Additive capable of adjusting operable time of cement mortar, preparation method of additive, cement mortar and preparation method of cement mortar

Abstract

The invention belongs to the technical field of building materials, and particularly discloses an additive capable of adjusting the operable time of cement mortar, the additive comprises the following raw materials by weight: 50-60 parts of redispersible latex powder, 0-5 parts of heavy calcium powder, 1 part of an antifoaming agent, 0-1 part of a surfactant, and 0-1 part of a water reducer. According to the additive capable of adjusting the operable time of the cement mortar, the preparation method of the additive, the cement mortar and the preparation method of the cement mortar, the cement mortar additive gives consideration to operability and bonding performance, can be applied to various construction scenes when being applied to the cement mortar, meets market requirements and has high social value.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and in particular relates to an additive capable of adjusting the operable time of cement mortar and a preparation method thereof, cement mortar and a preparation method thereof. Background Art

[0002] As an indispensable basic material in the construction industry, cement mortar plays a key role in connecting structures, filling gaps and forming a protective layer. The length of time that cement mortar can be used directly affects construction efficiency, process control, and the stability and durability of the final building structure. Too short a working time may make it difficult for construction workers to complete delicate operations, affecting construction quality; while too long a working time may cause a decline in mortar performance, such as insufficient early strength development and easy cracking.

[0003] Traditionally, in order to adjust the workable time of cement mortar, the construction industry has widely used a variety of additives, such as early strength agents and retarders. Early strength agents accelerate the cement hydration reaction and shorten the time required for the mortar to reach the set strength, and are suitable for occasions that require rapid hardening. Retarders, on the other hand, extend the workable time of the mortar by delaying the cement hydration reaction, providing construction workers with a sufficient working window. However, while these additives adjust the setting time, they are often accompanied by negative effects on other key properties of the mortar. For example, early strength agents may sacrifice the long-term strength development of cement mortar or increase its shrinkage, while retarders may weaken the ultimate strength of the mortar or cause its crack resistance to decrease. In addition, when using cement mortar, in order to improve its water retention, a certain amount of cellulose ether is usually added, but due to the relatively high price of cellulose ether, the cost of use is correspondingly increased.

[0004] Invention patent CN116462474A discloses a method for producing concrete exterior wall insulation masonry. The specific material formula uses a polymer emulsion component, which is a redispersible latex powder of ethylene-vinyl acetate copolymer, which can improve the bonding performance of the masonry material. However, it cannot regulate the operable time of cement mortar. The production method mentions the use of phosphogypsum to adjust the setting time of the cementitious system. However, phosphogypsum has the disadvantages of low hardness, great construction difficulty, specific odor and color, and cannot be applied to a variety of construction scenarios. Summary of the invention

[0005] The purpose of the present invention is to overcome the above problems existing in the prior art and to provide an additive capable of adjusting the operability time of cement mortar and a preparation method thereof, cement mortar and a preparation method thereof. The cement mortar additive takes into account both operability and bonding properties. When applied to cement mortar, it can be applied to a variety of construction scenarios, meets market demand, and has high social value.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides an additive capable of adjusting the operable time of cement mortar, comprising the following raw materials in parts by weight: 50-60 parts of redispersible latex powder, 0-5 parts of heavy calcium powder, 1 part of defoaming agent, 0-1 part of surfactant, and 0-1 part of water reducing agent.

[0008] Furthermore, the redispersible latex powder is prepared by spray drying a dispersible raw material;

[0009] The dispersible raw materials include ethylene-vinyl acetate copolymer emulsion and protective colloid;

[0010] Furthermore, the protective colloid is polyvinyl alcohol.

[0011] Furthermore, the dispersible raw material also includes an anti-caking agent;

[0012] In the dispersible raw material, the mass percentage of the anti-caking agent is 20-25%.

[0013] Furthermore, the surfactant is one or more of fatty alcohol polyvinyl ether sodium sulfate and sodium gluconate mixed in any proportion;

[0014] The water reducing agent is any one or more of a polycarboxylic acid high performance water reducing agent and a melamine-based high efficiency water reducing agent mixed in any proportion.

[0015] In a second aspect, the present invention provides a method for preparing an additive that can adjust the operating time of cement mortar, the preparation method comprising the following steps: according to the raw material formula of the additive, weighing redispersible latex powder, heavy calcium powder, surfactant, defoamer and water reducer, mixing and stirring evenly to prepare the additive.

[0016] Furthermore, during the stirring process, the stirring time is 1-3 hours.

[0017] In a third aspect, the present invention provides a cement mortar comprising the following raw materials in parts by weight: 170 parts of cement, 260 parts of sand, 1-2 parts of cellulose ether, 110 parts of water, and 2-10 parts of additives;

[0018] The additive is an additive capable of adjusting the operable time of cement mortar provided in the embodiment of the first aspect of the present invention or an additive prepared by the method for preparing an additive capable of adjusting the operable time of cement mortar provided in the embodiment of the second aspect of the present invention.

[0019] Further, the cement is silicate cement;

[0020] The particle size of the sand is 40-140 meshes.

[0021] In a fourth aspect, the present invention provides a method for preparing cement mortar, the preparation method comprising the following steps:

[0022] S1. According to the formula, cement, sand, cellulose ether, water and additives are weighed, and the cement, sand, cellulose ether and additives are mixed and stirred uniformly to prepare a mixture;

[0023] S2. Add water to the mixture prepared in S1, stir and allow to stand for aging to obtain cement mortar.

[0024] Furthermore, in step S1, during the mixing and stirring process, the stirring time is 5-10 minutes;

[0025] In step S2, during the stirring and standing aging process, the stirring time is 2 minutes and the aging time is 5 minutes.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention provides an additive capable of adjusting the operability time of cement mortar and a preparation method thereof, cement mortar and a preparation method thereof. The cement mortar additive takes into account both operability and bonding performance. When applied to cement mortar, it can be applied to a variety of construction scenarios, meets market demand, and has high social value.

[0028] 2. In the present invention, redispersible latex powder is added to the raw material formula of the additive, and the redispersible latex powder is prepared by spray drying the dispersible raw materials. Specifically, the dispersible raw materials include ethylene-vinyl acetate copolymer emulsion and protective colloid, and the protective colloid adopts polyvinyl alcohol. The two are blended to achieve complementary performance, so that the additive is applied to cement mortar and has both excellent bonding performance and good stability; in addition, the excellent performance of the additive can also be applied to construction scenes with different materials, different construction conditions and different performance requirements; further, the additive has a low cost while meeting the product performance requirements; further, the redispersible latex powder prepared by blending ethylene-vinyl acetate copolymer emulsion and protective colloid and spray drying can further improve the environmental friendliness of the additive.

[0029] 3. In the present invention, the preparation method of the additive is simple and easy. The additive is applied to cement mortar. The preparation method of the cement mortar is also simple and easy, and is suitable for use in various construction scenarios.

[0030] 4. The additive provided in the present invention can increase the fluidity of cement mortar and prolong the setting time, thereby adjusting the operability time and improving operability.

[0031] 5. In the present invention, the additive is applied to cement mortar, and the redispersible latex powder in the additive can enhance the bonding strength between the cement mortar and the substrate, thereby preventing the water reducing agent or surfactant from causing a decrease in the bonding ability between the cement mortar and the substrate.

[0032] 6. In the present invention, since additives are added to the raw material composition of cement mortar, cellulose ether can be substituted to a certain extent, the amount of cellulose ether in the cement mortar formula can be reduced, and cement bleeding can still be prevented. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] The present embodiment provides an additive capable of adjusting the operable time of cement mortar. The raw material composition of the additive is as follows: 50 parts of redispersible latex powder, 5 parts of heavy calcium powder, 1 part of defoaming agent and 1 part of sodium fatty alcohol polyvinyl ether sulfate.

[0036] The present embodiment also provides a method for preparing an additive capable of adjusting the operating time of cement mortar, which is specifically as follows: according to the raw material formula of the additive, redispersible latex powder, heavy calcium powder, defoaming agent and sodium sulfate of fatty alcohol polyvinyl ether are weighed, added into a mixer and stirred for 2 hours to mix various materials evenly to prepare the additive.

[0037] This embodiment also provides a cement mortar, and the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 2 parts of cellulose ether, 110 parts of water, and 10 parts of additives.

[0038] This embodiment also provides a method for preparing cement mortar, which is as follows:

[0039] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether, water, and additives are weighed, and the cement, sand, cellulose ether, and additives are mixed and added to a mixer and stirred for 10 minutes to prepare a mixture;

[0040] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0041] Example 2

[0042] The present embodiment provides an additive capable of adjusting the operable time of cement mortar. The raw material composition of the additive is as follows: 60 parts of redispersible latex powder, 1 part of defoaming agent, and 1 part of sodium gluconate.

[0043] The present embodiment also provides a method for preparing an additive capable of adjusting the operating time of cement mortar, which is specifically as follows: according to the raw material formula of the additive, redispersible latex powder, defoaming agent and sodium gluconate are weighed, added into a mixer and stirred for 2 hours to mix various materials evenly to prepare the additive.

[0044] This embodiment also provides a cement mortar, and the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 2 parts of cellulose ether, 110 parts of water, and 10 parts of additives.

[0045] This embodiment also provides a method for preparing cement mortar, which is as follows:

[0046] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether, water, and additives are weighed, and the cement, sand, cellulose ether, and additives are mixed and added to a mixer and stirred for 10 minutes to prepare a mixture;

[0047] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0048] Example 3

[0049] The present embodiment provides an additive capable of adjusting the operable time of cement mortar. The raw material composition of the additive is as follows: 50 parts of redispersible latex powder, 3 parts of heavy calcium powder, 1 part of defoaming agent, and 1 part of polycarboxylic acid high-performance water reducing agent.

[0050] The present embodiment also provides a method for preparing an additive capable of adjusting the operating time of cement mortar, which is specifically as follows: according to the raw material formula of the additive, redispersible latex powder, heavy calcium powder, defoaming agent, and polycarboxylic acid high-performance water reducing agent are weighed, added into a mixer and stirred for 2 hours to mix various materials evenly to prepare the additive.

[0051] The present embodiment also provides a cement mortar, the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 1 part of cellulose ether, 110 parts of water, and 10 parts of additives.

[0052] This embodiment also provides a method for preparing cement mortar, which is as follows:

[0053] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether, water, and additives are weighed, and the cement, sand, cellulose ether, and additives are mixed and added to a mixer and stirred for 10 minutes to prepare a mixture;

[0054] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0055] Example 4

[0056] The present embodiment provides an additive capable of adjusting the operable time of cement mortar. The raw material composition of the additive is as follows: 55 parts of redispersible latex powder, 3 parts of heavy calcium powder, 1 part of defoaming agent, and 1 part of melamine-based water reducing agent.

[0057] The present embodiment also provides a method for preparing an additive capable of adjusting the operating time of cement mortar, which is specifically as follows: according to the raw material formula of the additive, redispersible latex powder, heavy calcium powder, defoaming agent and melamine-based water reducing agent are weighed, added into a mixer and stirred for 2 hours to mix various materials evenly to prepare the additive.

[0058] The present embodiment also provides a cement mortar, the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 1 part of cellulose ether, 110 parts of water, and 10 parts of additives.

[0059] This embodiment also provides a method for preparing cement mortar, which is as follows:

[0060] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether, water, and additives are weighed, and the cement, sand, cellulose ether, and additives are mixed and added to a mixer and stirred for 10 minutes to prepare a mixture;

[0061] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0062] Example 5

[0063] The present embodiment provides an additive capable of adjusting the operable time of cement mortar. The raw material composition of the additive is as follows: 55 parts of redispersible latex powder, 3 parts of heavy calcium powder, 1 part of defoaming agent, 0.5 parts of sodium fatty alcohol polyvinyl ether sulfate, and 0.5 parts of melamine-based water reducer.

[0064] The present embodiment also provides a method for preparing an additive capable of adjusting the operating time of cement mortar, which is specifically as follows: according to the raw material formula of the additive, redispersible latex powder, heavy calcium powder, defoaming agent, sodium fatty alcohol polyvinyl ether sulfate and melamine-based water reducer are weighed, added into a mixer and stirred for 2 hours to mix various materials evenly to prepare the additive.

[0065] This embodiment also provides a cement mortar, and the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 1.5 parts of cellulose ether, 110 parts of water, and 6 parts of additives.

[0066] This embodiment also provides a method for preparing cement mortar, which is as follows:

[0067] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether, water, and additives are weighed, and the cement, sand, cellulose ether, and additives are mixed and added to a mixer and stirred for 10 minutes to prepare a mixture;

[0068] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0069] Comparative Example 1

[0070] In this comparative example, the difference from Example 1 is that fatty alcohol polyvinyl ether sodium sulfate is not added to the raw material composition of the additive capable of adjusting the operable time of cement mortar, which is specifically as follows:

[0071] This comparative example provides an additive capable of adjusting the operable time of cement mortar. The raw material composition of the additive is as follows: 50 parts of redispersible latex powder, 5 parts of heavy calcium powder, and 1 part of defoaming agent.

[0072] This comparative example also provides a method for preparing an additive capable of adjusting the operating time of cement mortar, which is as follows: according to the raw material formula of the additive, redispersible latex powder, heavy calcium powder, and defoaming agent are weighed, added into a mixer and stirred for 2 hours to mix various materials evenly to prepare the additive.

[0073] This comparative example also provides a cement mortar, and the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 2 parts of cellulose ether, 110 parts of water, and 10 parts of additives.

[0074] This comparative example also provides a method for preparing cement mortar, which is as follows:

[0075] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether, water, and additives are weighed, and the cement, sand, cellulose ether, and additives are mixed and added to a mixer and stirred for 10 minutes to prepare a mixture;

[0076] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0077] Comparative Example 2

[0078] In this comparative example, the difference from Example 1 is that no redispersible latex powder is added to the raw material composition of the additive capable of adjusting the operable time of the cement mortar; and in the raw material composition of the cement mortar, the amount of the additive is replaced by 2 parts, as follows:

[0079] This comparative example provides an additive capable of adjusting the operable time of cement mortar. The raw material composition of the additive is as follows: 5 parts of heavy calcium powder, 1 part of defoaming agent and 1 part of sodium sulfate of fatty alcohol polyvinyl ether.

[0080] This comparative example also provides a method for preparing an additive capable of adjusting the operating time of cement mortar, which is specifically as follows: according to the raw material formula of the additive, heavy calcium powder, defoaming agent and sodium sulfate of fatty alcohol polyvinyl ether are weighed, added into a mixer and stirred for 2 hours to mix various materials evenly to prepare the additive.

[0081] This comparative example also provides a cement mortar, and the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 2 parts of cellulose ether, 110 parts of water, and 2 parts of additives.

[0082] This comparative example also provides a method for preparing cement mortar, which is as follows:

[0083] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether, water, and additives are weighed, and the cement, sand, cellulose ether, and additives are mixed and added to a mixer and stirred for 10 minutes to prepare a mixture;

[0084] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0085] Comparative Example 3

[0086] In this comparative example, the difference from Example 1 is that no additives are added to the raw material composition of the cement mortar, which is as follows:

[0087] This comparative example provides a cement mortar, and the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 2 parts of cellulose ether, and 110 parts of water.

[0088] This comparative example also provides a method for preparing cement mortar, which is as follows:

[0089] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether and water are weighed, the cement, sand and cellulose ether are mixed and added into a mixer and stirred for 10 minutes to prepare a mixture;

[0090] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0091] Comparative Example 4

[0092] This comparative example is different from Example 1 in that no additive is added to the raw material composition of the cement mortar, and the amount of cellulose ether is replaced by 5 parts, as follows:

[0093] This comparative example provides a cement mortar, and the raw material composition of the cement mortar is as follows: 170 parts of cement, 260 parts of sand, 5 parts of cellulose ether, and 110 parts of water.

[0094] This comparative example also provides a method for preparing cement mortar, which is as follows:

[0095] S1. According to the raw material composition of cement mortar, cement, sand, cellulose ether and water are weighed, the cement, sand and cellulose ether are mixed and added into a mixer and stirred for 10 minutes to prepare a mixture;

[0096] S2. Add water to the uniformly mixed mixture in S1, stir for 2 minutes and allow to stand for 5 minutes to prepare cement mortar.

[0097] The raw material composition of the additive capable of adjusting the operable time of cement mortar provided in Examples 1-4 and Comparative Examples 1-4 and the raw material composition of the cement mortar are shown in Table 1 and Table 2, respectively;

[0098] Table 1 Raw material composition of additives for adjusting the operable time of cement mortar in Examples 1-4 and Comparative Examples 1-4

[0099]

[0100]

[0101] Note: In Table 1, among the surfactants, A represents sodium fatty alcohol polyvinyl ether sulfate, and B represents sodium gluconate;

[0102] In the water reducing agent, C represents a polycarboxylic acid high-performance water reducing agent, and D represents a melamine-based high-efficiency water reducing agent;

[0103] Table 2 Raw material composition of cement mortar in Examples 1-4 and Comparative Examples 1-4

[0104] Group Cement / part Sand / part Cellulose ether / part Water / part Additives / portion Example 1 170 260 2 110 10 Example 2 170 260 2 110 10 Example 3 170 260 1 110 10 Example 4 170 260 1 110 10 Example 5 170 260 1.5 110 6 Example 6 170 260 - 110 2 Comparative Example 1 170 260 2 110 10 Comparative Example 2 170 260 2 110 2 Comparative Example 3 170 260 2 110 - Comparative Example 4 170 260 5 110 -

[0105] Performance Testing

[0106] The cement mortars prepared in Examples 1-4 and Comparative Examples 1-4 were subjected to performance tests, and the relevant test items were as follows:

[0107] Fluidity: Determined in accordance with GB / T 8077-2023 Test method for homogeneity of concrete admixtures;

[0108] Bond strength: measured in accordance with GB / T 29906-2013 Standard for materials of molded polystyrene board thin plastering exterior wall insulation system;

[0109] Bleeding water test;

[0110] The relevant test results are shown in Table 3 and Table 4;

[0111] Table 3

[0112]

[0113] Combining the fluidity data of Examples 1-5 and Comparative Example 1 in Table 1, it can be seen that additives containing surfactants or water reducing agents can improve the fluidity of cement mortar;

[0114] Combining the tensile bonding strengths of Examples 1-5 and Comparative Example 2 in Table 1, it can be seen that the additive containing redispersible latex powder can improve the bonding performance of cement mortar.

[0115] Combining the operable time of Examples 1-5 and Comparative Examples 1-2 in Table 1, it can be seen that the additive containing both a surfactant or a water reducer and a redispersible latex powder can reasonably adjust the operable time of the cement mortar within the range specified in GB / T29906-2013 Molded Polystyrene Board Thin Plastering External Wall External Insulation System Material Standard while maintaining good bonding performance.

[0116] Table 4

[0117] Test items Example 1 Comparative Example 3 Comparative Example 4 Is there water seepage? no yes no

[0118] Combining the experimental results of Example 1 and Comparative Examples 3-4 in Table 4, it can be seen that when the additive is used, the water retention of the mortar can be maintained under the condition of reducing the usage of cellulose ether in the mortar formula, and water bleeding can be prevented.

[0119] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0120] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. An additive capable of adjusting the workable time of cement mortar, characterized in that: The invention comprises the following raw materials in parts by weight: 50-60 parts of redispersible latex powder, 0-5 parts of heavy calcium powder, 1 part of defoaming agent, 0-1 part of surfactant and 0-1 part of water reducing agent.

2. The additive capable of adjusting the working time of cement mortar according to claim 1, characterized in that: The redispersible latex powder is prepared by spray drying a dispersible raw material; The dispersible raw materials include ethylene-vinyl acetate copolymer emulsion and protective colloid.

3. The additive capable of adjusting the working time of cement mortar according to claim 2, characterized in that: The dispersible raw material also includes an anti-caking agent; In the dispersible raw material, the mass percentage of the anti-caking agent is 20-25%.

4. The additive capable of adjusting the working time of cement mortar according to claim 1, characterized in that: The surfactant is one or more of fatty alcohol polyvinyl ether sodium sulfate and sodium gluconate mixed in any proportion; The water reducing agent is any one or more of a polycarboxylic acid high performance water reducing agent and a melamine-based high efficiency water reducing agent mixed in any proportion.

5. A method for preparing an additive capable of adjusting the workable time of cement mortar according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: according to the raw material formula of the additive, weighing redispersible latex powder, heavy calcium powder, surfactant, defoamer and water reducing agent, mixing and stirring evenly to prepare the additive.

6. The method for preparing an additive capable of adjusting the workable time of cement mortar according to claim 5, characterized in that: During the stirring process, the stirring time is 1-3h.

7. A cement mortar, characterized in that: The raw materials include the following parts by weight: 170 parts of cement, 260 parts of sand, 1-2 parts of cellulose ether, 110 parts of water, and 2-10 parts of additives; The additive is an additive capable of adjusting the operable time of cement mortar as described in any one of claims 1 to 4 or an additive prepared by the method for preparing an additive capable of adjusting the operable time of cement mortar as described in any one of claims 5 to 6.

8. A cement mortar according to claim 7, characterized in that: The cement is Portland cement; The particle size of the sand is 40-140 meshes.

9. A method for preparing the cement mortar according to any one of claims 7 to 8, characterized in that: The preparation method comprises the following steps: S1. According to the formula, cement, sand, cellulose ether, water and additives are weighed, and the cement, sand, cellulose ether and additives are mixed and stirred to prepare a mixture; S2. Add water to the mixture prepared in S1, stir and allow to stand for aging to obtain cement mortar.

10. The method for preparing cement mortar according to claim 9, characterized in that: In step S1, during the mixing and stirring process, the stirring time is 5-10 minutes; In step S2, during the stirring and standing aging process, the stirring time is 2 minutes and the aging time is 5 minutes.

Images