Cement foam board and preparation method thereof

Abstract

The invention discloses a cement foam board and a preparation method thereof, the cement foam board is prepared from ordinary Portland cement, quick-hardening sulphoaluminate cement, a coagulant, hydrogen peroxide, fiber, a foam stabilizer, a catalyst and water, and bubbles generated by the hydrogen peroxide in matrix neat paste are in a thermodynamic unstable state; degradation phenomena such as disproportionation growth and merging occur constantly. And when the cement foam board is condensed and hardened, the bubbles are degraded and grow up to stop. Therefore, the initial setting time and the final setting time of the cement formed by mixing the ordinary Portland cement and the quick-hardening sulphoaluminate cement are greatly increased compared with those of the single ordinary Portland cement and the single quick-hardening sulphoaluminate cement, so that continuous degradation of bubbles is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of cement foaming, and particularly relates to a cement foaming board and a preparation method thereof. Background Art

[0002] A cement foaming board is a cement-based lightweight porous inorganic fireproof and heat-insulating board prepared by mixing foam prepared with a foaming agent and cement, stirring and mixing, casting and forming, and then curing. Its combustion performance is Class A1, and it is the best product applied to fireproof isolation belts.

[0003] The foaming method adopted for foamed cement is generally chemical foaming, that is, adding a foaming agent to a cement slurry, and a chemical reaction occurs to release bubbles, uniformly mixing the bubbles with the cement slurry, and forming a new type of lightweight heat-insulating material containing a large number of closed pores after casting and natural curing.

[0004] The commonly used chemical foaming agent is hydrogen peroxide, but the bubbles generated by hydrogen peroxide in the matrix neat paste are in a thermodynamically unstable state and will always undergo deterioration phenomena such as disproportionation growth and coalescence. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a cement foaming board and a preparation method thereof to solve the above-mentioned problems.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A cement foaming board comprises the following raw materials in parts by weight: 75-85 parts of ordinary Portland cement, 15-25 parts of rapid hardening sulphoaluminate cement, 4-8 parts of a coagulant, 4-8 parts of hydrogen peroxide, 2-4 parts of fibers, 1-3 parts of a foam stabilizer, 0.5-1 part of a catalyst, and 55-66 parts of water.

[0008] The fibers are polypropylene fibers.

[0009] The catalyst is manganese dioxide.

[0010] The coagulant is calcium oxide.

[0011] The foam stabilizer is any one of polyacrylamide, polyvinyl alcohol, and silicone resin.

[0012] A preparation method of a cement foaming board comprises the following steps:

[0013] S1. Intermix and uniformly mix ordinary Portland cement and rapid hardening sulphoaluminate cement to form a mixed cement;

[0014] S2. Mix and stir the mixed cement, fibers, foam stabilizer, coagulant, catalyst, and water until a paste-like mixture is obtained;

[0015] S3. Add hydrogen peroxide to the mixture, stir evenly, and then pour it into the mold.

[0016] S4. Place the mold in a place with suitable temperature, and introduce carbon dioxide gas into the mold. After the mixture in the mold solidifies, a cement foamed board is obtained.

[0017] The beneficial effects of the present invention are as follows:

[0018] (1) Research shows that only when the cement foamed board sets and hardens will the deterioration and growth of bubbles terminate. Therefore, using a cement mixed with ordinary Portland cement and rapid hardening sulfoaluminate cement, compared with single ordinary Portland cement and rapid hardening sulfoaluminate cement, the initial setting time and final setting time are both greatly increased, thus avoiding the continuous deterioration of bubbles.

[0019] (2) Add calcium oxide. When calcium oxide reacts with water, it will quickly react to form calcium hydroxide, and a large amount of heat will be released during this process, increasing the temperature of the cement paste, thereby accelerating the hydration reaction rate of various mineral components in the cement and promoting the setting and hardening of the cement. Moreover, the calcium hydroxide generated by calcium oxide enhances the alkalinity of the cement paste, which can stimulate the activity of water silicoaluminate and make it participate in the hydration reaction faster, thereby shortening the setting time of the cement.

[0020] (3) Since the content of calcium hydroxide in the cement is too high, the porosity of the cement stone increases and the structure becomes loose, thus reducing the long-term strength and durability of the cement. Therefore, carbon dioxide gas is introduced during cooling and solidification to convert calcium hydroxide into calcium carbonate, which not only reduces the content of calcium hydroxide, but also the generated calcium carbonate can be used as a filling material to occupy a certain space in the cement, making the structure of the cement stone more dense. When the particle size of the calcium carbonate particles is small and evenly distributed, it can fill the voids between the cement particles, reduce the porosity, thereby increasing the density of the cement stone, and further improving the strength of the cement to a certain extent. Specific embodiments

[0021] The following will combine with embodiments to clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0022] Embodiment 1

[0023] A preparation method of a cement foamed board includes the following steps:

[0024] S1. Intermix and evenly mix 75 parts of ordinary Portland cement and 25 parts of rapid hardening sulfoaluminate cement to form a mixed cement.

[0025] S2. Mix and stir the blended cement, 2 parts of fiber, 1 part of foam stabilizer, 4 parts of coagulant, 0.5 part of catalyst and 55 parts of water until a pasty mixture is formed;

[0026] S3. Add 4 parts of hydrogen peroxide to the mixture, stir evenly and then pour it into a mold;

[0027] S4. Place the mold in a place with suitable temperature, and introduce carbon dioxide gas into the mold. After the mixture in the mold is cured, a cement foamed board is obtained.

[0028] Among them, the fiber is polypropylene fiber, the catalyst is manganese dioxide, the coagulant is calcium oxide, and the foam stabilizer is polyacrylamide.

[0029] Example 2

[0030] A method for preparing a cement foamed board, comprising the following steps:

[0031] S1. Intermix 80 parts of ordinary Portland cement and 20 parts of rapid hardening sulphoaluminate cement and mix them evenly to form a blended cement;

[0032] S2. Mix and stir the blended cement, 3 parts of fiber, 2 parts of foam stabilizer, 6 parts of coagulant, 0.75 part of catalyst and 60 parts of water until a pasty mixture is formed;

[0033] S3. Add 6 parts of hydrogen peroxide to the mixture, stir evenly and then pour it into a mold;

[0034] S4. Place the mold in a place with suitable temperature, and introduce carbon dioxide gas into the mold. After the mixture in the mold is cured, a cement foamed board is obtained.

[0035] Among them, the fiber is polypropylene fiber, the catalyst is manganese dioxide, the coagulant is calcium oxide, and the foam stabilizer is polyvinyl alcohol.

[0036] Example 3

[0037] A method for preparing a cement foamed board, comprising the following steps:

[0038] S1. Intermix 85 parts of ordinary Portland cement and 15 parts of rapid hardening sulphoaluminate cement and mix them evenly to form a blended cement;

[0039] S2. Mix and stir the blended cement, 4 parts of fiber, 3 parts of foam stabilizer, 8 parts of coagulant, 1 part of catalyst and 65 parts of water until a pasty mixture is formed;

[0040] S3. Add 8 parts of hydrogen peroxide to the mixture, stir evenly and then pour it into a mold;

[0041] S4. Place the mold in a place with suitable temperature, and introduce carbon dioxide gas into the mold. After the mixture in the mold solidifies, a cement foamed board is obtained.

[0042] Among them, the fiber is polypropylene fiber, the catalyst is manganese dioxide, the coagulant is calcium oxide, and the foam stabilizer is polyvinyl alcohol.

[0043] Comparative example

[0044] A cement foamed board made of ordinary Portland cement by conventional means.

[0045] Test results

[0046] 1. Hardening time of foamed cement board

[0047] Record the initial setting and final setting times of the three examples and the comparative example in the test. See Table 1.

[0048] Table 1

[0049]

[0050]

[0051] 2. Compressive strength of foamed cement board

[0052] Conduct compressive strength tests on the three examples and the comparative example in accordance with the relevant regulations in the national standard "GB / T 11969-2008 Test Methods for Properties of Autoclaved Aerated Concrete". The results are shown in Table 2.

[0053] Table 2

[0054]

[0055] 3. Flexural strength of cement foamed board

[0056] Conduct flexural strength tests on the three examples and the comparative example in accordance with the relevant regulations in "GB / T 11971-1997 Test Methods for Mechanical Properties of Autoclaved Aerated Concrete". The results are shown in Table 3.

[0057] Table 3

[0058]

[0059] The above is only the preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in the relevant field. And any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A cement foam board, characterized in that: The invention comprises the following raw materials in parts by weight: 75-85 parts of ordinary Portland cement, 15-25 parts of rapid hardening sulphoaluminate cement, 4-8 parts of accelerator, 4-8 parts of hydrogen peroxide, 2-4 parts of fiber, 1-3 parts of foam stabilizer, 0.5-1 parts of catalyst and 55-66 parts of water.

2. A cement foam board according to claim 1, characterized in that: The fibers are polypropylene fibers.

3. The cement foam board according to claim 1, characterized in that: The catalyst is manganese dioxide.

4. The cement foam board according to claim 1, characterized in that: The coagulant is calcium oxide.

5. A cement foam board according to claim 1, characterized in that: The foam stabilizer is any one of polyacrylamide, polyvinyl alcohol and silicone resin.

6. A method for preparing the cement foam board according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Blending ordinary salt cement and rapid hardening sulphoaluminate cement and mixing them evenly to form mixed cement; S2, mixing the cement, fiber, foam stabilizer, coagulant, catalyst and water until the mixture is in a paste state; S3, add hydrogen peroxide to the mixture and stir evenly, then pour into the mold; S4. Place the mold in a place with suitable temperature, and introduce carbon dioxide gas into the mold, and obtain the cement foam board after the mixture in the mold is solidified.

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