A starch-based flow-promoting and enhancing binder for thin-layer repair mortar, and its preparation method and application

Abstract

The present application relates to the technical field of mortar adhesives, and specifically discloses a starch-based flow-promoting and enhancing adhesive for thin-layer repair mortar, and its preparation method and application. The adhesive includes the following parts by weight of raw starch hydrolyzate 200-400 parts, maleic anhydride 120-220 parts, dispersant 30-38 parts, catalyst 2-5 parts, water 140-180 parts, polyoxyethylene ether macromonomer 100-300 parts, sodium hypophosphite 5-11 parts, initiator 3-3.8 parts, A liquid 146-234 parts, B liquid 35-55 parts; the preparation method is molten starch hydrolyzate, maleic anhydride reaction, dispersant and catalyst, reaction under vacuum, water mixing, cooling; polyoxyethylene ether macromonomer, sodium hypophosphite, initiator, A liquid and B liquid are added dropwise, heat preservation, and drying to obtain an adhesive. The adhesive of the present application has the advantage of improving strength through the synergistic effect between the raw materials.

Description

Technical Field

[0001] The present application relates to the technical field of mortar binders, and in particular to a starch-based flow-promoting and enhancing binder for thin-layer repair mortar, and a preparation method and application thereof. Background Art

[0002] With the continuous advancement of modern polymer synthesis technology, polymer synthesis technology has also begun to be applied to traditional building materials, and a new bonding system has been developed based on this technology, namely "thin layer technology". Nowadays, in most industrialized countries, thin layer mortar technology has replaced the traditional thick layer mortar method and can achieve better repair effects.

[0003] Thin layer mortar is used to repair exposed stones, peeling and other damages on concrete pavements. The construction thickness of the thin layer repair mortar is 2-4mm. The main common problem is that the bonding strength with the base concrete pavement is poor, causing local hollowing, thus affecting the service life.

[0004] At present, most of the repair mortars are modified by adding polymers. Commonly used polymers are polymer emulsions and dispersible latex powders. However, polymer emulsions have the following disadvantages: 1. They have poor adaptability to repair mortars and are prone to demulsification, especially when there are alkali activators in the mortar, which is more prominent, and the result is counterproductive; 2. They affect the early compressive strength of the mortar; 3. The emulsion is in liquid state, has poor high temperature resistance, unstable physical properties, and is accompanied by a pungent odor. It needs to be stored separately from the powdered mortar. During construction, it can only be added to water and then introduced into the system, which is cumbersome. Dispersible latex powder has the following disadvantages: 1. When the dosage is low, the bonding strength is limited and the hollowing phenomenon cannot be effectively eliminated. When the dosage is high, it will seriously affect the compressive strength of the mortar at all ages; 2. It is expensive. As a cheap thin-layer repair mortar, the cost of use is high. Therefore, there is an urgent need for a binder that can improve the strength of the mortar and the base concrete while avoiding the formation of hollows. Summary of the invention

[0005] In order to improve the strength between the mortar and the base concrete while avoiding the formation of hollows, the present application provides a starch-based flow-promoting and reinforcing adhesive for thin-layer repair mortar, and a preparation method and application thereof.

[0006] In the first aspect, the present application provides a starch-based flow-promoting and enhancing binder for thin-layer repair mortar, which adopts the following technical solution:

[0007] A starch-based flow-promoting and enhancing adhesive for thin-layer repair mortar comprises the following raw materials in parts by weight: 200-400 parts of starch hydrolyzate, 120-220 parts of maleic anhydride, 30-38 parts of dispersant, 2-5 parts of catalyst, 140-180 parts of water, 100-300 parts of polyoxyethylene ether macromonomer, 5-11 parts of sodium hypophosphite, 3-3.8 parts of initiator, 146-234 parts of liquid A, and 35-55 parts of liquid B.

[0008] By adopting the above technical scheme, the starch-based flow-promoting and enhancing adhesive of the present application can be directly added as a raw material in the mortar production process, without special requirements for the mortar production and use process, and through the synergistic effect of the raw materials, the compressive strength, flexural strength and tensile bonding strength of the mortar can be improved, and the problem of hollowing between the mortar and the base concrete is solved. Among them, the compressive strength at 6h is 18.5-19.6MPa, the compressive strength at 1d is 24.5-25.3MPa, the compressive strength at 3d is 33.5-34.5MPa, the compressive strength at 7d is 44.4-45.6MPa, and the compressive strength at 28d is 54.4-55.4MPa; the flexural strength at 6h is The flexural strength of the untreated samples was 4.0-4.8MPa, the tensile strength after immersion in water was 3.8-4.6MPa, the tensile strength after heat aging was 3.6-4.6MPa, and the tensile strength after 25 freeze-thaw cycles was 3.6-4.5MPa; the initial fluidity was 380-395mm, and the fluidity after 20min was 320-335mm; the cohesion was excellent and the flow rate was fast.

[0009] Starch hydrolysate is polyhydroxy starch, which has good water retention, making the mortar have better cohesiveness. Starch hydrolysate can undergo esterification reaction with maleic anhydride to generate unsaturated monocarboxyl ester of starch. Dispersant can make the raw materials disperse more evenly, and catalyst can catalyze the reaction. Polyoxyethylene ether macromonomer participates in the reaction, sodium hypophosphite has the effect of water reducer, so that the binder has a water reduction rate of 20%, has good adaptability with various admixtures, can reduce or even completely replace the water reducer component in the mortar, and can improve the quick-drying rate of the mortar and increase the strength. Liquid A and liquid B also participate in the reaction, so that the binder has a phosphate group, which can reduce the viscosity of the mortar and make the mortar have a better flow rate during construction. The binder contains carboxyl as an anchoring group, and the molecular structure of the binder can form a good spatial network structure, so that the mortar and the base concrete form excellent bonding, thereby avoiding the occurrence of hollowing phenomenon and improving the bonding strength.

[0010] Preferably, it comprises the following raw materials in parts by weight: 250-350 parts of starch hydrolyzate, 150-190 parts of maleic anhydride, 32-36 parts of dispersant, 3-4 parts of catalyst, 150-170 parts of water, 150-250 parts of polyoxyethylene ether macromonomer, 7-10 parts of sodium hypophosphite, 3.2-3.6 parts of initiator, 168-212 parts of liquid A, and 40-50 parts of liquid B.

[0011] By adopting the above technical scheme, the dosage of starch hydrolyzate, maleic anhydride, dispersant, catalyst, polyoxyethylene ether macromonomer, sodium hypophosphite, initiator, liquid A and liquid B is optimized, so that each raw material can play a better role, the strength of the adhesive can be improved, and the formation of hollows can be avoided.

[0012] Preferably, the liquid A is a mixture of water, organic acid and 2-hydroxyethyl methacrylate phosphate, and the weight ratio of water, organic acid and 2-hydroxyethyl methacrylate phosphate is (8-12): (6-10): (0.6-1.4).

[0013] Preferably, the organic acid substance is any one of acrylic acid, methacrylic acid, itaconic acid and sodium acrylate.

[0014] By adopting the above technical scheme, each raw material in liquid A contains carboxyl groups, and the organic acid substances are limited. After the raw materials in liquid A participate in the reaction, the binder can contain carboxyl groups, which serve as anchoring groups and enable the binder to form a good spatial network structure, so that the mortar and the base concrete form bonding force, thereby improving the bonding strength of the mortar and avoiding hollowing phenomenon.

[0015] Preferably, the liquid B is a mixture of acrylate and vinyl acetate, and the weight ratio of acrylate to vinyl acetate is (2-4):(5-7).

[0016] Preferably, the acrylic acid ester is any one of methyl methacrylate, methyl acrylate and ethyl acrylate.

[0017] By adopting the above technical scheme, acrylate and vinyl acetate in liquid B participate in the reaction, and the type of acrylate is limited. Acrylate can improve the bonding ability of the mortar, and vinyl acetate can improve the compressive strength and flexural strength of the mortar. The synergistic effect between the raw materials of liquid B can further help improve the bonding strength of the mortar.

[0018] Preferably, the starch hydrolyzate is any one of corn starch hydrolyzate and wheat starch hydrolyzate; the dispersant is sorbitol, the catalyst is citric acid, the polyoxyethylene ether macromonomer is any one of isopentenyl polyoxyethylene ether, methyl allyl polyoxyethylene ether, and ethylene glycol monovinyl polyoxyethylene ether, and the initiator is any one of ammonium persulfate, potassium persulfate, hydrogen peroxide, and vitamin C.

[0019] By adopting the above technical solution, the types of starch hydrolyzate, dispersant, catalyst, polyoxyethylene ether macromonomer and initiator are limited, so that each raw material can play a better role, thereby improving the bonding strength and avoiding the formation of hollows.

[0020] In a second aspect, the present application provides a method for preparing a starch-based flow-promoting and enhancing binder for thin-layer repair mortar, using the following technical solution:

[0021] A method for preparing a starch-based flow-promoting and enhancing binder for thin-layer repair mortar comprises the following steps:

[0022] S1: Melting the starch hydrolysate, adding maleic anhydride, reacting for a period of time, adding a dispersant and a catalyst, reacting for a period of time under vacuum conditions, cooling, adding water, mixing evenly, cooling again, and obtaining a mixture;

[0023] S2: Add polyoxyethylene ether macromonomer, sodium hypophosphite and initiator to the mixture, and simultaneously drop liquid A and liquid B, and heat-retain the mixture for reaction after the dropwise addition is completed to obtain a product, and then dry the mixture to obtain a starch-based flow-promoting and enhancing adhesive.

[0024] Furthermore, a method for preparing a starch-based flow-promoting and enhancing binder for thin-layer repair mortar comprises the following steps:

[0025] S1: The starch hydrolysate is melted in an oil bath at a temperature of 150-170°C, maleic anhydride is added in three batches, reacted for 50-70 minutes, a dispersant and a catalyst are added, and the reaction is carried out for 50-70 minutes under a vacuum degree of ≥-0.2MPa, the temperature is lowered to a temperature of 110-130°C, water is added, and stirring is performed while adding, and after uniform mixing, the temperature is lowered again to a temperature of 50-70°C to obtain a mixture;

[0026] S2: Add polyoxyethylene ether macromonomer, sodium hypophosphite and initiator to the mixture, and simultaneously drip liquid A and liquid B for 3 hours. After the dripping is completed, keep warm and react for 50-70 minutes to obtain the product. Spray-dry the product to obtain a starch-based flow-enhancing adhesive.

[0027] By adopting the above technical solution and using the above preparation method to prepare the adhesive, it is convenient for each raw material to play a better role, so that the prepared adhesive has better strength and can also avoid the formation of hollows.

[0028] In a third aspect, the present application provides an application of a starch-based flow-promoting and enhancing binder for thin-layer repair mortar, using the following technical solution:

[0029] The invention discloses an application of a starch-based flow-promoting and enhancing binder for thin-layer repair mortar, comprising the following steps: mixing cement, silica powder, aluminum sulfate cement, quartz sand, a water reducer, a defoamer and a binder evenly to obtain a repair mortar, adding water and mixing evenly, spreading the mortar on the road surface to be repaired, and covering the mortar with a film for maintenance after final setting.

[0030] Furthermore, an application of a starch-based flow-promoting and enhancing binder for thin-layer repair mortar includes the following steps: cement, silica powder, aluminum sulfate cement, 40-120 mesh quartz sand, polycarboxylic acid water-reducing agent, defoaming agent, and binder are evenly mixed to obtain repair mortar, water is added according to a water-to-material ratio of 0.13, stirred for 2-4 minutes, spread on the road surface to be repaired, smoothed, the thickness of the spread is 2-4 mm, and after it is finally set, covered with a film for maintenance.

[0031] By adopting the above technical solution, the binder is directly added to the raw materials of the repair mortar. Through the synergistic effect of the raw materials, the bonding strength between the mortar and the base concrete can be improved, avoiding the formation of hollows.

[0032] In summary, the present application includes at least one of the following beneficial technical effects:

[0033] 1. Since the polyhydroxy starch-based binder used in this application not only has good water retention properties, making the mortar have better cohesiveness, but also the prepared binder can form a good spatial network structure, so that the mortar and the base concrete form a better bonding force, thereby avoiding the hollowing phenomenon, and also improving the compressive strength and flexural strength of the mortar, which can make the compressive strength of 6h reach 19.6MPa, the compressive strength of 1d reach 25.3MPa, the compressive strength of 3d reach 34.5MPa, the compressive strength of 7d reach 45.6MPa, and the compressive strength of 28d reach 55.4MPa; The flexural strength reaches 5.7MPa after 6h, 8.2MPa after 1d, 11.9MPa after 3d, 13.3MPa after 7d and 14.4MPa after 28d; the untreated tensile bond strength reaches 4.8MPa, the tensile bond strength after immersion in water reaches 4.6MPa, the tensile bond strength after heat aging reaches 4.6MPa, and the tensile bond strength after 25 freeze-thaw cycles reaches 4.5MPa; the initial fluidity reaches 395mm, and the fluidity reaches 335mm after 20min; it has excellent cohesiveness and fast flow rate.

[0034] 2. In the present application, it is preferred that liquid A and liquid B are simultaneously added dropwise to the raw materials of the binder to participate in the reaction to generate products containing carboxyl groups, which can serve as anchoring groups, so that a good spatial network structure is formed between the molecular structures of the mortar, thereby improving the bonding force between the mortar and the base concrete, and also improving the bonding strength of the mortar, avoiding the hollowing phenomenon. DETAILED DESCRIPTION

[0035] The present application is further described in detail below in conjunction with the specific contents.

[0036] raw material

[0037] The starch hydrolysate is corn starch hydrolysate; the dispersant is sorbitol; the catalyst is citric acid; the polyoxyethylene ether macromonomer is isopentyl polyoxyethylene ether; the initiator is ammonium persulfate; the organic acid substance is acrylic acid; the acrylate is methyl methacrylate, and the quartz sand is 80 mesh.

[0038] Example

[0039] Example 1

[0040] A starch-based flow-promoting and reinforcing adhesive for thin-layer repair mortar, the raw material ratio of which is shown in Figure 1.

[0041] A method for preparing a starch-based flow-promoting and enhancing binder for thin-layer repair mortar comprises the following steps:

[0042] S1: The starch hydrolysate is melted in an oil bath at 160°C, maleic anhydride is added in three batches, reacted for 60 minutes, a dispersant and a catalyst are added, and the reaction is carried out for 60 minutes under a vacuum degree of ≥-0.2MPa, the temperature is lowered to 120°C, water is added, and water is stirred while adding, and after mixing evenly, the temperature is lowered again to 60°C to obtain a mixture;

[0043] S2: Add polyoxyethylene ether macromonomer, sodium hypophosphite and initiator to the mixture, and simultaneously drip liquid A and liquid B for 3 hours. After the dripping is completed, keep the temperature for reaction for 60 minutes to obtain the product. Spray-dry the product to obtain a starch-based flow-enhancing adhesive.

[0044] Embodiment 2-5

[0045] A starch-based flow-promoting and enhancing adhesive for thin-layer repair mortar, which differs from Example 1 in that the raw material ratio of the adhesive is different. The raw material ratio is shown in Table 1.

[0046] Table 1 Amount of each raw material in the binder of Examples 1-5 (unit: g)

[0047]

[0048]

[0049] Embodiment 6-9

[0050] A starch-based flow-promoting and enhancing adhesive for thin-layer repair mortar, which differs from Example 3 in that the raw material ratio of the adhesive is different. The raw material ratio is shown in Table 2.

[0051] Table 2 Amount of each raw material in the binder of Examples 6-9 (unit: g)

[0052]

[0053] Comparative Example

[0054] Comparative Example 1

[0055] A binder for thin-layer repair mortar, which differs from Example 1 in that the binder is replaced by styrene-butadiene emulsion in equal amounts.

[0056] Comparative Example 2

[0057] A binder for thin-layer repair mortar, which differs from Example 1 in that the binder is replaced by dispersible latex powder in equal amounts.

[0058] Application Examples

[0059] Application Example 1

[0060] An application of a starch-based flow-promoting and enhancing binder for thin-layer repair mortar comprises the following steps:

[0061] Cement, silica powder, aluminum sulfate cement, 80-mesh quartz sand, polycarboxylic acid water-reducing agent, defoaming agent, and the binder prepared in Example 1 were evenly mixed to obtain repair mortar, water was added according to a water-to-material ratio of 0.13, stirred for 3 minutes, spread on the road surface to be repaired, smoothed, with a paving thickness of 3 mm, and covered with a film for maintenance after final setting.

[0062] Application Example 2-9

[0063] The difference between Application Example 2-9 and Application Example 1 is that the binder in Application Example 2-9 is selected from Examples 2-9, respectively.

[0064] Application Comparative Example 1-2

[0065] The difference between Application Comparative Examples 1-2 and Application Example 1 is that the binders in Application Comparative Examples 1-2 are selected from Comparative Examples 1-2, respectively.

[0066] Performance testing

[0067] The following performance tests were performed on the mortars in the corresponding examples 1-9 and the comparative examples 1-2:

[0068] Compressive strength and flexural strength: The compressive strength and flexural strength of the mortar were measured in accordance with JC / T2381-2016 "Repair Mortar". The test results are shown in Table 3.

[0069] Tensile bond strength, fluidity, cohesion, and flow rate: The tensile bond strength, fluidity, cohesion, and flow rate of the mortar were measured in accordance with JC / T2381-2016 "Repair Mortar". The test results are shown in Table 4.

[0070] Table 3 Test results

[0071]

[0072]

[0073] Table 4 Test results

[0074]

[0075]

[0076] Combining Table 3 and Table 4, it can be seen that the binder of the present application improves the compressive strength, flexural strength and tensile bond strength of the mortar through the synergistic effect of the raw materials, and also has excellent fluidity, cohesion and flow rate; among them, the compressive strength of 6h is 18.5-19.6MPa, the compressive strength of 1d is 24.5-25.3MPa, the compressive strength of 3d is 33.5-34.5MPa, the compressive strength of 7d is 44.4-45.6MPa, and the compressive strength of 28d is 54.4-55.4MPa; the flexural strength of 6h is 5.2-5.7MPa, the flexural strength of 1d is 8.0 -8.2MPa, the flexural strength at 3d is 11.3-11.9MPa, the flexural strength at 7d is 12.8-13.3MPa, and the flexural strength at 28d is 14.0-14.4MPa; the untreated tensile bond strength is 4.0-4.8MPa, the tensile bond strength after immersion in water is 3.8-4.6MPa, the tensile bond strength after heat aging is 3.6-4.6MPa, and the tensile bond strength after 25 freeze-thaw cycles is 3.6-4.5MPa; the initial fluidity is 380-395mm, and the fluidity at 20min is 320-335mm; the cohesion is excellent and the flow rate is fast.

[0077] Combining Application Example 1 and Application Comparative Examples 1-2, it can be seen that the compressive strength of the mortar in Application Example 1 is 18.5 MPa at 6h, 24.5 MPa at 1d, 33.5 MPa at 3d, 44.4 MPa at 7d, and 54.4 MPa at 28d; the flexural strength is 5.2 MPa at 6h, 8.0 MPa at 1d, 11.3 MPa at 3d, 12.8 MPa at 7d, and 54.4 MPa at 28d. The untreated tensile bond strength is 4.0 MPa, the tensile bond strength after immersion in water is 3.8 MPa, the tensile bond strength after heat aging is 3.6 MPa, and the tensile bond strength after 25 freeze-thaw cycles is 3.6 MPa; the initial fluidity is 380 mm, and the 20 min fluidity is 320 mm; the cohesiveness is excellent and the flow rate is fast, which is better than the application comparison examples 1-2, indicating that the adhesive performance of the present application is better, can avoid the formation of hollows, and also improves the compressive strength, flexural strength and tensile bond strength of the mortar.

[0078] Combining application examples 1-5, it can be seen that the compressive strength of the mortar in application example 3 is 19.1MPa at 6h, 24.8MPa at 1d, 34.0MPa at 3d, 45.1MPa at 7d, and 54.9MPa at 28d; the flexural strength is 5.3MPa at 6h, 8.1MPa at 1d, 11.5MPa at 3d, 13.0MPa at 7d, and 14.9MPa at 28d. 1MPa; the untreated tensile bond strength is 4.3MPa, the tensile bond strength after immersion in water is 4.1MPa, the tensile bond strength after heat aging is 4.1MPa, and the tensile bond strength after 25 freeze-thaw cycles is 3.9MPa; the initial fluidity is 385mm, and the 20min fluidity is 325mm; the cohesiveness is excellent and the flow rate is fast, which is better than other application examples, indicating that the proportion of each raw material in Application Example 3 is more suitable, which can avoid the formation of hollows, and also improves the compressive strength, flexural strength and tensile bond strength of the mortar.

[0079] Combined with application examples 6-9, it can be seen that the compressive strength of the mortar in application example 7 is 19.6MPa at 6h, 25.3MPa at 1d, 34.5MPa at 3d, 45.6MPa at 7d, and 55.4MPa at 28d; the flexural strength is 5.7MPa at 6h, 8.2MPa at 1d, 11.9MPa at 3d, 13.3MPa at 7d, and 14. 4MPa; the untreated tensile bond strength is 4.8MPa, the tensile bond strength after immersion in water is 4.6MPa, the tensile bond strength after heat aging is 4.6MPa, and the tensile bond strength after 25 freeze-thaw cycles is 4.5MPa; the initial fluidity is 395mm, and the 20min fluidity is 335mm; the cohesiveness is excellent and the flow rate is fast, which is better than other application examples, indicating that the proportion of each raw material in Application Example 7 is more suitable, which can avoid the formation of hollows, and also improves the compressive strength, flexural strength and tensile bond strength of the mortar.

[0080] The above-mentioned specific implementation examples are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A starch-based flow-promoting and enhancing binder for thin-layer repair mortar, characterized in that: The method comprises the following raw materials in parts by weight: 200-400 parts of starch hydrolysate, 120-220 parts of maleic anhydride, 30-38 parts of dispersant, 2-5 parts of catalyst, 140-180 parts of water, 100-300 parts of polyoxyethylene ether macromonomer, 5-11 parts of sodium hypophosphite, 3-3.8 parts of initiator, 146-234 parts of liquid A, and 35-55 parts of liquid B; The liquid A is a mixture of water, organic acid substances, and 2-hydroxyethyl methacrylate phosphate, and the weight ratio of water, organic acid substances, and 2-hydroxyethyl methacrylate phosphate is (8-12): (6-10): (0.6-1.4); The liquid B is a mixture of acrylate and vinyl acetate, and the weight ratio of acrylate to vinyl acetate is (2-4): (5-7).

2. The starch-based flow-promoting and enhancing binder for thin-layer repair mortar according to claim 1, characterized in that: The method comprises the following raw materials in parts by weight: 250-350 parts of starch hydrolysate, 150-190 parts of maleic anhydride, 32-36 parts of dispersant, 3-4 parts of catalyst, 150-170 parts of water, 150-250 parts of polyoxyethylene ether macromonomer, 7-10 parts of sodium hypophosphite, 3.2-3.6 parts of initiator, 168-212 parts of liquid A and 40-50 parts of liquid B.

3. The starch-based flow-promoting and enhancing binder for thin-layer repair mortar according to claim 1, characterized in that: The organic acid substance is any one of acrylic acid, methacrylic acid, itaconic acid and sodium acrylate.

4. The starch-based flow-promoting and enhancing binder for thin-layer repair mortar according to claim 1, characterized in that: The acrylic acid ester is any one of methyl methacrylate, methyl acrylate and ethyl acrylate.

5. The starch-based flow-promoting and enhancing binder for thin-layer repair mortar according to claim 1, characterized in that: The starch hydrolyzate is any one of corn starch hydrolyzate and wheat starch hydrolyzate; the dispersant is sorbitol, the catalyst is citric acid, the polyoxyethylene ether macromonomer is any one of isopentenyl polyoxyethylene ether, methyl allyl polyoxyethylene ether, and ethylene glycol monovinyl polyoxyethylene ether, and the initiator is any one of ammonium persulfate, potassium persulfate, hydrogen peroxide, and vitamin C.

6. A method for preparing a starch-based flow-promoting and enhancing binder for thin-layer repair mortar according to any one of claims 1 to 5, characterized in that: The steps include: S1: Melting the starch hydrolysate, adding maleic anhydride, reacting for a period of time, adding a dispersant and a catalyst, reacting for a period of time under vacuum conditions, cooling, adding water, mixing evenly, cooling again, and obtaining a mixture; S2: Add polyoxyethylene ether macromonomer, sodium hypophosphite and initiator to the mixture, and simultaneously drop liquid A and liquid B, and heat-retain the mixture for reaction after the dropwise addition is completed to obtain a product, and then dry the mixture to obtain a starch-based flow-promoting and enhancing adhesive.

7. An application of a starch-based flow-promoting and enhancing binder for thin-layer repair mortar according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: mixing cement, silica powder, aluminum sulfate cement, quartz sand, a water reducing agent, a defoaming agent and a binder evenly to obtain a repair mortar; adding water and mixing evenly; spreading the mortar on the road surface to be repaired; and covering the mortar with a film for maintenance after final setting.

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