A UHPC Protective Agent and Its Preparation Method

Abstract

This application relates to the field of protective agents, and more specifically, to a UHPC protective agent and its preparation method. A UHPC protective agent, by mass parts, comprises the following raw materials: 5-10 parts alcohol solvent, 60-85 parts water, 1-5 parts film-forming agent, 0-3 parts dispersant, 5-15 parts mullite, 1-5 parts tetraethoxysilane, and 1-5 parts vinyl-terminated polydimethylsiloxane. The preparation method involves mixing and stirring the tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution at 1500-2000 r / min to obtain a mixture; then adding water and the film-forming agent to the mixture and stirring until homogeneous to obtain the finished product. This application has the advantage of improving the protective effect against UHPC.

Description

Technical Field

[0001] This application relates to the field of protective agents, and more specifically, to a UHPC protective agent and a method for preparing the same. Background Technology

[0002] UHPC is short for Ultra-High Performance Concrete, a cement-based concrete material with superior mechanical properties, high toughness, and excellent pouring and forming performance. It typically uses silicate cement, silica fume, quartz powder, fine silica sand, high-efficiency water-reducing agents, water, steel, or organic fibers as raw materials. Due to its excellent properties, UHPC has a wide range of applications, including curtain walls, landscaping, bridges, and roads.

[0003] Due to its chemical composition and porous structure, UHPC is easily corroded by rain and humid weather when used in curtain walls and other fields, which greatly reduces the stability and safety of the building. Companies have to spend a lot of money and resources every year to maintain and repair the concrete structure.

[0004] In related technologies, concrete protection mainly employs surface coating methods, i.e., applying asphalt, polyurethane, epoxy resin, etc., to the surface of the concrete structure. These coatings have high alkali resistance and good adhesion. However, these materials can clog and seal the pores on the concrete surface, hindering the evaporation of moisture from within the concrete, thus degrading the concrete's performance and resulting in unsatisfactory protective effects. Therefore, further improvements are needed. Summary of the Invention

[0005] To improve the protection against UHPC, this application provides a UHPC protectant and its preparation method.

[0006] In a first aspect, this application provides a UHPC protective agent, which adopts the following technical solution:

[0007] A UHPC protective agent, comprising the following raw materials in parts by weight: 5-10 parts alcohol solvent, 60-85 parts water, 1-5 parts film-forming agent, 0-3 parts dispersant, 5-15 parts mullite, 1-5 parts tetraethoxysilane, and 1-5 parts vinyl-terminated polydimethylsiloxane.

[0008] By employing the above-mentioned technical solution, the combined action of mullite, tetraethoxysilane, and vinyl-terminated polydimethylsiloxane, when applied to the concrete surface, allows for rapid penetration into the deeper layers and into the concrete's pores. Catalyzed by water and concrete, tetraethoxysilane and vinyl-terminated polydimethylsiloxane hydrolyze to generate silanol groups, which then react with hydroxyl groups on the concrete surface and within capillary pores to form a network. Mullite, during the reaction, works in conjunction with the network, acting as a node to enhance its strength and stability, promoting more comprehensive integration of the network into the concrete. This network, embedded in the concrete surface and capillary channels, transforms the concrete surface and capillary pores into hydrophobic surfaces, reducing the retention of external moisture within the concrete.

[0009] Furthermore, besides serving as nodes in the mesh structure, mullite can also fill concrete gaps. After filling these gaps, mullite makes the concrete structure denser, reducing the space for external water to enter. Because mullite is highly porous, it ensures that while the concrete structure becomes denser, it still maintains good permeability, effectively promoting the evaporation of internal moisture.

[0010] Meanwhile, as a particle, mullite can effectively reduce bubble formation in the system; when the protective agent is applied to the concrete surface, it can also have more sufficient contact with the concrete and adhere firmly to the concrete surface.

[0011] Preferably, the mullite comprises 8-12 parts by mass, the tetraethoxysilane comprises 3.0-4.5 parts by mass, and the vinyl-terminated polydimethylsiloxane comprises 1.5-2.5 parts by mass.

[0012] By adopting the above technical solution, the dosage of mullite, tetraethoxysilane, and vinyl-terminated polydimethylsiloxane is further limited, resulting in a more complete combination that allows for rapid penetration into the deep interior of the concrete and the formation of a more stable network to fill the concrete gaps, thereby giving the concrete higher strength and stronger hydrophobicity.

[0013] Preferably, the mullite has a particle size of 30-100 μm.

[0014] By adopting the above technical solution, the particle size of mullite is further limited, which has a better filling effect on concrete cracks, and can improve the density and ensure air permeability as much as possible.

[0015] Preferably, the film-forming agent is one or a mixture of polyvinyl alcohol, acrylic copolymer emulsion, dodecyl alcohol ester, and butadiene resin.

[0016] Preferably, the film-forming agent is a polyvinyl alcohol and acrylic acid copolymer emulsion, and the mass ratio of polyvinyl alcohol and acrylic acid copolymer emulsion is 1:(0.8-1.2), based on the mass of polyvinyl alcohol.

[0017] By adopting the above technical solution, selecting specific types of film-forming agents, and further limiting the mass ratio between these agents, the various raw materials in the system can be thoroughly mixed. When the resulting protective agent is applied to the concrete surface, it forms a uniform and breathable protective film, effectively blocking external moisture.

[0018] Preferably, the alcohol solvent is one or a mixture of ethanol, propanol, isopropanol, and ethylene glycol.

[0019] Preferably, the alcohol solvent is ethanol.

[0020] By adopting the above technical solution, selecting low molecular weight alcohols can help promote more thorough mixing of various raw materials in the system, thereby achieving better synergistic effects.

[0021] Secondly, this application provides a method for preparing a UHPC protective agent, which adopts the following technical solution:

[0022] A method for preparing a UHPC protective agent includes the following steps:

[0023] Tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution were mixed and stirred at 1500-2000 r / min to obtain a mixture.

[0024] Continue adding water and film-forming agent to the mixture, and stir until homogeneous to obtain the finished product.

[0025] By adopting the above technical solution, the rotation speed is further limited when mixing tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution. The above raw materials are fully dispersed and mixed by high-speed rotation, which fully promotes the reaction.

[0026] Preferably, when mixing the mixture, water, and film-forming agent, the rotation speed is increased to 2500-3000 r / min.

[0027] By adopting the above technical solution, further increasing the rotation speed in the subsequent process makes the mixing more thorough and reduces the possibility of agglomeration and unevenness.

[0028] In summary, this application has the following beneficial effects:

[0029] 1. With the combined action of mullite, tetraethoxysilane, and vinyl-terminated polydimethylsiloxane, when coated on the concrete surface, it can quickly penetrate deep into the concrete and into the cracks, giving the concrete a deeper hydrophobic effect and effectively isolating water vapor.

[0030] 2. With the combined action of mullite, tetraethoxysilane, and vinyl-terminated polydimethylsiloxane, it effectively fills concrete gaps. Furthermore, due to the high porosity of mullite, it ensures that the concrete structure becomes denser while maintaining good air permeability, effectively promoting the evaporation of internal moisture.

[0031] 3. With the combined action of mullite, tetraethoxysilane, and vinyl-terminated polydimethylsiloxane, the system generates fewer bubbles, allowing for more thorough contact with concrete and firm adhesion to the concrete surface. Detailed Implementation

[0032] The present application will be further described in detail below with reference to the embodiments.

[0033] The raw materials used in the following examples and comparative examples are all commercially available products.

[0034] Example

[0035] Example 1

[0036] A UHPC protective agent comprises the following raw materials: 8 kg alcohol solvent, 72 kg water, 3 kg film-forming agent, 1.5 kg dispersant, 10 kg mullite, 3.5 kg tetraethoxysilane, and 2 kg vinyl-terminated polydimethylsiloxane.

[0037] The specific dosage is summarized in Table 1.

[0038] The alcohol solvent is ethanol.

[0039] The film-forming agents are polyvinyl alcohol and 12-ethylhexyl alcohol, with a mass ratio of 1:1, meaning that the amount of polyvinyl alcohol used is 1.5 kg and the amount of 12-ethylhexyl alcohol used is 1.5 kg.

[0040] The dispersant is sodium dodecyl sulfate.

[0041] The mullite has a particle size of 50 μm.

[0042] The CAS number for tetraethoxysilane is 78-10-4.

[0043] The vinyl-terminated polydimethylsiloxane was purchased from Shenzhen Jipeng Silicon Fluorine Materials Co., Ltd., model number JP-02V-200.

[0044] This application also provides a method for preparing a UHPC protective agent, comprising the following steps:

[0045] Step 1): Add tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution into a stirred tank and stir at 2000 r / min for 15 min to obtain a mixture.

[0046] Step 2): Continue to add water and film-forming agent to the mixture in the mixing tank, increase the speed to 3000 r / min, mix and stir for 25 min to obtain the finished product.

[0047] Example 2

[0048] A UHPC protective agent comprises the following raw materials: 5 kg alcohol solvent, 85 kg water, 1 kg film-forming agent, 0.1 kg dispersant, 5 kg mullite, 1 kg tetraethoxysilane, and 1 kg vinyl-terminated polydimethylsiloxane.

[0049] The specific dosage is summarized in Table 1.

[0050] The alcohol solvent is ethylene glycol.

[0051] The film-forming agents are polyvinyl alcohol and 12-ethylhexyl alcohol, with a mass ratio of 1:0.8, meaning that the amount of polyvinyl alcohol used is 0.56 kg and the amount of 12-ethylhexyl alcohol used is 0.44 kg.

[0052] The dispersant is sodium dodecylbenzenesulfonate.

[0053] The mullite has a particle size of 30 μm.

[0054] The CAS number for tetraethoxysilane is 78-10-4.

[0055] The vinyl-terminated polydimethylsiloxane was purchased from Shenzhen Jipeng Silicon Fluorine Materials Co., Ltd., model number JP-02V-300.

[0056] This application also provides a method for preparing a UHPC protective agent, comprising the following steps:

[0057] Step 1): Add tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution into a stirred tank and stir at 1500 r / min for 15 min to obtain a mixture.

[0058] Step 2): Continue to add water and film-forming agent to the mixture in the mixing tank, increase the rotation speed to 2500 r / min, mix and stir for 25 min to obtain the finished product.

[0059] Example 3

[0060] A UHPC protective agent comprises the following raw materials: 10 kg alcohol solvent, 60 kg water, 5 kg film-forming agent, 3 kg dispersant, 15 kg mullite, 5 kg tetraethoxysilane, and 5 kg vinyl-terminated polydimethylsiloxane.

[0061] The specific dosage is summarized in Table 1.

[0062] The alcohol solvent is propanol.

[0063] The film-forming agents are polyvinyl alcohol and 12-ethylhexyl alcohol, with a mass ratio of 1:1.2, meaning that the amount of polyvinyl alcohol used is 2.27 kg and the amount of 12-ethylhexyl alcohol used is 2.73 kg.

[0064] The dispersant is sodium dodecyl sulfate.

[0065] The mullite has a particle size of 100 μm.

[0066] The CAS number for tetraethoxysilane is 78-10-4.

[0067] The vinyl-terminated polydimethylsiloxane was purchased from Shenzhen Jipeng Silicon Fluorine Materials Co., Ltd., model number JP-02V-200.

[0068] This application also provides a method for preparing a UHPC protective agent, comprising the following steps:

[0069] Step 1): Add tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution into a stirred tank and stir at 1800 r / min for 15 min to obtain a mixture.

[0070] Step 2): Continue to add water and film-forming agent to the mixture in the mixing tank, increase the speed to 2800 r / min, mix and stir for 25 min to obtain the finished product.

[0071] Example 4

[0072] A UHPC protective agent comprises the following raw materials: 8 kg alcohol solvent, 72 kg water, 3 kg film-forming agent, 1.5 kg dispersant, 8 kg mullite, 3 kg tetraethoxysilane, and 1.5 kg vinyl-terminated polydimethylsiloxane.

[0073] The specific dosage is summarized in Table 1.

[0074] The alcohol solvent is ethanol.

[0075] The film-forming agents are polyvinyl alcohol and 12-ethylhexyl alcohol, with a mass ratio of 1:1, meaning that the amount of polyvinyl alcohol used is 1.5 kg and the amount of 12-ethylhexyl alcohol used is 1.5 kg.

[0076] The dispersant is sodium dodecyl sulfate.

[0077] The mullite has a particle size of 50 μm.

[0078] The CAS number for tetraethoxysilane is 78-10-4.

[0079] The vinyl-terminated polydimethylsiloxane was purchased from Shenzhen Jipeng Silicon Fluorine Materials Co., Ltd., model number JP-02V-200.

[0080] This application also provides a method for preparing a UHPC protective agent, comprising the following steps:

[0081] Step 1): Add tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution into a stirred tank and stir at 2000 r / min for 15 min to obtain a mixture.

[0082] Step 2): Continue to add water and film-forming agent to the mixture in the mixing tank, increase the speed to 3000 r / min, mix and stir for 25 min to obtain the finished product.

[0083] Example 5

[0084] A UHPC protective agent comprises the following raw materials: 8 kg alcohol solvent, 72 kg water, 3 kg film-forming agent, 1.5 kg dispersant, 12 kg mullite, 4.5 kg tetraethoxysilane, and 2.5 kg vinyl-terminated polydimethylsiloxane.

[0085] The specific dosage is summarized in Table 1.

[0086] The alcohol solvent is ethanol.

[0087] The film-forming agents are polyvinyl alcohol and 12-ethylhexyl alcohol, with a mass ratio of 1:1, meaning that the amount of polyvinyl alcohol used is 1.5 kg and the amount of 12-ethylhexyl alcohol used is 1.5 kg.

[0088] The dispersant is sodium dodecyl sulfate.

[0089] The mullite has a particle size of 50 μm.

[0090] The CAS number for tetraethoxysilane is 78-10-4.

[0091] The vinyl-terminated polydimethylsiloxane was purchased from Shenzhen Jipeng Silicon Fluorine Materials Co., Ltd., model number JP-02V-200.

[0092] This application also provides a method for preparing a UHPC protective agent, comprising the following steps:

[0093] Step 1): Add tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution into a stirred tank and stir at 2000 r / min for 15 min to obtain a mixture.

[0094] Step 2): Continue to add water and film-forming agent to the mixture in the mixing tank, increase the speed to 3000 r / min, mix and stir for 25 min to obtain the finished product.

[0095] Table 1

[0096]

[0097] Example 6

[0098] A UHPC protective agent comprises the following raw materials: 8 kg alcohol solvent, 72 kg water, 3 kg film-forming agent, 1.5 kg dispersant, 10 kg mullite, 3.5 kg tetraethoxysilane, and 2 kg vinyl-terminated polydimethylsiloxane.

[0099] The alcohol solvent is ethanol.

[0100] The film-forming agents are polyvinyl alcohol and 12-ethylhexyl alcohol, with a mass ratio of 1:1, meaning the amount of polyvinyl alcohol used is kg and the amount of 12-ethylhexyl alcohol used is kg.

[0101] The dispersant is sodium dodecyl sulfate.

[0102] The mullite has a particle size of 1 mm.

[0103] The CAS number for tetraethoxysilane is 78-10-4.

[0104] The vinyl-terminated polydimethylsiloxane was purchased from Shenzhen Jipeng Silicon Fluorine Materials Co., Ltd., model number JP-02V-200.

[0105] This application also provides a method for preparing a UHPC protective agent, comprising the following steps:

[0106] Step 1): Add tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution into a stirred tank and stir at 2000 r / min for 15 min to obtain a mixture.

[0107] Step 2): Continue to add water and film-forming agent to the mixture in the mixing tank, increase the speed to 3000 r / min, mix and stir for 25 min to obtain the finished product.

[0108] Example 7

[0109] A UHPC protective agent comprises the following raw materials: 8 kg alcohol solvent, 72 kg water, 3 kg film-forming agent, 1.5 kg dispersant, 10 kg mullite, 3.5 kg tetraethoxysilane, and 2 kg vinyl-terminated polydimethylsiloxane.

[0110] The alcohol solvent is ethanol.

[0111] The film-forming agents are polyvinyl alcohol and 12-ethylhexyl alcohol, with a mass ratio of 1:0.1, meaning that the amount of polyvinyl alcohol used is 2.73 kg and the amount of 12-ethylhexyl alcohol used is 0.27 kg.

[0112] The dispersant is sodium dodecyl sulfate.

[0113] The mullite has a particle size of 50 μm.

[0114] The CAS number for tetraethoxysilane is 78-10-4.

[0115] The vinyl-terminated polydimethylsiloxane was purchased from Shenzhen Jipeng Silicon Fluorine Materials Co., Ltd., model number JP-02V-200.

[0116] This application also provides a method for preparing a UHPC protective agent, comprising the following steps:

[0117] Step 1): Add tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution into a stirred tank and stir at 2000 r / min for 15 min to obtain a mixture.

[0118] Step 2): Continue to add water and film-forming agent to the mixture in the mixing tank, increase the speed to 3000 r / min, mix and stir for 25 min to obtain the finished product.

[0119] Comparative Example

[0120] Comparative Example 1

[0121] A UHPC protective agent differs from Example 1 in that mullite is replaced with silica. Specifically, the amount of mullite used is 0 kg, and the amount of silica used is 10 kg.

[0122] Comparative Example 2

[0123] A UHPC protective agent differs from Example 1 in that tetraethoxysilane is replaced with n-octyltriethoxysilane. Specifically, the amount of tetraethoxysilane used is 0 kg, and the amount of n-octyltriethoxysilane used is 3.5 kg.

[0124] Comparative Example 3

[0125] A UHPC protective agent differs from Example 1 in that the vinyl-terminated polydimethylsiloxane is replaced with polydimethylsiloxane. Specifically, the amount of vinyl-terminated polydimethylsiloxane used is 0 kg, and the amount of polydimethylsiloxane used is 2 kg.

[0126] Comparative Example 4

[0127] A UHPC protective agent, which differs from Example 1 in that the amount of mullite is 3.5 kg, the amount of tetraethoxysilane is 6 kg, and the amount of vinyl-terminated polydimethylsiloxane is 6 kg.

[0128] Comparative Example 5

[0129] A method for preparing a UHPC protective agent differs from Example 1 in that the rotation speed in steps 1) and 2) is 1000 r / min.

[0130] Performance testing

[0131] 1) Test samples: Protective agents of Examples 1-7 and Comparative Examples 1-5.

[0132] 2) Concrete sample preparation:

[0133] Raw materials: 54kg silicate cement (52.5R grade), 9kg silica fume, 18kg fly ash, 9kg slag powder, 62kg manufactured sand, 93kg basalt coarse aggregate, 0.8kg polycarboxylate superplasticizer; weigh water according to a water-cement ratio of 0.18.

[0134] Preparation method: Mix manufactured sand with 20% water and stir until uniform; then add cement, silica fume, fly ash and slag powder and mix until uniform; then add basalt coarse aggregate and stir until uniform; finally add polycarboxylate superplasticizer and the remaining water and mix until uniform to obtain concrete mix.

[0135] Concrete specimens were obtained by soaking and curing in water at room temperature for 28 days.

[0136] 3) Testing items:

[0137] 1. Water absorption test: The concrete specimen dimensions are 100×100×100mm.

[0138] The concrete specimen was placed in a fume hood for 48 hours. After removal, the test sample was brushed onto all six sides of the concrete specimen, with two coats on each side. The weight of the concrete specimen was measured as m1.

[0139] Then, completely immerse the concrete specimen in deionized water, with the water level 1 cm above the specimen, and soak for 4 hours; remove the concrete specimen and place it in a 260 μW / cm solution. 2 The concrete specimen was left to stand in a UV environment for 4 hours; then it was taken out and soaked in deionized water for 2 hours.

[0140] Remove the concrete specimen and weigh the concrete specimen (m2).

[0141] Calculate the water absorption rate and record it in Table 2.

[0142] 2. Immersion depth: The concrete specimen dimensions are 100×100×100mm.

[0143] The concrete specimen was placed in a fume hood for 48 hours. After removal, the test sample was brushed onto all six sides of the concrete specimen, with two coats on each side. The weight of the concrete specimen was measured as m1.

[0144] Place multiple glass rods with a diameter of 10 mm evenly at the bottom of the soaking container, place the concrete specimen on the glass rods, and then pour deionized water into the soaking container until the glass rods are submerged by 1-2 mm. After soaking for 6 hours, take it out and weigh the concrete specimen m2.

[0145] Calculate the immersion height and record it in Table 2.

[0146] During the experiment, the temperature was maintained within the range of (20±2)℃.

[0147] S: Actual contact area between the concrete specimen and water, mm 2 .

[0148] 3. Splitting tensile strength: The test sample was brushed onto all six sides of the concrete specimen, with two coats on each side. The splitting tensile strength of the concrete specimen was then tested according to GB / T50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete". This strength was used as the untreated strength and recorded in Table 2.

[0149] The test sample was brushed onto all six sides of the concrete specimen, with two coats applied to each side. The concrete specimen was then completely immersed in deionized water, with the water level 1 cm above the specimen, for 4 hours. After removal, the splitting tensile strength of the concrete specimen was measured; this is the post-treatment strength, and the results are recorded in Table 2.

[0150] Table 2

[0151]

[0152] Note: The blank control is a concrete specimen without brush coating.

[0153] As shown in Table 2, the concrete specimens without the protective agents of Examples 1-7 and Comparative Examples 1-5 exhibited significantly lower performance in all tests compared to Example 1. This demonstrates that the protective agent provided in this application can indeed provide protection for concrete, reducing the impact of external moisture on the concrete without hindering internal moisture evaporation, thus enabling the concrete to maintain high strength.

[0154] The protective agents in Comparative Examples 1-3 were developed based on Example 1, replacing any one of mullite, tetraethoxysilane, or vinyl-terminated polydimethylsiloxane. Concrete using this protective agent exhibited a water absorption rate between 1.1% and 1.3%, an impregnation height of 4-4.4 mm, and a splitting tensile strength of 6.1-6.9 MPa before treatment, which decreased to 4.3-4.6 MPa after treatment. Compared to the data in Example 1, the water absorption rate and impregnation height significantly increased, while the splitting tensile strength significantly decreased. This demonstrates that by deviating from the specific combination described in this application, the resulting protective agent cannot achieve the intended protective effect on concrete.

[0155] Comparative Example 4, based on Example 1, disrupted the specific dosage ratios of mullite, tetraethoxysilane, and vinyl-terminated polydimethylsiloxane. While Comparative Example 4 showed better hydrophobicity and higher strength compared to Comparative Examples 1-3, it was significantly inferior to Example 1. This demonstrates that not only is a combination of mullite, tetraethoxysilane, and vinyl-terminated polydimethylsiloxane necessary, but further precise control over their dosage ratios is also required to achieve the desired specific synergistic effect.

[0156] According to the comparison of the test results of Example 1 and Example 6 in Table 2, the water absorption rate of Example 6 is significantly higher than that of Example 1, but the immersion height is not much different from that of Example 1. In terms of splitting tensile strength, the strength of Example 6 before treatment is lower than that of Example 1, and the decrease is even more obvious after treatment.

[0157] The inventors speculate that this is because the larger mullite particles have a strong blocking effect on shallow and surface pores, thus affecting the evaporation of internal moisture and resulting in poor splitting tensile strength. Furthermore, because the mullite particles are too large, they block some of the surface pores, while failing to fill the deeper pores. During water absorption testing, the water initially absorbed during immersion remains in the deeper pores, increasing the water absorption rate. Also, the immersion height only partially submerges the concrete; the surface pores are blocked by mullite, preventing external moisture from temporarily penetrating the concrete, resulting in a low immersion height. Therefore, it is necessary to further limit the particle size of mullite, in addition to specifying the composition of mullite, tetraethoxysilane, and vinyl-terminated polydimethylsiloxane, to better achieve the desired special synergistic effect.

[0158] According to the comparison of the test data of Example 1 and Example 7 in Table 2, it can be seen that further limiting the type and dosage ratio of the film-forming agent is beneficial to improving the protective effect of the protective agent on concrete.

[0159] According to the comparison of the detection data of Example 1 and Comparative Example 5 in Table 2, it can be seen that the stirring conditions during preparation need to be further limited to allow the various raw materials to react more fully in order to achieve better results.

[0160] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A UHPC protective agent, characterized in that, According to the mass fractions, the following raw materials are included: 5-10 parts alcohol solvent, 60-85 parts water, 1-5 parts film-forming agent, 0-3 parts dispersant, 5-15 parts mullite, 1-5 parts tetraethoxysilane, and 1-5 parts vinyl-terminated polydimethylsiloxane. The preparation method of the UHPC protective agent includes the following steps: Tetraethoxysilane, vinyl-terminated polydimethylsiloxane, mullite, dispersant, and alcohol solution were mixed and stirred at 1500-2000 r / min to obtain a mixture. Continue to add water and film-forming agent to the mixture, and stir until uniform to obtain the finished product; when mixing the mixture, water and film-forming agent, increase the rotation speed to 2500-3000 r / min.

2. The UHPC protective agent according to claim 1, characterized in that: The mullite comprises 8-12 parts by mass, the tetraethoxysilane comprises 3.0-4.5 parts by mass, and the vinyl-terminated polydimethylsiloxane comprises 1.5-2.5 parts by mass.

3. The UHPC protective agent according to claim 1, characterized in that: The mullite has a particle size of 30-100 μm.

4. The UHPC protective agent according to claim 1, characterized in that: The film-forming agent is one or more of polyvinyl alcohol, acrylic copolymer emulsion, dodecyl alcohol ester, and butadiene resin.

5. The UHPC protective agent according to claim 4, characterized in that: The film-forming agent is polyvinyl alcohol and 12-ethylhexyl alcohol, with a mass ratio of 1:(0.8-1.2) based on the mass of polyvinyl alcohol.

6. The UHPC protective agent according to claim 1, characterized in that: The alcohol solvent is one or a mixture of ethanol, propanol, isopropanol, and ethylene glycol.

7. The UHPC protective agent according to claim 6, characterized in that: The alcohol solvent is ethanol.

Images