A method for preparing a freeze-thaw cracking resistant cement wall material

Abstract

The application relates to the field of cement wall materials, and particularly discloses a preparation method of a freeze-thaw cracking resistant cement wall material, which comprises the following steps: (1) adding sodium alginate powder and magnesium oxide powder into a heated saturated sodium stearate solution and stirring until uniform, then adding the obtained viscous mixed solution into a saturated calcium nitrate solution, and after standing, drying and grinding the obtained gel product to obtain a primary powder; (2) uniformly mixing the primary powder with anhydrous ethanol containing triethanolamine, drying and grinding to obtain an anti-freezing agent; and (3) adding the anti-freezing agent into a material system composed of cement, coarse aggregate, fine aggregate, fly ash, silica fume, a water reducing agent and fibers, uniformly mixing, then adding mixing water and uniformly mixing to obtain the cement wall material. The prepared novel anti-freezing agent effectively improves the freeze resistance of the cement wall material.

Description

Technical Field

[0001] This invention relates to the field of cement wall materials, and specifically to a method for preparing a freeze-thaw resistant cement wall material. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Cement walls are building materials made by bonding and solidifying aggregates (such as sand and stone) through a hydration reaction with cement-based cementitious materials at their core. Cement walls are the most common and basic form of modern building structure, constructed by pouring or masonry concrete. Their strength, durability, and stability directly determine the safety and lifespan of a building. Because cement walls are formed by binding aggregates through the formation of hydrated calcium silicate gel after hydration, they inevitably contain a large number of pores left after water evaporation.

[0004] Freeze-thaw resistance refers to the ability of a cement-based structure to withstand repeated freeze-thaw cycles without damage while in a hydrated state. It directly relates to the structural safety, functionality, and maintenance costs of a building. Among numerous environmental erosion factors, freeze-thaw cycles pose one of the most destructive threats to cement walls, especially in cold regions with large diurnal temperature variations. When the temperature drops below freezing, free water in the pores of the cement wall freezes and expands, generating crystallization pressure. Simultaneously, unfrozen water migrates towards the frozen zone under the temperature gradient, generating osmotic pressure. The combined effect of these two pressures, when exceeding the tensile strength of the cement wall material, triggers the propagation of microcracks, leading to a decrease in wall strength or even structural failure. Summary of the Invention

[0005] This invention provides a method for preparing a freeze-thaw resistant cement wall material, which effectively improves the freeze-thaw resistance of the cement wall material by adding a novel antifreeze agent. Specifically, the technical solution of this invention is as follows.

[0006] A method for preparing a freeze-thaw resistant cement wall material includes the following steps: (1) Add sodium alginate powder and magnesium oxide powder to a heated saturated sodium stearate solution and stir until uniform. Then add the resulting viscous mixture to a saturated calcium nitrate solution. After standing, dry the resulting gel product and grind it to obtain the primary powder.

[0007] (2) The primary powder is mixed with anhydrous ethanol containing triethanolamine, dried and ground to obtain the antifreeze.

[0008] (3) The antifreeze agent is added to the material system composed of cement, coarse aggregate, fine aggregate, fly ash, silica fume, water reducing agent and fiber and mixed evenly. Then, mixing water is added and mixed evenly to obtain the cement wall material.

[0009] Further, in step (1), the content of sodium alginate in the viscous mixture is 5~7.5g / L.

[0010] Further, in step (1), the magnesium oxide content in the viscous mixture is 9~13 g / L. Optionally, the magnesium oxide has a fineness of 200~400 mesh.

[0011] Furthermore, in step (1), the temperature of the saturated sodium stearate solution is 50~60℃.

[0012] Further, in step (1), the volume ratio of the viscous mixture to the saturated calcium nitrate solution is 1:3.5~5.

[0013] Further, in step (1), the settling time is 20-30 minutes. Optionally, the primary powder is obtained by passing the powder through a 100-200 mesh sieve after grinding.

[0014] Further, in step (2), the ratio of the primary powder to anhydrous ethanol is 1g:0.7~1mL.

[0015] Furthermore, in step (2), the mass fraction of triethanolamine in the anhydrous ethanol is 12-16%.

[0016] Further, in step (2), the drying temperature is 75~85℃, and the drying time is 15~20min. Optionally, the antifreeze is obtained by passing the powder through a 100~200 mesh sieve.

[0017] Further, in step (3), the proportions of each component in the material system are as follows: 210-228 parts by weight of cement, 400-478 parts by weight of coarse aggregate, 250-303 parts by weight of fine aggregate, 17-23 parts by weight of fly ash, 15-25 parts by weight of silica fume, 1-2 parts by weight of water-reducing agent, 10-14 parts by weight of fiber, and 20-26.5 parts by weight of antifreeze agent.

[0018] Furthermore, in step (3), the total mass ratio of the mixing water to cement, fly ash, and silica fume is 0.38~0.44:1.

[0019] Further, in step (3), the water-reducing agent includes at least one of the following: polycarboxylate water-reducing agent, aminosulfonate water-reducing agent, naphthalene-based water-reducing agent, lignin sulfonate water-reducing agent, etc.

[0020] Further, in step (3), the fiber includes at least one of polyethylene fiber, polypropylene fiber, polyvinyl alcohol fiber, and polyacrylonitrile fiber. Optionally, the fiber has a length of 5-15 mm and a diameter of 0.15-0.21 mm.

[0021] Compared with the prior art, the technical solution of the present invention has at least the following beneficial technical effects: This invention first adds sodium alginate powder and magnesium oxide powder to a heated saturated sodium stearate solution to form a viscous mixture, which is then added to a saturated calcium nitrate solution. The calcium ions in this mixture convert the sodium stearate into calcium stearate, while simultaneously causing the sodium alginate to cross-link and form a gel, locking the calcium stearate within. This results in the calcium stearate being distributed in a very uniform and fine manner in the obtained antifreeze agent. The agent also contains calcium nitrate and sodium nitrate formed during the above process. These two components help lower the freezing point of water. Furthermore, the large amount of calcium stearate in the antifreeze agent gives it a certain degree of hydrophobicity, improving the impermeability of cement wall materials. In addition, the antifreeze agent also has good stress absorption properties, effectively enhancing the frost resistance of cement wall materials. Simultaneously, the antifreeze agent prepared by this invention effectively overcomes the problem that calcium stearate is poorly soluble in water, causing it to easily float to the top of the cement wall slurry, thus hindering its uniform distribution and affecting the improvement of the wall material's frost resistance. In addition, the antifreeze agent of this invention, through the synergistic effect of magnesium oxide and triethanolamine, allows the triethanolamine to capture carbon dioxide from the air and create a slightly acidic environment around the antifreeze particles after moisture seeps into the wall during its service life. This promotes the hydration reaction of the magnesium oxide in the antifreeze agent, forming an expansive product. Simultaneously, the migrating magnesium ions form precipitates that fill and seal pores. Especially for the surface layer of the wall, this mechanism effectively increases the density of the surface layer and reduces moisture penetration. Moreover, since the hydration of magnesium oxide is an exothermic process, it also helps to reduce the driving force for water freezing, thereby improving the freeze resistance of cement wall materials. The antifreeze agent of this invention, through the synergy of multiple mechanisms, comprehensively improves the freeze resistance of cement wall materials from different perspectives, overcoming the limitations of single antifreeze components. Attached Figure Description

[0022] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings, wherein: Figure 1 The image shows an antifreeze sample prepared in Example 1 below.

[0023] Figure 2 The following is a diagram showing the compressive strength test results for Example 1.

[0024] Figure 3 The image shows an antifreeze sample prepared in Example 2 below.

[0025] Figure 4 The following is a diagram showing the compressive strength test results for Example 2.

[0026] Figure 5 The image shows an antifreeze sample prepared in Example 3 below.

[0027] Figure 6 The following is a diagram showing the compressive strength test results for Example 3.

[0028] Figure 7 The image shows an antifreeze sample prepared in Example 4 below.

[0029] Figure 8 The following is a diagram showing the compressive strength test results for Example 4.

[0030] Figure 9 The image shows an antifreeze sample prepared in Example 5 below.

[0031] Figure 10 The following is a diagram showing the compressive strength test results for Example 5.

[0032] Figure 11 The image shows an antifreeze sample prepared in Example 6 below.

[0033] Figure 12 The following is a diagram showing the compressive strength test results for Example 6.

[0034] Figure 13 The following is a diagram showing the compressive strength test results for Example 7.

[0035] Figure 14 The image shows an antifreeze sample prepared in Example 8 below.

[0036] Figure 15 The following is a diagram showing the compressive strength test results for Example 8. Detailed Implementation

[0037] The present invention is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods in the art or as per the product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention.

[0039] Example 1: A method for preparing a freeze-thaw resistant cement wall material, comprising the following steps: (1) Sodium alginate powder and 350-mesh magnesium oxide powder were added to a saturated sodium stearate aqueous solution at 60°C and stirred until homogeneous to obtain a viscous mixture, wherein the content of sodium alginate was 6.5 g / L and the content of magnesium oxide was 12 g / L. Then the viscous mixture was added to a saturated calcium nitrate solution at a volume ratio of 1:4. After standing for 25 min, the gel product was filtered out, heated to 80°C and dried until its weight no longer changed, then ground and passed through a 200-mesh sieve to obtain a primary powder for later use.

[0040] (2) Triethanolamine was added to anhydrous ethanol and stirred until homogeneous to obtain an alcohol solution with a triethanolamine mass fraction of 15%. Then, according to the ratio of the primary powder to the alcohol solution = 1g: 0.85mL, the alcohol solution was sprayed onto the primary powder under stirring to mix the two evenly. The resulting mixture was then heated to 80℃ and dried for 20min. After grinding, it was passed through a 200-mesh sieve to obtain the antifreeze (e.g., Figure 1 (As shown).

[0041] (3) Take the following components in the following proportions: 218 parts by weight of 42.5 ordinary Portland cement, 450 parts by weight of coarse aggregate, 270 parts by weight of fine aggregate, 20 parts by weight of fly ash, 20 parts by weight of silica fume, 1.4 parts by weight of polycarboxylate superplasticizer, 12 parts by weight of polypropylene fiber, and 23 parts by weight of the antifreeze agent described in this embodiment; wherein: the coarse aggregate is crushed stone with a particle size distribution between 9 and 15 mm, the fine aggregate is river sand with a particle size distribution between 1 and 3 mm, and the fiber has a length of 10 mm and a diameter of 0.21 mm. Add the above components to a mixer and dry mix for 5 minutes, then add 103 parts by weight of mixing water and continue mixing for 2 minutes to obtain the cement wall material.

[0042] Performance Testing: The cement wall material prepared in this embodiment was poured into a mold for molding, and then transferred to a curing chamber for standard curing for 28 days to obtain specimens. The water absorption rate of the specimens was then tested according to the "Standard for Test Methods of Physical and Mechanical Properties of Concrete" (GBT 50081-2019). Additionally, the compressive strength of the specimens was tested after 25 freeze-thaw cycles according to the "Standard for Test Methods of Long-Term Performance and Durability of Concrete" (GBT 50082-2024). Figure 2 As shown in the figure, the test results are: water absorption rate = 1.71%, compressive strength = 54.19 MPa.

[0043] Example 2: A method for preparing a freeze-thaw resistant cement wall material, comprising the following steps: (1) Sodium alginate powder and 400-mesh magnesium oxide powder were added to a saturated sodium stearate aqueous solution at 60°C and stirred until homogeneous to obtain a viscous mixture, wherein the content of sodium alginate was 7.5 g / L and the content of magnesium oxide was 9 g / L. Then the viscous mixture was added to a saturated calcium nitrate solution at a volume ratio of 1:5. After standing for 30 min, the gel product was filtered out, heated to 80°C and dried until its weight no longer changed, then ground and passed through a 200-mesh sieve to obtain a primary powder for later use.

[0044] (2) Triethanolamine was added to anhydrous ethanol and stirred until homogeneous to obtain an alcohol solution with a triethanolamine mass fraction of 12%. Then, according to the ratio of the primary powder to the alcohol solution = 1g: 0.7mL, the alcohol solution was sprayed onto the primary powder under stirring to mix the two. The resulting mixture was then heated to 75℃ and dried for 20min. After grinding, it was passed through a 200-mesh sieve to obtain the antifreeze (e.g., Figure 3 (As shown).

[0045] (3) Take the following components in the following proportions: 210 parts by weight of 42.5 ordinary Portland cement, 400 parts by weight of coarse aggregate, 250 parts by weight of fine aggregate, 17 parts by weight of fly ash, 15 parts by weight of silica fume, 1.0 part by weight of polycarboxylate superplasticizer, 10 parts by weight of polyvinyl alcohol fiber, and 20 parts by weight of the antifreeze agent described in this embodiment; wherein: the coarse aggregate is crushed stone with a particle size distribution between 9 and 15 mm, the fine aggregate is river sand with a particle size distribution between 1 and 3 mm, and the fiber has a length of 5 mm and a diameter of 0.15 mm. Add the above components to a mixer and dry mix for 5 minutes, then add 92 parts by weight of mixing water and continue mixing for 2 minutes to obtain the cement wall material.

[0046] Performance testing: The water absorption rate and compressive strength (e.g., as described in Example 1) of the cement wall material prepared in this example were tested using the same method. Figure 4 As shown in the figure, the test results are: water absorption rate = 1.42%, compressive strength = 58.36 MPa.

[0047] Example 3: A method for preparing a freeze-thaw resistant cement wall material, comprising the following steps: (1) Sodium alginate powder and 200-mesh magnesium oxide powder were added to a saturated sodium stearate aqueous solution at 50°C and stirred until homogeneous to obtain a viscous mixture, wherein the content of sodium alginate was 5 g / L and the content of magnesium oxide was 13 g / L. Then the viscous mixture was added to a saturated calcium nitrate solution at a volume ratio of 1:3.5. After standing for 20 min, the gel product was filtered out, heated to 75°C and dried until its weight no longer changed, then ground and passed through a 150-mesh sieve to obtain a primary powder for later use.

[0048] (2) Triethanolamine was added to anhydrous ethanol and stirred until homogeneous to obtain an alcohol solution with a triethanolamine mass fraction of 16%. Then, the alcohol solution was sprayed onto the primary powder with stirring at a ratio of 1 g: 1 mL to the primary powder to mix them thoroughly. The resulting mixture was then heated to 85°C and dried for 15 min. After grinding, it was passed through a 150-mesh sieve to obtain the antifreeze (e.g., ...). Figure 5 (As shown).

[0049] (3) Take the following components in the following proportions: 228 parts by weight of 42.5 ordinary Portland cement, 478 parts by weight of coarse aggregate, 303 parts by weight of fine aggregate, 23 parts by weight of fly ash, 25 parts by weight of silica fume, 2 parts by weight of naphthalene-based water-reducing agent, 14 parts by weight of polyethylene fiber, and 26.5 parts by weight of the antifreeze agent described in this embodiment; wherein: the coarse aggregate is crushed stone with a particle size distribution between 9 and 15 mm, the fine aggregate is river sand with a particle size distribution between 1 and 3 mm, and the fiber has a length of 15 mm and a diameter of 0.21 mm. Add the above components to a mixer and dry mix for 5 minutes, then add 121.5 parts by weight of mixing water and continue mixing for 2 minutes to obtain the cement wall material.

[0050] Performance testing: The water absorption rate and compressive strength (e.g., as described in Example 1) of the cement wall material prepared in this example were tested using the same method. Figure 6 As shown in the figure, the test results are: water absorption rate = 1.86%, compressive strength = 53.07 MPa.

[0051] Example 4: A method for preparing a freeze-thaw resistant cement wall material, comprising the following steps: (1) Sodium alginate powder was added to a saturated sodium stearate aqueous solution at 60°C and stirred until homogeneous to obtain a viscous mixture, wherein the sodium alginate content was 6.5 g / L. Then, the viscous mixture was added to a saturated calcium nitrate solution at a volume ratio of 1:4. After standing for 25 min, the gel product was filtered out, heated to 80°C and dried until its weight no longer changed, then ground and passed through a 200-mesh sieve to obtain a primary powder for later use.

[0052] (2) Triethanolamine was added to anhydrous ethanol and stirred until homogeneous to obtain an alcohol solution with a triethanolamine mass fraction of 15%. Then, according to the ratio of the primary powder to the alcohol solution = 1g: 0.85mL, the alcohol solution was sprayed onto the primary powder under stirring to mix the two evenly. The resulting mixture was then heated to 80℃ and dried for 20min. After grinding, it was passed through a 200-mesh sieve to obtain the antifreeze (e.g., Figure 7 (As shown).

[0053] (3) Take the following components in the following proportions: 218 parts by weight of 42.5 ordinary Portland cement, 450 parts by weight of coarse aggregate, 270 parts by weight of fine aggregate, 20 parts by weight of fly ash, 20 parts by weight of silica fume, 1.4 parts by weight of polycarboxylate superplasticizer, 12 parts by weight of polypropylene fiber, and 23 parts by weight of the antifreeze agent described in this embodiment; wherein: the coarse aggregate is crushed stone with a particle size distribution between 9 and 15 mm, the fine aggregate is river sand with a particle size distribution between 1 and 3 mm, and the fiber has a length of 10 mm and a diameter of 0.21 mm. Add the above components to a mixer and dry mix for 5 minutes, then add 103 parts by weight of mixing water and continue mixing for 2 minutes to obtain the cement wall material.

[0054] Performance testing: The water absorption rate and compressive strength (e.g., as described in Example 1) of the cement wall material prepared in this example were tested using the same method. Figure 8 As shown in the figure, the test results are: water absorption rate = 3.14%, compressive strength = 46.51 MPa.

[0055] Example 5: A method for preparing a freeze-thaw resistant cement wall material, comprising the following steps: (1) Sodium alginate powder and 200-mesh magnesium oxide powder were added to a saturated sodium stearate aqueous solution at 50°C and stirred until homogeneous to obtain a viscous mixture, wherein the content of sodium alginate was 5 g / L and the content of magnesium oxide was 13 g / L. Then the viscous mixture was added to a saturated calcium nitrate solution at a volume ratio of 1:3.5. After standing for 20 min, the gel product was filtered out, heated to 75°C and dried until its weight no longer changed, then ground and passed through a 150-mesh sieve to obtain a primary powder for later use.

[0056] (2) According to the ratio of the primary powder to anhydrous ethanol = 1g: 1mL, spray the anhydrous ethanol into the stirred primary powder and mix them evenly. Then heat the resulting mixture to 85°C and dry it for 15 minutes. After grinding, pass it through a 150-mesh sieve to obtain the antifreeze (e.g. Figure 9 (As shown).

[0057] (3) Take the following components in the following proportions: 228 parts by weight of 42.5 ordinary Portland cement, 478 parts by weight of coarse aggregate, 303 parts by weight of fine aggregate, 23 parts by weight of fly ash, 25 parts by weight of silica fume, 2 parts by weight of naphthalene-based water-reducing agent, 14 parts by weight of polyethylene fiber, and 26.5 parts by weight of the antifreeze agent described in this embodiment; wherein: the coarse aggregate is crushed stone with a particle size distribution between 9 and 15 mm, the fine aggregate is river sand with a particle size distribution between 1 and 3 mm, and the fiber has a length of 15 mm and a diameter of 0.21 mm. Add the above components to a mixer and dry mix for 5 minutes, then add 121.5 parts by weight of mixing water and continue mixing for 2 minutes to obtain the cement wall material.

[0058] Performance testing: The water absorption rate and compressive strength (e.g., as described in Example 1) of the cement wall material prepared in this example were tested using the same method. Figure 10 As shown in the figure, the test results are: water absorption rate = 2.68%, compressive strength = 48.32 MPa.

[0059] Example 6: A method for preparing a freeze-thaw resistant cement wall material, comprising the following steps: (1) Mix sodium alginate powder, 350-mesh magnesium oxide powder and calcium stearate powder in a mass ratio of 6.5g:12g:50g, grind them, and then pass them through a 200-mesh sieve to obtain primary powder for later use.

[0060] (2) Triethanolamine was added to anhydrous ethanol and stirred until homogeneous to obtain an alcohol solution with a triethanolamine mass fraction of 15%. Then, according to the ratio of the primary powder to the alcohol solution = 1g: 0.85mL, the alcohol solution was sprayed onto the primary powder under stirring to mix the two evenly. The resulting mixture was then heated to 80℃ and dried for 20min. After grinding, it was passed through a 200-mesh sieve to obtain the antifreeze (e.g., Figure 11 (As shown).

[0061] (3) Take the following components in the following proportions: 218 parts by weight of 42.5 ordinary Portland cement, 450 parts by weight of coarse aggregate, 270 parts by weight of fine aggregate, 20 parts by weight of fly ash, 20 parts by weight of silica fume, 1.4 parts by weight of polycarboxylate superplasticizer, 12 parts by weight of polypropylene fiber, and 23 parts by weight of the antifreeze agent described in this embodiment; wherein: the coarse aggregate is crushed stone with a particle size distribution between 9 and 15 mm, the fine aggregate is river sand with a particle size distribution between 1 and 3 mm, and the fiber has a length of 10 mm and a diameter of 0.21 mm. Add the above components to a mixer and dry mix for 5 minutes, then add 103 parts by weight of mixing water and continue mixing for 2 minutes to obtain the cement wall material.

[0062] Performance testing: The water absorption rate and compressive strength (e.g., as described in Example 1) of the cement wall material prepared in this example were tested using the same method. Figure 12 As shown in the figure, the test results are: water absorption rate = 5.53%, compressive strength = 41.04 MPa.

[0063] Example 7: A method for preparing a freeze-thaw resistant cement wall material, comprising the following steps: Take the following components in the following proportions: 210 parts by weight of 42.5 ordinary Portland cement, 400 parts by weight of coarse aggregate, 250 parts by weight of fine aggregate, 17 parts by weight of fly ash, 15 parts by weight of silica fume, 1.0 part by weight of polycarboxylate superplasticizer, 10 parts by weight of polyvinyl alcohol fiber, and 20 parts by weight of 80-mesh calcium stearate powder; wherein: the coarse aggregate is crushed stone with a particle size distribution between 9 and 15 mm, the fine aggregate is river sand with a particle size distribution between 1 and 3 mm, and the fiber has a length of 5 mm and a diameter of 0.15 mm. Add the above components to a mixer and dry mix for 5 minutes, then add 92 parts by weight of mixing water and continue mixing for 2 minutes to obtain the cement wall material.

[0064] Performance testing: The water absorption rate and compressive strength (e.g., as described in Example 1) of the cement wall material prepared in this example were tested using the same method. Figure 13 As shown in the figure, the test results are: water absorption rate = 6.49%, compressive strength = 35.21 MPa.

[0065] Example 8: A method for preparing a freeze-thaw resistant cement wall material, comprising the following steps: (1) Sodium alginate powder and 200-mesh magnesium oxide powder were added to water and stirred evenly to obtain a viscous mixture, wherein the content of sodium alginate was 5 g / L and the content of magnesium oxide was 13 g / L. Then the viscous mixture was added to a saturated calcium nitrate solution at a volume ratio of 1:3.5. After standing for 20 minutes, the gel product was filtered out, heated to 75°C and dried until its weight no longer changed, then ground and passed through a 150-mesh sieve to obtain a primary powder for later use.

[0066] (2) Triethanolamine was added to anhydrous ethanol and stirred until homogeneous to obtain an alcohol solution with a triethanolamine mass fraction of 16%. Then, the alcohol solution was sprayed onto the primary powder with stirring at a ratio of 1 g: 1 mL to the primary powder to mix them thoroughly. The resulting mixture was then heated to 85°C and dried for 15 min. After grinding, it was passed through a 150-mesh sieve to obtain the antifreeze (e.g., ...). Figure 14 (As shown).

[0067] (3) Take the following components in the following proportions: 228 parts by weight of 42.5 ordinary Portland cement, 478 parts by weight of coarse aggregate, 303 parts by weight of fine aggregate, 23 parts by weight of fly ash, 25 parts by weight of silica fume, 2 parts by weight of naphthalene-based water-reducing agent, 14 parts by weight of polyethylene fiber, and 26.5 parts by weight of the antifreeze agent described in this embodiment; wherein: the coarse aggregate is crushed stone with a particle size distribution between 9 and 15 mm, the fine aggregate is river sand with a particle size distribution between 1 and 3 mm, and the fiber has a length of 15 mm and a diameter of 0.21 mm. Add the above components to a mixer and dry mix for 5 minutes, then add 121.5 parts by weight of mixing water and continue mixing for 2 minutes to obtain the cement wall material.

[0068] Performance testing: The water absorption rate and compressive strength (e.g., as described in Example 1) of the cement wall material prepared in this example were tested using the same method. Figure 15 As shown in the figure, the test results are: water absorption rate = 6.12%, compressive strength = 39.94 MPa.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a freeze-thaw resistant cement wall material, characterized in that, Includes the following steps: (1) Add sodium alginate powder and magnesium oxide powder to a heated saturated sodium stearate solution and stir until uniform. Then add the resulting viscous mixture to a saturated calcium nitrate solution. After standing, dry the resulting gel product and grind it to obtain the primary powder. (2) The primary powder is mixed with anhydrous ethanol containing triethanolamine, dried and ground to obtain the antifreeze. (3) The antifreeze agent is added to the material system composed of cement, coarse aggregate, fine aggregate, fly ash, silica fume, water reducing agent and fiber and mixed evenly. Then, mixing water is added and mixed evenly to obtain the cement wall material.

2. The method for preparing freeze-thaw resistant and crack-resistant cement wall material according to claim 1, characterized in that, In step (1), the sodium alginate content in the viscous mixture is 5~7.5 g / L.

3. The method for preparing freeze-thaw resistant crack-resistant cement wall material according to claim 1, characterized in that, In step (1), the content of magnesium oxide in the viscous mixture is 9~13g / L; or, in step (1), the fineness of the magnesium oxide is 200~400 mesh.

4. The method for preparing freeze-thaw resistant and crack-resistant cement wall material according to claim 1, characterized in that, In step (1), the temperature of the saturated sodium stearate solution is 50~60℃.

5. The method for preparing freeze-thaw resistant crack-resistant cement wall material according to claim 1, characterized in that, In step (1), the volume ratio of the viscous mixture to the saturated calcium nitrate solution is 1:3.5~5; Alternatively, in step (1), the settling time is 20-30 minutes; Alternatively, in step (1), the primary powder is obtained by passing the powder through a 100-200 mesh sieve after grinding.

6. The method for preparing freeze-thaw resistant and crack-resistant cement wall material according to claim 1, characterized in that, In step (2), the ratio of the primary powder to anhydrous ethanol is 1g:0.7~1mL.

7. The method for preparing freeze-thaw resistant crack-resistant cement wall material according to claim 1, characterized in that, In step (2), the mass fraction of triethanolamine in the anhydrous ethanol is 12-16%; Alternatively, in step (2), the drying temperature is 75~85℃ and the drying time is 15~20min; Alternatively, in step (2), the antifreeze is obtained by passing the powder through a 100-200 mesh sieve.

8. The method for preparing freeze-thaw resistant crack-prone cement wall material according to any one of claims 1-7, characterized in that, In step (3), the proportions of each component in the material system are as follows: 210-228 parts by weight of cement, 400-478 parts by weight of coarse aggregate, 250-303 parts by weight of fine aggregate, 17-23 parts by weight of fly ash, 15-25 parts by weight of silica fume, 1-2 parts by weight of water-reducing agent, 10-14 parts by weight of fiber, and 20-26.5 parts by weight of antifreeze agent.

9. The method for preparing freeze-thaw resistant crack-prone cement wall material according to any one of claims 1-7, characterized in that, In step (3), the total mass ratio of the mixing water to cement, fly ash, and silica fume is 0.38~0.44:

1.

10. The method for preparing freeze-thaw resistant crack-prone cement wall material according to any one of claims 1-7, characterized in that, In step (3), the water-reducing agent includes at least one of the following: polycarboxylate water-reducing agent, aminosulfonate water-reducing agent, naphthalene-based water-reducing agent, and lignin sulfonate water-reducing agent; Alternatively, in step (3), the fiber includes at least one of polyethylene fiber, polypropylene fiber, polyvinyl alcohol fiber, and polyacrylonitrile fiber. Alternatively, in step (3), the fiber has a length of 5~15mm and a diameter of 0.15~0.21mm.

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