Alkali-free accelerator and preparation method thereof

Abstract

The invention discloses an alkali-free setting accelerator and a preparation method thereof, and relates to the technical field of concrete admixtures, and the alkali-free setting accelerator is prepared from the following components in percentage by mass: 30-40wt% of aluminum sulfate, 3-5wt% of aluminum dihydrogen phosphate, 3-5wt% of silicate, 3-5wt% of carbonate, 4-6wt% of amphoteric organic ionic salt, 1-3wt% of lactobionic acid, 3-6wt% of 1, 3-bis ((trihydroxymethyl) methylamino) propane, 3-6wt% of (3, 4-dihydroxyphenyl)-1, 3, 4-trimethyl-1, 3-pentanediol monoisobutyrate, 3-6wt% of (3, 4-dihydroxyphenyl) The invention discloses a water-soluble hyperbranched polyamide cleaning agent which comprises the following components in percentage by weight: 0.5-1 percent of 2, 6-diamino acridine-9-yl) boric acid, 0.4-0.8 percent of adenosine, 1-3 percent of malic acid, 2-4 percent of polyethylene glycol, 1-3 percent of water-soluble hyperbranched polyamide and the balance of water. The alkali-free accelerator is good in accelerating effect, high in early-stage and later-stage strength and sufficient in stability.

Description

Technical Field

[0001] The invention relates to the technical field of concrete admixtures, and in particular to an alkali-free quick-setting agent and a preparation method thereof. Background Art

[0002] Accelerators are admixtures that make cement-containing binders quickly solidify and harden to produce a certain strength. They are widely used in tunnel spray mortar or concrete construction and emergency repair construction. Their main purpose is to accelerate the setting time of the binder, speed up the construction speed, reduce rebound, improve the early strength without reducing the later strength, and meet the construction requirements of special projects. Accelerators mainly include alkali-containing accelerators and alkali-free accelerators. Alkali-free accelerators are both safe and environmentally friendly, and can ensure stable and rapid construction implementation. They have become the mainstream development direction of accelerators.

[0003] The raw materials of the commonly used alkali-free accelerators are generally aluminum compounds. Aluminum ions are very likely to undergo hydrolysis-polymerization-precipitation reactions in water, and the solubility of aluminum salts is relatively low. As time goes by, alkali-free accelerators are prone to unstable phenomena such as flocculation, precipitation, and crystallization. In addition, the alkali-free accelerators on the market have more or less problems such as low early strength, late strength loss, poor stability, easy precipitation, and long setting time.

[0004] In order to solve the above problems, the Chinese invention patent with authorization announcement number CN105503016B discloses a high-strength sulfur-free and alkali-free liquid accelerator and its preparation method and application. The raw material components and the weight percentage of each component in the total raw material are as follows: 10-25% of nano alumina, 15-27% of nano silicon dioxide, 5-12% of trifluoroacetic acid, 1-5% of organic dispersant, 1-3% of stabilizer, 0.5-1.5% of suspending agent, and the balance is water, and the total weight is supplemented to 100%. The high-strength sulfur-free and alkali-free liquid quick-setting agent of the invention can be used in the wet spraying industry of shotcrete. Its alkali content is less than 1%, the stable period is more than 6 months, the 1d compressive strength is as high as 23.7MPa, and the 28d compressive strength ratio is as high as 125%. When the dosage is 4-5%, it can meet the technical requirements of JC477-2005 "Accelerator for Shotcrete". It is a high-strength alkali-free quick-setting agent that can be widely used in the initial support and emergency repair of highways, railways, coal mines, municipal engineering and other projects. However, the nano-alumina and nano-silicon dioxide used in the patent are limited to nano-level, which have problems such as high price, difficulty in dispersion and high viscosity and difficulty in construction. In addition, it contains fluoride. In addition to the slow development of early strength of concrete, the harm of fluorine-containing quick-setting agents to human body and environment during production and application should not be underestimated. When the fluoride storage in the human body is too high, it will lead to poisoning, which may cause fluorosis at the mildest and fluorosis bone cancer at the worst.

[0005] It can be seen that the development of an alkali-free accelerating agent with good accelerating effect, high early and late strengths, and sufficient stability, as well as its preparation method, meets the market demand, has broad market value and application prospects, and is of great significance for promoting the development of the field of concrete admixtures. Summary of the Invention

[0006] The purpose of the present invention is to provide an alkali-free accelerating agent with good accelerating effect, high early and late strengths, and sufficient stability, as well as its preparation method, in order to overcome the deficiencies of the prior art.

[0007] To achieve the above object, the technical solution adopted by the present invention is: an alkali-free accelerating agent is made of the following components in mass percentage: 30-40 wt% of aluminum sulfate, 3-5 wt% of aluminum dihydrogen phosphate, 3-5 wt% of silicate, 3-5 wt% of carbonate, 4-6 wt% of zwitterionic organic salt, 1-3 wt% of lactic acid, 3-6 wt% of 1,3-bis((tris(hydroxymethyl)methylamino)propane), 0.5-1 wt% of (3,6-diaminoacridin-9-yl)boronic acid, 0.4-0.8 wt% of adenosine, 1-3 wt% of malic acid, 2-4 wt% of polyethylene glycol, 1-3 wt% of water-soluble hyperbranched polyamide, and the balance is water.

[0008] Preferably, the silicate is at least one of sodium silicate and potassium silicate.

[0009] Preferably, the carbonate is sodium carbonate.

[0010] Preferably, the zwitterionic organic salt is at least one of hydroxypropyl propane sulfonate pyridinium salt and 1-benzylpyridinium-3-carboxylate.

[0011] Preferably, the water-soluble hyperbranched polyamide is an amino-terminated water-soluble hyperbranched polyamide with a molecular weight of 15300, which is prepared according to the method of Example 1 of the Chinese invention patent with the authorization announcement number CN1232567C.

[0012] Preferably, the polyethylene glycol is polyethylene glycol 200.

[0013] Another object of the present invention is to provide a preparation method of the alkali-free accelerating agent, which includes the following steps: after adding aluminum sulfate and aluminum dihydrogen phosphate into water, then adding silicate, carbonate, zwitterionic organic salt, lactic acid, 1,3-bis((tris(hydroxymethyl)methylamino)propane), (3,6-diaminoacridin-9-yl)boronic acid, adenosine, malic acid, polyethylene glycol, and water-soluble hyperbranched polyamide in sequence, and stirring and heating the mixture with a mechanical stirring device until the mixture becomes a clear solution, and then cooling it to room temperature.

[0014] Preferably, the heating temperature is 45-55 °C.

[0015] Another object of the present invention is to provide an application of the alkali-free accelerating agent in shotcrete, and the dosage is 4-6% of the mass of cement.

[0016] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0017] (1) The preparation method of the alkali-free accelerating agent disclosed by the present invention has low process difficulty, convenient operation control, is easy to obtain a high yield, has low dependence on equipment and low energy consumption, high preparation efficiency, is suitable for continuous large-scale production, and has high popularization and application value.

[0018] (2) The alkali-free accelerating agent disclosed by the present invention is made of the following components by mass percentage: 30-40wt% of aluminum sulfate, 3-5wt% of aluminum dihydrogen phosphate, 3-5wt% of silicate, 3-5wt% of carbonate, 4-6wt% of zwitterionic salt, 1-3wt% of lactic acid, 3-6wt% of 1,3-bis((tris(hydroxymethyl)methylamino)propane), 0.5-1wt% of (3,6-diaminoacridin-9-yl)boric acid, 0.4-0.8wt% of adenosine, 1-3wt% of malic acid, 2-4wt% of polyethylene glycol, 1-3wt% of water-soluble hyperbranched polyamide, and the balance is water. Through the mutual cooperation and joint action of each component, the prepared alkali-free accelerating agent has good accelerating effect, high early and late strength, and sufficient stability; through the reasonable selection of the type and dosage ratio of the components, the dosage of the accelerating agent can be effectively reduced, and a good accelerating effect can also be obtained when the dosage is very small; it does not contain alkali, avoiding its adverse effects on the long-term durability of concrete, and does not contain fluorine, making it safer and more environmentally friendly to use.

[0019] (3) The alkali-free accelerating agent disclosed by the present invention, through the mutual cooperation of each component, when added to concrete for use, can make the concrete rapidly coagulate and quickly build strength in a short time, is suitable for shotcrete construction technology and special projects such as repair, water stop and leakage plugging, and the negative impact of this accelerating agent on the later strength of concrete is relatively small. Detailed Embodiments

[0020] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations.

[0021] Example 1

[0022] A non-alkali accelerating agent is made of components with the following mass percentages: 30 wt% of aluminum sulfate, 3 wt% of aluminum dihydrogen phosphate, 3 wt% of silicate, 3 wt% of carbonate, 4 wt% of amphoteric organic ion salt, 1 wt% of lactic acid, 3 wt% of 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, 0.5 wt% of (3,6-diaminoacridin-9-yl)boronic acid, 0.4 wt% of adenosine, 1 wt% of malic acid, 2 wt% of polyethylene glycol, 1 wt% of water-soluble hyperbranched polyamide, and the balance is water.

[0023] The silicate is sodium silicate; the carbonate is sodium carbonate; the amphoteric organic ion salt is pyridinium hydroxypropyl sulfonate; the water-soluble hyperbranched polyamide is an amino-terminated water-soluble hyperbranched polyamide with a molecular weight of 15,300, which is prepared by the method of Example 1 of the Chinese invention patent with the authorization announcement number CN1232567C; the polyethylene glycol is polyethylene glycol 200.

[0024] A preparation method of the non-alkali accelerating agent includes the following steps: After adding aluminum sulfate and aluminum dihydrogen phosphate into water, then successively adding silicate, carbonate, amphoteric organic ion salt, lactic acid, 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, (3,6-diaminoacridin-9-yl)boronic acid, adenosine, malic acid, polyethylene glycol, and water-soluble hyperbranched polyamide, stirring and heating the mixture with a mechanical stirring device until the mixture becomes a clear solution, and then cooling to room temperature; the heating temperature is 45 °C.

[0025] Example 2

[0026] A non-alkali accelerating agent is made of components with the following mass percentages: 33 wt% of aluminum sulfate, 3.5 wt% of aluminum dihydrogen phosphate, 3.5 wt% of silicate, 3.5 wt% of carbonate, 4.5 wt% of amphoteric organic ion salt, 1.5 wt% of lactic acid, 4 wt% of 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, 0.6 wt% of (3,6-diaminoacridin-9-yl)boronic acid, 0.5 wt% of adenosine, 1.5 wt% of malic acid, 2.5 wt% of polyethylene glycol, 1.5 wt% of water-soluble hyperbranched polyamide, and the balance is water.

[0027] The silicate is potassium silicate; the carbonate is sodium carbonate; the amphoteric organic ion salt is 1-benzylpyridin-3-carboxylate; the water-soluble hyperbranched polyamide is an amino-terminated water-soluble hyperbranched polyamide with a molecular weight of 15,300, which is prepared by the method of Example 1 of the Chinese invention patent with the authorization announcement number CN1232567C; the polyethylene glycol is polyethylene glycol 200.

[0028] A preparation method of the alkali-free accelerating agent includes the following steps: After adding aluminum sulfate and aluminum dihydrogen phosphate into water, successively add silicate, carbonate, zwitterionic organic salt, lactic acid, 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, (3,6-diaminoacridin-9-yl)boronic acid, adenosine, malic acid, polyethylene glycol, and water-soluble hyperbranched polyamide, and stir and heat the mixture with a mechanical stirring device until the mixture becomes a clear solution, then cool it to room temperature; the heating temperature is 47 °C.

[0029] Example 3

[0030] An alkali-free accelerating agent is made of components with the following mass percentages: 35 wt% of aluminum sulfate, 4 wt% of aluminum dihydrogen phosphate, 4 wt% of silicate, 4 wt% of carbonate, 5 wt% of zwitterionic organic salt, 2 wt% of lactic acid, 4.5 wt% of 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, 0.7 wt% of (3,6-diaminoacridin-9-yl)boronic acid, 0.6 wt% of adenosine, 2 wt% of malic acid, 3 wt% of polyethylene glycol, 2 wt% of water-soluble hyperbranched polyamide, and the balance is water.

[0031] The silicate is a mixture of sodium silicate and potassium silicate in a mass ratio of 1:3; the carbonate is sodium carbonate; the zwitterionic organic salt is a mixture of pyridinium hydroxypropylsulfonate and 1-benzylpyridinium-3-carboxylate in a mass ratio of 3:5; the water-soluble hyperbranched polyamide is an amino-terminated water-soluble hyperbranched polyamide with a molecular weight of 15300, which is made by the method of Example 1 of the Chinese invention patent with the authorization announcement number CN1232567C; the polyethylene glycol is polyethylene glycol 200.

[0032] A preparation method of the alkali-free accelerating agent includes the following steps: After adding aluminum sulfate and aluminum dihydrogen phosphate into water, successively add silicate, carbonate, zwitterionic organic salt, lactic acid, 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, (3,6-diaminoacridin-9-yl)boronic acid, adenosine, malic acid, polyethylene glycol, and water-soluble hyperbranched polyamide, and stir and heat the mixture with a mechanical stirring device until the mixture becomes a clear solution, then cool it to room temperature; the heating temperature is 50 °C.

[0033] Example 4

[0034] A non-alkali accelerating agent is made of components with the following mass percentages: 38 wt% of aluminum sulfate, 4.5 wt% of aluminum dihydrogen phosphate, 4.5 wt% of silicate, 4.5 wt% of carbonate, 5.5 wt% of amphoteric organic ion salt, 2.5 wt% of lactic acid, 5.5 wt% of 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, 0.9 wt% of (3,6-diaminoacridin-9-yl)boronic acid, 0.75 wt% of adenosine, 2.5 wt% of malic acid, 3.5 wt% of polyethylene glycol, 2.5 wt% of water-soluble hyperbranched polyamide, and the balance is water.

[0035] The silicate is sodium silicate; the carbonate is sodium carbonate; the amphoteric organic ion salt is 1-benzylpyridine-3-carboxylate; the water-soluble hyperbranched polyamide is an amino-terminated water-soluble hyperbranched polyamide with a molecular weight of 15300, which is prepared by the method of Example 1 of the Chinese invention patent with the authorization announcement number CN1232567C; the polyethylene glycol is polyethylene glycol 200.

[0036] A preparation method of the non-alkali accelerating agent includes the following steps: After adding aluminum sulfate and aluminum dihydrogen phosphate into water, then successively adding silicate, carbonate, amphoteric organic ion salt, lactic acid, 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, (3,6-diaminoacridin-9-yl)boronic acid, adenosine, malic acid, polyethylene glycol, and water-soluble hyperbranched polyamide, stirring the mixture with a mechanical stirring device and heating it until the mixture becomes a clear solution, and then cooling it to room temperature; the heating temperature is 53 °C.

[0037] Example 5

[0038] A non-alkali accelerating agent is made of components with the following mass percentages: 40 wt% of aluminum sulfate, 5 wt% of aluminum dihydrogen phosphate, 5 wt% of silicate, 5 wt% of carbonate, 6 wt% of amphoteric organic ion salt, 3 wt% of lactic acid, 6 wt% of 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, 1 wt% of (3,6-diaminoacridin-9-yl)boronic acid, 0.8 wt% of adenosine, 3 wt% of malic acid, 4 wt% of polyethylene glycol, 3 wt% of water-soluble hyperbranched polyamide, and the balance is water.

[0039] The silicate is sodium silicate; the carbonate is sodium carbonate; the amphoteric organic ion salt is pyridinium hydroxypropanesulfonate; the water-soluble hyperbranched polyamide is an amino-terminated water-soluble hyperbranched polyamide with a molecular weight of 15300, which is prepared by the method of Example 1 of the Chinese invention patent with the authorization announcement number CN1232567C; the polyethylene glycol is polyethylene glycol 200.

[0040] A preparation method of the alkali-free accelerating agent includes the following steps: After adding aluminum sulfate and aluminum dihydrogen phosphate into water, successively add silicate, carbonate, amphoteric organic ion salt, lactobionic acid, 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, (3,6-diaminoacridin-9-yl)boronic acid, adenosine, malic acid, polyethylene glycol, and water-soluble hyperbranched polyamide. Stir and heat the mixture with a mechanical stirring device until the mixture becomes a clear solution, and then cool it to room temperature; the heating temperature is 55°C.

[0041] Comparative Example 1

[0042] An alkali-free accelerating agent and its preparation method are basically the same as those in Example 1, except that the amphoteric organic ion salt and the water-soluble hyperbranched polyamide are not added.

[0043] Comparative Example 2

[0044] An alkali-free accelerating agent and its preparation method are basically the same as those in Example 1, except that lactobionic acid and (3,6-diaminoacridin-9-yl)boronic acid are not added.

[0045] Comparative Example 3

[0046] An alkali-free accelerating agent and its preparation method are basically the same as those in Example 1, except that 1,3-bis((tris(hydroxymethyl)methyl)amino)propane and polyethylene glycol are not added.

[0047] To further illustrate the beneficial technical effects of the alkali-free accelerating agents involved in the embodiments of the present invention, relevant performance tests were carried out on the alkali-free accelerating agents involved in Examples 1-5 and Comparative Examples 1-3. The test results are shown in Table 1. The test method refers to GB / T35159-2017 "Accelerating Agent for Shotcrete". During the test, the dosage of the alkali-free accelerating agent is 6%; the stability test method is as follows: First, put the samples into 3 transparent sample bottles of 380 mL respectively, and let them stand for 48 hours for impurities to precipitate. Then, take 200 mL of the upper-middle liquid and put it into 3 clean transparent sample bottles of 380 mL respectively. After sealing, store them in environments of 5°C, 20°C, and 30°C respectively; if there is no stratification, precipitation, or crystallization phenomenon in the samples after 240 days, the stability passes, otherwise it fails.

[0048] As can be seen from Table 1, the alkali-free accelerating agents involved in the embodiments of the present invention have better accelerating effects, higher early and late strengths, and better stability than the products of the comparative examples; the combined addition of amphoteric organic ion salt, water-soluble hyperbranched polyamide, lactobionic acid, (3,6-diaminoacridin-9-yl)boronic acid, 1,3-bis((tris(hydroxymethyl)methyl)amino)propane, and polyethylene glycol is beneficial to improving the above properties.

[0049] Table 1

[0050]

[0051] The above embodiments are only used to illustrate the technical concept and features of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It is not intended to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. An alkali-free quick-setting agent, characterized in that: The invention comprises the following components in percentage by weight: 30-40 wt% of aluminum sulfate, 3-5 wt% of aluminum dihydrogen phosphate, 3-5 wt% of silicate, 3-5 wt% of carbonate, 4-6 wt% of amphoteric organic ion salt, 1-3 wt% of lactobionic acid, 3-6 wt% of 1,3-bis((trihydroxymethyl)methylamino)propane, 0.5-1 wt% of (3,6-diaminoacridine-9-yl)boric acid, 0.4-0.8 wt% of adenosine, 1-3 wt% of malic acid, 2-4 wt% of polyethylene glycol, 1-3 wt% of water-soluble hyperbranched polyamide, and the balance is water.

2. The alkali-free quick-setting agent according to claim 1, characterized in that: The silicate is at least one of sodium silicate and potassium silicate.

3. The alkali-free accelerating setting agent according to claim 1, characterized in that: The carbonate is sodium carbonate.

4. The alkali-free accelerating setting agent according to claim 1, characterized in that: The amphoteric organic ion salt is at least one of hydroxypropane sulfonate pyridinium salt and 1-benzylpyridine-3-carboxylate.

5. The alkali-free accelerating setting agent according to claim 1, characterized in that: The water-soluble hyperbranched polyamide is an amino-terminated water-soluble hyperbranched polyamide with a molecular weight of 15300, and is prepared according to the method of Example 1 of the Chinese invention patent with authorization announcement number CN1232567C.

6. The alkali-free quick-setting agent according to claim 1, characterized in that: The polyethylene glycol is polyethylene glycol 200.

7. A method for preparing the alkali-free accelerating setting agent according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: adding aluminum sulfate and aluminum dihydrogen phosphate into water, and then sequentially adding silicate, carbonate, amphoteric organic ion salt, lactobionic acid, 1,3-bis((trihydroxymethyl)methylamino)propane, (3,6-diaminoacridine-9-yl)boric acid, adenosine, malic acid, polyethylene glycol and water-soluble hyperbranched polyamide, stirring and heating the mixture with a mechanical stirring device until the mixture becomes a clear solution, and cooling to room temperature.

8. The method for preparing the alkali-free accelerating setting agent according to claim 7, characterized in that: The heating temperature is 45-55°C.

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