A method for improving the setting strength of organic materials and cement and the cement prepared thereby

Abstract

The present invention discloses a method for improving the setting strength of organic material and cement and the cement prepared thereby. The method is as follows: (1) Mix cement with water to prepare cement slurry for standby; (2) Grind and crush inorganic filler, and then mix it evenly with acrylate to form composite filler; the dosage of the acrylate is 10-20% of the weight of the inorganic filler; (3) Mix the cement slurry in step (1), the composite filler in step (2) and modified zeolitic imidazolate framework-8, and stir evenly. The cement prepared by the present invention has high bonding strength among its components, and has excellent mechanical properties and corrosion resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of cement preparation, and particularly relates to a method for improving the setting strength of organic materials and cement and the cement prepared thereby. Background Art

[0002] Cement is a widely used building material, first discovered by British engineers. With the development of the national economy, the construction field in China has shown a booming development trend, and the corresponding building materials have developed rapidly. However, when applying them to construction projects, there are still many problems. For example: ordinary cement cannot withstand the erosion of water, is not easy to set, and the bonding degree between cement and organic materials is not high, resulting in problems such as insufficient strength after the cement is set, which not only increases the construction cost but also requires a long construction time. Summary of the Invention

[0003] In view of the above deficiencies in the prior art, the present invention provides a method for improving the setting strength of organic materials and cement and the cement prepared thereby, which can effectively solve the problem of insufficient setting strength of the cement products prepared by the existing methods.

[0004] To achieve the above object, the technical solution adopted by the present invention to solve its technical problems is:

[0005] A method for improving the setting strength of organic materials and cement, comprising the following steps:

[0006] (1) Mix cement with water to prepare cement slurry for standby;

[0007] (2) After grinding and pulverizing inorganic fillers, mix them evenly with acrylate to form a composite filler; the dosage of acrylate is 10-20% of the weight of the inorganic filler;

[0008] (3) Mix the cement slurry in step (1), the composite filler in step (2), and modified zeolitic imidazolate framework-8, and stir and mix evenly.

[0009] Further, the inorganic filler includes at least one of slag, fly ash, and silica fume.

[0010] Further, the acrylate is magnesium acrylate, calcium acrylate, or sodium acrylate.

[0011] Further, the inorganic filler includes slag and fly ash in a weight ratio of 1-2:0.5-1.

[0012] Further, the particle size of the pulverized inorganic filler is 60-80 μm.

[0013] Further, the dosage of the composite filler is 1.5-5% of the weight of the cement slurry.

[0014] Furthermore, the dosage of the composite filler is 1.8% of the weight of the cement slurry.

[0015] Furthermore, the dosage of the modified zeolitic imidazolate framework-8 is 0.01 - 0.5% of the weight of the cement slurry.

[0016] Furthermore, the dosage of the modified zeolitic imidazolate framework-8 is 0.25% of the weight of the cement slurry.

[0017] Furthermore, the modified zeolitic imidazolate framework-8 is obtained by modification with an alkanolamine compound.

[0018] Furthermore, the alkanolamine compound is triethanolamine, and the specific modification process is as follows:

[0019] Add 2-methylimidazole to the zinc acetate solution, then add triethanolamine, stir and react for 4 - 6 h, centrifuge at a speed of 10000 - 14000 r / min for 10 - 15 min, collect and wash the solid-phase product, and then dry it.

[0020] Furthermore, the cement is common portland cement, RPC concrete, etc.

[0021] The cement prepared by the above method.

[0022] Advantages of the present invention:

[0023] 1. Zeolitic imidazolate framework-8 and the composite filler can act as ultra-fine filling materials together, fill into the cement slurry matrix, and can play a nucleation role, so that the prepared cement matrix has excellent mechanical properties such as compressive strength and flexural strength.

[0024] 2. In the preparation process of this application, the zeolitic imidazolate framework-8 is modified with an alkanolamine component. Since the alkanolamine has a hydroxyl group with adsorption properties and an amino group with electronegativity that can generate electrostatic repulsion. Therefore, after modification with an alkanolamine, especially triethanolamine, on the one hand, its dispersibility can be enhanced, reducing the possibility of agglomeration, and on the other hand, the bonding performance between the cement matrix and the composite filler can also be enhanced, improving the denseness of the prepared product, thereby improving the durability, setting strength, mechanical structure performance, etc. of the prepared cement.

[0025] 3. When using the inorganic filler, it is crushed into fine particles. The smaller the particle size, the larger its specific surface area, so the contact area with either the cement matrix, acrylate, or modified zeolitic imidazolate framework-8 will increase significantly. However, the particle size is not the smaller the better. The size of the particle size will also affect the hydration degree of the cement to a certain extent. Therefore, it is the best choice to limit its particle size to 60 - 80 μm. Detailed implementation mode

[0026] The specific embodiments of the present invention will be described below to facilitate those skilled in the art of this technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of this technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions created using the concept of the present invention are within the scope of protection.

[0027] Example 1

[0028] A method for improving the setting strength of organic materials and cement, comprising the following steps:

[0029] (1) Mix cement and water to prepare cement slurry for later use;

[0030] (2) Grind and crush the inorganic filler to a particle size of 60 μm, then mix it evenly with calcium acrylate to form a composite filler; the dosage of calcium acrylate is 15% of the weight of the inorganic filler; the inorganic filler is slag;

[0031] (3) Add 2-methylimidazole to the zinc acetate solution, then add triethanolamine, stir and react for 4 h, then centrifuge at a speed of 10000 r / min for 15 min, collect and wash the solid-phase product, and then dry it at 60 °C to prepare modified zeolitic imidazolate framework-8;

[0032] (4) Mix the cement slurry in step (1), the composite filler in step (2), and the modified zeolitic imidazolate framework-8, and stir and mix evenly; among them, the dosage of the composite filler is 1.8% of the weight of the cement slurry; the dosage of the modified zeolitic imidazolate framework-8 is 0.25% of the weight of the cement slurry. And, adjust the water addition amount according to the actual cement consistency during the preparation process.

[0033] Example 2

[0034] A method for improving the setting strength of organic materials and cement, comprising the following steps:

[0035] (1) Mix cement and water to prepare cement slurry for later use;

[0036] (2) Grind and crush the inorganic filler to a particle size of 70 μm, then mix it evenly with magnesium acrylate to form a composite filler; the dosage of acrylate is 10% of the weight of the inorganic filler; the inorganic filler is fly ash;

[0037] (3) Add 2-methylimidazole to the zinc acetate solution, then add triethanolamine, stir and react for 6 h, then centrifuge at a speed of 14000 r / min for 10 min, collect and wash the solid-phase product, and then dry it at 60 °C to prepare modified zeolitic imidazolate framework-8;

[0038] (4) Mix the cement slurry in step (1), the composite filler in step (2), and the modified zeolitic imidazolate framework-8, and stir and mix them evenly; wherein, the dosage of the composite filler is 1.5% of the weight of the cement slurry; the dosage of the modified zeolitic imidazolate framework-8 is 0.1% of the weight of the cement slurry. And, adjust the water addition amount according to the actual cement consistency during the preparation process.

[0039] Example 3

[0040] A method for improving the setting strength of organic materials and cement, comprising the following steps:

[0041] (1) Mix cement and water to prepare cement slurry for standby;

[0042] (2) Grind and crush the inorganic filler to a particle size of 80 μm, and then mix it evenly with magnesium acrylate to form a composite filler; the dosage of acrylate is 20% of the weight of the inorganic filler; the inorganic filler is slag;

[0043] (3) Add 2-methylimidazole to the zinc acetate solution, then add triethanolamine, stir and react for about 6 h, centrifuge at a speed of 12000 r / min for 10 min, collect and wash the solid phase product, and then dry it at 60 °C to prepare the modified zeolitic imidazolate framework-8;

[0044] (4) Mix the cement slurry in step (1), the composite filler in step (2), and the modified zeolitic imidazolate framework-8, and stir and mix them evenly; wherein, the dosage of the composite filler is 2.6% of the weight of the cement slurry; the dosage of the modified zeolitic imidazolate framework-8 is 0.35% of the weight of the cement slurry. And, adjust the water addition amount according to the actual cement consistency during the preparation process.

[0045] Comparative Example 1

[0046] Compared with Example 1, a conventional retarder and inorganic admixtures are used to replace the modified zeolitic imidazolate framework-8 used in this application to improve the cement compactness and setting strength, and the rest of the process is the same as the technical solution of this application.

[0047] Comparative Example 2

[0048] Compared with Example 1, the zeolitic imidazolate framework-8 is not modified, and the rest of the process is the same as that of Example 1.

[0049] Experimental Example

[0050] 1. Prepare concrete according to the methods described in Examples 1 to 3 and Comparative Examples 1 to 2 respectively, and then carry out conventional curing under the same conditions, and detect their setting times and strength properties at 7 days and 28 days respectively. The results are shown in Table 1.

[0051] Table 1 Concrete Properties

[0052]

[0053] According to the data in Table 1, it can be seen that the mechanical properties of the concrete prepared by the methods described in Examples 1 to 3 of the present application are significantly better than those of Comparative Example 1 and Comparative Example 2. By comparing Example 1 with Comparative Example 1, it can be seen that the setting strength of the product prepared by the present application is higher. The retarder added in Comparative Example 1 also has the effect of improving the late strength of cement, and the inorganic filler used can further cooperate to improve the compactness and other properties of cement, thereby improving the cement strength. However, the cement strength prepared by it is still lower than the technical solution of the present application, probably because the technical solution of the present application can better combine the cement matrix, inorganic filler, and organic acrylate together, so that the prepared product has excellent mechanical properties.

[0054] By comparing Example 1 and Comparative Example 2, and comparing Comparative Example 1 and Comparative Example 2, it can be seen that the performance of the cement prepared by using unmodified zeolitic imidazolate framework-8 is far inferior to the technical solution of the present application and Comparative Example 1.

[0055] 2. Immerse the concrete specimens prepared in Examples 1 to 3 and Comparative Examples 1 and 2 after 28 days of curing in a hydrochloric acid solution with a concentration of 5%, and measure the changes in compressive strength and tensile strength of the specimens after soaking for different times. The results are shown in Table 2.

[0056] Table 2 Concrete Corrosion Resistance

[0057]

[0058] From the data in Table 2, it can be seen that the concrete prepared by the present application has excellent corrosion resistance because the binding strength of each component is high and the compactness is good. Although there are differences in the binding properties between the components of Comparative Example 1 and the technical solution of the present application, the retarder and inorganic filler added in it can enhance the performance of the material to a certain extent, so that it also has a certain corrosion resistance. However, since Comparative Example 2 only uses unmodified zeolitic imidazolate framework-8, its corrosion resistance is far inferior to the technical solutions of the present application and Comparative Example 1.

[0059] In summary, from the test data in Table 1 and Table 2, it can be seen that the cement prepared by the present application not only has good strength in the early stage, but also has good corrosion resistance.

Claims

1. A method for improving the setting strength of organic materials and cement, characterized in that It includes the following steps: (1) Mix cement and water to prepare cement slurry for standby; (2) Grind and crush the inorganic filler to a particle size of 60 - 80 μm, and then mix it evenly with acrylate to form a composite filler; the dosage of the acrylate is 10 - 20% of the weight of the inorganic filler; the inorganic filler is slag or fly ash; the acrylate is magnesium acrylate, calcium acrylate or sodium acrylate; (3) Mix the cement slurry in step (1), the composite filler in step (2) and the modified zeolitic imidazolate framework - 8, and stir and mix evenly; The modified zeolitic imidazolate framework - 8 is obtained by modification with triethanolamine. The specific modification process is as follows: Add 2 - methylimidazole to the zinc acetate solution, then add triethanolamine, stir and react for 4 - 6 h, centrifuge at a speed of 10000 - 14000 r / min for 10 - 15 min, collect and wash the solid phase product, and then dry it; the cement is Portland cement or RPC concrete; the dosage of the modified zeolitic imidazolate framework - 8 is 0.01 - 0.5% of the weight of the cement slurry.

2. The method according to claim 1, wherein The dosage of the composite filler is 1.5 - 5% of the weight of the cement slurry.

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