Alkali-free liquid quick-setting agent composition, alkali-free liquid quick-setting agent, and preparation method and application thereof

Abstract

The present invention relates to the technical field of building materials, and discloses a composition for an alkali-free liquid accelerator, an alkali-free liquid accelerator, and a preparation method and application thereof. Based on the total weight of the composition, the composition contains: 53-56wt% of aluminum sulfate 18hydrate, 5-6.5wt% of diethanolamine, 3-6wt% of silane emulsion, 0.8-2wt% of amino acid, 0.8-1.5wt% of kaolinite, 0.7-1.2wt% of pH regulator, and 30-35wt% of water; the purity of the kaolinite is ≥90wt%; the silane emulsion is octyltriethoxysilane emulsion and / or tetraethoxysilane emulsion; and the amino acid is lysine and / or threonine. The alkali-free liquid accelerator provided by the present invention has better stability, and is more excellent in early strength, accelerating coagulation, and anti-seepage and hydrophobic properties.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and in particular to a composition for an alkali-free liquid quick-setting agent, an alkali-free liquid quick-setting agent, and a preparation method and application thereof. Background Art

[0002] Tunnel water inrush, due to its strong concealment and unpredictability, has become one of the main difficulties in tunnel construction and can easily cause serious economic losses and casualties.

[0003] At present, the traditional method for improving the waterproof and anti-seepage performance of cement concrete mainly contains suitably reducing water-cement ratio, selecting suitable sand and gravel, rationally improving the consumption of cement, selecting suitable sand ratio etc.The overall hydrophobic modification of cement concrete is to add hydrophobic material when mixing cement concrete, mainly contains hydrophobic powder, polymer emulsion etc.But, along with adding of polymer emulsion (such as styrene-butadiene emulsion, chloroprene rubber emulsion, polyacrylate emulsion etc.), although can improve concrete toughness, water retention, water-reducing property, fluidity and the anti-seepage property to varying degrees, also can occupy the position of hydration product simultaneously, cause its ultimate compressive strength lower.In addition, the mixing of hydrophobic powder also can delay the hydration of cement mortar, changes the mechanical property of cement mortar.These traditional methods improvement effect is not obvious, can not really improve the waterproof and anti-seepage performance of cement concrete in essence.

[0004] Alkali-free accelerators, the most important admixture in the shotcrete forming process, utilize aluminum sulfate as the primary accelerating component. Combined with other early-strength components such as diethanolamine, they achieve early-strength and setting-accelerating effects. Alkali-free accelerators address the high alkali content of traditional alkaline accelerators, reducing the likelihood of alkali-aggregate reaction in shotcrete. They also offer the advantage of being environmentally friendly. However, alkali-free accelerators also face challenges such as unstable complexation with accelerating materials, the presence of toxic raw materials such as fluorine, insufficient early strength, and later strength reduction.

[0005] In response to the water gushing phenomenon in tunnels in high water gushing areas, it is crucial to organically combine early strength and accelerated setting with anti-seepage and hydrophobic properties and develop an early strength and hydrophobic alkali-free liquid quick-setting agent. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned problems existing in the prior art and to provide an alkali-free liquid quick-setting agent with excellent early strength and accelerated setting as well as anti-seepage and hydrophobic properties.

[0007] To achieve the above object, the first aspect of the present invention provides a composition for an alkali-free liquid accelerating setting agent, comprising, based on the total weight of the composition, 53-56 wt% of aluminum sulfate 18hydrate, 5-6.5 wt% of diethanolamine, 3-6 wt% of silane emulsion, 0.8-2 wt% of amino acid, 0.8-1.5 wt% of kaolinite, 0.7-1.2 wt% of pH regulator, and 30-35 wt% of water; the purity of the kaolinite being ≥90 wt%;

[0008] The silane emulsion is octyltriethoxysilane emulsion and / or tetraethoxysilane emulsion;

[0009] The amino acid is lysine and / or threonine.

[0010] The second aspect of the present invention provides a method for preparing an alkali-free liquid quick-setting admixture, which is carried out using the components of the composition described in the first aspect, comprising:

[0011] (1) first mixing water and a pH adjuster to obtain a mixture I;

[0012] (2) performing a second mixing of the mixture I and aluminum sulfate 18hydrate to obtain a mixture II, wherein the temperature of the second mixing is 85-95° C.;

[0013] (3) mixing the mixture II with amino acids for a third time to obtain a mixture III;

[0014] (4) mixing the mixture III with diethanolamine and kaolinite for a fourth time to obtain a mixture IV;

[0015] (5) mixing the mixture IV with a silane emulsion for a fifth time to obtain an alkali-free liquid quick-setting agent;

[0016] The temperature of the third mixing is 15-45°C lower than the temperature of the second mixing;

[0017] The stirring rates of the second mixing, the third mixing, the fourth mixing, and the fifth mixing are each independently ≤300 rpm.

[0018] The third aspect of the present invention provides an alkali-free liquid quick-setting admixture prepared by the method described in the second aspect.

[0019] The fourth aspect of the present invention provides use of the alkali-free liquid quick-setting admixture described in the third aspect in cement or concrete.

[0020] Compared with the prior art, the technical solution provided by the present invention has at least the following advantages:

[0021] 1) The alkali-free liquid accelerator provided by the present invention preferably uses acetic acid and / or malonic acid as a pH regulator, which can increase the solubility of aluminum sulfate 18hydrate and improve the content of the effective aluminum phase; at the same time, the introduction of lysine and / or threonine can complex and coordinate with the dissolved metal aluminum ions, thereby effectively increasing the concentration of aluminum ions, preventing aluminum ion hydrolysis, coagulation and stratification, and is beneficial to increasing the early strength performance of the liquid accelerator in 6 hours and 1 day.

[0022] 2) The present invention enhances the stability of the liquid accelerator by introducing a specific amount of kaolinite, and promotes the setting of the mortar paste using a specific amount of diethanolamine. Furthermore, by combining the use of specific amounts of octyltriethoxysilane and tetraethoxysilane, the resulting alkali-free liquid accelerator not only meets the rapid setting, early strength, and stability requirements of both the national standard GB / T 35159-2017 and the railway standard Q / CR 807-2020, but also enhances the accelerator's hydrophobicity, enabling it to maintain good performance in areas with high water inflow.

[0023] 3) The method for preparing an alkali-free liquid accelerator provided by the present invention can significantly improve the solubility of each component through a specific order of addition and specific temperature control, provide optimal complexing conditions for aluminum ions, and fully enhance the accelerating effect and hydrophobicity of the alkali-free liquid accelerator. DETAILED DESCRIPTION

[0024] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0025] It should be noted that, in various aspects of the present invention, for the same components or terms in various aspects, the present invention is only described once in one aspect without repeated description, which should not be understood by those skilled in the art as a limitation of the present invention.

[0026] The average particle size described in the present invention refers to the average diameter.

[0027] As mentioned above, the first aspect of the present invention provides a composition for an alkali-free liquid accelerating setting agent, which comprises, based on the total weight of the composition, 53-56 wt% of aluminum sulfate 18hydrate, 5-6.5 wt% of diethanolamine, 3-6 wt% of silane emulsion, 0.8-2 wt% of amino acid, 0.8-1.5 wt% of kaolinite, 0.7-1.2 wt% of pH regulator, and 30-35 wt% of water; the purity of the kaolinite is ≥90 wt%;

[0028] The silane emulsion is octyltriethoxysilane emulsion and / or tetraethoxysilane emulsion;

[0029] The amino acid is lysine and / or threonine.

[0030] The inventors of the present invention have discovered through research that an alkali-free liquid accelerator prepared using a specific amount of octyltriethoxysilane emulsion and / or tetraethoxysilane emulsion can significantly improve the hydrophobicity of the accelerator product.

[0031] Preferably, the solid content of the silane emulsion is 50-60 wt%.

[0032] Preferably, based on the total weight of the composition, the composition comprises: 54-55% by weight of aluminum sulfate 18hydrate, 5.5-6% by weight of diethanolamine, 3-5% by weight of a silane emulsion, 0.9-1.2% by weight of an amino acid, 0.8-1% by weight of kaolinite, 0.7-1% by weight of a pH adjuster, and 30-35% by weight of water; the purity of the kaolinite being ≥90% by weight. The inventors have found that within this preferred dosage range, the alkali-free liquid quick-setting admixture obtained by the present invention exhibits stronger early strength, better coagulant-promoting effects, and better anti-seepage effects.

[0033] In the composition for the alkali-free liquid quick-setting agent provided by the present invention, the water content does not include the water that may exist in the silane emulsion.

[0034] Preferably, the average particle size of the kaolinite is 0.2-5 μm, more preferably 0.5-5 μm.

[0035] Preferably, the pH adjuster is acetic acid and / or malonic acid. The inventors of the present invention have found that the use of this preferred pH adjuster can increase the content of effective aluminum phase in the alkali-free liquid accelerator product, shorten the setting time of the slurry, and improve the 6-hour strength, thereby better meeting the requirements of early strength, rapid setting, anti-seepage and water-repellent properties.

[0036] As mentioned above, the second aspect of the present invention provides a method for preparing an alkali-free liquid quick-setting admixture, which is carried out using the components of the composition described in the first aspect, comprising:

[0037] (1) first mixing water and a pH adjuster to obtain a mixture I;

[0038] (2) performing a second mixing of the mixture I and aluminum sulfate 18hydrate to obtain a mixture II, wherein the temperature of the second mixing is 85-95° C.;

[0039] (3) mixing the mixture II with amino acids for a third time to obtain a mixture III;

[0040] (4) mixing the mixture III with diethanolamine and kaolinite for a fourth time to obtain a mixture IV;

[0041] (5) mixing the mixture IV with a silane emulsion for a fifth time to obtain an alkali-free liquid quick-setting agent;

[0042] The temperature of the third mixing is 15-45°C lower than the temperature of the second mixing;

[0043] The stirring rates of the second mixing, the third mixing, the fourth mixing, and the fifth mixing are each independently ≤300 rpm.

[0044] Preferably, the temperature of the third mixing is 30-45° C. lower than the temperature of the second mixing. The inventors of the present invention have found in their research that within this specific preferred range, the alkali-free liquid quick-setting admixture prepared by the present invention has better stability, and has better early strength, accelerated setting, and anti-seepage and hydrophobic properties.

[0045] Preferably, the second mixing conditions include: a time of 45-60 min, a stirring rate ≤ 200 rpm, more preferably 100-200 rpm.

[0046] Preferably, the conditions for the third mixing include: a temperature of 50-70° C., a time of 60-90 min, and a stirring rate of ≤200 rpm, more preferably 100-200 rpm.

[0047] Preferably, the fourth mixing conditions include: temperature of 50-70° C., time ≥60 min, stirring rate ≤300 rpm, more preferably 200-300 rpm.

[0048] Preferably, the conditions for the fifth mixing include: a time of 30-60 min, a stirring rate ≤ 200 rpm, more preferably 100-200 rpm.

[0049] As mentioned above, the third aspect of the present invention provides an alkali-free liquid quick-setting admixture prepared by the method described in the second aspect.

[0050] Preferably, the alkali-free liquid quick-setting agent has a 6h compressive strength of ≥1.2 MPa, a 1d compressive strength of ≥13 MPa, and a contact angle of >90°.

[0051] The present invention increases the concentration of the effective aluminum phase in the liquid accelerator by combining the use of specific amino acids, pH regulators, and kaolinite, thereby achieving the early strength effect of the liquid accelerator after 6 hours and 1 day. Moreover, the addition of silane emulsion can also improve the hydrophobicity of the cement concrete after molding, thereby reducing the water gushing phenomenon in the tunnel.

[0052] As mentioned above, the fourth aspect of the present invention provides use of the alkali-free liquid quick-setting admixture described in the third aspect in cement or concrete.

[0053] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, the raw materials are all commercially available.

[0054] Lysine: purity 90%;

[0055] Threonine: purity 90%;

[0056] Kaolinite: purity 90%, average particle size 2μm;

[0057] Octyltriethoxysilane emulsion: solid content 55 wt%, purchased from Shandong Yuanjin New Materials Co., Ltd., model YJ-n-octyltriethoxysilane;

[0058] Tetraethoxysilane emulsion: solid content 57 wt%, purchased from Shandong Yuanjin New Materials Co., Ltd., model YJ-TEOS (28);

[0059] Aluminum sulfate 18hydrate: purchased from Zibo Juying Aluminum Co., Ltd., meeting the requirements of HG / T 2225-2018 "Industrial aluminum sulfate" Class II products;

[0060] Diethanolamine: purchased from Zibo Sangfei Economic and Trade Co., Ltd., meeting the requirements of HG / T 2916-1997 "Diethanolamine for Industrial Use" Type II product.

[0061] In the following examples and comparative examples, the total weight of the alkali-free liquid quick-setting agent prepared after mixing the components is 1 kg.

[0062] Example 1

[0063] (1) adding water and a pH adjuster into a reaction kettle, heating the reaction kettle to 90° C., and stirring to perform a first mixing to obtain a mixture I;

[0064] (2) while maintaining the temperature in step (1) unchanged, aluminum sulfate 18hydrate was added to the reaction kettle and mixed with mixture I for a second time (stirring at 170 rpm for 45 min) to obtain mixture II;

[0065] (3) lowering the temperature to 50° C. and maintaining the temperature, adding the amino acid to the reaction kettle and performing a third mixing with the mixture II (stirring at 150 rpm for 60 min) to obtain a mixture III;

[0066] (4) While maintaining the temperature in step (3), diethanolamine and kaolinite were slowly added to the reaction kettle and mixed with mixture III for a fourth time (stirring at 250 rpm for 80 min) to obtain mixture IV;

[0067] (5) The silane emulsion was added to the reactor, and then the heat preservation was stopped. During the fifth mixing (stirring at 150 rpm for 45 min) with the mixture IV, the mixture was stirred and cooled to obtain an alkali-free liquid accelerating setting agent.

[0068] The types and amounts of the components are listed in Table 1.

[0069] Examples 2-8

[0070] The process was similar to that of Example 1, except that the types and amounts of the components were different, as shown in Table 1.

[0071] Example 9

[0072] A similar process to Example 1 was used, and the types and amounts of the components used were the same as in Example 1. The difference was that in step (3) and step (4), the temperatures for the third mixing and the fourth mixing were both 70° C. Specifically:

[0073] (1) adding water and a pH adjuster into a reaction kettle, heating the reaction kettle to 90° C., and stirring to perform a first mixing to obtain a mixture I;

[0074] (2) while maintaining the temperature in step (1) unchanged, aluminum sulfate 18hydrate was added to the reaction kettle and mixed with mixture I for a second time (stirring at 170 rpm for 45 min) to obtain mixture II;

[0075] (3) lowering the temperature to 70°C and maintaining the temperature, adding the amino acid to the reaction kettle and performing a third mixing with the mixture II (stirring at 150 rpm for 60 min) to obtain a mixture III;

[0076] (4) While maintaining the temperature in step (3), diethanolamine and kaolinite were slowly added to the reaction kettle and mixed with mixture III for a fourth time (stirring at 250 rpm for 80 min) to obtain mixture IV;

[0077] (5) The silane emulsion was added to the reactor, and then the heat preservation was stopped. During the fifth mixing (stirring at 150 rpm for 45 min) with the mixture IV, the mixture was stirred and cooled to obtain an alkali-free liquid accelerating setting agent.

[0078] Comparative Examples 1-8

[0079] The process was similar to that of Example 1, except that the types and amounts of the components were different, as shown in Table 1.

[0080] Comparative Example 9

[0081] This comparative example was carried out using a process similar to that of Example 1, and the types and amounts of the components used were the same as those of Example 1. The difference was that the stirring rates of the second mixing, third mixing, fourth mixing and fifth mixing in steps (2) to (5) of this comparative example were all 400 rpm.

[0082] An alkali-free liquid quick-setting agent is prepared.

[0083] Comparative Example 10

[0084] This comparative example was carried out using a process similar to that of Example 1. The types and amounts of the components used were the same as those of Example 1. The difference was that in step (3) and step (4), the temperatures for the third mixing and the fourth mixing were both 80° C. Specifically:

[0085] (1) adding water and a pH adjuster into a reaction kettle, heating the reaction kettle to 90° C., and stirring to perform a first mixing to obtain a mixture I;

[0086] (2) while maintaining the temperature in step (1) unchanged, aluminum sulfate 18hydrate was added to the reaction kettle and mixed with mixture I for a second time (stirring at 170 rpm for 45 min) to obtain mixture II;

[0087] (3) lowering the temperature to 80°C and maintaining the temperature, adding the amino acid into the reaction kettle and mixing it with the mixture II for the third time (stirring at 150 rpm for 60 min) to obtain a mixture III;

[0088] (4) While maintaining the temperature in step (3), diethanolamine and kaolinite were slowly added to the reaction kettle and mixed with mixture III for a fourth time (stirring at 250 rpm for 80 min) to obtain mixture IV;

[0089] (5) The silane emulsion was added to the reactor, and then the heat preservation was stopped. During the fifth mixing (stirring at 150 rpm for 45 min) with the mixture IV, the mixture was stirred and cooled to obtain an alkali-free liquid accelerating setting agent.

[0090] Comparative Example 11

[0091] The process of this comparative example is similar to that of Example 1. The types and amounts of the components used are the same as those of Example 1. The difference is that in this comparative example, the amino acid is added to the reaction kettle before the aluminum sulfate 18hydrate and the mixture is kept warm and stirred. Specifically:

[0092] (1) adding water and a pH adjuster into a reaction kettle, heating the reaction kettle to 90° C., and stirring to perform a first mixing to obtain a mixture I;

[0093] (2) lowering the temperature to 50°C and maintaining the temperature, adding the amino acid to the reaction kettle and mixing it with the mixture I for a second time (stirring at 150 rpm for 60 min) to obtain a mixture II;

[0094] (3) heating the reactor to 90° C. and maintaining the temperature, adding aluminum sulfate 18hydrate to the reactor and mixing with mixture II for a third time (stirring at 170 rpm for 45 min) to obtain mixture III;

[0095] (4) lowering the temperature to 50° C. and maintaining the temperature, and slowly adding diethanolamine and kaolinite to the reaction kettle and mixing with the mixture III for the fourth time (stirring at 250 rpm for 80 min) to obtain a mixture IV;

[0096] (5) The silane emulsion was added to the reactor, and then the heat preservation was stopped. During the fifth mixing (stirring at 150 rpm for 45 min) with the mixture IV, the mixture was stirred and cooled to obtain an alkali-free liquid accelerating setting agent.

[0097] Table 1

[0098]

[0099] Test Example 1

[0100] The alkali-free liquid accelerators prepared in each example and comparative example were tested for their corresponding properties according to the test methods for density, pH value, solid content, stability, chloride ion content, and alkali content specified in GB / T 35159-2017, "Accelerators for Shotcrete." Furthermore, the alkali-free liquid accelerators prepared in each example and comparative example were tested for their corresponding fluoride ion content according to the test method for fluoride ion content specified in Q / CR 807-2020, "Liquid Alkali-Free Accelerators for Tunnel Shotcrete." The test results are detailed in Table 2.

[0101] Table 2

[0102]

[0103] Table 2

[0104]

[0105] Test Example 2

[0106] According to the test methods specified in the national standard GB / T 35159-2017 "Accelerators for Shotcrete" and JGJ / T 70-2009 "Standard for Test Methods for Basic Properties of Building Mortar", the alkali-free liquid accelerators prepared in each embodiment and comparative example were tested for net slurry setting time, mortar compressive strength, static contact angle, and water absorption using PI42.5 benchmark Portland cement and standard sand produced by Xiamen Aiso. The dosage of the alkali-free liquid accelerator was 8wt% of the cement mass. The test results are shown in Table 3.

[0107] Table 3

[0108]

[0109]

[0110] Table 3

[0111]

[0112] The results in Tables 2 and 3 demonstrate that the present invention can produce an early-strength, hydrophobic, alkali-free liquid accelerator suitable for use in areas with high water inflow. The mortar's early compressive strength reaches 1.6 MPa and 16.4 MPa at 6 hours and 1 day, respectively, demonstrating excellent early-strength performance. Furthermore, the mortar's surface contact angle reaches 107.5°, and its maximum water absorption rate after 40 hours does not exceed 4.6%, demonstrating excellent hydrophobicity.

[0113] All indicators of the alkali-free liquid quick-setting agent prepared by the technical solution provided by the present invention meet the requirements of the national standard GB / T 35159-2017 and the railway standard Q / CR 807-2020, and the sample stability is good.

[0114] The alkali-free liquid accelerators obtained in each example not only meet the national standard GB / T 35159-2017 but also meet the higher standards of railway standard Q / CR 807-2020 for 6h compressive strength, 1d compressive strength, 28d strength ratio, and 90d strength retention, demonstrating excellent early strength performance. Furthermore, the surface contact angle and water absorption of the alkali-free liquid accelerators obtained in each example far exceed those of ordinary mortar, demonstrating excellent hydrophobicity.

[0115] Test Example 3

[0116] The alkali-free liquid accelerator prepared in Example 2 was applied to different types of cement (Guizhou Southwest Cement, Shandong Yangchun Cement, Hebei Jidong Cement, Guangdong Jinyang Cement, and Jiangxi Wannianqing Cement). Specifically, the alkali-free liquid accelerators prepared in each example and comparative example were tested for setting time, mortar compressive strength, static contact angle, and water absorption according to the testing methods specified in GB / T 35159-2017 "Accelerators for Shotcrete" and JGJ / T70-2009 "Standard for Test Methods for Basic Properties of Building Mortar." The alkali-free liquid accelerator was added at 8 wt% of the cement mass. The results are shown in Table 4.

[0117] Table 4

[0118]

[0119] The results in Table 4 show that the early-strength hydrophobic alkali-free liquid setting agent prepared in the present invention can improve the hydrophobicity of different cements, and its slurry setting time and mortar compressive strength meet the requirements of GB / T 35159-2017 and Q / CR 807-2020, showing good adaptability.

[0120] Compared with Example 1, in Comparative Example 9, the high stirring rate causes bubbles to form in the prepared liquid quick-setting agent, and white lumps appear at the bubbles after cooling, seriously affecting the stability.

[0121] Compared to Example 1, in Comparative Example 10, increasing the stirring temperature during the addition of the amino acid resulted in a change in the structure of the amino acid's effective coordination group, which was unable to effectively coordinate with the free aluminum ions. After stirring, the accelerator was a white paste, which did not meet the requirements of a liquid accelerator.

[0122] Compared to Example 1, in Comparative Example 11, the amino acid was added to the reactor before aluminum sulfate 18hydrate and stirred at room temperature. This resulted in the prepared liquid accelerator producing 15 ml of clear liquid at 28 days and a 6-hour mortar compressive strength of 0.8 MPa. This indicates that the prepared liquid accelerator exhibited poor stability and failed to meet the early strength requirements.

[0123] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for preparing an alkali-free liquid quick-setting admixture, characterized in that: The method is carried out using the components of an alkali-free liquid quick-setting agent composition, including: (1) first mixing water and a pH adjuster to obtain a mixture I; (2) performing a second mixing of the mixture I and aluminum sulfate 18hydrate to obtain a mixture II, wherein the temperature of the second mixing is 85-95° C.; (3) performing a third mixing of the mixture II and amino acids to obtain a mixture III; the temperature of the third mixing is 50-70° C.; (4) performing a fourth mixing of the mixture III with diethanolamine and kaolinite to obtain a mixture IV; the temperature of the fourth mixing is 50-70° C.; (5) performing a fifth mixing of the mixture IV and the silane emulsion to obtain an alkali-free liquid quick-setting agent; The stirring rates of the second mixing, the third mixing, the fourth mixing, and the fifth mixing are each independently ≤300 rpm; Based on the total weight of the composition, the composition contains: 53-56 wt% of aluminum sulfate 18hydrate, 5-6.5 wt% of diethanolamine, 3-6 wt% of silane emulsion, 0.8-2 wt% of amino acid, 0.8-1.5 wt% of kaolinite, 0.7-1.2 wt% of pH regulator, and 30-35 wt% of water; the purity of the kaolinite is ≥90 wt%; The silane emulsion is octyltriethoxysilane emulsion and / or tetraethoxysilane emulsion; The amino acid is lysine and / or threonine; the pH regulator is acetic acid and / or malonic acid.

2. The method according to claim 1, wherein The solid content of the silane emulsion is 50-60 wt%; and / or, The average particle size of the kaolinite is 0.2-5 μm.

3. The method according to claim 1, wherein The conditions for the second mixing include: a time of 45-60 min, and a stirring rate of ≤200 rpm.

4. The method according to any one of claims 1 to 3, wherein: The conditions for the third mixing include: a time of 60-90 min, and a stirring rate of ≤200 rpm.

5. The method according to any one of claims 1 to 3, wherein: The fourth mixing conditions include: time ≥ 60 min, stirring rate ≤ 300 rpm.

6. The method according to any one of claims 1 to 3, wherein: The conditions for the fifth mixing include: a time of 30-60 min, and a stirring rate of ≤200 rpm.

7. An alkali-free liquid quick-setting admixture prepared by the method according to any one of claims 1 to 6.

8. Use of the alkali-free liquid quick-setting admixture according to claim 7 in cement or concrete.

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