阅读说明：本技术 一种机制砂抹灰砂浆专用外加剂及其制备方法 (Special additive for machine-made sand plastering mortar and preparation method thereof ) 是由 曾帅 于 2021-10-10 设计创作，主要内容包括：本申请涉及建筑领域,具体公开了一种机制砂抹灰砂浆专用外加剂及其制备方法。外加剂由包含以下重量份的原料制成：纤维素醚12-20份、淀粉醚1-5份、减水剂7-12份、增稠剂5-11份、引气剂2-10份、硅酸镁铝1-4份、缓凝剂5-10份和水40-60份；制备方法：将水分成两份,将减水剂与其中一份水混合均匀,随后在搅拌下加入纤维素醚和淀粉醚,搅拌均匀,得到混合物Ⅰ；在搅拌下将增稠剂、引气剂、硅酸镁铝和缓凝剂加入另一份水中,搅拌均匀,得到混合物Ⅱ；将混合物Ⅰ和混合物Ⅱ搅拌2-3h,即可制得外加剂。将本申请的外加剂用于机制砂抹灰砂浆中,可显著的改善机制砂抹灰砂浆的施工性能。(The application relates to the field of buildings, and particularly discloses a special additive for machine-made sand plastering mortar and a preparation method thereof. The additive is prepared from the following raw materials in parts by weight: 12-20 parts of cellulose ether, 1-5 parts of starch ether, 7-12 parts of a water reducing agent, 5-11 parts of a thickening agent, 2-10 parts of an air entraining agent, 1-4 parts of magnesium aluminum silicate, 5-10 parts of a retarder and 40-60 parts of water; the preparation method comprises the following steps: dividing water into two parts, uniformly mixing a water reducing agent with one part of water, then adding cellulose ether and starch ether under stirring, and uniformly stirring to obtain a mixture I; adding the thickening agent, the air entraining agent, the magnesium aluminum silicate and the retarder into the other part of water under stirring, and uniformly stirring to obtain a mixture II; and stirring the mixture I and the mixture II for 2-3h to obtain the additive. When the additive is used in machine-made sand plastering mortar, the construction performance of the machine-made sand plastering mortar can be obviously improved.)

1. The special additive for the machine-made sand plastering mortar is characterized in that: the additive is prepared from the following raw materials in parts by weight:

12-20 parts of cellulose ether, 1-5 parts of starch ether, 7-12 parts of a water reducing agent, 5-11 parts of a thickening agent, 2-10 parts of an air entraining agent, 1-4 parts of magnesium aluminum silicate, 5-10 parts of a retarder and 40-60 parts of water.

2. The admixture special for machine-made sand plastering mortar of claim 1, which is characterized in that: the thickening agent is selected from any one of maltodextrin and xanthan gum.

3. The admixture special for machine-made sand plastering mortar of claim 1, which is characterized in that: the air entraining agent is selected from any one of an air entraining agent AOS, an air entraining agent AES and an air entraining agent K12.

4. The admixture special for machine-made sand plastering mortar of claim 1, which is characterized in that: when the thickening agent is maltodextrin and the air entraining agent is air entraining agent AOS, the weight ratio of the maltodextrin to the air entraining agent AOS to the magnesium aluminum silicate is (7-11): (1-5): (0.5-1).

5. The admixture special for machine-made sand plastering mortar of claim 4, which is characterized in that: the weight ratio of the maltodextrin to the air entraining agent AOS to the magnesium aluminum silicate is 9: 5: 1.

6. the admixture special for machine-made sand plastering mortar of claim 1, which is characterized in that: the retarder is selected from at least two of white sugar, sodium gluconate, tartaric acid and boric acid.

7. The admixture special for machine-made sand plastering mortar of claim 6, which is characterized in that: the retarder is white sugar and sodium gluconate, and the weight ratio of the white sugar to the sodium gluconate is (3-4): 2.

8. the admixture special for machine-made sand plastering mortar of any one of claims 1 to 7, wherein: in the additive, the additive also comprises redispersible latex powder; the weight of the redispersible latex powder accounts for 1.5 to 3.2 parts of the total weight of the admixture.

9. The preparation method of the admixture special for machine-made sand plastering mortar of any one of claims 1 to 8, wherein the admixture comprises the following steps: the method comprises the following steps:

weighing raw materials of each component according to a formula proportion, and dividing water into two parts;

uniformly mixing a water reducing agent with one part of water, then adding cellulose ether and starch ether under stirring, and uniformly stirring to obtain a mixture I; adding the thickening agent, the air entraining agent, the magnesium aluminum silicate and the retarder into the other part of water under stirring, and uniformly stirring to obtain a mixture II;

and stirring the mixture I and the mixture II for 2-3h to obtain the additive.

10. The preparation method of the special additive for machine-made sand-plastering mortar according to claim 9, characterized in that: when the additive system contains the redispersible latex powder, the redispersible latex powder is added into another part of water along with the thickening agent, the air entraining agent, the magnesium aluminum silicate and the retarder.

Technical Field

The application relates to the field of buildings, in particular to an additive special for machine-made sand plastering mortar and a preparation method thereof.

Background

China is a capital construction country, and the demand of construction of various infrastructures such as roads, railways, airports and the like for sand and gravel is very high. However, under the combined influence of natural sand exploitation restriction, illegal sand exploitation attack, environmental supervision and the like, the price of sand in most areas of China rises again and then supplies and meets the demand, and under the environment, machine-made sand is produced at the right moment. Machine-made sand refers to sand processed by sand making machines and other ancillary equipment. The sand can be processed into sands with different rules and sizes according to different process requirements, so that the daily requirement can be met.

The inventor finds that the existing mortar admixture on the market is mainly developed for mortar taking natural sand as mortar aggregate, and the mortar admixture is directly applied to machine-made sand mortar, so that the construction performance of the machine-made sand mortar is seriously influenced, for example, the mortar has serious bleeding, poor batch scraping and easy cracking, hollowing and the like.

Disclosure of Invention

The application provides a special additive for machine-made sand plastering mortar and a preparation method thereof, which can obviously improve the construction performance of the machine-made sand plastering mortar.

In a first aspect, the application provides a special additive for machine-made sand plastering mortar, which adopts the following technical scheme: the special additive for the machine-made sand plastering mortar is prepared from the following raw materials in parts by weight:

12-20 parts of cellulose ether, 1-5 parts of starch ether, 7-12 parts of a water reducing agent, 5-11 parts of a thickening agent, 2-10 parts of an air entraining agent, 1-4 parts of magnesium aluminum silicate, 5-10 parts of a retarder and 40-60 parts of water.

By adopting the technical scheme, the components are matched with each other, and the admixture with excellent performance can be prepared. The additive is used for machine-made sand plastering mortar, so that the construction performance of the machine-made sand plastering mortar can be greatly improved. Compared with natural sand, the edges and corners of the machine-made sand are clear, so that the application of the machine-made sand to plastering mortar can affect the construction performance of the plastering mortar, such as: severe bleeding, poor scraping type, easy hollowing, cracking and the like. In this application, magnesium aluminum silicate and air entraining agent mutually support, can strengthen the lubricity of system, and vitamin ether and starch ether etc. can strengthen the viscosity of system, and have certain water retention effect, so, each component is mutually supported to reduce the influence of mechanism sand edges and corners, solved the workability problem well. In the application, the performance of the machine-made plastering mortar can be made to be the same as that of natural plastering mortar through reasonable proportioning of the components.

Preferably, the thickener is selected from any one of maltodextrin and xanthan gum; further preferably, the thickener is maltodextrin.

By adopting the technical scheme, the viscosity of the system can be enhanced by maltodextrin or xanthan gum and the like, and compared with the maltodextrin, the maltodextrin has better thickening effect and light volume weight, and can reduce the burden of the system, so that the maltodextrin is preferably selected as the thickening agent in the application.

Preferably, the air entraining agent is selected from any one of an air entraining agent AOS, an air entraining agent AES and an air entraining agent K12; further preferably, the air-entraining agent is an air-entraining agent AOS.

By adopting the technical scheme, the air entraining agent is added into the additive, so that a large amount of tiny bubbles can be introduced in the mortar mixing process, the rolling property and the fluidity of the mortar are improved, the machine-made mortar plastering mortar is better in batch scraping and easy to construct.

Preferably, when the thickening agent in the additive system is maltodextrin and the air entraining agent is air entraining agent AOS, the weight ratio of the maltodextrin to the air entraining agent AOS to the magnesium aluminum silicate is (7-11): (3-5): (0.5-1); most preferably, the weight ratio of the maltodextrin to the air entraining agent AOS to the magnesium aluminum silicate is 9: 5: 1.

by adopting the technical scheme, the maltodextrin, the air entraining agent AOS and the magnesium aluminum silicate are matched with each other, so that the influence of edges and corners of the machine-made sand can be reduced to the greatest extent, the fluidity and the viscosity of the machine-made sand plastering mortar can be greatly improved, and the machine-made sand plastering mortar has strong constructability. In addition, the maltodextrin, the air entraining agent AOS and the magnesium aluminum silicate are matched with each other, so that the water-retaining effect is certain, the anti-sagging effect is good, the cracking and hollowing of the mortar can be effectively prevented, and the performance of the machine-made sand plastering mortar can reach the performance of natural sand plastering mortar.

Preferably, the retarder is selected from at least two of white sugar, sodium gluconate, tartaric acid and boric acid. Further preferably, the retarder is white sugar and sodium gluconate, and the weight ratio of the white sugar to the sodium gluconate is (3-4): 2; most preferably, the weight ratio of the white sugar to the sodium gluconate is 3: 2.

by adopting the technical scheme, the white sugar and the sodium gluconate are compounded in proportion, so that the setting time of the mortar can be regulated and controlled within 2-36 hours, and the stability of the mortar can be greatly improved. The applicant found that in the additive, when white sugar and sodium gluconate are used alone, the setting time of the mortar can be adjusted, but the performance of the mortar is unstable, so that the weight ratio of white sugar to sodium gluconate in the present application is (3-4): 2 for use in combination. In addition, compared with the independent use or the compound use of at least two of the rest retarders, the white sugar and the sodium gluconate are matched with each other, so that the cost can be minimized while the setting time of the mortar is stably adjusted, and the implementation cost is saved.

Preferably, the additive also comprises redispersible latex powder; the weight of the redispersible latex powder accounts for 1.5 to 3.2 parts of the total weight of the admixture, and the more preferable weight is 1.5 to 2 parts.

By adopting the technical scheme, the addition of the redispersible latex powder in the system can enhance the viscosity of the system and enhance the fluidity and the construction performance of the system. In addition, the inventor finds that in the presence of cellulose ether, if the amount of the redispersible latex powder is not controlled, a mortar system is very viscous, so that the fluidity of the mortar is poor, and construction is affected. Therefore, in the system with the cellulose ether, the weight of the redispersible latex powder accounts for 1.5 to 3.2 parts of the total weight of the admixture, and the system has better application property.

In this application, the water-reducing agent is preferably polycarboxylate water-reducing agent, and the viscosity of cellulose ether is 10 ten thousand, through polycarboxylate water-reducing agent dispersion cellulose ether, can arouse the water-retaining effect of cellulose ether to the at utmost, practices thrift the cost. The inventor finds that the water retention of the cellulose ether generally increases along with the increase of viscosity under the condition of the same mixing amount; however, the higher the viscosity, the more cohesive the mortar will be. In the system, the polycarboxylate superplasticizer is matched with cellulose ether with the viscosity of 10 ten thousand, so that the water retention effect is optimal, the cohesiveness of the system is good, and the construction performance is optimal.

In a second aspect, the present application provides a method for preparing a special additive for machine-made sand plastering mortar, which adopts the following technical scheme:

a preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

weighing raw materials of each component according to a formula proportion, and dividing water into two parts;

uniformly mixing a water reducing agent with one part of water, then adding cellulose ether and starch ether under stirring, and uniformly stirring to obtain a mixture I; adding the thickening agent, the air entraining agent, the magnesium aluminum silicate and the retarder into the other part of water under stirring, and uniformly stirring to obtain a mixture II;

and stirring the mixture I and the mixture II for 2-3h to obtain the additive.

By adopting the technical scheme, firstly, part of water is mixed with the water reducing agent, and then the water reducing agent is uniformly mixed with the cellulose ether and the starch ether, and the cellulose ether and the starch ether are not in direct contact with water, so that the dispersion of the cellulose ether and the starch ether is facilitated, the stability of a system is enhanced, and the stirring time is shortened. The admixture is prepared according to the preparation method of the application, so that the homogeneous and stable admixture can be obtained.

Preferably, when the additive system contains the re-dispersible latex powder, the re-dispersible latex powder is added into another part of water along with the thickening agent, the air entraining agent, the magnesium aluminum silicate and the retarder.

Preferably, the water reducing agent is mixed with "one part of water" accounting for 15-25% of the total water amount, and "the other part of water" accounting for 75-85% of the total water amount.

In a third aspect, the present application provides a machine-made sand plastering mortar, which adopts the following technical scheme:

the plastering mortar comprises the additive and/or the additive prepared by the preparation method, and the additive accounts for 0.05-0.06% of the total amount of the mortar.

In summary, the present application has the following beneficial effects:

1. the components are reasonably mixed, so that the construction performance of the machine-made sand plastering mortar can be greatly improved;

2. maltodextrin, an air entraining agent AOS and magnesium aluminum silicate are matched with each other, and thixotropic property, lubrication, air entraining and the like are combined to adjust the constructability of the machine-made sand plastering mortar;

3. the use of the white sugar and sodium gluconate double-component retarder increases the system stability;

4. the maximum water-retaining effect of the system can be excited by dispersing cellulose ether by using the polycarboxylic acid water reducing agent.

Detailed Description

The present application will be described in further detail with reference to examples. Specifically, the following are described: the following examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer; the starting materials used in the following examples are all those conventionally commercially available except where specifically noted.

Polycarboxylic acid water reducing agent: the water reducing rate is 28 percent; the solid content was 39%;

naphthalene sulfonate water reducing agent: the water reducing rate is 21 percent, and the Shanxi Shuicheng building materials chemical company Limited;

air entraining agent AOS: medium and light chemical industries, ltd;

an air entraining agent AES (advanced air entraining agent) from middle and light chemical industries, Ltd.

Examples

Example 1

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 0.7kg of polycarboxylic acid water reducing agent and 1kg of water in a first reaction kettle, adding 2kg of cellulose ether and 0.5kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 4kg of water into a second reaction kettle, starting stirring, adding 0.8kg of maltodextrin, 0.2kg of air entraining agent AOS, 0.3kg of magnesium aluminum silicate and 0.5kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 2

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.2kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.2kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 4kg of water into a second reaction kettle, starting stirring, adding 0.8kg of maltodextrin, 0.2kg of air entraining agent AOS, 0.3kg of magnesium aluminum silicate and 1.0kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 3

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 4.0kg of water into a second reaction kettle, starting stirring, adding 0.8kg of maltodextrin, 0.2kg of air entraining agent AOS, 0.3kg of magnesium aluminum silicate and 0.7kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 4

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of naphthalene sulfonate water reducing agent and 1.0kg of water in a first reaction kettle, then adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 4.0kg of water into a second reaction kettle, starting stirring, adding 0.8kg of maltodextrin, 0.2kg of air entraining agent AOS, 0.3kg of magnesium aluminum silicate and 0.7kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 5

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 4.0kg of water into a second reaction kettle, starting stirring, adding 0.8kg of maltodextrin, 0.2kg of air entraining agent AES, 0.3kg of magnesium aluminum silicate and 0.7kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 6

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 3.7kg of water into a second reaction kettle, starting stirring, adding 1.0kg of maltodextrin, 0.5kg of air entraining agent AOS, 0.1kg of magnesium aluminum silicate and 0.7kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 7

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 4.25kg of water into a second reaction kettle, starting stirring, adding 0.7kg of maltodextrin, 0.3kg of air entraining agent AOS, 0.05kg of magnesium aluminum silicate and 0.7kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 8

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 3.8kg of water into a second reaction kettle, starting stirring, adding 0.9kg of maltodextrin, 0.5kg of air entraining agent AOS, 0.1kg of magnesium aluminum silicate and 0.7kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 9

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 3.4kg of water into a second reaction kettle, starting stirring, adding 0.5kg of maltodextrin, 1.0kg of air entraining agent AOS, 0.4kg of magnesium aluminum silicate and 0.7kg of tartaric acid into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 10

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 3.9kg of water into a second reaction kettle, starting stirring, adding 0.9kg of maltodextrin, 0.5kg of air entraining agent AOS, 0.1kg of magnesium aluminum silicate, 0.3kg of white sugar and 0.3kg of sodium gluconate into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 11

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 4.0kg of water into a second reaction kettle, starting stirring, adding 0.9kg of maltodextrin, 0.5kg of air entraining agent AOS, 0.1kg of magnesium aluminum silicate, 0.3kg of white sugar and 0.2kg of sodium gluconate into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 12

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 4.0kg of water into a second reaction kettle, starting stirring, adding 0.9kg of maltodextrin, 0.5kg of air entraining agent AOS, 0.1kg of magnesium aluminum silicate, 0.2kg of white sugar and 0.3kg of sodium gluconate into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 13

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 3.8kg of water into a second reaction kettle, starting stirring, adding 0.9kg of maltodextrin, 0.5kg of air entraining agent AOS, 0.1kg of magnesium aluminum silicate, 0.3kg of white sugar, 0.2kg of sodium gluconate and 0.2kg of redispersible latex powder into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Example 14

A preparation method of the special additive for the machine-made sand plastering mortar comprises the following steps:

uniformly mixing 1.0kg of polycarboxylic acid water reducing agent and 1.0kg of water in a first reaction kettle, adding 1.7kg of cellulose ether and 0.3kg of starch ether into the first reaction kettle while stirring, and uniformly stirring to obtain a mixture I;

adding 3.5kg of water into a second reaction kettle, starting stirring, adding 0.9kg of maltodextrin, 0.5kg of air entraining agent AOS, 0.1kg of magnesium aluminum silicate, 0.3kg of white sugar, 0.2kg of sodium gluconate and 0.5kg of redispersible latex powder into the second reaction kettle under stirring, and uniformly stirring to obtain a mixture II;

and pouring the mixture I in the first reaction kettle into the second reaction kettle to be mixed with the mixture II, stirring for 3 hours, and uniformly stirring to obtain the special additive for the machine-made sand plastering mortar.

Comparative example

Comparative example 1

Comparative example 1 differs from example 3 only in that: in comparative example 1 no cellulose ether was added and the remainder was in accordance with example 3.

Comparative example 2

Comparative example 2 differs from example 3 only in that: in comparative example 2, 1.0kg of cellulose ether and 1.0kg of starch ether were used, the remainder being identical to example 3.

Comparative example 3

Comparative example 3 differs from example 8 only in that: in comparative example 3, no magnesium aluminum silicate was added and the remainder was in accordance with example 8.

Machine-made sand plastering mortar

The machine-made sand plastering mortar comprises the following components: the mortar comprises cement, machine-made sand, water and an additive, wherein the weight of the additive accounts for 0.05-0.06% of the total weight of the machine-made sand plastering mortar.

The preparation of the machine-made sand plastering mortar is as follows:

6.9kg of cement, 42.9kg of machine-made sand, 4.2kg of water and 0.03kg of additive are uniformly mixed to obtain the machine-made sand plastering mortar.

As described above for the preparation of machine-made sand plastering mortar, the admixtures of examples 1-14 and comparative examples 1-3 were applied to the machine-made sand plastering mortar, respectively, to obtain machine-made sand plastering mortars 1-14 and comparative plastering mortars 1-3, as shown in Table 1 below.

Table 1 machine-made sand plastering mortar table

Performance test

The basic performances of the machine-made sand plastering mortar 1-14 and the comparative plastering mortar 1-3 are detected according to GB/T25181-.

TABLE 2 mortar basic Property test Table

Combining the machine-made sand plastering mortar 2, the machine-made sand plastering mortar 3, the comparative machine-made sand plastering mortar 1, the combined machine-made sand plastering mortar 3 and the comparative machine-made sand plastering mortar 2 and combining the table 2, it can be seen that cellulose ether has a critical influence on the water retention of the mortar, the more the cellulose ether is mixed, the better the water retention of the mortar is, and the longer the plastic retention time of the mortar is;

the combination of the machine-made sand plastering mortar 3 and the machine-made sand plastering mortar 4 and the combination of the table 2 shows that the polycarboxylate water reducing agent has better water reducing effect and higher mortar strength than the naphthalenesulfonate water reducing agent;

in combination with the machine-made sand plastering mortar 3 and the machine-made sand plastering mortar 5 and in combination with the table 2, it can be seen that the loss of the air-entraining agent AES to the strength of the mortar is larger under the condition of the same mixing amount of the air-entraining agent AOS and the air-entraining agent AES;

in combination with the machine-made sand plastering mortar 11, the machine-made sand plastering mortar 13 and the machine-made sand plastering mortar 14 and in combination with table 2, it can be seen that the more the amount of the redispersible latex powder is, the greater the tensile bonding strength is;

by combining all the machine-made sand plastering mortars and all the comparative machine-made sand plastering mortars and combining table 2, the white sugar, the sodium gluconate and the tartaric acid have an effect on the plastic retention time of the mortars, and the plastic retention time can be adjusted as the mixing amount is larger and the plastic retention time is longer;

the combination of the combined machine-made sand plastering mortar 8 and the comparative machine-made sand plastering mortar 3 with the table 2 shows that the addition of the magnesium aluminum silicate can enhance the water retention of the mortar and has slight influence on the strength of the mortar;

in combination with the machine-made sand plastering mortar 6 and the machine-made sand plastering mortar 8 and in combination with the table 2, it can be seen that maltodextrin has a thickening effect on the mortar mainly and has almost no influence on other properties of the mortar.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.