Foamed concrete, admixture thereof, and admixture adding method

Abstract

The present invention relates to the technical field of building materials, and a kind of foamed concrete and its admixture and admixture adding method are provided. The admixture of the present invention is composed of component A and component B, and by mass fraction, the component A is composed of 130-160 parts of sulfonated acetone formaldehyde condensation products, 40-60 parts of lignin sulfonate, 80-120 parts of calcium formate, 8-25 parts of hydroxypropyl starch ether or soluble starch, and 4-8 parts of sodium sulfate, and the component B is composed of 30-60 parts of triethanolamine or triisopropanolamine, and 18-25 parts of hydroxypropyl methylcellulose. The admixture of the present invention is designed for coal slag, has the function of alkali excitation, makes coal slag self-reaction, can replace the amount of part of cement, the admixture of the present invention can fully replace fly ash, reduces material cost, and the present invention also provides a method for adding an admixture, which is added in two steps to ensure that the admixture plays the best role with the minimum amount.

Description

Technical Field

[0001] The invention relates to the technical field of foamed concrete, in particular to foamed concrete and an admixture thereof and an admixture adding method. Background Art

[0002] At present, foamed concrete is mainly used in scenes such as roof insulation and roadbed fertilizer trough backfilling. It is less used in partition walls and enclosure walls. The main problem is unstable quality. The use of aerated bricks or ALC boards is troublesome to construct, the efficiency of manual masonry is low, and it is easy to have problems such as hollowing and cracking. The thermal insulation performance is also worse than that of foamed concrete. With the improvement of building energy consumption standards, the demand for foamed concrete walls with thermal insulation function has increased significantly. At present, foamed concrete with coal slag as aggregate is widely used. Most technicians follow the practice of ordinary concrete, use general polycarboxylic acid or naphthalene water reducers, add fly ash, and no longer add admixtures during the foaming process. The problem is that the particle size, bulk density, and carbon content of coal slag are unstable, resulting in segregation, sedimentation, bubble breaking, and high bulk density during the construction process. Concrete admixtures refer to substances added to improve and adjust the performance of concrete, which is a very important part of improving quality. Therefore, it is urgent to develop a new admixture for foamed concrete to address the above problems. Summary of the invention

[0003] The present invention provides a foamed concrete and an admixture thereof and an admixture adding method, and the specific implementation methods are as follows:

[0004] An admixture for foamed concrete, the admixture consisting of component A and component B, wherein, by weight, component A consists of 130-160 parts of sulfonated acetone formaldehyde condensate, 40-60 parts of lignin sulfonate, 80-120 parts of calcium formate, 8-25 parts of hydroxypropyl starch ether or soluble starch, and 4-8 parts of sodium sulfate, and component B consists of 30-60 parts of triethanolamine or triisopropanolamine and 18-25 parts of hydroxypropyl methylcellulose;

[0005] Furthermore, component A is composed of 150 parts of sulfonated acetone formaldehyde condensate, 50 parts of lignin sulfonate, 100 parts of calcium formate, 20 parts of hydroxypropyl starch ether or soluble starch, and 5 parts of sodium sulfate; component B is composed of 50 parts of triethanolamine or triisopropanolamine and 20 parts of hydroxypropyl methylcellulose;

[0006] Further, the lignin sulfonate is sodium lignin sulfonate, calcium lignin sulfonate or magnesium lignin sulfonate;

[0007] The present invention also provides a foamed concrete, which is added with the above-mentioned admixture for foamed concrete, wherein component A of the admixture is added during the concrete mixing process, and component B is added during the mixing and foaming process before pouring;

[0008] In addition, the present invention also provides a method for adding an admixture for foamed concrete, wherein component A is added during the concrete mixing process, and component B is added during the foaming process before pouring;

[0009] Further, component A is mixed and added into a mixer and mixed with concrete for 3-5 minutes;

[0010] Furthermore, the usage ratio of the component A to the cement in the concrete is 2.0-3.0:100 by weight;

[0011] Furthermore, the ratio of the component A to the cement in the concrete is 2.5:100 by mass.

[0012] Furthermore, the B component and the foaming liquid are mixed in a ratio of 40-85:1000 by mass and added in the mixing and foaming process before pouring;

[0013] Furthermore, the B component and the foaming liquid are mixed in a ratio of 70:1000 by mass and then added in the mixing and foaming process before pouring.

[0014] Due to the adoption of the above technical solution, the beneficial technical effects of the present invention are:

[0015] 1. The present invention provides an admixture for foamed concrete, which is designed for coal slag in concrete and has the function of alkali excitation, so that the coal slag itself reacts and can replace part of the cement dosage;

[0016] 2. The admixture of the present invention can improve workability, that is, improve viscosity and water retention;

[0017] 3. The admixture of the present invention can completely replace fly ash, thus reducing the material cost;

[0018] 4. The present invention also provides a method for adding an admixture, wherein the admixture is added in two steps to ensure that the admixture has the best effect with the least amount. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 making creative work are within the scope of protection of the present invention.

[0020] A foam concrete admixture, the admixture consists of component A and component B, wherein the component A consists of 130-160 parts of sulfonated acetone formaldehyde condensate, 40-60 parts of lignin sulfonate, 80-120 parts of calcium formate, 8-25 parts of hydroxypropyl starch ether or soluble starch, and 4-8 parts of sodium sulfate, and the component B consists of 30-60 parts of triethanolamine or triisopropanolamine, and 18-25 parts of hydroxypropyl methylcellulose; in the present invention, the lignin sulfonate is used as a dispersant and a flocculant, and can greatly improve the workability of concrete; the hydroxypropyl starch ether has a medium viscosity, good rapid thickening ability and certain water retention, and its addition enables the foam concrete to retain more water and a certain viscosity, and can remain uniform for a long time during the construction process without separation Analysis, which will make the product have good consistency, full corners and easy construction; Hydroxypropyl methylcellulose plays the role of stabilizing foam, so that the foam can be kept as long as possible without breaking and merging with each other; Sodium sulfate has a quick-setting effect, shortening the final setting time of cement. Sodium sulfate, as an alkali activator, cooperates with sulfonated acetone formaldehyde condensate to promote the hydration reaction of coal slag concrete and improve the strength of the product; Triisopropanolamine and calcium formate improve the early strength of cement around the foam wall, shorten the demolding time and improve the construction efficiency; Sulfonated acetone formaldehyde condensate has the effect of activating coal slag, and sodium sulfate is a good alkali activator for coal slag. Through activation and excitation, the coal slag itself can be hydrated to form cement stone, which improves the strength (the strength can be kept unchanged and the amount of cement can be reduced), so it is easier to obtain a product with low bulk density.

[0021] Example 1

[0022] The admixture consists of component A and component B. Calculated by weight, component A consists of 150 parts of sulfonated acetone formaldehyde condensate, 50 parts of sodium lignin sulfonate, 100 parts of calcium formate, 20 parts of hydroxypropyl starch ether, and 5 parts of sodium sulfate; and component B consists of 50 parts of triethanolamine and 20 parts of hydroxypropyl methylcellulose.

[0023] The method of adding admixtures is as follows: after mixing component A evenly, add it to the mixer with cement at a ratio of 2.5:100, stir for 4 minutes and load it into the tank truck; after mixing component B with the foaming liquid at a ratio of 70:1000, add it in the mixing and foaming process before pouring. The mass ratio of cement to coal slag in the concrete is 1:3.

[0024] Example 2

[0025] The admixture consists of component A and component B. Calculated by weight, component A consists of 130 parts of sulfonated acetone formaldehyde condensate, 40 parts of calcium lignin sulfonate, 80 parts of calcium formate, 8 parts of hydroxypropyl starch ether, and 4 parts of sodium sulfate; and component B consists of 30 parts of triethanolamine and 18 parts of hydroxypropyl methylcellulose.

[0026] The method of adding admixtures is as follows: after mixing component A evenly, add it to the mixer with cement at a ratio of 2:100, stir for 3 minutes, and then load it into the tank truck; after mixing component B with the foaming liquid at a ratio of 40:1000, add it in the mixing and foaming process before pouring. The mass ratio of cement to coal slag in the concrete is 1:3.

[0027] Example 3

[0028] The admixture consists of component A and component B. Calculated by weight, component A consists of 160 parts of sulfonated acetone formaldehyde condensate, 60 parts of magnesium lignin sulfonate, 120 parts of calcium formate, 25 parts of soluble starch, and 8 parts of sodium sulfate; and component B consists of 60 parts of triethanolamine and 25 parts of hydroxypropyl methylcellulose.

[0029] The method of adding admixtures is as follows: after mixing component A evenly, add it to the mixer with cement at a ratio of 3:100, stir for 5 minutes, and then load it into the tank truck; after mixing component B with the foaming liquid at a ratio of 85:1000, add it in the mixing and foaming process before pouring. The mass ratio of cement to coal slag in the concrete is 1:3.

[0030] Example 4

[0031] The admixture consists of component A and component B. Calculated by weight, component A consists of 160 parts of sulfonated acetone formaldehyde condensate, 60 parts of sodium lignin sulfonate, 120 parts of calcium formate, 25 parts of soluble starch, and 8 parts of sodium sulfate; and component B consists of 30 parts of triethanolamine and 18 parts of hydroxypropyl methylcellulose.

[0032] The method of adding admixtures is as follows: after mixing component A evenly, add it to the mixer with cement at a ratio of 3:100, stir for 5 minutes, and then load it into the tank truck; after mixing component B with the foaming liquid at a ratio of 85:1000, add it in the mixing and foaming process before pouring. The mass ratio of cement to coal slag in the concrete is 1:3.

[0033] Example 5

[0034] The admixture consists of component A and component B. Calculated by weight, component A consists of 130 parts of sulfonated acetone formaldehyde condensate, 40 parts of magnesium lignin sulfonate, 80 parts of calcium formate, 8 parts of soluble starch, and 4 parts of sodium sulfate; and component B consists of 60 parts of triethanolamine and 25 parts of hydroxypropyl methylcellulose.

[0035] The method of adding admixtures is as follows: after mixing component A evenly, add it to the mixer with cement at a ratio of 3:100, stir for 5 minutes, and then load it into the tank truck; after mixing component B with the foaming liquid at a ratio of 60:1000, add it in the mixing and foaming process before pouring. The mass ratio of cement to coal slag in the concrete is 1:3.

[0036] Comparative Example 1

[0037] Compared with Example 1, component A and component B are added simultaneously during the concrete mixing process, and the other parts are exactly the same.

[0038] Comparative Example 2

[0039] Compared with Example 1, no sulfonated acetone formaldehyde condensate was added, and the other parts were exactly the same.

[0040] Comparative Example 3

[0041] Compared with Example 1, sodium lignin sulfonate was not added, and other parts were exactly the same.

[0042] Comparative Example 4

[0043] Compared with Example 1, calcium formate was not added, and other parts were exactly the same.

[0044] Comparative Example 5

[0045] Compared with Example 1, hydroxypropyl starch ether was not added, and the other parts were exactly the same.

[0046] Comparative Example 6

[0047] Compared with Example 1, no sodium sulfate was added, and the other parts were exactly the same.

[0048] Comparative Example 7

[0049] Compared with Example 1, hydroxypropyl methylcellulose was not added, and the other parts were exactly the same.

[0050] Comparative Example 8

[0051] Compared with Example 1, triisopropanolamine was not added, and the other parts were exactly the same.

[0052] The admixtures of Examples 1-5 and Comparative Examples 1-8 were added to concrete according to their respective addition methods to prepare foamed concrete with a wet bulk density of 1000 g / L. A transparent plastic pipe with a diameter of 200 mm and a height of 3 meters was used to simulate a wall for a settlement test. A 5L measuring cup was used to perform a comparative test of water seepage. Three groups of tests were performed for each test using a 100x100x100mm triple test mold. The test results are shown in Table 1.

[0053] Table 1 Performance results of foamed concrete prepared by adding the admixtures of Examples 1-5 and Comparative Examples 1-8 to concrete according to their respective addition methods

[0054]

[0055]

[0056] The test results are analyzed as follows: Through the comparison of test data, we can see that the results of the embodiments meet the requirements in the actual application process, but the ratio results of embodiments 1, 3, and 4 are the best; the strength of comparative examples 1, 2, 3, 4, 5, 6, and 8 are all reduced, near the standard requirement value of 3.5MPa, and the actual construction process may deviate from the standard requirements and the sedimentation value of comparative example 5 is also seriously exceeded; although the strength of comparative example 7 meets the requirements, the sedimentation is too large and does not meet the requirements. 1. Hydroxypropyl starch ether or soluble starch has a great influence on the viscosity of the slurry. If the addition amount is small or not added, the viscosity of the slurry is low, the suspension ability is weak, and the particles with high density sink to the bottom, which will cause severe stratification and segregation. 2. The role of hydroxypropyl methylcellulose is to stabilize foam, absorb water and keep moisture. The presence or absence of its addition has a great influence on the sedimentation and water secretion. 3. Sulfonated acetone formaldehyde condensate and sodium lignin sulfonate are not water reducers in foam concrete. Their role is to activate the admixture coal slag and make the cement fully diffuse. They work together with sodium sulfate to make the admixture with increased activity react with water to form cement stone under the stimulation of sodium sulfate, thereby increasing the strength. 4. Calcium formate can increase the early strength of the material, facilitate the demoulding as soon as possible during construction, and have little effect on the final strength. Calcium formate can also have a good diffusion effect on cement. 5. The addition of triethanolamine can reduce the amount of cementitious material or increase the strength of the material. In this experiment, it was not added and the strength was reduced. This application comprehensively considers the performance of each material, and by regulating the type and amount of the material, each component is coordinated to prepare a high-performance foam concrete admixture. In addition, the admixture is divided into two components A and B mainly because when the calcium formate in component A is added together with sodium sulfate, due to the high concentration, a reaction occurs to generate sodium formate and calcium sulfate precipitation, which reduces the effect of the two components. However, the two substances do not react in a very dilute solution, and they basically do not react after the concentration is reduced after being added separately and diluted.

[0057] In summary, the types of admixtures we use are synergistic, making the slurry easy to work with, with small settlement, low water seepage, and no stratification and segregation. The strength of the foamed concrete is improved by hydration reaction of the admixture itself through activation and alkali excitation.

[0058] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for adding an admixture to foamed concrete, It is characterized in that The admixture consists of component A and component B. Calculated by weight, the component A consists of 130-160 parts of sulfonated acetone formaldehyde condensate, 40-60 parts of lignin sulfonate, 80-120 parts of calcium formate, 8-25 parts of hydroxypropyl starch ether or soluble starch, and 4-8 parts of sodium sulfate; the component B consists of 30-60 parts of triethanolamine or triisopropanolamine and 18-25 parts of hydroxypropyl methylcellulose. The component A is added during the concrete mixing process, and the component B is added during the mixing and foaming process before pouring.

2. A method for adding an admixture for foamed concrete according to claim 1, It is characterized in that The component A is composed of 150 parts of sulfonated acetone formaldehyde condensate, 50 parts of lignin sulfonate, 100 parts of calcium formate, 20 parts of hydroxypropyl starch ether or soluble starch, and 5 parts of sodium sulfate; the component B is composed of 50 parts of triethanolamine or triisopropanolamine and 20 parts of hydroxypropyl methylcellulose.

3. A method for adding an admixture for foamed concrete according to claim 1 or 2, It is characterized in that The lignin sulfonate is sodium lignin sulfonate, calcium lignin sulfonate or magnesium lignin sulfonate.

4. A method for adding an admixture for foamed concrete according to claim 1, It is characterized in that After mixing component A, add it into the mixer and mix with the concrete for 3-5 minutes.

5. A method for adding an admixture for foamed concrete according to claim 4, It is characterized in that Calculated by mass, the usage ratio of the component A to the cement in the concrete is 2.0-3.0:

100.

6. A method for adding an admixture for foamed concrete according to claim 4 or 5, It is characterized in that Calculated by mass, the usage ratio of the component A to the cement in the concrete is 2.5:

100.

7. The method for adding an admixture for foamed concrete according to claim 1, It is characterized in that Calculated by weight, the B component and the foaming liquid are mixed in a ratio of 40-85:1000 and added in the mixing and foaming process before pouring.

8. A method for adding an admixture for foamed concrete according to claim 7, It is characterized in that Calculated by weight, the B component and the foaming liquid are mixed in a ratio of 70:1000 and added in the mixing and foaming process before pouring.

9. A foamed concrete, It is characterized in that In the preparation process of foamed concrete, the admixture is added by the method for adding admixture for foamed concrete according to any one of claims 1 to 8, component A of the admixture is added during the concrete mixing process, and component B is added during the mixing and foaming process before pouring.

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