An impermeable concrete admixture

Abstract

The application relates to the technical field of building materials, and discloses an anti-permeation concrete additive, raw materials of which comprise the following components in parts by weight: limestone powder 40-50 parts, sodium silicate 30-40 parts, hexadecyl trimethoxysilane 20-30 parts, silicon dioxide 10-20 parts, and water blocking agent 5-10 parts, wherein the water blocking agent is formed by mixing benzoic anhydride and barium oxide. The anti-permeation concrete additive solves the problem that the anti-permeation concrete additive in the prior art cannot obviously improve the anti-permeation capacity of concrete.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular, relates to a kind of anti-permeability concrete admixture. BACKGROUND

[0002] Concrete is a kind of non-homogeneous brittle material mixed by sandstone aggregate, cement, additive and water. There are inevitably a large number of micro-pores and air pockets in hardened concrete, which seriously reduces the impermeability of concrete and shortens the service life of the building. Therefore, it is crucial to improve the impermeability of concrete.

[0003] Adding anti-permeability concrete admixture to concrete is one of the main methods to improve the impermeability of concrete. However, the impermeability effect of the existing anti-permeability concrete admixture is not ideal, which cannot meet the use requirements of some special fields. In addition, the existing anti-permeability concrete admixture generally needs to be added in a large amount to significantly improve the impermeability of concrete, which not only increases the cost, but also brings certain side effects to the concrete. Therefore, it is of great significance to develop a new type of anti-permeability concrete admixture. SUMMARY

[0004] The present application provides an anti-permeability concrete admixture, which solves the problem of not obvious improvement of the anti-permeability of concrete admixture in related art.

[0005] The technical scheme of the present application is as follows:

[0006] The present application provides an anti-permeability concrete admixture, which comprises the following components by weight: limestone powder 40-50 parts, sodium silicate 30-40 parts, hexadecyl trimethoxysilane 20-30 parts, silicon dioxide 10-20 parts, and water blocking agent 5-10 parts.

[0007] The water blocking agent is mixed by benzoic anhydride and barium oxide.

[0008] As a further technical scheme, the mass ratio of benzoic anhydride to barium oxide is 1:4-4:1.

[0009] When the mass ratio of benzoic anhydride to barium oxide is 1:4-4:1, the impermeability of concrete can be further improved.

[0010] As a further technical scheme, the mass ratio of benzoic anhydride to barium oxide is 3:2.

[0011] When the mass ratio of benzoic anhydride to barium oxide is 3:2, the concrete has better and excellent impermeability.

[0012] As a further technical scheme, the particle size of silicon dioxide is ≤50 μm.

[0013] As a further technical scheme, the silicon dioxide is polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide, and a preparation method of the polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide is as follows: polyvinylidene fluoride-hexafluoroethylene copolymer is dissolved in acetone, mixed uniformly, silicon dioxide is added and uniformly dispersed, concentrated and solidified, and broken and ground to obtain the polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide.

[0014] As a further technical scheme, the mass ratio of the polyvinylidene fluoride-hexafluoroethylene copolymer to the silicon dioxide is 1:9-3:7.

[0015] When the mass ratio of the polyvinylidene fluoride-hexafluoroethylene copolymer to the silicon dioxide is 1:9-3:7, the impermeability of the concrete can be further enhanced.

[0016] As a further technical scheme, the particle size of the polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide is ≤30 μm.

[0017] When the particle size of the polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide is ≤30 μm, the polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide can better "block" the pores in the concrete, so that the impermeability of the concrete can be further enhanced.

[0018] The application further provides a preparation method of the impermeable concrete admixture, and the method comprises the following steps: uniformly mixing the raw materials to obtain the impermeable concrete admixture.

[0019] The application further provides application of the impermeable concrete admixture in concrete.

[0020] As a further technical scheme, the use method comprises the following steps: uniformly mixing the impermeable concrete admixture and the concrete.

[0021] As a further technical scheme, the mass ratio of the impermeable concrete admixture to the concrete is 3:97-5:95.

[0022] The working principle and beneficial effects of the application are as follows:

[0023] 1、In the application, the water blocking agent in the impermeable concrete admixture is formed by mixing benzoic anhydride and barium oxide, and the permeation speed of water in the concrete can be reduced through synergistic effect of the two, so that the impermeability of the concrete is enhanced.

[0024] 2. In this invention, silicon dioxide is modified by polyvinylidene fluoride-hexafluoroethylene copolymer. On the one hand, the chemical inertness of the silicon dioxide surface is improved, making it less likely to increase the porosity of concrete. On the other hand, the fluidity and hydrophobicity of silicon dioxide are enhanced, so that silicon dioxide can "block" the pores in concrete and prevent water from further penetrating, thereby further enhancing the impermeability of concrete. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Unless otherwise specified, in the following examples and comparative examples, the calcium content in the limestone powder is ≥85wt%, the silica content in the sodium silicate is ≥53wt%, the purity of hexadecyltrimethoxysilane is ≥97%, the particle size of silica is 50μm, the purity of benzoic anhydride is ≥98%, the purity of barium oxide is ≥97%, and the average molecular weight of the polyvinylidene fluoride-hexafluoroethylene copolymer is 400,000.

[0027] Example 1

[0028] A method for preparing an anti-seepage concrete admixture includes the following steps: mixing 40 parts limestone powder, 30 parts sodium silicate, 20 parts hexadecyltrimethoxysilane, 10 parts silica and 5 parts water-blocking agent evenly to obtain the anti-seepage concrete admixture;

[0029] The water-blocking agent is composed of benzoic anhydride and barium oxide in a mass ratio of 1:9.

[0030] Example 2

[0031] A method for preparing an anti-seepage concrete admixture includes the following steps: mixing 40 parts limestone powder, 30 parts sodium silicate, 20 parts hexadecyltrimethoxysilane, 10 parts silica and 5 parts water-blocking agent evenly to obtain the anti-seepage concrete admixture;

[0032] The water-blocking agent is composed of benzoic anhydride and barium oxide in a mass ratio of 9:1.

[0033] Example 3

[0034] A method for preparing an anti-seepage concrete admixture includes the following steps: mixing 40 parts limestone powder, 30 parts sodium silicate, 20 parts hexadecyltrimethoxysilane, 10 parts silica and 5 parts water-blocking agent evenly to obtain the anti-seepage concrete admixture;

[0035] The water blocking agent is formed by mixing benzoic anhydride and barium oxide in a mass ratio of 1:4.

[0036] Example 4

[0037] A preparation method of the anti-permeability concrete additive comprises the following steps: uniformly mixing 40 parts of limestone powder, 30 parts of sodium silicate, 20 parts of hexadecyl trimethoxysilane, 10 parts of silicon dioxide and 5 parts of a water blocking agent to obtain the anti-permeability concrete additive.

[0038] The water blocking agent is formed by mixing benzoic anhydride and barium oxide in a mass ratio of 4:1.

[0039] Example 5

[0040] A preparation method of the anti-permeability concrete additive comprises the following steps: uniformly mixing 40 parts of limestone powder, 30 parts of sodium silicate, 20 parts of hexadecyl trimethoxysilane, 10 parts of silicon dioxide and 5 parts of a water blocking agent to obtain the anti-permeability concrete additive.

[0041] The water blocking agent is formed by mixing benzoic anhydride and barium oxide in a mass ratio of 3:2.

[0042] Example 6

[0043] A preparation method of the anti-permeability concrete additive comprises the following steps: uniformly mixing 50 parts of limestone powder, 40 parts of sodium silicate, 30 parts of hexadecyl trimethoxysilane, 20 parts of silicon dioxide and 10 parts of a water blocking agent to obtain the anti-permeability concrete additive.

[0044] The water blocking agent is formed by mixing benzoic anhydride and barium oxide in a mass ratio of 3:2.

[0045] Example 7

[0046] The difference between the embodiment and example 6 is that, in the embodiment, the silicon dioxide is polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide.

[0047] The preparation method of the polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide is as follows: 1 part of polyvinylidene fluoride-hexafluoroethylene copolymer is dissolved in 3 parts of acetone, uniformly mixed, 19 parts of silicon dioxide is added and uniformly dispersed, concentrated and solidified, and then broken and ground to obtain polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide with a particle size of 50 μm.

[0048] Example 8

[0049] The difference between the embodiment and example 6 is that, in the embodiment, the silicon dioxide is polyvinylidene fluoride-hexafluoroethylene copolymer modified silicon dioxide.

[0050] The preparation method of the polyvinylidene fluoride-hexafluoropropene copolymer modified silica is as follows: 10 parts of polyvinylidene fluoride-hexafluoropropene copolymer is dissolved in 30 parts of acetone, mixed uniformly, 10 parts of silica is added, uniformly dispersed, concentrated and solidified, and broken and pulverized to obtain polyvinylidene fluoride-hexafluoropropene copolymer modified silica with a particle size of 50 μm.

[0051] Example 9

[0052] The difference between this example and Example 6 is that, in this example, the silica is polyvinylidene fluoride-hexafluoropropene copolymer modified silica;

[0053] The preparation method of the polyvinylidene fluoride-hexafluoropropene copolymer modified silica is as follows: 2 parts of polyvinylidene fluoride-hexafluoropropene copolymer is dissolved in 6 parts of acetone, mixed uniformly, 18 parts of silica is added, uniformly dispersed, concentrated and solidified, and broken and pulverized to obtain polyvinylidene fluoride-hexafluoropropene copolymer modified silica with a particle size of 50 μm.

[0054] Example 10

[0055] The difference between this example and Example 6 is that, in this example, the silica is polyvinylidene fluoride-hexafluoropropene copolymer modified silica;

[0056] The preparation method of the polyvinylidene fluoride-hexafluoropropene copolymer modified silica is as follows: 6 parts of polyvinylidene fluoride-hexafluoropropene copolymer is dissolved in 18 parts of acetone, mixed uniformly, 14 parts of silica is added, uniformly dispersed, concentrated and solidified, and broken and pulverized to obtain polyvinylidene fluoride-hexafluoropropene copolymer modified silica with a particle size of 50 μm.

[0057] Example 11

[0058] The difference between this example and Example 10 is that, in this example, the particle size of the polyvinylidene fluoride-hexafluoropropene copolymer modified silica is 30 μm.

[0059] Comparative Example 1

[0060] The difference between this comparative example and Example 1 is that, in this comparative example, the water blocking agent is benzoic anhydride.

[0061] Comparative Example 2

[0062] The difference between this comparative example and Example 1 is that, in this comparative example, the water blocking agent is barium oxide.

[0063] Comparative Example 3

[0064] The difference between this comparative example and Example 1 is that, in this comparative example, no water blocking agent is added.

[0065] The anti-permeability concrete admixture prepared from Examples 1-11 and Comparative Examples 1-3 and a commercially available C30 grade concrete were mixed uniformly at a mass ratio of 4:96, cured according to the curing method of test pieces in GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", and then the impermeability was tested by the water penetration height method in GB / T 50082-2009 "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete", wherein the test piece was a circular truncated cone with an inner diameter of 175 mm at the upper opening, an inner diameter of 185 mm at the lower opening, and a height of 150 mm, sealed with paraffin, the test age was 28 d, and the water pressure was 1.2 MPa. The test results are shown in Table 1.

[0066] Table 1 Test results by the water penetration height method

[0067]

[0068] The comparison of Examples 1 and Comparative Examples 1-3 shows that the synergistic effect of benzoic anhydride and barium oxide can significantly enhance the impermeability of concrete.

[0069] The comparison of Examples 1-2 and Examples 3-5 shows that when the mass ratio of benzoic anhydride and barium oxide is 1:4-4:1, the impermeability of concrete can be further enhanced. The comparison of Examples 5 and Examples 3-4 shows that when the mass ratio of benzoic anhydride and barium oxide is 3:2, the concrete has better and excellent impermeability. The comparison of Examples 6 and Examples 7-11 shows that the modification of silica by polyvinylidene fluoride-hexafluoroethylene copolymer helps to further enhance the impermeability of concrete. The comparison of Examples 9-10 and Examples 7-8 shows that when the mass ratio of polyvinylidene fluoride-hexafluoroethylene copolymer and silica is 1:9-3:7, the impermeability of concrete can be further enhanced. The comparison of Examples 11 and Example 10 shows that when the particle size of the silica modified by polyvinylidene fluoride-hexafluoroethylene copolymer is ≤30 μm, the silica modified by polyvinylidene fluoride-hexafluoroethylene copolymer can better "plug" the pores in the concrete, thereby further enhancing the impermeability of concrete.

[0070] The above are only preferred embodiments of the present application and are not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An admixture for impermeable concrete, characterized in that, The raw materials include the following components in parts by weight: 40-50 parts limestone powder, 30-40 parts sodium silicate, 20-30 parts hexadecyltrimethoxysilane, 10-20 parts silicon dioxide, and 5-10 parts water-blocking agent. The water-blocking agent is a mixture of benzoic anhydride and barium oxide; The silica is polyvinylidene fluoride-hexafluoroethylene copolymer modified silica. The preparation method of the polyvinylidene fluoride-hexafluoroethylene copolymer modified silica is as follows: dissolve the polyvinylidene fluoride-hexafluoroethylene copolymer in acetone, mix evenly, add silica, disperse evenly, concentrate and solidify, crush and grind to obtain the polyvinylidene fluoride-hexafluoroethylene copolymer modified silica.

2. The anti-seepage concrete admixture according to claim 1, characterized in that, The mass ratio of benzoic anhydride to barium oxide is 1:4-4:

1.

3. The anti-seepage concrete admixture according to claim 2, characterized in that, The mass ratio of benzoic anhydride to barium oxide is 3:

2.

4. The anti-seepage concrete admixture according to claim 1, characterized in that, The mass ratio of the polyvinylidene fluoride-hexafluoroethylene copolymer to silicon dioxide is 1:9-3:

7.

5. The anti-seepage concrete admixture according to claim 3, characterized in that, The particle size of the polyvinylidene fluoride-hexafluoroethylene copolymer modified silica is ≤30μm.

6. A method for preparing an anti-seepage concrete admixture as described in any one of claims 1-5, characterized in that, The process includes the following steps: mixing the raw materials evenly to obtain an anti-seepage concrete admixture.

7. The application of the anti-permeability concrete admixture according to any one of claims 1-5 or the anti-permeability concrete admixture obtained by the preparation method according to claim 6 in concrete.

8. The application according to claim 7, characterized in that, The method of use includes the following steps: mix the impermeable concrete admixture with the concrete evenly.

9. The application according to claim 8, characterized in that, The mass ratio of the anti-permeability concrete admixture to the concrete is 3:97-5:95.

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