Foam concrete formula and production process

Abstract

The invention provides a foam concrete formula and a production process. The foam concrete formula comprises the following raw materials in parts by weight: 150-200 parts of cement, 45-75 parts of a mineral admixture, 10-20 parts of a foaming agent, 30-40 parts of aggregate, 10-20 parts of an additive, 10-20 parts of a cracking agent and a proper amount of water. According to the present invention, the foam concrete is easily cracked, the cracking agent can effectively solve the problem, and the surface tension of the foam concrete is increased by the cracking agent through the surface tension reinforcing agent so as to reduce the chance of the crack generation; the cement hydration reaction is promoted, so that the compressive strength and splitting compressive strength of the foam concrete are remarkably improved, and the service life of the foam concrete is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of foamed concrete, and in particular to a foamed concrete formula and a production process. Background Art

[0002] Foamed concrete is a concrete product with a certain strength and containing a large number of tiny closed pores by introducing air or nitrogen, carbon dioxide, oxygen and other gases into the concrete slurry through chemical or physical means according to application needs, and then formed through reasonable curing. Foamed concrete is widely used in road backfill, thermal insulation roof and internal partition walls due to its light weight and durability.

[0003] The invention patent application CN112028569A published in China discloses a foam concrete formula and its preparation method and application: 100-130 parts of cement, 150-200 parts of lightweight aggregate, 30-50 parts of fly ash, 50-80 parts of water, 8-30 parts of TPU particles, 6-16 parts of composite foaming agent, and 0.2-0.6 parts of thickener. The TPU particles, composite foaming agent, thickener and water are mixed and stirred until bubbles are generated and then continued to stir to obtain a foam solution; fly ash and lightweight aggregate are mixed and stirred, and then cement is added and continued to stir to obtain concrete slurry; the foam solution and concrete slurry are mixed and stirred and then poured and molded for curing.

[0004] The inventors believe that the above technology has the following defects: traditional foam concrete has a large drying shrinkage rate and is prone to cracking risks. After long-term use, the compressive strength of foam concrete is low, which shortens the service life of foam concrete. Therefore, it is necessary to improve the design of foam concrete in related technologies. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a foamed concrete formula and a production process, wherein the foamed concrete formula can.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] A foamed concrete formula comprises the following raw materials in parts by weight: 150-200 parts of cement, 45-75 parts of mineral admixture, 10-20 parts of foaming agent, 30-40 parts of aggregate, 10-20 parts of admixture, 10-20 parts of cracking agent and appropriate amount of water.

[0008] Preferably, the composition of the foamed concrete formula also includes the following raw materials in parts by weight: 30-40 parts of metakaolin and 10-20 parts of fiber admixture.

[0009] Preferably, the composition of the foamed concrete formula also includes the following raw materials in parts by weight: 10-20 parts of eggshell powder.

[0010] Preferably, the mineral admixture is one or more of fly ash, gangue, light-burned aluminate or silica fume.

[0011] Preferably, the foaming agent is one or more of sodium alkylbenzene sulfonate, olefin sulfonate, and alkyl ethoxy sulfonate.

[0012] Preferably, the fiber admixture is one or more of polypropylene fiber, polyester fiber, carbon fiber or glass fiber.

[0013] A production process of a foamed concrete formulation includes the following steps:

[0014] S1. Weigh cement, mineral admixture, foaming agent, aggregate, admixture and cracking agent in proportion, add appropriate amount of water, put into a mixing device and mix evenly;

[0015] S2, weighing kaolin, fiber admixture and eggshell powder in proportion, adding them to the mixture obtained in S1, and mixing them evenly at a speed of 600r / min-700r / min;

[0016] S3, pouring the stirred mixed slurry into a mold, placing the mold in a concrete carbonation curing box with a carbon dioxide concentration of 30%-40% at normal pressure for pre-curing for 20min-25min to obtain foamed concrete, and after demolding, the finished product is obtained.

[0017] Preferably, in step S1, before adding water, the water is magnetized in an environment with a magnetic field strength of 330 mT for 20 min-30 min.

[0018] The beneficial effects of the present invention are:

[0019] Cracks are prone to occur in foam concrete, and crack removers can effectively solve this problem. Crack removers increase the surface tension of foam concrete through surface tension enhancers, thereby reducing the chance of cracks.

[0020] Fly ash has a wide source, low price, and certain activity, which can significantly improve the strength of foamed concrete and improve the effect after molding. The toughening agent is one of gelatin, maltodextrin, sodium dodecylbenzene sulfonate or hydroxypropyl methylcellulose. The addition of maltodextrin has a certain promoting effect on the foaming ability of the foaming agent. Gelatin, maltodextrin, sodium dodecylbenzene sulfonate or hydroxypropyl methylcellulose can enhance the toughness of the foam film wall, reduce tension, improve the quality of the foam film to enhance the stability of the foam, which is beneficial to improve the foaming effect of the foaming agent, thereby improving the stability and quality of the product.

[0021] The amount of mineral admixtures should not exceed 40%, otherwise the foam concrete will not be hard enough. The addition of fiber admixtures makes the stress distribution in the concrete uniform, enhancing the tensile strength, flexural strength and toughness of the concrete.

[0022] Eggshell powder has a small particle size. After being added to foamed concrete, it improves the pore structure of foamed concrete, making the pore size smaller, and improving the anti-seepage and anti-corrosion properties of foamed concrete. In addition, the large-scale use of eggshell powder can recycle resources, reduce the amount of cement used, protect the environment, and reduce costs. In addition, since eggshell powder has a low specific gravity, adding eggshell powder will reduce the bulk density of mortar. Eggshell powder is also easy to grind into tiny particles and can be more evenly distributed in cement. At the same time, the high calcium content of eggshell powder can be combined with aluminum in cement and kaolin to increase the total amount of hydration products and form a dense CSH (calcium silicate hydrate) gel, thereby improving the microstructure of cement and reducing voids and porosity to enhance the strength of foamed concrete.

[0023] Magnetized water can reduce the water-cement ratio, change the structure of foamed concrete, reduce the shrinkage pore energy of concrete, reduce the water permeability of foamed concrete, and greatly improve its frost resistance. Adding magnetized water to foamed concrete has a good effect on improving the concrete's anti-permeability, volume stability and resistance to freeze-thaw cycles, thereby improving the overall durability of foamed concrete.

[0024] Finally, magnetized water replaces ordinary water to mix foamed concrete, which improves the activity of cement and kaolin. The activity of water molecules in magnetized water better exerts the filling effect of kaolin, improves the volcanic ash activity of kaolin, and promotes the cement hydration reaction, thereby significantly improving the compressive strength and splitting compressive strength of foamed concrete. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1:

[0027] The present embodiment discloses a foamed concrete formula, which is prepared from the following raw materials in proportion: 150 parts of cement, 45 parts of mineral admixture, 10 parts of foaming agent, 30 parts of aggregate, 10 parts of admixture, 10 parts of crack agent, 30 parts of metakaolin and 10 parts of fiber admixture, 10 parts of eggshell powder, and an appropriate amount of water.

[0028] Among them, the mineral admixture is fly ash.

[0029] The foaming agent is sodium alkylbenzene sulfonate.

[0030] The admixture is a dispersant.

[0031] The fiber admixture is.

[0032] This embodiment also discloses a production process of a foamed concrete formula, comprising the following steps:

[0033] S1. Weigh cement, mineral admixture, foaming agent, aggregate, admixture, and cracking agent in proportion, add an appropriate amount of water that has been magnetized for 20 minutes at a magnetic field strength of 330 mT, and mix them evenly in a stirring device;

[0034] S2, weighing kaolin, fiber admixture and eggshell powder in proportion, adding them to the mixture obtained in S1, and mixing at a speed of 600 r / min;

[0035] S3. Pour the stirred mixed slurry into a mold, place the mold in a concrete carbonation curing box with a carbon dioxide concentration of 30% at normal pressure for pre-curing for 20 minutes to obtain foamed concrete, and after demolding, the finished product is obtained.

[0036] Embodiment 2:

[0037] The present embodiment discloses a foamed concrete formula, which is prepared from the following raw materials in proportion: 200 parts of cement, 75 parts of mineral admixture, 20 parts of foaming agent, 40 parts of aggregate, 20 parts of admixture, 20 parts of crack agent, 40 parts of metakaolin and 20 parts of fiber admixture, 20 parts of eggshell powder, and an appropriate amount of water.

[0038] Among them, the mineral admixture is gangue.

[0039] The blowing agent is olefin sulfonate.

[0040] The admixture is a waterproofing agent.

[0041] The fiber blend is polyester fiber.

[0042] This embodiment also discloses a production process of a foamed concrete formula, comprising the following steps:

[0043] S1. Weigh cement, mineral admixture, foaming agent, aggregate, admixture, and cracking agent in proportion, add an appropriate amount of water that has been magnetized for 30 minutes at a magnetic field strength of 330 mT, and mix well in a stirring device;

[0044] S2, weighing kaolin, fiber admixture and eggshell powder in proportion, adding them to the mixture obtained in S1, and mixing at a speed of 700 r / min;

[0045] S3. Pour the stirred mixed slurry into a mold, place the mold in a concrete carbonation curing box with a carbon dioxide concentration of 40% at normal pressure for pre-curing for 25 minutes to obtain foamed concrete, and after demolding, the finished product is obtained.

[0046] Embodiment 3:

[0047] The present embodiment discloses a foamed concrete formula, which is prepared from the following raw materials in proportion: 175 parts of cement, 60 parts of mineral admixture, 15 parts of foaming agent, 35 parts of aggregate, 15 parts of admixture, 15 parts of crack agent, 35 parts of metakaolin and 15 parts of fiber admixture, 15 parts of eggshell powder, and an appropriate amount of water.

[0048] Among them, the mineral admixture is light-burned aluminate.

[0049] The blowing agent is alkyl ethoxy sulfonate.

[0050] The admixture is an early strength agent.

[0051] The fiber admixture is carbon fiber.

[0052] This embodiment also discloses a production process of a foamed concrete formula, comprising the following steps:

[0053] S1. Weigh cement, mineral admixture, foaming agent, aggregate, admixture, and cracking agent in proportion, add an appropriate amount of water that has been magnetized for 25 minutes at a magnetic field strength of 330 mT, and mix them evenly in a stirring device;

[0054] S2, weighing kaolin, fiber admixture and eggshell powder in proportion, adding them to the mixture obtained in S1, and mixing at a speed of 650 r / min;

[0055] S3. Pour the stirred mixed slurry into a mold, place the mold in a concrete carbonation curing box with a carbon dioxide concentration of 35% at normal pressure for pre-curing for 23 minutes, and obtain foamed concrete. After demolding, the finished product is obtained.

[0056] Comparative Example 1:

[0057] A foamed concrete formula, the foamed concrete formula differs from Example 3 only in that no crack agent is added.

[0058] Comparative Example 2:

[0059] A foamed concrete formula, the foamed concrete formula differs from Example 3 only in that no metakaolin is added.

[0060] Comparative Example 3:

[0061] A foamed concrete formulation, the foamed concrete formulation differs from Example 3 only in that no fiber admixture is added.

[0062] Comparative Example 4:

[0063] A foamed concrete formula, the foamed concrete formula differs from Example 3 only in that no eggshell powder is added.

[0064] Comparative Example 5:

[0065] A foamed concrete formula, the foamed concrete formula differs from Example 3 only in that the water is not magnetized.

[0066] The foamed concrete formulas obtained in the above Examples 1-3 and Comparative Examples 1-5 were subjected to performance tests to measure the comprehensive performance of the foamed concrete formulas. The results are shown in Table 1.

[0067] Table 1 Performance parameters of the foamed concrete formula obtained in Examples 1-3 and Comparative Examples 1-5

[0068] Group Splitting compressive strength / MPa Compressive strength / MPa Shrinkage rate / % Example 1 2.91 44.3 0.07 Example 2 2.89 44.7 0.07 Example 3 3.02 45.4 0.06 Comparative Example 1 2.28 33.6 0.81 Comparative Example 2 1.89 29.4 0.94 Comparative Example 3 2.31 34.2 0.77 Comparative Example 4 2.41 34.6 0.69 Comparative Example 5 2.49 35.8 0.73

[0069] In summary:

[0070] Cracks are prone to occur in foam concrete, and crack removers can effectively solve this problem. Crack removers increase the surface tension of foam concrete through surface tension enhancers, thereby reducing the chance of cracks.

[0071] Magnetized water replaces ordinary water in mixing foamed concrete, which improves the activity of cement and kaolin. The activity of water molecules in magnetized water better exerts the filling effect of kaolin, improves the activity of kaolin volcanic ash, and promotes the cement hydration reaction, thereby significantly improving the compressive strength and splitting compressive strength of foamed concrete.

[0072] The high calcium content of eggshell powder can combine with the aluminum in cement and kaolin to increase the total amount of hydration products and form a dense CSH (calcium silicate hydrate) gel, thereby improving the microstructure of cement and reducing voids and porosity to enhance the strength of foamed concrete.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A foamed concrete formula, characterized in that: The components of the foam concrete formula include the following raw materials in parts by weight: 150-200 parts of cement, 45-75 parts of mineral admixture, 10-20 parts of foaming agent, 30-40 parts of aggregate, 10-20 parts of admixture, 10-20 parts of cracking agent and appropriate amount of water.

2. The foamed concrete formula according to claim 1, characterized in that: The composition of the foamed concrete formula also includes the following raw materials in parts by weight: 30-40 parts of metakaolin and 10-20 parts of fiber admixture.

3. The foamed concrete formula according to claim 2, characterized in that: The composition of the foamed concrete formula also includes the following raw materials in parts by weight: 10-20 parts of eggshell powder.

4. The foamed concrete formula according to claim 3, characterized in that: The mineral admixture is one or more of fly ash, gangue, light-burned aluminate or silica fume.

5. The foamed concrete formula according to claim 3, characterized in that: The foaming agent is one or more of sodium alkylbenzene sulfonate, olefin sulfonate, and alkyl ethoxy sulfonate.

6. The foamed concrete formula according to claim 3, characterized in that: The fiber admixture is one or more of polypropylene fiber, polyester fiber, carbon fiber or glass fiber.

7. A production process of a foamed concrete formulation according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: S1. Weigh cement, mineral admixture, foaming agent, aggregate, admixture and cracking agent in proportion, add appropriate amount of water, put into a mixing device and mix evenly; S2, weighing kaolin, fiber admixture and eggshell powder in proportion, adding them to the mixture obtained in S1, and mixing them evenly at a speed of 600r / min-700r / min; S3, pouring the stirred mixed slurry into a mold, placing the mold in a concrete carbonation curing box with a carbon dioxide concentration of 30%-40% at normal pressure for pre-curing for 20min-25min to obtain foamed concrete, and after demolding, the finished product is obtained.

8. The production process of the foamed concrete formula according to claim 7, characterized in that: In step S1, before adding water, the water is magnetized in an environment with a magnetic field strength of 330 mT for 20 min-30 min.