Gypsum-based self-leveling mortar and method for preparing the same

Abstract

The application relates to the field of mortars, and particularly discloses a gypsum-based self-leveling mortar and a preparation method thereof. The gypsum-based self-leveling mortar comprises the following raw materials in parts by weight: 300-500 parts of gypsum, 30-50 parts of cement, 40-80 parts of coated sand, 0.2-1 part of a defoaming agent, 1-2 parts of a water reducing agent, 5-15 parts of insect resin modified lightweight fiber, 1-3 parts of coated sodium borate and 15-25 parts of connecting fillers. The preparation method comprises the following steps: S1, uniformly mixing and stirring the gypsum, the cement and the coated sand to prepare initial mixture; S2, adding the insect resin modified lightweight fiber, the coated sodium borate and the connecting fillers into the initial mixture, uniformly mixing to prepare mixed material; and S3, adding the defoaming agent and the water reducing agent into the mixed material, uniformly mixing and stirring to prepare finished product mortar. The gypsum-based self-leveling mortar has the advantages of high strength, good durability and resistance to moisture and metamorphic change.

Description

Technical Field

[0001] This application relates to the field of mortar, and more specifically, to a gypsum-based self-leveling mortar and a method for preparing the same. Background Technology

[0002] Self-leveling mortar is a highly fluid and plastic self-leveling base material formed by mixing cement, aggregates, various additives and water. It is widely used for fine leveling of concrete floors and all paving materials, and is widely applied in residential and commercial buildings.

[0003] Although gypsum-based self-leveling mortar has good self-leveling properties and can achieve a smooth and even surface without manual finishing, its strength is relatively low. Its strength and durability are lower than those of materials such as cement floors and epoxy floors, and it is also prone to moisture damage, thus limiting its use.

[0004] Therefore, how to prepare a self-leveling mortar with high strength, good durability, and resistance to moisture and deterioration is a problem that needs to be solved. Summary of the Invention

[0005] In order to prepare a self-leveling mortar with high strength, good durability and not easily affected by moisture and deterioration, this application provides a gypsum-based self-leveling mortar and its preparation method.

[0006] In the first aspect, this application provides a gypsum-based self-leveling mortar, which adopts the following technical solution:

[0007] A gypsum-based self-leveling mortar comprises the following raw materials in parts by weight: 300-500 parts gypsum, 30-50 parts cement, 40-80 parts coated sand, 0.2-1 parts defoamer, 1-2 parts water-reducing agent, 5-15 parts shellac-modified lightweight fiber, 1-3 parts coated sodium borate, and 15-25 parts binder.

[0008] By employing the above technical solution, shellac-modified lightweight fibers, coated sodium borate, and connecting fillers are combined. The bonding effect of the fibers, combined with the filling effect of the fillers, improves the strength and durability of the mortar. Furthermore, the mortar's hydration is alkaline, and sodium borate and its alkaline hydrates readily dissolve the shellac, promoting the release of the lightweight fibers. Due to the low density of the lightweight fibers, they easily float on the surface of the cured mortar. The adhesive properties of shellac facilitate bonding the lightweight fibers with gypsum, cement, and other raw materials, thereby increasing the internal density of the cured mortar and enhancing its strength and durability. Simultaneously, the network formed by the floating lightweight fibers on the mortar surface effectively blocks moisture. Combined with the reaction of boric acid in sodium borate with calcium and hydroxide ions in the water, the hydrated ions in the mortar become finer and more evenly dispersed, thus improving the impermeability and durability of the cured mortar and making it less prone to moisture absorption.

[0009] Preferably, the shellac-modified lightweight fiber is prepared by mixing hydrophobic seaweed fiber, polyimide fiber, casein, and shellac solution in a mass ratio of 1:0.5-1:0.1-0.4:0.2-0.32.

[0010] By adopting the above technical solution, hydrophobic seaweed fiber, polyimide fiber, casein and shellac solution are combined. The viscosity of shellac solution makes it easy for casein to adhere to the surface of hydrophobic seaweed fiber and polyimide fiber. The shellac film formed by shellac solution has a water-blocking effect, ensuring that the fiber does not easily absorb moisture, while facilitating the uniform mixing of shellac modified lightweight fiber with raw materials such as gypsum and cement.

[0011] During the hydration process, alkaline substances are used in conjunction with sodium borate to facilitate the dissolution of shellac. After the shellac dissolves, the fibers are exposed. Taking advantage of the relatively lightweight nature of seaweed fibers and polyimide fibers, they can easily float on the surface of the mortar. The bonding effect between the fibers, combined with the bonding effect between the casein on the fiber surface and the gypsum, cement, and binder, facilitates the formation of a sealed fiber network on the mortar surface. This not only blocks moisture but also increases the strength of the cured mortar, makes the surface of the cured mortar smooth, and extends the service life of the cured mortar.

[0012] Both seaweed fiber and polyimide fiber have good flexibility and elasticity, which can improve the impact resistance of mortar surfaces.

[0013] Preferably, the hydrophobic seaweed fiber is prepared by soaking seaweed fiber in methyl silicone oil and then adhering it to sodium alginate solution.

[0014] By adopting the above technical solution, seaweed fiber and methyl silicone oil are combined. The porous structure of seaweed fiber facilitates the adsorption and loading of methyl silicone oil, while the good lubrication and hydrophobicity of methyl silicone oil make the hydrophobic seaweed fiber hydrophobic. The hydrophobic seaweed fiber, casein, and polyimide fiber are combined. The hydrophilic groups in casein facilitate the interconnection with the residual amino groups of polyimide fiber, while the hydrophobic groups in casein facilitate the contact and connection with the hydrophobic seaweed fiber, realizing the cross-connection of hydrophobic seaweed fiber and polyimide fiber. The good elasticity and toughness of polyimide fiber, combined with the good flexibility and connection effect of seaweed fiber, allow the polyimide fiber to buffer the impact force after the mortar is subjected to impact, while the seaweed fiber connects the various raw materials inside the mortar, ensuring the internal structure of the mortar, thereby improving the mechanical strength and impact resistance of the cured mortar.

[0015] Preferably, the polyimide fiber is made of polyimide fiber filaments and sodium alginate solution in a mass ratio of 1:0.1-0.3.

[0016] By adopting the above technical solution, polyimide fibers and sodium alginate solution are combined. The viscosity of sodium alginate solution helps the carboxyl groups in sodium alginate adhere stably to the surface of polyimide fibers. During the mortar hydration process, the carboxyl groups in sodium alginate facilitate cross-linking with calcium ions and casein in the mortar. This not only improves the structural density of the mortar and prevents water bleeding, but also enhances the impact resistance and mechanical strength of the mortar.

[0017] Preferably, the coated sodium borate is made from a sodium borate and sodium polyacrylate solution in a mass ratio of 1:0.1-0.38.

[0018] By adopting the above technical solution, sodium borate and sodium polyacrylate solutions are combined. The viscosity of the sodium polyacrylate solution facilitates coating on the surface of sodium borate. During the mortar hydration process, sodium polyacrylate slowly dissolves in water, and the dissolution rate of sodium polyacrylate accelerates with the increase of hydration temperature. This gradually releases sodium borate, which not only gradually dissolves the shellac but also seals the bonding effect between the raw materials in the mortar, preventing the mortar from segregating and the particles from settling.

[0019] Preferably, the connecting filler is composed of polyetheretherketone powder, coated silicon carbide powder and hydrophobic silica powder in a mass ratio of 1:1-2:0.5-1.

[0020] By adopting the above technical solution, polyetheretherketone powder, coated silicon carbide powder, and hydrophobic silica powder are combined. The low density of polyetheretherketone powder and hydrophobic silica powder facilitates their connection and contact with lightweight fibers, while hydrophobic silica powder easily fills the spaces between the fibers, further enhancing the hydrophobic effect of the mortar surface. The connection between polyetheretherketone and the fibers can improve the impact resistance and mechanical strength of the mortar. Due to the high density of silicon carbide powder, silicon carbide particles and sand are easily dispersed in the middle and near the bottom of the mortar. The water-binding effect of the silicon carbide surface film layer is used to prevent water from being absorbed by the ground, thereby minimizing the problems of mortar segregation and bleeding. Combined with the viscosity of dissolved shellac, large particles such as sand and silicon carbide particles are further sealed, minimizing the problem of particle deposition at the bottom of the mortar.

[0021] Preferably, the polyetheretherketone powder is made of polyetheretherketone microparticles, polyvinyl alcohol solution and chitin powder in a mass ratio of 1:0.2-0.5:0.1-0.32.

[0022] By adopting the above technical solution, polyetheretherketone (PEEK) microparticles, polyvinyl alcohol (PVA) solution, and chitin powder are combined. The viscosity of the PVA solution facilitates the adhesion of chitin powder to the surface of the PEEK microparticles. The amino groups on the surface of chitin, the hydroxyl groups in the PVA solution, the carboxyl groups in the sodium polyacrylate on the surface of sodium borate, the hydroxyl and carboxyl groups in shellac, and the amino and carboxyl groups in casein form a three-dimensional cross-linked network inside the mortar. This not only binds cement, sand, and other particles but also stabilizes the structure of the mortar, giving it the advantages of particles not easily settling to the bottom, high strength, and good impact resistance.

[0023] Preferably, the coated silicon carbide powder is prepared by mixing silicon carbide powder and polyvinyl alcohol solution in a mass ratio of 1:0.1-0.38.

[0024] By adopting the above technical solution, silicon carbide powder and polyvinyl alcohol solution are combined. The hydroxyl groups of polyvinyl alcohol can improve the dispersion stability of silicon carbide powder in mortar. Even if some silicon carbide powder and mortar settle to the bottom, polyvinyl alcohol can lock in water and minimize the absorption of water by the ground, thus affecting the hydration effect of the mortar and ensuring the strength and durability of the mortar after curing.

[0025] Preferably, the coating sand is made from river sand and flaxseed gum solution in a mass ratio of 1:0.02-0.07.

[0026] By adopting the above technical solution, river sand and flaxseed adhesive solution are combined. Even if some sand is deposited near the bottom of the mortar, the flaxseed adhesive film on the surface of the sand gradually dissolves as the gypsum and cement hydrate. By utilizing the binding effect of flaxseed adhesive solution on water, the water in the mortar is prevented from being absorbed by the ground, thus affecting the hydration effect of the mortar. This ensures that the mortar has high strength and good durability.

[0027] The hydroxyl groups in the flaxseed gum on the sand surface facilitate the interconnection with shellac-modified lightweight fibers, binders, and other substances, forming a cross-linked network inside the mortar, thereby improving the mechanical strength and durability of the mortar.

[0028] Secondly, this application provides a method for preparing gypsum-based self-leveling mortar, which adopts the following technical solution: A method for preparing gypsum-based self-leveling mortar includes the following steps:

[0029] S1. Weigh out gypsum, cement and coating sand, mix and stir evenly to obtain the initial mixture;

[0030] S2. Add shellac-modified lightweight fiber, coated sodium borate, and binder to the initial mixture and mix evenly to obtain the mixture; S3. Add defoamer and water-reducing agent to the mixture and mix evenly to obtain the finished mortar.

[0031] By adopting the above technical solutions, the finished mortar has the advantages of high strength, good durability, and is not prone to segregation or bleeding. In addition, the surface has good water resistance and waterproofing properties, as well as moisture-proof effect, which can extend the service life of the mortar.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. Shellac-modified lightweight fibers, coated sodium borate, and binder work together to provide good moisture resistance to the mortar surface through the water-repellent properties of the fibers. Combined with the bottom water-locking effect of the binder and coated sand, this prevents mortar segregation and bleeding. Furthermore, the cross-linking effect between the shellac-modified lightweight fibers, coated sodium borate, binder, and coated sand further improves the internal density of the mortar, thereby enhancing the strength, durability, and service life of the cured mortar, and providing excellent moisture resistance and damp-proofing.

[0034] 2. The combination of hydrophobic seaweed fiber, polyimide fiber, casein, and shellac solution utilizes hydrated alkaline substances and sodium borate to facilitate the dissolution of shellac. After the shellac dissolves, the fibers are exposed. Taking advantage of the relatively lightweight nature of seaweed fiber and polyimide fiber, they can easily float on the surface of the mortar. The bonding effect between the fibers, combined with the bonding effect between the casein on the fiber surface and the gypsum, cement, and binder, facilitates the formation of a sealed fiber network on the mortar surface. This not only blocks moisture but also improves the strength of the cured mortar, makes the surface of the cured mortar smooth, and extends the service life of the mortar.

[0035] 3. The combination of polyetheretherketone powder, coated silicon carbide powder, and hydrophobic silica powder utilizes the low density of polyetheretherketone powder and hydrophobic silica powder to facilitate contact and bonding with lightweight fibers. The hydrophobic silica powder is also easy to fill the structural gaps between fibers, further enhancing the hydrophobic effect of the mortar surface. Silicon carbide powder has a higher density, and silicon carbide particles and sand can be easily dispersed in the middle and near the bottom of the mortar. The water-binding effect of the silicon carbide surface film layer helps to prevent water from being absorbed by the ground, thereby minimizing the problems of mortar segregation and bleeding. Detailed Implementation

[0036] The present application will be further described in detail below with reference to the embodiments.

[0037] Example of preparation of shellac-modified lightweight fiber

[0038] Preparation Example 1: Shellac-modified lightweight fiber was prepared by the following method:

[0039] 1 kg of seaweed fiber was weighed and soaked in 10 kg of methyl silicone oil. The length of the seaweed fiber was 35-40 μm. The mixture was stirred at 1000 r / min for 20 min, then filtered out and dried to obtain modified seaweed fiber. 0.2 kg of sodium alginate solution was uniformly sprayed onto the surface of 1 kg of modified seaweed fiber to obtain hydrophobic seaweed fiber.

[0040] Weigh 0.2 kg of sodium alginate solution and spray it evenly onto the surface of 1 kg of polyimide fiber filaments. The length of the polyimide fiber filaments is 30-35 μm, and polyimide fiber is obtained.

[0041] 0.2 kg of casein was uniformly sprayed onto the surface of 1 kg of hydrophobic seaweed fiber. The average particle size of the casein was 10-12 μm. 0.1 kg of casein was uniformly sprayed onto the surface of 0.8 kg of polyimide fiber. After drying and dispersion, lightweight fibers were obtained.

[0042] 0.25 kg of shellac solution was uniformly sprayed onto the surface of 1 kg of lightweight fiber. The shellac solution was prepared by completely dissolving shellac in anhydrous ethanol with a mass fraction of 2%. After drying and dispersion, the finished shellac-modified lightweight fiber was obtained.

[0043] Preparation Example 2: The difference between this preparation example and Preparation Example 1 is that:

[0044] 1 kg of seaweed fiber was weighed and soaked in 10 kg of methyl silicone oil. The length of the seaweed fiber was 35-40 μm. The mixture was stirred at 1000 r / min for 20 min, then filtered out and dried to obtain modified seaweed fiber. 0.2 kg of sodium alginate solution was uniformly sprayed onto the surface of 1 kg of modified seaweed fiber to obtain hydrophobic seaweed fiber.

[0045] Weigh 0.1 kg of sodium alginate solution and spray it evenly onto the surface of 1 kg of polyimide fiber filaments. The length of the polyimide fiber filaments is 30-35 μm, and polyimide fiber is obtained.

[0046] 0.05 kg of casein was uniformly sprayed onto the surface of 1 kg of hydrophobic seaweed fiber. The average particle size of the casein was 10-12 μm. 0.05 kg of casein was also uniformly sprayed onto the surface of 1 kg of polyimide fiber. After drying and dispersion, lightweight fiber was obtained.

[0047] 0.2 kg of shellac solution was uniformly sprayed onto the surface of 1 kg of lightweight fiber. The shellac solution was prepared by completely dissolving shellac in anhydrous ethanol with a mass fraction of 2%. After drying and dispersion, the finished shellac-modified lightweight fiber was obtained.

[0048] Preparation Example 3: The difference between this preparation example and Preparation Example 1 is that:

[0049] 1 kg of seaweed fiber was weighed and soaked in 10 kg of methyl silicone oil. The length of the seaweed fiber was 35-40 μm. The mixture was stirred at 1000 r / min for 20 min, then filtered out and dried to obtain modified seaweed fiber. 0.2 kg of sodium alginate solution was uniformly sprayed onto the surface of 1 kg of modified seaweed fiber to obtain hydrophobic seaweed fiber.

[0050] Weigh 0.3 kg of sodium alginate solution and spray it evenly onto the surface of 1 kg of polyimide fiber filaments. The length of the polyimide fiber filaments is 30-35 μm, and polyimide fiber is obtained.

[0051] 0.2 kg of casein was uniformly sprayed onto the surface of 1 kg of hydrophobic seaweed fiber. The average particle size of the casein was 10-12 μm. 0.2 kg of casein was also uniformly sprayed onto the surface of 1 kg of polyimide fiber. After drying and dispersion, lightweight fiber was obtained.

[0052] 0.32 kg of shellac solution was uniformly sprayed onto the surface of 1 kg of lightweight fiber. The shellac solution was prepared by completely dissolving shellac in anhydrous ethanol with a mass fraction of 2%. After drying and dispersion, the finished shellac-modified lightweight fiber was obtained.

[0053] Preparation example of coated sodium borate

[0054] Preparation Example 4: Coated sodium borate was prepared by the following method:

[0055] 0.25 kg of sodium polyacrylate solution was weighed and evenly sprayed onto the surface of 1 kg of sodium borate. The sodium polyacrylate solution had a mass fraction of 1%, and the solvent was a 5% sodium hydroxide aqueous solution. The sodium borate particles had a particle size of 3-5 μm. After drying and dispersion, coated sodium borate was obtained.

[0056] Preparation Example 5: The difference between this preparation example and Preparation Example 4 is that:

[0057] Weigh 0.1 kg of sodium polyacrylate solution and spray it evenly onto the surface of 1 kg of sodium borate. After drying and dispersion, coated sodium borate is obtained.

[0058] Preparation Example 6: The difference between this preparation example and Preparation Example 4 is that:

[0059] Example of preparing coated sodium borate binder: 0.38 kg of sodium polyacrylate solution was weighed and uniformly sprayed onto the surface of 1 kg of sodium borate. After drying and dispersion, the filler was prepared.

[0060] Preparation Example 7: The connecting packing was prepared by the following method:

[0061] 0.36 kg of polyvinyl alcohol solution was uniformly sprayed onto the surface of 1 kg of polyetheretherketone (PEEK) microparticles, followed by uniform spraying of 0.25 kg of chitin powder. After drying and dispersion, the finished PEEK powder was obtained. The average particle size of the PEEK microparticles was 20-22 μm, the polyvinyl alcohol solution was a 5% (w / w) aqueous solution of polyvinyl alcohol, and the average particle size of the chitin powder was 8-10 μm.

[0062] 0.25 kg of polyvinyl alcohol solution was uniformly sprayed onto the surface of 1 kg of silicon carbide powder, and then dried and dispersed to obtain the finished silicon carbide powder; the particle size of the silicon carbide powder was 70-80 μm, and the polyvinyl alcohol solution was a 5% (w / w) aqueous solution of polyvinyl alcohol.

[0063] Weigh 1 kg of silica powder and place it in 10 kg of methyl silicone oil to disperse and soak for 10 min. Stir at 1000 r / min, filter out the silica powder, and then dry and break it up to obtain hydrophobic silica powder.

[0064] Weigh 1 kg of polyetheretherketone powder, 1.5 kg of silicon carbide powder, and 0.7 kg of hydrophobic silica powder, mix and stir evenly to obtain the connecting filler.

[0065] Preparation Example 8: The difference between this preparation example and Preparation Example 7 is that:

[0066] 0.2 kg of polyvinyl alcohol solution was uniformly sprayed onto the surface of 1 kg of polyetheretherketone (PEEK) microparticles, followed by uniform spraying of 0.1 kg of chitin powder. After drying and dispersion, the finished PEEK powder was obtained.

[0067] 0.1 kg of polyvinyl alcohol solution was uniformly sprayed onto the surface of 1 kg of silicon carbide powder, and then dried and dispersed to obtain the finished silicon carbide powder.

[0068] Weigh 1 kg of polyetheretherketone powder, 1 kg of silicon carbide powder, and 0.5 kg of hydrophobic silica powder, mix and stir evenly to obtain the connecting filler.

[0069] Preparation Example 9: The difference between this preparation example and Preparation Example 7 is that:

[0070] 0.5 kg of polyvinyl alcohol solution was uniformly sprayed onto the surface of 1 kg of polyetheretherketone (PEEK) microparticles, followed by uniform spraying of 0.32 kg of chitin powder. After drying and dispersion, the finished PEEK powder was obtained.

[0071] 0.38 kg of polyvinyl alcohol solution was uniformly sprayed onto the surface of 1 kg of silicon carbide powder, and then dried and dispersed to obtain the finished silicon carbide powder.

[0072] Weigh 1 kg of polyetheretherketone powder, 2 kg of silicon carbide powder, and 1 kg of hydrophobic silica powder, mix and stir evenly to obtain the connecting filler.

[0073] Preparation example of coated sand

[0074] Preparation Example 10: Coated sand was prepared by the following method:

[0075] 5 kg of flaxseed gum solution was uniformly sprayed onto the surface of 100 kg of river sand. The average particle size of the river sand was 0.2-0.5 mm. The flaxseed gum solution was a 1% (w / w) aqueous solution of flaxseed gum at a water temperature of 60 °C. After drying and dispersion, the flaxseed gum solution formed a film, thus producing coated sand.

[0076] Preparation Example 11: The difference between this preparation example and Preparation Example 10 is that:

[0077] 2 kg of flaxseed gum solution was evenly sprayed onto the surface of 100 kg of river sand, and then dried and dispersed to obtain the finished product.

[0078] Preparation Example 12: The difference between this preparation example and Preparation Example 10 is that:

[0079] 7 kg of flaxseed gum solution was evenly sprayed onto the surface of 100 kg of river sand, and then dried and dispersed to obtain the finished product.

[0080] Example

[0081] Example 1: A gypsum-based self-leveling mortar:

[0082] The following ingredients were selected: 400 kg gypsum, 40 kg cement, 60 kg coated sand, 0.7 kg defoamer, 1.6 kg water-reducing agent, 10 kg shellac-modified lightweight fiber, 2 kg coated sodium borate, and 20 kg connecting filler. The gypsum was desulfurized gypsum; the cement was P.O42.5 silicate cement; the coated sand was the coated sand prepared in Preparation Example 10; the defoamer was an organosilicon defoamer; the water-reducing agent was a polycarboxylate high-efficiency water-reducing agent; the shellac-modified lightweight fiber was the shellac-modified lightweight fiber prepared in Preparation Example 1; the coated sodium borate was the coated sodium borate prepared in Preparation Example 4; and the connecting filler was the connecting filler prepared in Preparation Example 7.

[0083] The preparation method is as follows:

[0084] S1. Weigh out gypsum, cement and sand, mix and stir evenly to obtain the initial mixture;

[0085] S2. Add shellac-modified lightweight fiber, coated sodium borate, and binder to the initial mixture and mix evenly to obtain the mixture; S3. Add defoamer and water-reducing agent to the mixture and mix evenly to obtain the finished mortar.

[0086] Example 2: The difference between this example and Example 1 is that:

[0087] 300 kg of gypsum, 30 kg of cement, 30 kg of coating sand, 0.2 kg of defoamer, 1 kg of water-reducing agent, 5 kg of shellac-modified lightweight fiber, 1 kg of coated sodium borate, and 15 kg of connecting filler; the coating sand is the coating sand prepared in Preparation Example 11; the shellac-modified lightweight fiber is the shellac-modified lightweight fiber prepared in Preparation Example 2; the coated sodium borate is the coated sodium borate prepared in Preparation Example 5; and the connecting filler is the connecting filler prepared in Preparation Example 8.

[0088] Example 3: The difference between this example and Example 1 is that:

[0089] 500 kg of gypsum, 50 kg of cement, 80 kg of coating sand, 1 kg of defoamer, 2 kg of water-reducing agent, 15 kg of shellac-modified lightweight fiber, 3 kg of coated sodium borate, and 25 kg of connecting filler; the coating sand is the coating sand prepared in Preparation Example 12; the shellac-modified lightweight fiber is the shellac-modified lightweight fiber prepared in Preparation Example 3; the coated sodium borate is the coated sodium borate prepared in Preparation Example 6; and the connecting filler is the connecting filler prepared in Preparation Example 9.

[0090] Example 4: The difference between this example and Example 1 is that:

[0091] In the preparation of shellac-modified lightweight fiber, hydrophobic seaweed fiber and polyimide fiber are replaced with seaweed fiber of equal mass.

[0092] Example 5: The difference between this example and Example 1 is that:

[0093] No sodium alginate solution was added during the preparation of the hydrophobic seaweed fiber, and no sodium alginate solution was added to the surface of the polyimide fiber filaments.

[0094] Example 6: The difference between this example and Example 1 is that:

[0095] In the preparation of the connecting filler, silicon carbide powder is used to replace polyetheretherketone powder and hydrophobic silica powder of equal mass in the raw materials.

[0096] Example 7: The difference between this example and Example 1 is that:

[0097] The filler is made by replacing polyetheretherketone powder with polyetheretherketone microparticles of equal mass, meaning that the polyetheretherketone powder surface is not loaded with polyvinyl alcohol solution and chitin powder.

[0098] Example 8: The difference between this example and Example 1 is that:

[0099] The bonding filler material is made by replacing the coated silicon carbide powder with an equal mass of silicon carbide powder, meaning that the surface of the silicon carbide powder is not loaded with polyvinyl alcohol solution.

[0100] Comparative Example

[0101] Comparative Example 1: The difference between this comparative example and Example 1 is that:

[0102] In the raw materials, shellac-modified lightweight fibers are replaced with shellac-modified silica fibers of equal mass, that is, lightweight fibers are replaced with silica fibers of equal mass.

[0103] Comparative Example 2: This comparative example differs from Example 1 in that:

[0104] Shellac-modified lightweight fibers were replaced with lightweight fibers of equal weight in the raw materials.

[0105] Comparative Example 3: The difference between this comparative example and Example 1 is that:

[0106] The coating sodium borate is replaced with an equal mass of sodium borate in the raw materials.

[0107] Comparative Example 4: This comparative example differs from Example 1 in that:

[0108] Shellac-modified lightweight fibers, coated sodium borate, and binding fillers were not added to the raw materials.

[0109] Performance testing

[0110] 1. Mechanical strength testing

[0111] Finished mortars were prepared using the preparation methods of Examples 1-8 and Comparative Examples 1-4, respectively. Referring to JC / T1023-2021 Gypsum-based Self-leveling Mortar, the 28-day oven-dry compressive strength of Examples 1-8 and Comparative Example 1, the impact resistance of Examples 1-3 and Comparative Example 4, and the 28-day oven-dried tensile bond strength of Examples 1-8 and Comparative Example 4 were tested and the data were recorded.

[0112] 2. Moisture resistance test

[0113] Finished mortars were prepared using the methods described in Examples 1-8 and Comparative Examples 1-4, respectively, and poured into a 1m... 2 On a simulated ground surface, after curing for 28 days, it was placed under conditions of 85% relative humidity for 3 days, and then the compressive strength was tested again and the data was recorded.

[0114] Note: In the following data, " / " indicates that the corresponding embodiment did not detect the item, so there is no data.

[0115] Table 1 Performance Test Table

[0116]

[0117] As can be seen from Examples 1-3 and Table 1, the mortar prepared in this application has high compressive strength, and the compressive strength remains high after wet treatment. It does not crack upon impact and has high tensile bond strength after drying, indicating that the mortar has the advantages of high strength, good moisture resistance, and stable bonding.

[0118] Combining Examples 1 and 4-8 with Table 1, it can be seen that in the preparation of shellac-modified lightweight fiber in Example 4, when the same mass of seaweed fiber was used to replace hydrophobic seaweed fiber and polyimide fiber, the compressive strength of the mortar prepared in Example 4 was lower than that in Example 1, the compressive strength loss after wet treatment was higher than that in Example 1, and the drying tensile bond strength was lower than that in Example 1. This indicates that seaweed fiber is hydrophilic and easily affects the waterproofness of the mortar, while the water-absorbing mortar has its internal structure destroyed, which affects the strength and bonding stability of the mortar.

[0119] In Example 5, no sodium alginate solution was added during the preparation of the hydrophobic seaweed fiber, nor was sodium alginate solution added to the surface of the polyimide fiber. Compared with Example 1, the compressive strength of the mortar prepared in Example 5 was lower than that in Example 1, the compressive strength loss after wet treatment was higher than that in Example 1, and the tensile bond strength after drying was lower than that in Example 1. This indicates that the addition of sodium alginate solution can improve the bonding effect between lightweight fibers and other raw materials, thereby increasing the internal structure density of the mortar and giving the hydrated mortar higher compressive strength and a longer service life.

[0120] In Example 6, during the preparation of the filler, the polyether ether ketone powder and hydrophobic silica powder were replaced with the same mass of silicon carbide powder in the raw materials. Compared with Example 1, the loss value of the mortar prepared in Example 6 after wet treatment was greater than that in Example 1, and the tensile bond strength was lower than that in Example 1. This indicates that because silicon carbide has a high density, it is not easy to disperse and adhere on the surface of the hydrated mortar, but tends to appear near the bottom, thus affecting the waterproof and moisture-proof properties of the hydrated mortar.

[0121] In Example 7, the polyetheretherketone (PEEK) powder was replaced with an equal mass of PEEK microparticles in the filler, meaning that the PEEK powder surface was not loaded with polyvinyl alcohol solution and chitin powder. Compared to Example 1, the mortar prepared in Example 7 had a lower compressive strength than that in Example 1, a higher compressive strength loss after wet treatment than that in Example 1, and a lower tensile bond strength after drying than that in Example 1. This indicates that the addition of polyvinyl alcohol solution and chitin powder can improve the cross-linking effect of the mortar's internal network, thereby improving the mechanical strength, moisture resistance, and durability of the hydrated mortar.

[0122] In Example 8, the coated silicon carbide powder was replaced with an equal mass of silicon carbide powder in the filler material, meaning that the silicon carbide powder surface was not loaded with polyvinyl alcohol solution. Compared with Example 1, the mortar prepared in Example 8 had a lower compressive strength than that in Example 1, a higher compressive strength loss after wet treatment than that in Example 1, and a lower tensile bond strength after drying than that in Example 1. This indicates that coating the silicon carbide powder surface can improve the bonding effect between the silicon carbide powder and other raw materials, thereby improving the strength and bonding stability of the hydrated mortar.

[0123] Combining Example 1 and Comparative Examples 1-4 with Table 1, it can be seen that in Comparative Example 1, the shellac-modified lightweight fiber was replaced with an equal mass of shellac-modified silica fiber, i.e., the lightweight fiber was replaced with an equal mass of silica fiber. Compared with Example 1, the compressive strength loss of the mortar prepared in Comparative Example 1 after wet treatment was greater than that in Example 1. This indicates that although silica fiber has high strength, its bonding effect with other raw materials in the mortar is limited, and its structural density is limited, which affects the moisture resistance and mechanical strength of the mortar.

[0124] In Comparative Example 2, the shellac-modified lightweight fibers were replaced with the same mass of lightweight fibers. Compared with Example 1, the compressive strength loss of the mortar prepared in Comparative Example 2 after wet treatment was greater than that in Example 1, indicating that the waterproof properties of shellac can improve the waterproof and moisture-proof effect of the hydrated mortar surface.

[0125] In Comparative Example 3, the same mass of sodium borate was used to replace the coated sodium borate. Compared with Example 1, the compressive strength loss of the mortar prepared in Comparative Example 3 after wet treatment was greater than that in Example 1. This indicates that the coating treatment of sodium borate can not only slowly dissolve shellac and ensure the self-leveling effect of the mortar, but also play a role in water retention, minimizing the problems of segregation, stratification, and bleeding in the mortar, thereby ensuring the strength and durability of the hydrated mortar.

[0126] Comparative Example 4 did not contain shellac-modified lightweight fibers, coated sodium borate, or binding fillers. Compared to Example 1, the mortar prepared in Comparative Example 4 had lower compressive strength, showed cracking upon impact, and lower tensile bond strength than Example 1. This indicates that the combination of shellac-modified lightweight fibers, coated sodium borate, and binding fillers can improve the strength and durability of the hydrated mortar.

[0127] 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 gypsum-based self-leveling mortar, characterized in that, The raw materials comprise the following parts by weight: 300-500 parts gypsum, 30-50 parts cement, 40-80 parts coated sand, 0.2-1 parts defoamer, 1-2 parts water-reducing agent, 5-15 parts shellac-modified lightweight fiber, 1-3 parts coated sodium borate, and 15-25 parts connecting filler; the connecting filler is composed of polyetheretherketone powder, coated silicon carbide powder, and hydrophobic silica powder in a mass ratio of 1:1-2:0.5-1; the polyetheretherketone powder is made of polyetheretherketone microparticles, polyvinyl alcohol solution, and chitin powder in a mass ratio of 1:0.2-0.5:0.1-0.

32. The preparation method of shellac-modified lightweight fiber is as follows: 1 kg of seaweed fiber was weighed and soaked in 10 kg of methyl silicone oil. The length of the seaweed fiber was 35-40 μm. The mixture was stirred at 1000 r / min for 20 min, then filtered out and dried to obtain modified seaweed fiber. 0.2 kg of sodium alginate solution was uniformly sprayed onto the surface of 1 kg of modified seaweed fiber to obtain hydrophobic seaweed fiber. Weigh 0.2 kg of sodium alginate solution and spray it evenly onto the surface of 1 kg of polyimide fiber filaments. The length of the polyimide fiber filaments is 30-35 μm, and polyimide fiber is obtained. 0.2 kg of casein was uniformly sprayed onto the surface of 1 kg of hydrophobic seaweed fiber. The average particle size of the casein was 10-12 μm. 0.1 kg of casein was uniformly sprayed onto the surface of 0.8 kg of polyimide fiber. After drying and dispersion, lightweight fibers were obtained. 0.25 kg of shellac solution was uniformly sprayed onto the surface of 1 kg of lightweight fiber. The shellac solution was prepared by completely dissolving shellac in anhydrous ethanol with a mass fraction of 2%. After drying and dispersion, the finished shellac-modified lightweight fiber was obtained.

2. The gypsum-based self-leveling mortar according to claim 1, characterized in that, The coated sodium borate is made from a solution of sodium borate and sodium polyacrylate in a mass ratio of 1:0.1-0.

38.

3. The gypsum-based self-leveling mortar according to claim 1, characterized in that, The coated silicon carbide powder is prepared by mixing silicon carbide powder and polyvinyl alcohol solution in a mass ratio of 1:0.1-0.

38.

4. The gypsum-based self-leveling mortar according to claim 1, characterized in that, The coating sand is made from river sand and flaxseed gum solution in a mass ratio of 1:0.02-0.

07.

5. A method for preparing a gypsum-based self-leveling mortar according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Weigh out gypsum, cement and coating sand, mix and stir evenly to obtain the initial mixture; S2. Add shellac-modified lightweight fiber, coated sodium borate, and connecting filler to the initial mixture, mix evenly, and obtain the mixture. S3. Add the defoamer and water-reducing agent to the mixture and stir evenly to obtain the finished mortar.

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