CN107721243B

CN107721243B - Additive for improving concrete strength and preparation method thereof

Info

Publication number: CN107721243B
Application number: CN201710954784.5A
Authority: CN
Inventors: 胡波; 马帅; 李玉耀; 孙艺; 张玉平; 代步青; 刘大路; 张振; 张勇; 李寅磊
Original assignee: Shanghai Hongyun New Building Material Co ltd
Current assignee: SHANGHAI HONGYUN NEW BUILDING MATERIAL Co.,Ltd.
Priority date: 2017-10-13
Filing date: 2017-10-13
Publication date: 2021-02-09
Anticipated expiration: 2037-10-13
Also published as: CN107721243A

Abstract

The invention provides an additive for improving the strength of concrete and a preparation method thereof, wherein the additive comprises the following steps: 1) in the presence of a catalyst, methoxy polyethylene glycol and methacrylic acid react at 70-100 ℃ to obtain M1; 2) mixing the prepared M1, stearate, sodium gluconate and water to obtain M2; 3) mixing glacial acetic acid, tetrabutyl titanate and absolute ethyl alcohol under the condition that the pH value is 3-5 to prepare M3; 4) under the condition of temperature of 160-180 ℃, M3 is dropwise added into the M2 prepared above to prepare the admixture for improving the strength of the concrete. The invention has the following beneficial effects: when the concrete is used, the additive is directly added into the concrete, so that the strength of the concrete can be effectively improved, the cost is reduced, and the effect of effectively improving the strength is achieved.

Description

Additive for improving concrete strength and preparation method thereof

Technical Field

The invention relates to the field of concrete admixtures, in particular to an admixture for improving the strength of concrete and a preparation method thereof.

Background

Concrete is an important building material, is indispensable in buildings, and is widely used in bridge engineering, hydraulic engineering and construction engineering. In addition, since the safety of a building is considered when the concrete is used, an extremely important index of the concrete is a strength index. The safety of buildings is greatly influenced by the strength of the concrete, and particularly, when a bridge is built in environments such as Yangtze river, yellow river wetland and the like, the quality of the concrete is enhanced, and a method measure for improving the strength of the concrete is sought.

Disclosure of Invention

The invention aims to provide an additive for improving the strength of concrete and a preparation method thereof, and aims to solve the problems that the strength of the conventionally prepared concrete cannot effectively meet higher requirements, and the special concrete is expensive.

In order to achieve the above object, the present invention provides a method for preparing an admixture for improving concrete strength, comprising the steps of:

1) in the presence of a catalyst, methoxy polyethylene glycol and methacrylic acid react at 70-100 ℃ to obtain M1;

2) mixing the prepared M1, stearate, sodium gluconate and water to obtain M2;

3) mixing glacial acetic acid, tetrabutyl titanate and absolute ethyl alcohol under the condition that the pH value is 3-5 to prepare M3;

4) under the condition of temperature of 160-180 ℃, M3 is dropwise added into the M2 prepared above to prepare the admixture for improving the strength of the concrete.

The invention also provides an additive for improving the concrete strength, wherein the additive for improving the concrete strength is prepared according to the preparation method.

The invention has the following beneficial effects: the methoxy polyethylene glycol and the methacrylic acid react in the presence of a catalyst, the product after the reaction is mixed with stearate, sodium gluconate and water to obtain M2, further, glacial acetic acid, tetrabutyl titanate and absolute ethyl alcohol react under certain conditions to obtain M3, and the M3 is dripped into M2 under the condition of temperature of 160-180 ℃ to prepare the additive for concrete.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below.

Detailed Description

The following is a detailed description of embodiments of the invention, but the invention can be implemented in many different ways, as defined and covered by the claims.

The invention provides a preparation method of an additive for improving the strength of concrete, which comprises the following steps:

2) mixing the prepared M1, stearate, sodium gluconate and water to obtain M2;

The amounts of the above-mentioned starting materials can be selected within wide limits, for example, in a preferred embodiment, in order to be able to effectively improve the use properties thereof with a cost saving, the ratio of the amounts of substance of methoxypolyethylene glycol and methacrylic acid in step 1) is 1: 1.5-3.

The type of catalyst used herein can be selected by those skilled in the art in view of the practice, and in a preferred embodiment, the catalyst is p-toluenesulfonic acid.

In a further preferred embodiment, in step 2), the amount of stearate is 5 to 20 parts by weight, the amount of sodium gluconate is 10 to 20 parts by weight, and the amount of water is 30 to 70 parts by weight, relative to 10 parts by weight of M1.

In a preferred embodiment of the present invention, in the step 2), the stearate is at least one selected from the group consisting of sodium stearate, magnesium stearate, and calcium stearate.

Likewise, in a preferred embodiment, the mixing process in step 3) is stirring and mixing under a closed condition.

Further, the stirring time for stirring and mixing in the step 3) is 20-60min, and the stirring speed is 700-1500 r/min.

In another preferred embodiment, in step 3), glacial acetic acid is used in an amount of 0.1 to 1mol and n-tetrabutyl titanate is used in an amount of 0.15 to 0.3mol, relative to 10mol of anhydrous ethanol.

In a preferred embodiment, in step 4), M3 is used in an amount of 1 to 3 parts by weight relative to 10 parts by weight of M2.

Likewise, the dropping process may be carried out in a manner conventional in the art, and further, the dropping rate in the step 4) is 60 to 100 drops/min.

Of course, the amount of the admixture to be used in the concrete herein can be selected within a wide range, and for example, 1 to 10 parts by weight of the admixture can be added to 100 parts by weight of the concrete. Further, the adjustment can be made by those skilled in the art according to the actual situation.

The following will explain with specific examples.

Example 1

1) In an aqueous solution of p-toluenesulfonic acid with the concentration of 5 weight percent, 1mol of methoxypolyethylene glycol and 1.5mol of methacrylic acid are reacted at the temperature of 70 ℃, and then the mixture is subjected to reduced pressure distillation to obtain M1;

2) mixing 10 parts by weight of the prepared M1, 5 parts by weight of sodium stearate, 10 parts by weight of sodium gluconate and 30 parts by weight of water to prepare M2;

3) under the condition that the pH value is 3, 0.1mol of glacial acetic acid, 0.15mol of tetrabutyl titanate and 10mol of absolute ethyl alcohol are placed under the closed condition and stirred and mixed for 20min at the stirring speed of 700r/min to prepare M3;

4) to 10 parts by weight of the above-obtained M2, 1 part by weight of M3 was added dropwise at a rate of 60 drops/min at a temperature of 160 ℃ to obtain admixture A1 for improving the strength of concrete.

Example 2

1) In an aqueous solution of p-toluenesulfonic acid with the concentration of 5 weight percent, 1mol of methoxypolyethylene glycol and 3mol of methacrylic acid are reacted at the temperature of 100 ℃, and then the mixture is subjected to reduced pressure distillation to obtain M1;

2) mixing 10 parts by weight of M1, 20 parts by weight of magnesium stearate, 20 parts by weight of sodium gluconate and 70 parts by weight of water to obtain M2;

3) under the condition that the pH value is 5, 1mol of glacial acetic acid, 0.3mol of tetrabutyl titanate and 10mol of absolute ethyl alcohol are placed under the closed condition and stirred and mixed for 60min at the stirring speed of 1500r/min to prepare M3;

4) to 10 parts by weight of the above-obtained M2, 3 parts by weight of M3 was added dropwise at a rate of 100 drops/min at a temperature of 180 ℃ to obtain admixture A2 for improving the strength of concrete.

Example 3

1) In an aqueous solution of p-toluenesulfonic acid with the concentration of 5 weight percent, 1mol of methoxypolyethylene glycol and 2mol of methacrylic acid are reacted at the temperature of 85 ℃, and then the mixture is subjected to reduced pressure distillation to obtain M1;

2) mixing 10 parts by weight of the prepared M1, 10 parts by weight of sodium stearate, 15 parts by weight of sodium gluconate and 50 parts by weight of water to prepare M2;

3) under the condition that the pH value is 4, 0.5mol of glacial acetic acid, 0.2mol of tetrabutyl titanate and 10mol of absolute ethyl alcohol are placed under the closed condition and stirred and mixed for 40min at the stirring speed of 1000r/min to prepare M3;

4) 2 parts by weight of M3 was added dropwise to 10 parts by weight of the above prepared M2 at a rate of 80 drops/min at a temperature of 170 ℃ to prepare an admixture A3 for improving the strength of concrete.

Example 4

Prepared as in example 1 except that in step 2), 2 parts by weight of sodium stearate and 3 parts by weight of sodium gluconate were used to prepare admixture A4 for improving the strength of concrete.

Example 5

Prepared as in example 2 except that M3 was used in an amount of 0.5 part by weight in step 4) to prepare an admixture A5 for improving the strength of concrete.

Example 6

Prepared as in example 3 except that the dropping rate in step 4) was 200 drops/min to obtain admixture A6 for improving the strength of concrete.

Comparative example 1

Prepared as in example 1 except that, without going through step 1), admixture B1 was prepared by directly mixing stearic acid, sodium gluconate and water.

Comparative example 2

Prepared as in example 2 except that M1 was added dropwise directly to M3 without going through step 2) to prepare admixture B2.

Comparative example 3

Prepared by the method of example 3 except that the steps 3) and 4) are not carried out, and M2 is prepared, namely the admixture B3.

Comparative example 4

Prepared as in example 1 except that the operation was carried out at pH 10 in step 3) to obtain admixture B4.

Comparative example 5

Prepared by the same method as in example 2 except that the reaction temperature in step 4) was 20 ℃, i.e., under ordinary room temperature conditions, admixture B5 was obtained.

Test data

Preparation of conventional concrete: the preparation is carried out according to the standard of concrete C30 conventional in the art, namely cement (portland cement): sand: stone: water =1:1.92:3.14:0.54, and the mixture was stirred to obtain C30 concrete.

The above additives were mixed with the C30 concrete at a ratio of 3:100, and at the same time, a set of C30 concrete B6 without any additive was set, and the compressive strengths of 7d and 28d thereof were measured in accordance with GB/T50081, and the results are shown below.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The preparation method of the admixture for improving the concrete strength is characterized by comprising the following steps:

1) in an aqueous solution of p-toluenesulfonic acid with the concentration of 5 weight percent, 1mol of methoxypolyethylene glycol and 2mol of methacrylic acid are reacted at the temperature of 85 ℃, and then the obtained mixture is subjected to reduced pressure distillation to obtain M1;

4) 2 parts by weight of M3 was added dropwise to 10 parts by weight of the M2 thus obtained at a rate of 80 drops/min at a temperature of 170 ℃ to prepare an admixture for improving the strength of concrete.