Accelerating agent for sprayable ultra-high performance concrete in high altitude area and preparation of accelerating agent

Abstract

The invention relates to the technical field of concrete accelerators, and particularly discloses a high-altitude area sprayable ultra-high performance concrete accelerator, which is prepared from the following raw materials in parts by mass: 30 to 60 parts of aluminum sulfate, 1 to 5 parts of magnesium sulfate, 1 to 2 parts of 3-hydroxy-3-carboxyl glutaric acid, 1 to 3 parts of N, N-diethylethanolamine, 1 to 2 parts of disodium ethylene diamine tetraacetate and 1 to 3 parts of oxidized chitosan. The composition comprises the following components in parts by weight: 5-10 parts of microcrystalline cellulose, 1-2 parts of amino-terminated polyamidoamine, 0.1-1 part of dibutyl phthalate and 0.1-1 part of hydroxyethyl cellulose. The invention further discloses a preparation method of the accelerator for the sprayable ultra-high performance concrete in the high altitude area. The cement is short in setting time and high in strength, the strength within one day can reach 14 MP or above, and the compressive strength ratio within 28 days can reach 119%; the concrete has the advantages of small stimulation to human bodies, safety and reliability, optimizes the construction environment, and can still play a quick-setting role when the environment temperature is relatively low (the lowest temperature is 0 DEG C).

Description

Technical Field

[0001] The invention relates to the technical field of concrete accelerating agents, and in particular to an accelerating agent for spraying ultra-high performance concrete in high altitude areas and a preparation method thereof. Background Art

[0002] Concrete accelerator refers to an admixture that can make concrete set and harden quickly. Its early strength mechanism is to convert gypsum in cement into sodium sulfate, which loses its retarding effect, thereby promoting the rapid hydration of C3A (tricalcium aluminate) and precipitating its hydration product crystals in the solution, causing the cement slurry to solidify rapidly.

[0003] At present, liquid accelerators are developing rapidly, and the accelerators commonly used in shotcrete generally contain a large amount of alkaline substances. Although they can meet the needs of rapid hardening, they have a greater impact on the later strength of shotcrete. At the same time, a large amount of alkaline substances increases the alkali-aggregate reaction of concrete in the later stage, destroying the durability of concrete.

[0004] The existing alkali-free liquid accelerators are developing rapidly, but there are some common problems with the accelerating effect of liquid accelerators at relatively low temperatures. For example, the setting time is too long, the concrete strength develops slowly, and the rebound of shotcrete is too large. Especially in high-altitude mountainous areas, the temperature is low, and the existing liquid accelerators are not effective. They will solidify and crystallize at relatively low temperatures, and have a poor accelerating effect on concrete, resulting in the setting time not meeting the requirements, resulting in low production efficiency and increased overall costs. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an accelerated setting agent for spraying ultra-high performance concrete in high altitude areas and a preparation method thereof.

[0006] A quick-setting agent for ultra-high performance concrete that can be sprayed in high-altitude areas. The raw materials thereof include, by mass, 30-60 parts of aluminum sulfate, 1-5 parts of magnesium sulfate, 1-2 parts of 3-hydroxy-3-carboxyglutaric acid, 1-3 parts of N,N-diethylethanolamine, 1-2 parts of disodium ethylenediaminetetraacetate, 1-3 parts of oxidized chitosan, 5-10 parts of microcrystalline cellulose, 1-2 parts of amino-terminated polyamidoamine, 0.1-1 parts of dibutyl phthalate and 0.1-1 parts of hydroxyethyl cellulose.

[0007] Preferably, the viscosity-average molecular weight of the oxidized chitosan is 100,000-120,000, and the degree of deacetylation is 92.4-95.3%.

[0008] Preferably, the C6 carboxyl content of the oxidized chitosan is 35-40.2 wt%.

[0009] Preferably, the oxidized chitosan is 6-carboxychitosan.

[0010] Preferably, the oxidized chitosan is obtained by selectively oxidizing the C-6 primary hydroxyl group of chitosan using NO2 or laccase / 2,2,6,6-tetramethylpiperidine-1-oxyl free radical system.

[0011] See also:

[0012] [1] Yang Yuedong, Yu Jiugao, Zhou Yongguo, et al. Preparation and blood compatibility study of 6-carboxyl chitosan[J]. Chinese Journal of Biomedical Engineering, 2007, 26(4):5. DOI:10.3969 / j.issn.0258-8021.2007.04.024.

[0013] [2] Ji Lei, Liu Tianhong, Wang Ying, et al. Preparation and antibacterial properties of silver-loaded oxidized chitosan[J]. China Agricultural Science and Technology Herald, 2024(003):026.

[0014] Preferably, the generation number of the amino-terminated polyamidoamine is 4.0-6.0.

[0015] The method for preparing the above-mentioned quick-setting agent for spraying ultra-high performance concrete in high-altitude areas comprises the following steps:

[0016] S1. Add oxidized chitosan to acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 60-80°C for 1-2h, cool to 40-45°C, add amino-terminated polyamidoamine and stir for 10-20min, filter, wash, and vacuum dry to obtain activated cellulose;

[0017] S2, adding aluminum sulfate and activated cellulose to water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at 50-70° C. until the system becomes clear, to obtain a prefabricated material;

[0018] S3. Add dibutyl phthalate and hydroxyethyl cellulose to the prefabricated material, stir evenly, and cool to room temperature.

[0019] Preferably, in S1, the concentration of the acetic acid aqueous solution is 0.1-1 mol / L.

[0020] Preferably, in S2, during the process of stirring at 50-70°C until the system becomes clear, the stirring speed is 100-400 r / min.

[0021] Beneficial effects:

[0022] 1. The present invention combines oxidized chitosan with microcrystalline cellulose to enhance the chemical activity of microcrystalline cellulose, which can be further combined with the active groups on the amino-terminated polyamide amine molecular chain; and the stable branched structure of the amino-terminated polyamide amine is compounded with aluminum sulfate to form a stable macromolecular group through coordination, which not only improves the stability of the accelerator, but also increases the amount of aluminum sulfate added, thereby improving the early strength performance of concrete and ensuring the stability of the accelerator system.

[0023] 2. The present invention further adds dibutyl phthalate, which has a strong gelling ability and cooperates with hydroxyethyl cellulose to not only greatly improve the adaptability of the accelerator, but also quickly reduce the freezing point of the accelerator and effectively inhibit the recrystallization of ice, thereby maintaining the continuous hydration reaction of the concrete and greatly improving the durability of the concrete.

[0024] 3. The present invention adopts activated cellulose and hydroxyethyl cellulose, which have strong affinity and cooperate with each other to form a macromolecular group with high stability, good solution stability, good concrete spraying effect, good spray slurry cohesion, good rapid setting effect, and excellent early and late strength.

[0025] The present invention has a short setting time, the initial setting can be controlled at about 2 minutes and 39 seconds, the final setting can be controlled at about 6 minutes and 26 seconds, and the strength is high, the strength in one day can reach more than 14 MP, the compressive strength ratio in 28 days can be as high as 119%, and the retention rate of 90d compressive strength can reach 117%; it has little stimulation to the human body, is safe and reliable, optimizes the construction environment, and can still play a quick-setting role when the ambient temperature is low (minimum 0°C). BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a comparison chart of the setting time of the slurry of the quick-setting agents obtained in Example 5 and Comparative Examples 1-2.

[0027] Figure 2 It is a comparison chart of the 1d compressive strength and 28d compressive strength ratio of the quick-setting agents obtained in Example 5 and Comparative Examples 1-2.

[0028] Figure 3 The figure is a comparison chart of the 90d compressive strength retention rate and the stable period of the quick-setting agents obtained in Example 5 and Comparative Examples 1-2.

[0029] Figure 4 This is a photograph of the quick-setting agent obtained in Example 5 after low-temperature stability testing.

[0030] Figure 5 This is a photograph of the quick-setting agent obtained in Comparative Example 2 after low-temperature stability testing.

[0031] Figure 6 The following is a photograph of the effect of spraying the quick-setting agent obtained in Example 5 in a tunnel.

[0032] Figure 7 The following is a photograph of the effect of using the quick-setting agent obtained in Example 5 to spray on the slope.

[0033] Figure 8 This is a photo of the effect of slope spraying using a commercially available quick-setting agent. DETAILED DESCRIPTION

[0034] The present invention will be further explained below in conjunction with specific embodiments.

[0035] The applicant prepared 6-carboxy chitosan according to the document [2] (Ji Lei, Liu Tianhong, Wang Ying, et al. Preparation and antibacterial properties of silver-loaded oxidized chitosan [J]. China Agricultural Science and Technology Herald, 2024(003):026.).

[0036] The viscosity-average molecular weight of the 6-carboxyl chitosan used below is 110,000, the degree of deacetylation is 93.3%, and the carboxyl content at the C6 position is 36.75 wt%.

[0037] Example 1

[0038] A quick-setting agent for ultra-high performance concrete that can be sprayed in high-altitude areas, the raw materials of which include: 30kg of aluminum sulfate, 1kg of magnesium sulfate, 1kg of 3-hydroxy-3-carboxyglutaric acid, 1kg of N,N-diethylethanolamine, 1kg of disodium ethylenediaminetetraacetate, 1kg of 6-carboxychitosan, 5kg of microcrystalline cellulose, 1kg of 4.0-generation terminal amino polyamidoamine, 0.1kg of dibutyl phthalate, and 0.1kg of hydroxyethyl cellulose.

[0039] The method for preparing the above-mentioned quick-setting agent for spraying ultra-high performance concrete in high-altitude areas comprises the following steps:

[0040] S1. Add 6-carboxyl chitosan to 20 kg of 0.1 mol / L acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 60°C for 1 hour, cool to 40°C, add amino-terminated polyamidoamine and stir for 10 minutes, filter, wash, and vacuum dry to obtain activated cellulose;

[0041] S2, adding aluminum sulfate and activated cellulose to 40 kg of water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at a temperature of 50 ° C until the system is clear, and the stirring speed is 100 r / min to obtain a prefabricated material;

[0042] S3. Add dibutyl phthalate and hydroxyethyl cellulose to the prefabricated material, stir evenly, and cool to room temperature.

[0043] Example 2

[0044] A quick-setting agent for ultra-high performance concrete that can be sprayed in high-altitude areas, the raw materials of which include: 60kg of aluminum sulfate, 5kg of magnesium sulfate, 2kg of 3-hydroxy-3-carboxyglutaric acid, 3kg of N,N-diethylethanolamine, 2kg of disodium ethylenediaminetetraacetate, 3kg of 6-carboxychitosan, 10kg of microcrystalline cellulose, 2kg of 6.0-generation terminal amino polyamidoamine, 1kg of dibutyl phthalate, and 1kg of hydroxyethyl cellulose.

[0045] The method for preparing the above-mentioned quick-setting agent for spraying ultra-high performance concrete in high-altitude areas comprises the following steps:

[0046] S1. Add 6-carboxyl chitosan to 30 kg of 1 mol / L acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 80°C for 2 h, cool to 45°C, add amino-terminated polyamidoamine and stir for 20 min, filter, wash, and vacuum dry to obtain activated cellulose;

[0047] S2, adding aluminum sulfate and activated cellulose to 50 kg of water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at a temperature of 70° C. until the system becomes clear, and stirring at a speed of 400 r / min to obtain a prefabricated material;

[0048] S3. Add dibutyl phthalate and hydroxyethyl cellulose to the prefabricated material, stir evenly, and cool to room temperature.

[0049] Example 3

[0050] A quick-setting agent for ultra-high performance concrete that can be sprayed in high-altitude areas, the raw materials of which include: 40kg of aluminum sulfate, 4kg of magnesium sulfate, 1.3kg of 3-hydroxy-3-carboxyglutaric acid, 2.5kg of N,N-diethylethanolamine, 1.3kg of disodium ethylenediaminetetraacetate, 2.5kg of 6-carboxychitosan, 7kg of microcrystalline cellulose, 1.8kg of 5.5-generation terminal amino polyamidoamine, 0.3kg of dibutyl phthalate, and 0.8kg of hydroxyethyl cellulose.

[0051] The method for preparing the above-mentioned quick-setting agent for spraying ultra-high performance concrete in high-altitude areas comprises the following steps:

[0052] S1. Add 6-carboxyl chitosan to 22 kg of 0.7 mol / L acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 65° C. for 100 min, cool to 41° C., add amino-terminated polyamidoamine and stir for 18 min, filter, wash, and vacuum dry to obtain activated cellulose;

[0053] S2, adding aluminum sulfate and activated cellulose to 42 kg of water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at a temperature of 65 ° C until the system is clear, and the stirring speed is 200 r / min to obtain a prefabricated material;

[0054] S3. Add dibutyl phthalate and hydroxyethyl cellulose to the prefabricated material, stir evenly, and cool to room temperature.

[0055] Example 4

[0056] A quick-setting agent for ultra-high performance concrete that can be sprayed in high-altitude areas, the raw materials of which include: 50kg of aluminum sulfate, 2kg of magnesium sulfate, 1.7kg of 3-hydroxy-3-carboxyglutaric acid, 1.5kg of N,N-diethylethanolamine, 1.7kg of disodium ethylenediaminetetraacetate, 1.5kg of 6-carboxychitosan, 9kg of microcrystalline cellulose, 1.2kg of 4.5-generation terminal amino polyamidoamine, 0.7kg of dibutyl phthalate, and 0.2kg of hydroxyethyl cellulose.

[0057] The method for preparing the above-mentioned quick-setting agent for spraying ultra-high performance concrete in high-altitude areas comprises the following steps:

[0058] S1. Add 6-carboxyl chitosan to 28 kg of 0.3 mol / L acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 75°C for 80 min, cool to 43°C, add amino-terminated polyamidoamine and stir for 12 min, filter, wash, and vacuum dry to obtain activated cellulose;

[0059] S2, adding aluminum sulfate and activated cellulose to 48 kg of water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at a temperature of 55 ° C until the system is clear, and the stirring speed is 300 r / min to obtain a prefabricated material;

[0060] S3. Add dibutyl phthalate and hydroxyethyl cellulose to the prefabricated material, stir evenly, and cool to room temperature.

[0061] Example 5

[0062] A quick-setting agent for ultra-high performance concrete that can be sprayed in high-altitude areas, the raw materials of which include: 45kg of aluminum sulfate, 3kg of magnesium sulfate, 1.5kg of 3-hydroxy-3-carboxyglutaric acid, 2kg of N,N-diethylethanolamine, 1.5kg of disodium ethylenediaminetetraacetate, 2kg of 6-carboxychitosan, 8kg of microcrystalline cellulose, 1.5kg of 5.0-generation terminal amino polyamidoamine, 0.5kg of dibutyl phthalate, and 0.5kg of hydroxyethyl cellulose.

[0063] The method for preparing the above-mentioned quick-setting agent for spraying ultra-high performance concrete in high-altitude areas comprises the following steps:

[0064] S1. Add 6-carboxyl chitosan to 25 kg of 0.5 mol / L acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 70°C for 90 min, cool to 42°C, add amino-terminated polyamidoamine and stir for 15 min, filter, wash, and vacuum dry to obtain activated cellulose;

[0065] S2, adding aluminum sulfate and activated cellulose to 45 kg of water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at a temperature of 60 ° C until the system is clear, stirring at a speed of 250 r / min, to obtain a prefabricated material;

[0066] S3. Add dibutyl phthalate and hydroxyethyl cellulose to the prefabricated material, stir evenly, and cool to room temperature.

[0067] Comparative Example 1

[0068] A quick-setting agent, whose raw materials include: 45kg of aluminum sulfate, 3kg of magnesium sulfate, 1.5kg of 3-hydroxy-3-carboxyglutaric acid, 2kg of N,N-diethylethanolamine, 1.5kg of disodium ethylenediaminetetraacetate, 2kg of 6-carboxychitosan, 8kg of microcrystalline cellulose, 0.5kg of dibutyl phthalate and 0.5kg of hydroxyethyl cellulose.

[0069] The preparation method of the above-mentioned accelerating setting agent comprises the following steps:

[0070] S1. Add 6-carboxyl chitosan to 25 kg of 0.5 mol / L acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 70° C. for 90 min, cool, filter, wash, and vacuum dry to obtain activated cellulose;

[0071] S2, adding aluminum sulfate and activated cellulose to 45 kg of water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at a temperature of 60 ° C until the system is clear, stirring at a speed of 250 r / min, to obtain a prefabricated material;

[0072] S3. Add dibutyl phthalate and hydroxyethyl cellulose to the prefabricated material, stir evenly, and cool to room temperature.

[0073] Comparative Example 2

[0074] A quick-setting agent, whose raw materials include: 45kg of aluminum sulfate, 3kg of magnesium sulfate, 1.5kg of 3-hydroxy-3-carboxyglutaric acid, 2kg of N,N-diethylethanolamine, 1.5kg of disodium ethylenediaminetetraacetate, 2kg of 6-carboxychitosan, 8kg of microcrystalline cellulose, 1.5kg of 5.0-generation amino-terminated polyamidoamine, and 0.5kg of dibutyl phthalate.

[0075] The preparation method of the above-mentioned accelerating setting agent comprises the following steps:

[0076] S1. Add 6-carboxyl chitosan to 25 kg of 0.5 mol / L acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 70°C for 90 min, cool to 42°C, add amino-terminated polyamidoamine and stir for 15 min, filter, wash, and vacuum dry to obtain activated cellulose;

[0077] S2, adding aluminum sulfate and activated cellulose to 45 kg of water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at a temperature of 60 ° C until the system is clear, stirring at a speed of 250 r / min, to obtain a prefabricated material;

[0078] S3. Add dibutyl phthalate to the prefabricated material, stir evenly, and cool to room temperature.

[0079] The setting time, mortar strength and stability of the quick-setting agents obtained in Example 5 and Comparative Examples 1-2 were tested with reference to GB / T 35159-2017 "Accelerators for Shotcrete". The quick-setting agent dosage was 7% of the cement mass, and the stability was observed every day according to the method in Appendix C until the volume of the bottom sediment exceeded 5 mL, and the number of days was recorded.

[0080] like Figure 1-Figure 3 As shown, the setting time of the quick-setting agent obtained in Example 5 is shorter than that in Comparative Example 1-2 (P < 0.05), the mortar strength is better than that in Comparative Example 1-2 (P < 0.05), and the stability is also far superior to that in Comparative Example 1-2 (P < 0.05).

[0081] Referring to GB / T 35159-2017 "Accelerators for Shotcrete", the low temperature stability of the accelerators obtained in Example 5 and Comparative Example 2 was tested, the ambient temperature was maintained at 0±1°C, and the volume of the bottom sediment was measured after 28 days. Figure 4 As shown, the state of the quick-setting agent obtained in Comparative Example 2 is as follows Figure 5 shown.

[0082] The applicant believes that this is because, on the one hand, the present invention combines oxidized chitosan with microcrystalline cellulose to enhance the chemical activity of microcrystalline cellulose, which can be further combined with the active groups on the amino-terminated polyamide amine molecular chain; and the stable branched structure of the amino-terminated polyamide amine is compounded with aluminum sulfate to form a stable macromolecular group through coordination, which not only improves the stability of the accelerator, but also increases the amount of aluminum sulfate added, improves the early strength performance of concrete, and ensures the stability of the accelerator system; on the other hand, the present invention further adds dibutyl phthalate, which has a strong gelling ability and cooperates with hydroxyethyl cellulose to not only greatly improve the adaptability of the accelerator, but also quickly reduce the freezing point of the accelerator, effectively inhibit the recrystallization of ice, and can maintain the continuous progress of the concrete hydration reaction, and can greatly improve the durability of the concrete; and the activated cellulose and hydroxyethyl cellulose are combined, the two have strong affinity, and cooperate with each other to form a macromolecular group with high stability, good solution stability, good concrete spraying effect, good spraying slurry cohesion, good rapid setting effect, and excellent early and late strength.

[0083] The quick-setting agent obtained in Example 5 was added to shotcrete at a construction site in Xinjiang for actual operation. Figure 6 and Figure 7 As shown. The actual operation of shotcrete spraying on this construction site is carried out with the original accelerating agent. Figure 8 As shown. Figure 7 and Figure 8 By comparison, it can be found that the quick-setting agent obtained by the present invention is sprayed with very little dust, which is better than the existing commercial quick-setting agent.

[0084] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A quick-setting agent for ultra-high performance concrete that can be sprayed in high altitude areas, characterized in that: The raw materials include, by mass, 30-60 parts of aluminum sulfate, 1-5 parts of magnesium sulfate, 1-2 parts of 3-hydroxy-3-carboxyglutaric acid, 1-3 parts of N,N-diethylethanolamine, 1-2 parts of disodium ethylenediaminetetraacetate, 1-3 parts of oxidized chitosan, 5-10 parts of microcrystalline cellulose, 1-2 parts of amino-terminated polyamidoamine, 0.1-1 parts of dibutyl phthalate and 0.1-1 parts of hydroxyethyl cellulose.

2. The quick-setting agent for ultra-high performance concrete sprayable in high altitude areas according to claim 1, characterized in that: The viscosity-average molecular weight of oxidized chitosan is 100,000-120,000, and the degree of deacetylation is 92.4-95.3%.

3. The quick-setting agent for ultra-high performance concrete sprayable in high altitude areas according to claim 1, characterized in that: The C6 carboxyl content of oxidized chitosan is 35-40.2wt%.

4. The quick-setting agent for ultra-high performance concrete sprayable in high altitude areas according to claim 1, characterized in that: Oxidized chitosan is 6-carboxychitosan.

5. The quick-setting agent for ultra-high performance concrete sprayable in high altitude areas according to claim 1, characterized in that: The oxidized chitosan is obtained by selectively oxidizing the C-6 primary hydroxyl group of chitosan using NO2 or laccase / 2,2,6,6-tetramethylpiperidin-1-oxyl free radical system.

6. The quick-setting agent for ultra-high performance concrete sprayable in high altitude areas according to claim 1, characterized in that: The generation number of the amino-terminated polyamidoamine is 4.0-6.

0.

7. A method for preparing the quick-setting agent for ultra-high performance concrete sprayable in high altitude areas according to any one of claims 1 to 6, characterized in that: The steps include: S1. Add oxidized chitosan to acetic acid aqueous solution and stir evenly, add microcrystalline cellulose, stir at 60-80°C for 1-2h, cool to 40-45°C, add amino-terminated polyamidoamine and stir for 10-20min, filter, wash, and vacuum dry to obtain activated cellulose; S2, adding aluminum sulfate and activated cellulose to water and stirring evenly, adding magnesium sulfate, 3-hydroxy-3-carboxyglutaric acid, N,N-diethylethanolamine, and disodium ethylenediaminetetraacetate in sequence, stirring at 50-70° C. until the system becomes clear, to obtain a prefabricated material; S3. Add dibutyl phthalate and hydroxyethyl cellulose to the prefabricated material, stir evenly, and cool to room temperature.

8. The method for preparing an accelerated setting agent for sprayable ultra-high performance concrete in high altitude areas according to claim 7, characterized in that: In S1, the concentration of the acetic acid aqueous solution is 0.1-1 mol / L.

9. The method for preparing an accelerated setting agent for ultra-high performance concrete sprayable in high altitude areas according to claim 7, characterized in that: In S2, the system is stirred at 50-70°C until the system becomes clear, and the stirring speed is 100-400 r / min.

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