CN113636862A

CN113636862A - Concrete waterproofing agent and application thereof

Info

Publication number: CN113636862A
Application number: CN202111038140.4A
Authority: CN
Inventors: 胡强; 杨辉; 吴春春; 包泳先
Original assignee: Beibu Gulf Marine New Materials Research Institute
Current assignee: Beibu Gulf Marine New Materials Research Institute
Priority date: 2021-09-06
Filing date: 2021-09-06
Publication date: 2021-11-12
Anticipated expiration: 2041-09-06
Also published as: CN113636862B

Abstract

The invention provides a concrete waterproof agent and application thereof, and relates to the technical field of concrete additives, wherein the concrete waterproof agent comprises microcrystalline wax, metakaolin and polydimethylsiloxane; the mass ratio of the microcrystalline wax to the metakaolin to the polydimethylsiloxane is 1-3:0.5-5: 0.5-2; the concrete waterproof agent is mainly applied to the stage of concrete drying or concrete surface waterproof performance degradation, can be used for coating the surface of a concrete material by adopting simple coating methods such as spraying and the like, can meet various engineering requirements, and has wide application prospects.

Description

Concrete waterproofing agent and application thereof

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of concrete additives, in particular to a concrete waterproof agent and application thereof.

[ background of the invention ]

Concrete is the most widely used building material in civil engineering and construction, and with the wide application of concrete materials, the performance requirements of people on concrete are gradually improved, the problem that concrete is corroded is increasingly prominent, and a large number of concrete buildings are damaged to different degrees due to rain erosion, acid rain corrosion and the like every year, so that a lot of concrete (concrete materials) fail in advance due to various reasons, including failure due to moisture erosion.

Concrete is essentially waterproof, but variations in the ingredients used to formulate concrete affect the degree of waterproofing and porosity of the concrete because of the presence of pores and capillary networks in the concrete, which allow the entry of potentially hazardous materials, resulting in deterioration; thus, the relationship between the environment and the concrete elements determines its long-term performance durability, and in general, the water permeability of bare concrete structures such as pavements, bridge decks and the like affects the durability and corrosion level of the steel reinforcement in the structure, and problems associated with water, such as freezing and melting, can also lead to severe degradation of the reinforced concrete, and to reduce the pore space and permeability in order to avoid the water ingress associated with the above degradation process, existing approaches generally reduce water ingress by surface treatment, for example: (1) hydrophobic impregnation, (2) impregnation, (3) coating; for the degradation maintenance of some finished concrete projects, the service life of the concrete can be prolonged only by using a surface treatment mode, and the treatment effect is not ideal.

Based on this, the present invention provides a concrete waterproofing agent to solve the above problems.

[ summary of the invention ]

In view of the above, the present invention is directed to a concrete waterproofing agent and an application thereof, wherein the concrete waterproofing agent is mainly applied to a stage of concrete drying or concrete surface waterproofing performance degradation, and can be applied to the surface of a concrete material by a simple coating method such as spraying, so as to meet various engineering requirements, and have a broad application prospect.

In order to solve the technical problems, the invention adopts the following technical scheme:

a concrete waterproofing agent comprising microcrystalline wax, metakaolin and polydimethylsiloxane; the mass ratio of the microcrystalline wax to the metakaolin to the polydimethylsiloxane is 1-3:0.5-5: 0.5-2.

In the invention, the mass ratio of the microcrystalline wax to the metakaolin to the polydimethylsiloxane is further 2:3: 1.

The application also provides application of the concrete waterproofing agent in concrete.

The application also provides a preparation method of the concrete waterproof agent, which comprises the following steps:

(1) adding distilled water into Tween-80, and stirring at high speed of 1400-1600r/min for 4-6min to uniformly disperse Tween-80 in the distilled water to obtain a dispersed emulsifier;

(2) uniformly dispersing microcrystalline wax in absolute ethyl alcohol A, stirring in a water bath at 70-80 ℃ until the microcrystalline wax is completely dissolved, pouring the mixture into the dispersed emulsifier obtained in the step (1) while the mixture is hot, and stirring at the rotating speed of 1800-2200r/min for 15-25min to obtain white emulsion;

(3) adding metakaolin into the white solution obtained in the step (2) while stirring, wherein the stirring rotation speed is 780-5500 r/min, and after the kaolin is added, the stirring rotation speed is increased to 4500-5500r/min and stirring is carried out for 8-12min to obtain a mixed solution;

(4) adding polydimethylsiloxane into the absolute ethyl alcohol B, uniformly dispersing to obtain a PDMS ethyl alcohol solution, and then carrying out ultrasonic treatment on the PDMS ethyl alcohol solution for 4-6 min;

(5) slowly dripping the PDMS ethanol solution subjected to ultrasonic treatment in the step (4) into the mixed solution in the step (3) while stirring at the rotation speed of 780-;

the mass parts of the materials in the steps are respectively as follows: tween-801-3 parts, distilled water 80-100 parts, microcrystalline wax 1-3 parts, absolute ethyl alcohol A60-90 parts, metakaolin 0.5-5 parts, polydimethylsiloxane 0.5-2 parts and absolute ethyl alcohol B8-12 parts.

In the invention, the concrete waterproof agent further comprises the following raw materials in parts by mass: tween-802 parts, distilled water 90 parts, microcrystalline wax 2 parts, absolute ethyl alcohol A80 parts, metakaolin 3 parts, polydimethylsiloxane 1 part and absolute ethyl alcohol B10 parts.

In the present invention, the absolute ethyl alcohol a and the absolute ethyl alcohol B each have a purity of 99.7% or more.

The absolute ethanol A and the absolute ethanol B are the same substances, and are named respectively in order to distinguish raw materials of the two steps.

In the present invention, the metakaolin has a particle size of 4 to 6 μm.

In the present invention, the microcrystalline wax is a No. 65 microcrystalline wax or a No. 70 microcrystalline wax.

The application also provides the application of the concrete waterproofing agent prepared by the method in concrete.

Particularly, the method is mainly applied to the stage of concrete drying or concrete surface waterproof performance degradation, and the concrete waterproof agent is prepared according to the proportion of 500g/m²The amount of the coating is uniformly sprayed on the surface of concrete and dried for 3 days at room temperature (about 20 ℃).

In summary, due to the adoption of the technical scheme, the invention at least comprises the following beneficial effects:

1. the concrete waterproof agent is mainly applied to the stage of concrete drying or concrete surface waterproof performance degradation, the concrete waterproof agent mainly comprises microcrystalline wax, metakaolin and polydimethylsiloxane, the three components have synergistic effects, and a coating formed by combining the microcrystalline wax, the metakaolin and the polydimethylsiloxane generates a hierarchical micro-nano structure, so that high-level super-hydrophobicity is caused, and the concrete waterproof agent is combined on the surface and in a cavity of concrete to prevent harmful ions from permeating into the concrete; in the application process, the concrete material surface can be coated by simple coating methods such as spraying, and the like, so that the method can meet various engineering requirements and has wide application prospects.

2. The concrete waterproof agent disclosed by the invention is simple in preparation process, easy to store, strong in finished product stability, not easy to layer and agglomerate, and still has high hydrophobicity after being placed for a period of time, so that good waterproof performance is maintained.

[ detailed description ] embodiments

The following examples may help one skilled in the art to more fully understand the present invention, but are not intended to limit the invention in any way.

Example 1

Preparation of concrete waterproofing agent

The embodiment provides a preparation method of a concrete waterproof agent, which comprises the following steps:

(1) adding distilled water into tween-80, stirring at 1600r/min for 4min to uniformly disperse tween-80 in the distilled water to obtain a dispersed emulsifier;

(2) uniformly dispersing microcrystalline wax in absolute ethyl alcohol A, stirring in a water bath at 80 ℃ until the microcrystalline wax is completely dissolved, pouring the mixture into the dispersed emulsifier obtained in the step (1) while the mixture is hot, and stirring at the rotating speed of 2200r/min for 25min to obtain white emulsion;

(3) adding metakaolin into the white solution obtained in the step (2) while stirring, wherein the stirring speed is 820r/min, and after the addition of the metakaolin is finished, increasing the stirring speed to 5500r/min, and stirring for 12min to obtain a mixed solution;

(4) adding polydimethylsiloxane into the absolute ethyl alcohol B, uniformly dispersing to obtain a PDMS ethyl alcohol solution, and then carrying out ultrasonic treatment on the PDMS ethyl alcohol solution for 6 min;

(5) slowly dripping the PDMS ethanol solution subjected to ultrasonic treatment in the step (4) into the mixed solution in the step (3) while stirring at the rotation speed of 820r/min, and after dripping is finished, increasing the stirring rotation speed to 2200r/min and stirring for 25min again to obtain the concrete waterproof agent;

the mass parts of the materials in the steps are respectively as follows: tween-803, 100 parts of distilled water, 3 parts of microcrystalline wax, 90 parts of absolute ethyl alcohol A, 5 parts of metakaolin, 2 parts of polydimethylsiloxane and 12 parts of absolute ethyl alcohol B; the purity of the absolute ethyl alcohol A and the purity of the absolute ethyl alcohol B are both absolute ethyl alcohol with the purity of more than 99.7 percent, and the particle size of the metakaolin is 6 mu m; the microcrystalline wax is No. 65 microcrystalline wax.

Example 2

(1) adding distilled water into tween-80, stirring at high speed of 1500r/min for 5min to uniformly disperse tween-80 in the distilled water to obtain a dispersed emulsifier;

(2) uniformly dispersing microcrystalline wax in absolute ethyl alcohol A, stirring in a water bath at 75 ℃ until the microcrystalline wax is completely dissolved, pouring the mixture into the dispersed emulsifier obtained in the step (1) while the mixture is hot, and stirring at the rotating speed of 2000r/min for 20min to obtain white emulsion;

(3) adding metakaolin into the white solution obtained in the step (2) while stirring, wherein the stirring speed is 800r/min, and after the kaolin is added, increasing the stirring speed to 5000r/min and stirring for 10min to obtain a mixed solution;

(4) adding polydimethylsiloxane into the absolute ethyl alcohol B, uniformly dispersing to obtain a PDMS ethyl alcohol solution, and then carrying out ultrasonic treatment on the PDMS ethyl alcohol solution for 5 min;

(5) slowly dripping the PDMS ethanol solution subjected to ultrasonic treatment in the step (4) into the mixed solution in the step (3) while stirring at the rotating speed of 800r/min, and after dripping is finished, increasing the stirring rotating speed to 2000r/min and stirring for 30min again to obtain the concrete waterproof agent;

the mass parts of the materials in the steps are respectively as follows: tween-802 parts, 90 parts of distilled water, 2 parts of microcrystalline wax, 80 parts of absolute ethyl alcohol A, 3 parts of metakaolin, 1 part of polydimethylsiloxane and 10 parts of absolute ethyl alcohol B; the purity of the absolute ethyl alcohol A and the purity of the absolute ethyl alcohol B are both absolute ethyl alcohol with the purity of more than 99.7 percent, and the particle size of the metakaolin is 5 mu m; the microcrystalline wax is No. 65 microcrystalline wax.

Example 3

(1) adding distilled water into tween-80, stirring at 1600r/min for 6min to uniformly disperse tween-80 in the distilled water to obtain a dispersed emulsifier;

(2) uniformly dispersing microcrystalline wax in absolute ethyl alcohol A, stirring in a 70 ℃ water bath until the microcrystalline wax is completely dissolved, pouring the mixture into the dispersed emulsifier obtained in the step (1) while the mixture is hot, and stirring at the rotating speed of 1800r/min for 25min to obtain white emulsion;

(3) adding metakaolin into the white solution obtained in the step (2) while stirring, wherein the stirring speed is 820r/min, and after the kaolin is added, increasing the stirring speed to 4500r/min and stirring for 8min to obtain a mixed solution;

(4) adding polydimethylsiloxane into the absolute ethyl alcohol B, uniformly dispersing to obtain a PDMS ethyl alcohol solution, and then carrying out ultrasonic treatment on the PDMS ethyl alcohol solution for 4 min;

(5) slowly dripping the PDMS ethanol solution subjected to ultrasonic treatment in the step (4) into the mixed solution in the step (3) while stirring at the rotating speed of 780r/min, and after dripping is finished, increasing the stirring rotating speed to 1800r/min and stirring for 25min again to obtain the concrete waterproof agent;

the mass parts of the materials in the steps are respectively as follows: tween-801 parts, distilled water 80 parts, microcrystalline wax 1 part, absolute ethyl alcohol A60 parts, metakaolin 0.5 part, polydimethylsiloxane 0.5 part and absolute ethyl alcohol B8 part; the purity of the absolute ethyl alcohol A and the purity of the absolute ethyl alcohol B are both absolute ethyl alcohol with the purity of more than 99.7 percent, and the particle size of the metakaolin is 4 mu m; the microcrystalline wax is No. 65 microcrystalline wax.

Example 4

Stability test of concrete waterproofing agent

In order to obtain a concrete waterproofing agent with the best stability, the applicant further discusses the influence of the composition of the raw materials on the stability of the concrete waterproofing agent, namely sealing and standing the obtained concrete waterproofing agent at the temperature of 20 +/-0.5 ℃, recording the layering time of the waterproofing agent, and designing an orthogonal test by using the mass ratio of microcrystalline wax, metakaolin and polydimethylsiloxane, wherein the preparation method of the waterproofing agent is the same as that of the embodiment 2 except that the mass ratio of the microcrystalline wax, the metakaolin and the polydimethylsiloxane is different; levels of orthogonal experimental factors are shown in table 1:

TABLE 1 levels of orthogonal Experimental factors for stability of concrete waterproofers

Level of	Microcrystalline wax	Metakaolin clay	Polydimethylsiloxane
				A	1	1	1
B	2	2	2
				C	3	3	3

The results of the orthogonal analysis of the above ratios are shown in Table 2:

TABLE 2 Quadrature experiments and results

The preparation can be maintained in the original state for a long time without delamination, and the stability is judged to be high initially, and as can be seen from the results in table 2, test 5 is the best in stability effect.

Example 5

Application of concrete waterproofing agent

The concrete waterproofing agent is applied to the stage of concrete drying or concrete surface waterproof performance degradation, and the using method is that the concrete waterproofing agent is used according to the proportion of 500g/m²The amount of the concrete is evenly sprayed on the surface of the concrete and dried for 3 days at room temperature (about 20 ℃);

the present example will be further tested for the water resistance of concrete as follows:

testing one:

from the tests in example 4 above, it can be seen from Table 2 that the water repellent of test number 5 works best and the stability of the group is the best; in addition, the waterproof agents with the test numbers of 2 and 6 also show good stability, so the test selects the waterproof agents of the test groups of 2, 5 and 6 to carry out the concrete waterproof test, and the waterproof agents are sequentially marked as a first group, a second group and a third group, and then selects the waterproof agents of the test groups of 3, 7 and 8 with common stability to be sequentially marked as a fourth group, a fifth group and a sixth group;

according to the waterproofing method of this example, the above group of concrete waterproofers was prepared at 500g/m²The amount of (b) was uniformly sprayed on a concrete surface, dried at room temperature (about 20 ℃) for 3 days, and then the contact angle of the concrete surface was measured using a contact angle measuring instrument model JC2000C1, manufactured by shanghai mornings company. The recorded data are shown in table 3:

TABLE 3 contact Angle 1 of the concrete groups

In addition, in order to further test the water repellency after a period of storage, the applicant stored the above six groups of water repellent for 55 days, then continued to test the contact angle of each group of concrete in the manner described above, and recorded the data shown in table 4:

TABLE 4 contact angles of concrete groups treated with water repellent after 55 days of storage

From tables 3 and 4, it is understood that the water repellent of the third group has the best water repellent effect and high stability, and although the first group has higher stability than the third group, the water repellent effect is much worse than the third group, and the fourth group to the sixth group also have good water repellent effects, but after 55 days of storage, the water repellent almost loses the water repellent effect, and the water repellent cannot achieve the water repellent effect any more due to the poor stability, and therefore, from the above results, it is understood that the raw material composition of the water repellent greatly affects the water repellent effect, and the mass ratio of microcrystalline wax, metakaolin and polydimethylsiloxane is 2:3:1, which is the best.

And (2) testing:

in order to test the influence of other preparation parameters on the water repellent effect, in addition to the mass ratio of the raw materials, the applicant further conducted the following tests, respectively testing the contact angles of the following groups (the test method is the same as test one)

A first group: polymethyl methacrylate was substituted for polydimethylsiloxane in the same manner as in example 2;

second group: the ultrasonic treatment in the step (4) is removed, and the other modes are the same as the embodiment 2;

third group: microcrystalline wax was removed in the same manner as in example 2;

and a fourth group: the polydimethylsiloxane was removed in the same manner as in example 2;

and a fifth group: the preparation method of the concrete waterproofing agent comprises the following steps: dispersing 0.5g of hydrophobic sio2 nanoparticles in ethanol (50mL), stirring vigorously, and then sonicating for 30min to ensure sufficient dispersion of the nanoparticles; 0.5g of hydrophobic SiO₂Dispersing the nanoparticles into 50mL of ethanol, stirring the mixture vigorously, and then carrying out ultrasonic treatment for 30min to ensure that the nanoparticles are fully dispersed; dispersing 2g of ethyl silicate in 10mL of ethanol solution, and stirring at 1000r/min for 5 min; slowly dripping the PDMS ethanol solution obtained in the step 2) into the step 1), and stirring for 10min at 800r/min after dripping; ultrasonically dispersing the solution obtained in the step 3) in an ice-water bath for 30min to finally obtain an ethyl silicate waterproof agent;

a sixth group: the material is added while stirring in the step (3) and the step (5) is changed into the material is directly added and then stirred at high speed, and the other modes are the same as the embodiment 2;

also according to the waterproofing method of this example, the above group of concrete waterproofers was prepared at 500g/m²The amount of (b) was uniformly sprayed on a concrete surface, dried at room temperature (about 20 ℃) for 3 days, and then the contact angle of the concrete surface was measured using a contact angle measuring instrument model JC2000C1, manufactured by shanghai mornings company. The recorded data are shown in table 5:

TABLE 5 contact Angle 2 of each group of concretes

From the above tests, it is found that the optimal water repellent can be obtained by the raw material ratio and the preparation method of the concrete water repellent of the present application, and the concrete water repellent has excellent stability and water repellency.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A concrete waterproofing agent is characterized by comprising microcrystalline wax, metakaolin and polydimethylsiloxane; the mass ratio of the microcrystalline wax to the metakaolin to the polydimethylsiloxane is 1-3:0.5-5: 0.5-2.

2. The concrete waterproofing agent according to claim 1, wherein the mass ratio of the microcrystalline wax, the metakaolin and the polydimethylsiloxane is 2:3: 1.

3. A method for producing a concrete waterproofing agent according to claim 1, characterized by comprising the steps of:

4. The method according to claim 3, wherein the concrete waterproofing agent is composed of the following raw materials in parts by mass: tween-802 parts, distilled water 90 parts, microcrystalline wax 2 parts, absolute ethyl alcohol A80 parts, metakaolin 3 parts, polydimethylsiloxane 1 part and absolute ethyl alcohol B10 parts.

5. The method according to any one of claims 3 or 4, wherein the absolute ethanol A and the absolute ethanol B each have a purity of 99.7% or more.

6. The method according to any one of claims 3 or 4, wherein the metakaolin has a particle size of 4 to 6 μm.

7. Use of a concrete waterproofing agent according to any one of claims 1 or 2 in concrete.

8. Use of a concrete waterproofing agent prepared by the method according to any one of claims 3 to 6 in concrete.