Cement-based composite material containing slag cement and preparation method of cement-based composite material

Abstract

The invention provides a cement-based composite material containing slag cement and a preparation method of the cement-based composite material. Portland cement is replaced by the slag cement, and particularly, an acrylamide monomer in the prior art is replaced by dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate; the compression resistance, fracture resistance and the like of the cement-based composite material can be obviously improved; while the mechanical property is improved, the material consumption and the cost are effectively reduced, and the industrial application prospect is relatively good.

Description

Technical Field

[0001] This application relates to the field of building materials, specifically to a cement-based composite material containing slag cement and its preparation method. Background Technology

[0002] Cement-based composite materials are one of the basic materials in various infrastructure constructions. They are widely used in buildings, bridges and other projects. Due to the different application scenarios, the performance requirements of cement-based composite materials are also different.

[0003] To obtain cement-based composite materials with different properties, researchers have adopted various methods to modify cement materials. In-situ polymerization is one of the important methods. For example, in CN202410459519.X, dimethyl diallyl ammonium chloride monomer undergoes an addition polymerization reaction to form a polymeric material. During the formation process, a linear polymer is formed through an initiator, and then a three-dimensional network structure is formed with a crosslinking agent. This three-dimensional network structure is connected to the network structure formed by cement hydration through chemical bonds, and the dual-network structure improves the cement hydration products. In CN202010274758.X, a mixed solution of an initiation system and acrylate monomers is mixed with cement-based materials, and the acrylate monomers are in-situ polymerized in the cement-based materials to form another network interwoven with the cement hydration products, resulting in an in-situ polymerized cement-based material. In CN202311066401.2, an in-situ polymerization method using acrylamide and alginate is used to introduce a dual-network polymer. The polymer network and the network formed by the cement-based material hydration products have good compatibility and can form an interwoven dual network.

[0004] Although the mechanical properties and toughness of CN202311066401.2 have been improved to some extent, there is still room for optimization, and further research and development are needed. Summary of the Invention

[0005] This invention provides a cement-based composite material with excellent compressive and flexural strength, and compared with the in-situ polymerized cement-based composites in the prior art, the amount of polymerizable material required in the in-situ polymerization liquid is less, which can significantly reduce the amount used and the cost, and has good prospects for industrial application.

[0006] Specifically, the present invention provides a cement-based composite material, which is obtained by adding a cementitious material to an in-situ polymerization solution;

[0007] The cementitious material includes slag cement;

[0008] Optionally, the cementitious material also contains quicklime;

[0009] The weight ratio of the slag cement to the quicklime is 19:0-2, preferably 19:1;

[0010] In some embodiments, the cementitious material can also not contain quicklime;

[0011] In some embodiments, the slag cement can be P·S·A32.5, P·S·A42.5, or P·S·A52.5; preferably P·S·A32.5;

[0012] The in-situ polymerization solution comprises dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate, sodium alginate, ammonium persulfate, N,N'-methylenebisacrylamide and water;

[0013] The weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the sodium alginate is 9:1;

[0014] The weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the ammonium persulfate is 10-30:1;

[0015] The weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the N,N'-methylenebisacrylamide is 20-55:1;

[0016] The weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the water is 3-6:20;

[0017] The weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the cementitious material is 30-120:1000, preferably 45-90:1000;

[0018] The application also provides a preparation method of the cement-based composite material, comprising the following steps:

[0019] 1) Preparation of the in-situ polymerization solution:

[0020] The dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate and the sodium alginate are dissolved in water, and the ammonium sulfate and the N,N'-methylenebisacrylamide are added to obtain the in-situ polymerization solution;

[0021] 2) The slag cement and optionally the quicklime are added to the in-situ polymerization solution;

[0022] 3) Casting, vibration molding, covering the curing film, mold curing, and natural curing;

[0023] The mold curing is carried out at 60℃ and 90 RH% for 24 hours;

[0024] The time of the natural curing is 28 days;

[0025] In the step 1), mechanical stirring or magnetic stirring is preferably used, and mechanical stirring is more preferably used;

[0026] In the step 1), the stirring speed of the mechanical stirring or magnetic stirring is preferably 200-500 300 r / min, and more preferably 300 r / min;

[0027] The step 1) is preferably performed at 10-30°C, and more preferably at room temperature;

[0028] In some embodiments, the weight ratio of the slag cement to the quicklime is 19:0-2, and preferably 19:1;

[0029] In some embodiments, the cementitious material can also not contain quicklime;

[0030] In some embodiments, the type of the slag cement can be P·S·A32.5, P·S·A42.5, or P·S·A52.5; and preferably P·S·A32.5;

[0031] In some embodiments, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the sodium alginate is 9:1;

[0032] In some embodiments, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the ammonium persulfate is 10-30:1;

[0033] In some embodiments, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the N,N'-methylenebisacrylamide is 20-55:1;

[0034] In some embodiments, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to water is 3-6:20;

[0035] In some embodiments, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the cementitious material is 30-120:1000, and preferably 45-90:1000.

[0036] The application also provides a cement-based composite material prepared by the method for preparing a cement-based composite material provided by the application.

[0037] The application also provides a cement-based composite material for use in making buildings, roads, bridges, structural components, and the like.

[0038] The application uses dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to replace the acrylamide monomer in the prior art, and uses slag cement to replace Portland cement, so that the compressive and flexural properties of the cement-based composite material can be significantly improved; and the amount of dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate and sodium alginate in the in-situ polymerization solution can be reduced, the mechanical properties are improved, the material usage and cost are effectively reduced, and the application prospect is good.

[0039] In addition, the applicant also found that the cement-based composite material formed by the in-situ polymerization solution of the application and the slag cement has better compressive strength and flexural strength than the cement-based composite material formed by the in-situ polymerization solution of the application and the ordinary Portland cement, which shows that the in-situ polymerization solution of the application and the slag cement have better compatibility and better synergistic effect. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The scanning electron microscope image (10,000 times) of the cement-based composite material after the formwork was removed and the natural curing was continued for 28 days in Example 3. DETAILED DESCRIPTION

[0041] The above and other advantages and features of the application will become apparent from the following description of the application with reference to the accompanying drawings, in which:

[0042] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, one skilled in the art will understand that the application can be practiced without these specific details.

[0043] In the examples, the specific experimental steps or conditions are not specified, and the operation or conditions can be performed according to the conventional experimental steps described in the literature in the art. The reagents or instruments used are not specified by the manufacturer, and are conventional reagent products that can be obtained by purchase.

[0044] Example 1

[0045] Mix 45 parts of dimethylaminoethyl methacrylate, 5 parts of sodium alginate, 300 parts of water, and mechanically stir (300 r / min) at room temperature until all are dissolved; add 3.5 parts of ammonium persulfate as an initiator, 1.75 parts of N,N'-methylenebisacrylamide as a crosslinking agent, and continue stirring for 5 minutes to obtain an in-situ polymerization solution;

[0046] Add 950 parts of slag cement (P·S·A32.5) and 50 parts of quicklime to the above solution, continue stirring for 10 minutes, pour, vibrate and form, cover with a curing film, and maintain at 60°C and 90 RH% for 24 hours with the mold, then remove the mold and continue natural curing for 28 days.

[0047] Example 2

[0048] Mix 45 parts of dimethylaminoethyl methacrylate, 5 parts of sodium alginate, 300 parts of water, and mechanically stir (300 r / min) at room temperature until all are dissolved; add 3.5 parts of ammonium persulfate as an initiator, 1.75 parts of N,N'-methylenebisacrylamide as a crosslinking agent, and continue stirring for 5 minutes to obtain an in-situ polymerization solution;

[0049] Add 950 parts of slag cement (P·S·A32.5) and 50 parts of quicklime to the above solution, continue stirring for 10 minutes, pour, vibrate and form, cover with a curing film, and maintain at 60°C and 90 RH% for 24 hours with the mold, then remove the mold and continue natural curing for 28 days.

[0050] Example 3

[0051] Mix 45 parts of dimethylaminoethyl methacrylate, 5 parts of sodium alginate, 300 parts of water, and mechanically stir (300 r / min) at room temperature until all are dissolved; add 3.5 parts of ammonium persulfate as an initiator, 1.75 parts of N,N'-methylenebisacrylamide as a crosslinking agent, and continue stirring for 5 minutes to obtain an in-situ polymerization solution;

[0052] Add 950 parts of slag cement (P·S·A32.5) and 50 parts of quicklime to the above solution, continue stirring for 10 minutes, pour, vibrate and form, cover with a curing film, and maintain at 60°C and 90 RH% for 24 hours with the mold, then remove the mold and continue natural curing for 28 days.

[0053] Example 4

[0054] Mix 45 parts of dimethylaminoethyl methacrylate, 5 parts of sodium alginate, 300 parts of water, and mechanically stir (300 r / min) at room temperature until all are dissolved; add 3.5 parts of ammonium persulfate as an initiator, 1.75 parts of N,N'-methylenebisacrylamide as a crosslinking agent, and continue stirring for 5 minutes to obtain an in-situ polymerization solution;

[0055] To the above solution, 950 parts of slag cement (P·S·A32.5) and 50 parts of quicklime were added, and stirring was continued for 10 minutes. Then, the solution was poured, vibrated, and molded, and a curing film was covered. The molded product was cured at 60℃ and 90% RH for 24 hours, and then demolded and naturally cured for 28 days.

[0056] Effect Example 1

[0057] The compressive strength and the flexural strength of the test blocks of Examples 1-4 were tested according to GB / T 176712021 Cement mortar strength test method (ISO method), and the test results are shown in Table 1.

[0058] Table 1: Test results of mechanical properties

[0059] Test blocks Compressive strength / MPa Flexural strength / MPa Example 1 98.6 36.7 Example 2 91.3 30.4 Example 3 125.2 45.5 Example 4 105.3 34.1

[0060] The results show that the test blocks of Examples 1-4 have good compressive and flexural properties, and the effects of Examples 1 and 3 are better than those of Examples 2 and 4, which shows that the effect of using dimethylaminoethyl methacrylate is better than that of diethylaminoethyl methacrylate.

[0061] Comparing Examples 1 and 3, it can be found that increasing the proportion of dimethylaminoethyl methacrylate and sodium alginate in the test blocks can improve the compressive and flexural properties.

[0062] In the specification, the same or similar parts between each embodiment can be referred to each other, and each embodiment focuses on the difference from other embodiments. In particular, for the embodiments described later, the description is simple, and the relevant parts can be referred to the part of the foregoing embodiments.

[0063] The above is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A cement-based composite material, obtained by adding a cementitious material to an in-situ polymerization solution, wherein the cementitious material comprises a slag cement, said cementitious material further comprising quicklime, characterized in that, the weight ratio of the slag cement to the quicklime is 19:0-2; the in-situ polymerization solution comprises: dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate, sodium alginate, ammonium persulfate, N,N'-methylenebisacrylamide and water.

2. The cement-based composite of claim 1, wherein, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the sodium alginate is 9:

1.

3. The cement-based composite of claim 1, wherein, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the ammonium persulfate is 10-30:

1.

4. The cement-based composite of claim 1, wherein, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the N,N'-methylenebisacrylamide is 20-55:

1.

5. The cement-based composite of claim 1, wherein, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the water is 3-6:

20.

6. The cement-based composite of claim 1, wherein, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the cementitious material is 30-120:1000.

7. The cement-based composite of claim 6, wherein, the weight ratio of the dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate to the cementitious material is 45-90:1000.

8. A method for preparing the cement-based composite material according to any one of claims 1-7, comprising the following steps: 1) preparation of the in-situ polymerization solution: dimethylaminoethyl methacrylate or diethylaminoethyl methacrylate and sodium alginate are dissolved in water, ammonium sulfate and N,N'-methylenebisacrylamide are added to obtain the in-situ polymerization solution; 2) adding the slag cement and optionally the quicklime to the in-situ polymerization solution; 3) casting, vibrating, covering with a curing film, mold curing, natural curing.

9. A method of producing a cementitious composite material as claimed in claim 8, characterised in that, the mold curing is at 60°C, 90 RH% for 24 hours.

10. A method of producing a cementitious composite material as claimed in claim 8, characterised in that, the time of the natural curing is 28 days.

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