and obtain additive;

[0031] S5: Take 30 parts of aluminum sulfate, 10 parts of additives, 5 parts of zinc sulfate, 6 parts of iron sulfate, 6 parts of aluminum nitrate, 3 parts of hydroxypropyl methylcellulose, and 40 parts of water, and stir at a high speed of 2000 rpm for 30 minutes to obtain a high-efficiency concrete accelerating agent.

[0032] Comparative Example 1 (using chloromethoxy polyethylene glycol instead of modified polyethylene glycol ether, and the rest of the method is consistent with Example 1): S1: Take 50 parts of thionyl chloride and 70 parts of dichloromethane, stir evenly to obtain a mixed solution; take 60 parts of polyethylene glycol monomethyl ether and 140 parts of dichloromethane, stir to dissolve, add 15 parts of potassium carbonate, heat the oil bath to 42° C., stir and dropwise add the mixed solution, after 50 minutes of dropwise addition, heat to 50° C., condense and reflux for 24 hours, cool, filter, and evaporate the solvent to obtain chloromethoxy polyethylene glycol;

[0033] S2: 8 parts of amino graphene were evenly dispersed in acetonitrile to obtain a dispersion with a concentration of 1 mol / L, 70 parts of chloromethoxy polyethylene glycol were added, and the mixture was stirred evenly. 25 parts of potassium carbonate and 1.5 parts of potassium iodide were added, and the mixture was reacted at 85°C under nitrogen protection and shaded, and condensed and refluxed for 24 hours. 24 parts of complexing agent hydroxyethyldiethylenetriamine and 7 parts of defoaming agent were added, and the mixture was reacted at 85°C under nitrogen protection and shaded, and condensed and refluxed for 14 hours to obtain modified graphene;

[0034] S3: Take 12 parts of acryloyl chloride and 25 parts of acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add 15 parts of potassium carbonate, add acryloyl chloride solution dropwise for 35 minutes under ice bath, stir for 2 hours under ice bath, introduce nitrogen gas at 0℃ in the dark for 24 hours, filter, and evaporate to obtain graphene modifier;

[0035] S4: Take 2 parts of initiator and 25 parts of water, stir evenly to obtain solution A; take 30 parts of acrylic acid, 70 parts of sodium methyl propylene sulfonate and 400 parts of water, stir evenly to obtain solution B; take 55 parts of graphene modifier and 500 parts of water, stir, and heat to 65°C; add solution A and solution B dropwise at the same time, reflux at normal pressure, stir mechanically, add dropwise for 3 hours, heat to 75°C and stir for 4 hours, adjust pH to neutral, and obtain additive;

[0036] S5: Take 25 parts of aluminum sulfate, 8 parts of additives, 4 parts of zinc sulfate, 4 parts of iron sulfate, 4 parts of aluminum nitrate, 2 parts of hydroxypropyl methylcellulose, and 35 parts of water, and stir at a high speed of 2000 rpm for 30 minutes to obtain a high-efficiency concrete accelerating agent.

[0037] Comparative Example 2 (changing the amount of complexing agent and defoaming agent added, and the method steps are consistent with Example 1): S1: Take 50 parts of thionyl chloride and 70 parts of dichloromethane, stir evenly to obtain a mixed solution; take 60 parts of polyethylene glycol ether and 140 parts of dichloromethane, stir to dissolve, add 15 parts of potassium carbonate, heat the oil bath to 42° C., stir and drop the mixed solution, after 50 minutes of dropwise addition, heat to 50° C., condense and reflux for 24 hours, cool, filter, and evaporate the solvent to obtain modified polyethylene glycol ether;

[0038] S2: 8 parts of amino graphene are evenly dispersed in acetonitrile to obtain a dispersion with a concentration of 1 mol / L, 70 parts of modified polyethylene glycol ether are added, and stirred evenly, 25 parts of potassium carbonate and 1.5 parts of potassium iodide are added, and the mixture is reacted at 85°C under the protection of nitrogen and shaded, and condensed and refluxed for 24 hours, 30 parts of complexing agent hydroxyethyldiethylenetriamine and 1 part of defoaming agent are added, and the mixture is reacted at 85°C under the protection of nitrogen and shaded, and condensed and refluxed for 14 hours to obtain modified graphene;

[0039] S3: Take 12 parts of acryloyl chloride and 25 parts of acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add 15 parts of potassium carbonate, add acryloyl chloride solution dropwise for 35 minutes under ice bath, stir for 2 hours under ice bath, introduce nitrogen gas at 0℃ in the dark for 24 hours, filter, and evaporate to obtain graphene modifier;

[0040] S4: Take 2 parts of initiator and 25 parts of water, stir evenly to obtain solution A; take 30 parts of acrylic acid, 70 parts of sodium methyl propylene sulfonate and 400 parts of water, stir evenly to obtain solution B; take 55 parts of graphene modifier and 500 parts of water, stir, and heat to 65°C; add solution A and solution B dropwise at the same time, reflux at normal pressure, stir mechanically, add dropwise for 3 hours, heat to 75°C and stir for 4 hours, adjust pH to neutral, and obtain additive;

[0041] S5: Take 25 parts of aluminum sulfate, 8 parts of additives, 4 parts of zinc sulfate, 4 parts of iron sulfate, 4 parts of aluminum nitrate, 2 parts of hydroxypropyl methylcellulose, and 35 parts of water, and stir at a high speed of 2000 rpm for 30 minutes to obtain a high-efficiency concrete accelerating agent.

[0042] Comparative Example 3 (changing the amount of modified polyethylene glycol ether added, the remaining method steps are consistent with Example 1): S1: Take 50 parts of thionyl chloride and 70 parts of dichloromethane, stir evenly to obtain a mixed solution; take 60 parts of polyethylene glycol ether and 140 parts of dichloromethane, stir to dissolve, add 15 parts of potassium carbonate, heat the oil bath to 42° C., stir and dropwise add the mixed solution, after 50 minutes of dropwise addition, heat to 50° C., condense and reflux for 24 hours, cool, filter, and evaporate the solvent to obtain the modified polyethylene glycol ether;

[0043] S2: Disperse 8 parts of amino graphene in acetonitrile to obtain a dispersion with a concentration of 1 mol / L, add 30 parts of modified polyethylene glycol ether, stir evenly, add 25 parts of potassium carbonate and 1.5 parts of potassium iodide, react at 85°C in a dark environment under nitrogen protection, condense and reflux for 24 hours, add 24 parts of complexing agent hydroxyethyldiethylenetriamine and 7 parts of defoaming agent, react at 85°C in a dark environment under nitrogen protection, condense and reflux for 14 hours to obtain modified graphene;

[0044] S3: Take 12 parts of acryloyl chloride and 25 parts of acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add 15 parts of potassium carbonate, add acryloyl chloride solution dropwise for 35 minutes under ice bath, stir for 2 hours under ice bath, introduce nitrogen gas at 0℃ in the dark for 24 hours, filter, and evaporate to obtain graphene modifier;

[0045] S4: Take 2 parts of initiator and 25 parts of water, stir evenly to obtain solution A; take 30 parts of acrylic acid, 70 parts of sodium methyl propylene sulfonate and 400 parts of water, stir evenly to obtain solution B; take 55 parts of graphene modifier and 500 parts of water, stir, and heat to 65°C; add solution A and solution B dropwise at the same time, reflux at normal pressure, stir mechanically, add dropwise for 3 hours, heat to 75°C and stir for 4 hours, adjust pH to neutral, and obtain additive;

[0046] S5: Take 25 parts of aluminum sulfate, 8 parts of additives, 4 parts of zinc sulfate, 4 parts of iron sulfate, 4 parts of aluminum nitrate, 2 parts of hydroxypropyl methylcellulose, and 35 parts of water, and stir at a high speed of 2000 rpm for 30 minutes to obtain a high-efficiency concrete accelerating agent.

[0047] Comparative Example 4 (reducing the amount of amino-modified graphene added, and the remaining method steps are consistent with Example 1): S1: Take 50 parts of thionyl chloride and 70 parts of dichloromethane, stir evenly to obtain a mixed solution; take 60 parts of polyethylene glycol ether and 140 parts of dichloromethane, stir to dissolve, add 15 parts of potassium carbonate, heat the oil bath to 42° C., stir and drop the mixed solution, after 50 minutes of dropwise addition, heat to 50° C., condense and reflux for 24 hours, cool, filter, and evaporate the solvent to obtain modified polyethylene glycol ether;

[0048] S2: Disperse 4 parts of amino graphene in acetonitrile to obtain a dispersion with a concentration of 1 mol / L, add 70 parts of modified polyethylene glycol ether, stir evenly, add 25 parts of potassium carbonate and 1.5 parts of potassium iodide, react at 85°C in a dark environment under nitrogen protection, condense and reflux for 24 hours, add 24 parts of complexing agent hydroxyethyldiethylenetriamine and 7 parts of defoaming agent, react at 85°C in a dark environment under nitrogen protection, condense and reflux for 14 hours to obtain modified graphene;

[0049] S3: Take 12 parts of acryloyl chloride and 25 parts of acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add 15 parts of potassium carbonate, add acryloyl chloride solution dropwise for 35 minutes under ice bath, stir for 2 hours under ice bath, introduce nitrogen gas at 0℃ in the dark for 24 hours, filter, and evaporate to obtain graphene modifier;

[0050] S4: Take 2 parts of initiator and 25 parts of water, stir evenly to obtain solution A; take 30 parts of acrylic acid, 70 parts of sodium methyl propylene sulfonate and 400 parts of water, stir evenly to obtain solution B; take 55 parts of graphene modifier and 500 parts of water, stir, and heat to 65°C; add solution A and solution B dropwise at the same time, reflux at normal pressure, stir mechanically, add dropwise for 3 hours, heat to 75°C and stir for 4 hours, adjust pH to neutral, and obtain additive;

[0051] S5: Take 25 parts of aluminum sulfate, 8 parts of additives, 4 parts of zinc sulfate, 4 parts of iron sulfate, 4 parts of aluminum nitrate, 2 parts of hydroxypropyl methylcellulose, and 35 parts of water, and stir at a high speed of 2000 rpm for 30 minutes to obtain a high-efficiency concrete accelerating agent.

[0052] In the above embodiments, all raw materials are from the following sources: polyethylene glycol monomethyl ether (Mw ~ 500, Shanghai MacLean Biochemical Technology Co., Ltd.), amino graphene (JK-R0785, Jingkang Biological), thionyl chloride (CAS: 7719-09-7), dichloromethane (CAS: 75-09-2), polyethylene glycol ether (YK7201, Hubei Yongkuo Technology Co., Ltd.), potassium carbonate (S30391, Shanghai Yuanye), acetonitrile (CAS: 75-05-8), potassium iodide (S30393, Shanghai Yuanye), hydroxyethyl diethylenetriamine (CAS: 1965-29-3), Foaming agent (GP330, CAS: 87435-55-0), acryloyl chloride (CAS: 814-68-6), initiator (APS, CAS: 7727-54-0), acrylic acid (CAS: 79-10-7), sodium methyl methacrylate sulfonate (CAS: 1561-92-8), aluminum sulfate (S40087, Shanghai Yuanye), zinc sulfate (S22124, Shanghai Yuanye), iron sulfate (S70004, Shanghai Yuanye), aluminum nitrate (237973, Sigma-Aldrich Trading Co., Ltd.), hydroxypropyl methylcellulose (S14173, Shanghai Yuanye).

[0053] Experiment: Take the concrete high-efficiency accelerating setting agent prepared in Examples 1 to 3 and Comparative Examples 1 to 4, and refer to the detection method specified in Q / CR 807-2020 to test the initial setting time, 6h compressive strength, and 28d compressive strength ratio. The test cement is the benchmark cement P.I42.5, and the addition amount of the concrete high-efficiency accelerating setting agent is 5%; see the table below for specific data;

[0054]

[0055] Conclusion: In comparative example 1, chloromethoxy polyethylene glycol is used instead of modified polyethylene glycol ether, wherein after the reaction of -Cl with the amino graphene is completed, there is no group that can react with the complexing agent and the defoaming agent, and the prepared high-efficiency concrete accelerating agent has poorer performance than the embodiment; in comparative example 2, the addition amount of the complexing agent and the defoaming agent is changed, and the performance is reduced, from which it can be seen that the control ratio is of great significance; in comparative example 3, the addition amount of the modified polyethylene glycol ether is changed, and compared with the embodiment, the degree of hyperbranching is reduced, so the performance is not as good as the embodiment; in comparative example 4, the addition amount of graphene is reduced, and the performance is significantly reduced; in summary, the high-efficiency concrete accelerating agent prepared by the present invention has good effect, is conducive to improving the early strength, and does not lose the later strength, and has good practicality.

[0056] Finally, it should be noted that the above is only a preferred embodiment of the present invention, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the spirit and principle of the present invention and within the technical scope disclosed in this application should be included in the protection scope of this application; in the absence of conflict, the embodiments of this application and the features in the embodiments can be combined with each other. Therefore, the protection scope of this application shall be based on the protection scope of the claims.

Claims

1. A method for preparing a high-efficiency quick-setting agent for concrete, characterized in that: The following steps are involved: S1: Take an initiator and water, stir evenly to obtain solution A; take acrylic acid, sodium methacrylate sulfonate and water, stir evenly to obtain solution B; take a graphene modifier and water, stir and heat, and simultaneously drop solution A and solution B into the mixture, raise the temperature and stir after the addition is complete, adjust the pH to neutral, and obtain an additive; S2: Take aluminum sulfate, additives, zinc sulfate, iron sulfate, aluminum nitrate, hydroxypropyl methylcellulose and water, stir at high speed to mix well, and obtain a high-efficiency concrete accelerating agent.

2. The method for preparing a high-efficiency accelerated setting agent for concrete according to claim 1, characterized in that: The high-efficiency concrete quick-setting agent comprises the following raw materials, calculated by weight: 20 to 30 parts of aluminum sulfate, 5 to 10 parts of additives, 2 to 5 parts of zinc sulfate, 3 to 6 parts of iron sulfate, 3 to 6 parts of aluminum nitrate, 1 to 3 parts of hydroxypropyl methylcellulose, and 30 to 40 parts of water.

3. The method for preparing a high-efficiency accelerated setting agent for concrete according to claim 1, characterized in that: The additive comprises the following raw materials, calculated by weight: 1 to 3 parts of initiator, 600 to 1200 parts of water, 20 to 40 parts of acrylic acid, 60 to 80 parts of sodium methyl propylene sulfonate, and 50 to 60 parts of graphene modifier.

4. The method for preparing a high-efficiency accelerated setting agent for concrete according to claim 1, characterized in that: Preparation of the graphene modifier The following steps are involved: S1: Disperse the amino graphene in acetonitrile to obtain a dispersion with a concentration of 1 mol / L, add modified polyethylene glycol ether, stir evenly, add potassium carbonate and potassium iodide, react under nitrogen protection at 80-90°C in a dark environment, condense and reflux for 20-25 hours, add a complexing agent and a defoaming agent, react under nitrogen protection at 80-90°C in a dark environment, condense and reflux for 10-15 hours, and obtain modified graphene; S2: Take acryloyl chloride and acetonitrile, stir evenly to obtain acryloyl chloride solution; take modified graphene, add potassium carbonate, dropwise add acryloyl chloride solution in an ice bath, stir in an ice bath for 1 to 2 hours, introduce nitrogen gas at 0°C in the dark to react for 20 to 25 hours, filter, and rotary evaporate to obtain a graphene modifier.

5. The method for preparing a high-efficiency accelerated setting agent for concrete according to claim 4, characterized in that: The modified graphene includes the following raw materials, calculated by weight: 5 to 10 parts of amination graphene, 60 to 80 parts of modified polyethylene glycol ether, 15 to 30 parts of potassium carbonate, 0.5 to 2 parts of potassium iodide, 20 to 30 parts of complexing agent, and 5 to 10 parts of defoaming agent; the graphene modifier includes the following raw materials, calculated by weight: 5 to 15 parts of acryloyl chloride, 20 to 30 parts of acetonitrile, and 10 to 20 parts of potassium carbonate.

6. The method for preparing a high-efficiency accelerated setting agent for concrete according to claim 5, characterized in that: The complexing agent includes hydroxyethyldiethylenetriamine, and the defoaming agent includes defoaming agent GP330; the mass ratio of the complexing agent to the defoaming agent is (3-4):

1.

7. The method for preparing a high-efficiency accelerated setting agent for concrete according to claim 4, characterized in that: The preparation of the modified polyethylene glycol ether comprises the following steps: Take thionyl chloride and dichloromethane, stir evenly to obtain a mixed solution; take polyethylene glycol ether and dichloromethane, stir to dissolve, add potassium carbonate, heat the oil bath to 40-45°C, stir and drop the mixed solution, after 40-60 minutes of dropwise addition, heat to 45-50°C, condense and reflux for 20-25 hours, cool, filter, and evaporate the solvent to obtain modified polyethylene glycol ether.

8. The method for preparing a high-efficiency accelerated setting agent for concrete according to claim 7, characterized in that: The modified polyethylene glycol ether comprises the following raw materials, calculated by weight: 40 to 60 parts of thionyl chloride, 60 to 80 parts of dichloromethane, 50 to 80 parts of polyethylene glycol ether, 100 to 150 parts of dichloromethane, and 10 to 20 parts of potassium carbonate.

9. A high-efficiency concrete accelerating setting agent prepared according to the method for preparing a high-efficiency concrete accelerating setting agent according to any one of claims 1 to 8.

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