CN113060969A

CN113060969A - Special additive for self-compacting concrete and preparation method and application thereof

Info

Publication number: CN113060969A
Application number: CN202110307397.9A
Authority: CN
Inventors: 严颖增
Original assignee: Xiamen Xinrunyan New Material Co ltd
Current assignee: Fujian Road And Bridge Xiangtong Building Material Technology Co ltd
Priority date: 2021-03-23
Filing date: 2021-03-23
Publication date: 2021-07-02

Abstract

The invention provides a special self-compacting concrete admixture and a preparation method and application thereof, wherein the special self-compacting concrete admixture comprises the following materials in parts by weight: 370-400 polycarboxylic acid water-reducing ether; 100-130 polycarboxylic acid pure slump retaining ether; 0-20 parts of borax; 8-12 parts of sodium gluconate; 8-12 of white sugar; 3-7 of sodium citrate; 9-27 polyethylene glycol; 0.1-0.4 polyacrylamide; 0.1-0.5 hydroxyethyl methyl cellulose ether; 0.1-0.5 antifoaming agent; 0.2-0.6 of air entraining agent; 430-. The special additive for the self-compacting concrete provided by the invention has large flow and good wrapping, can solve the engineering structure that the common concrete can not be constructed or is difficult to construct, and simultaneously avoids the engineering quality problem caused by leakage vibration and over vibration of the common concrete. By adopting the special additive for the self-compacting concrete, the concrete is time-saving, labor-saving, noiseless and high in construction speed during construction, the labor intensity of workers is reduced, and energy is saved.

Description

Special additive for self-compacting concrete and preparation method and application thereof

Technical Field

The invention relates to a special additive for self-compacting concrete and a preparation method and application thereof.

Background

Self-compacting concrete refers to concrete which can flow and be compact under the action of self gravity, can completely fill a template even if compact steel bars exist, and simultaneously obtains good homogeneity without additional vibration.

The principle of preparing the self-compacting concrete is that through selection and matching of the additive, the cementing material and the coarse and fine aggregates and careful design of the mixing ratio, the yield stress of the concrete is reduced to be enough to be overcome by the shear stress generated by the self weight, so that the fluidity of the concrete is increased, and meanwhile, the self-compacting concrete has enough plastic viscosity, so that the aggregates are suspended in cement paste, the problems of segregation and bleeding do not occur, the self-compacting concrete can freely flow and fully fill the space in a template, and a compact and uniform gelled structure is formed.

The self-compacting concrete is technically characterized in that the additive improves the fluidity of the concrete, so that the slump constant of the concrete is more than 250mm, the expansion degree of the concrete is more than 650mm, the T50 is less than 6s, the emptying time of a slump constant barrel is not more than 10s, and the workability and durability of the concrete can be improved by the thickening water-retaining component in the additive and the introduction of stable and uniform micro-bubbles.

At present, the admixture on the market is the concrete with high fluidity produced by using the common high-performance concrete admixture mainly by adjusting the mixing proportion, but the common high-performance concrete admixture is not the self-compacting concrete in the true sense, and the common high-performance concrete admixture only increases the fluidity, can not meet the increasing demands of users, and needs to be improved.

Disclosure of Invention

Aiming at the background technology, the invention aims to provide a special additive for self-compacting concrete, which can replace the same type of products on the market.

In a first aspect, a self-compacting concrete special additive is provided, which comprises the following materials in parts by weight:

370-400 polycarboxylic acid water-reducing ether; 100-130 polycarboxylic acid pure slump retaining ether; 0-20 parts of borax; 8-12 parts of sodium gluconate; 8-12 of white sugar; 3-7 of sodium citrate; 9-27 polyethylene glycol; 0.1-0.4 polyacrylamide; 0.1-0.5 hydroxyethyl methyl cellulose ether; 0.1-0.5 antifoaming agent; 0.2-0.6 of air entraining agent; 430-.

Preferably, the materials and the parts by weight thereof are as follows: 385 polycarboxylic acid water-reducing ethers; 115 polycarboxylic acid pure slump retaining ether; 10, borax; 10 sodium gluconate; 10, white sugar; 5, sodium citrate; 18 polyethylene glycol; 0.4 polyacrylamide; 0.2 hydroxyethyl methyl cellulose ether; 0.4 defoaming agent; 0.2 air entraining agent; 444.5 of water.

In a second aspect, a preparation method of a special additive for self-compacting concrete is provided, which comprises the following steps:

placing water in a kettle;

adding solid adjuvants borax, sodium gluconate, white sugar, sodium citrate, polyacrylamide and hydroxyethyl methyl cellulose ether, and stirring;

adding two mother solutions of water-reducing ether and pure slump-retaining ether, and continuously stirring uniformly;

adding a defoaming agent, and stirring until the mixture is uniformly dispersed;

adding air entraining agent and stirring until the mixture is uniformly dispersed.

In a third aspect, an application of the self-compacting concrete admixture is provided, wherein the self-compacting concrete admixture provided in the first aspect or the self-compacting concrete admixture obtained by the preparation method provided in the second aspect is mixed with concrete for use.

Preferably, the concrete comprises C30-C70 self-compacting concrete.

Preferably, the doping amount of the special self-compacting concrete additive is 1.2-1.5%.

Preferably, the concrete is machine-made sand or natural sand.

Preferably, the water content of the machine-made sand is 2%.

Preferably, after the admixture special for the self-compacting concrete is mixed with the concrete, the water-gel ratio is 0.34-0.36.

Compared with the traditional admixture, the admixture special for the self-compacting concrete and the preparation method thereof provided by the invention have the following advantages:

1. the special admixture for the self-compacting concrete has large flow and good wrapping, can solve the engineering structure that the common concrete can not be constructed or is difficult to construct, and simultaneously avoids the engineering quality problem caused by leakage vibration and over vibration of the common concrete;

2. by adopting the special additive for the self-compacting concrete, the concrete is time-saving, labor-saving, noiseless and high in construction speed during construction, the labor intensity of workers is reduced, and energy is saved.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention clearer and more obvious, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

An additive special for self-compacting concrete comprises the following materials in parts by weight:

The preparation method comprises the following steps: putting water into a kettle, adding solid auxiliary materials of borax, sodium gluconate, white sugar, sodium citrate, polyacrylamide and hydroxyethyl methyl cellulose ether, starting to forcibly stir uniformly, adding two mother liquids of water-reducing ether and pure slump-retaining ether, continuously stirring uniformly, adding a defoaming agent, stirring until the mother liquids are uniformly dispersed, and continuously adding an air entraining agent, and stirring until the air entraining agent is uniformly dispersed.

When in use, the self-compacting concrete can be used on various types of concrete, including C30-C70 self-compacting concrete.

An orthogonal experiment is designed according to the range of the materials and the weight parts of the additives to obtain an orthogonal experiment table, as shown in the following table 1 (sodium gluconate, white sugar and sodium citrate are all retarders, are adjusted according to the change of air temperature and are not considered as main influence factors):

TABLE 1

Orthogonal experiments are carried out, and during the experiments, the concrete adopts the components and the material mixing ratio shown in the table 2:

TABLE 2

By experiment, the following table, table 3, was obtained:

TABLE 3

As can be seen from the above table, the experimental results of the 12 th and 13 th groups are better.

Data on the admixtures and the concretes of group 13 were examined to obtain Table 4

TABLE 4

The admixture of group 13 was used in combination with C30, C40, C50, C60, C70 self-compacting concrete, the following is a table of materials for various grades of concrete, Table 5.

TABLE 5

The following are experimental cases of the admixture of group 13 used in combination with various concretes in Table 5, Table 6.

TABLE 6

Through the experiments, the admixture special for the self-compacting concrete is mixed with the concrete for use, the concrete has good flowing and wrapping performance, can solve the engineering structure that the common concrete can not be constructed or is difficult to construct, and simultaneously avoids the engineering quality problem caused by leakage vibration and over vibration of the common concrete.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art; the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The admixture special for the self-compacting concrete is characterized by comprising the following materials in parts by weight:

2. The admixture special for the self-compacting concrete according to claim 1, which is characterized by comprising the following materials in parts by weight: 385 polycarboxylic acid water-reducing ethers; 115 polycarboxylic acid pure slump retaining ether; 10, borax; 10 sodium gluconate; 10, white sugar; 5, sodium citrate; 18 polyethylene glycol; 0.4 polyacrylamide; 0.2 hydroxyethyl methyl cellulose ether; 0.4 defoaming agent; 0.2 air entraining agent; 444.5 of water.

3. A preparation method of the admixture special for the self-compacting concrete is characterized by comprising the following steps:

placing water in a kettle;

4. The application of the additive special for the self-compacting concrete is characterized in that: the admixture for self-compacting concrete according to claim 1 or 2 or the admixture for self-compacting concrete obtained by the production method according to claim 3 is mixed with concrete for use.

5. The use of the additive special for self-compacting concrete according to claim 4, wherein:

the concrete comprises C30-C70 self-compacting concrete.

6. The use of the additive special for self-compacting concrete according to claim 4, wherein:

the doping amount of the special additive for the self-compacting concrete is 1.2-1.5%.

7. The use of the additive special for self-compacting concrete according to claim 4, wherein:

the concrete adopts machine-made sand or natural sand.

8. The application of the special additive for self-compacting concrete according to claim 7, wherein the special additive comprises the following components in percentage by weight:

the water content of the machine-made sand is 2%.

9. The application of the special additive for self-compacting concrete according to claim 1, wherein the additive comprises the following components in percentage by weight:

the water-cement ratio of the admixture special for the self-compacting concrete is 0.34-0.36 after the admixture is mixed with the concrete.