Geopolymer aerated concrete material based on active silicon powder gas generation and preparation method of geopolymer aerated concrete material

Abstract

The invention discloses a geopolymer aerated concrete material based on active silicon powder gas generation and a preparation method of the geopolymer aerated concrete material. The geopolymer aerated concrete material based on active silicon powder gas generation comprises a powder component and a liquid component, the powder component comprises 70-100 parts by weight of a silicon-aluminum material, 0-30 parts by weight of mineral powder, active silicon powder and a retarder; active silicon powder is used as a foaming agent; the liquid component comprises an alkali metal silicate solution; when in use, the powder component and the liquid component are mixed according to the mass ratio of 1: (0.5-1.0). According to the geopolymer aerated concrete material based on active silicon powder gas generation, the preparation process can be carried out at normal temperature, the reaction process is mild and controllable, the process is simple, high-temperature and high-pressure steam curing is not needed, and meanwhile, the prepared geopolymer aerated concrete is light, high in strength, excellent in heat preservation and heat insulation performance, low in cost and suitable for industrial production. The method is suitable for industrialized production and cast-in-place construction of building thermal insulation materials.

Description

Technical Field

[0001] The invention relates to the technical field of aerated concrete, in particular to a geopolymer aerated concrete material based on active silica powder gasification and a preparation method thereof. Background Art

[0002] Aerated concrete is a lightweight building material with excellent thermal insulation and heat preservation properties, and is widely used in roof and exterior wall insulation of buildings. However, the existing aerated concrete preparation method mainly relies on gas-forming agents such as aluminum powder or hydrogen peroxide, which react violently and require strict control of reaction conditions. At the same time, the existing aerated concrete usually requires high-temperature and high-pressure autoclaves for maintenance, which has high energy consumption and large equipment investment, and the production process will emit a large amount of greenhouse gases, which is not conducive to energy conservation and environmental protection. In addition, aerated concrete can only be prefabricated in the factory and then transported to the construction site for installation, which has the problems of high transportation cost, low construction efficiency, and difficulty in adapting to various complex structure insulation construction. Summary of the invention

[0003] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of the present invention is to provide a geopolymer aerated concrete material based on activated silica powder gasification, using activated silica powder as a gas generating agent. When used, the entire preparation process of the geopolymer aerated concrete can be carried out at room temperature, the reaction process is mild and controllable, and no high temperature and high pressure curing is required. At the same time, the geopolymer aerated concrete prepared by using the geopolymer aerated concrete has a small pore size, uniform pore distribution, and high compressive strength.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] The present invention provides a geopolymer aerated concrete material based on active silica powder gasification, comprising a powder component and a liquid component;

[0006] The powder component comprises 70-100 parts by weight of silicon-alumina material, 0-30 parts by weight of mineral powder, active silicon powder and retarder; the active silicon powder accounts for 0.06-0.1% of the total weight of the powder component; the retarder accounts for 0-0.5% of the total weight of the powder component; the active silicon powder is a gas generating agent;

[0007] The liquid component includes an alkali metal silicate solution with a modulus of 1.5-2.0 and a solid content of 30-50wt%;

[0008] When in use, the powder component and the liquid component are mixed in a mass ratio of 1:(0.5-1.0).

[0009] Preferably, the particle size of the active silicon powder is greater than 1000 mesh and the specific surface area is greater than 10m 2 / g.

[0010] Preferably, the gas evolution induction period of the active silicon powder is 15-30 minutes, and the volumetric gas evolution rate is 3-8% / min.

[0011] Preferably, the silicon-alumina material is at least one of fly ash, metakaolin, coal gangue, red mud, and tailings containing highly active silicon-alumina components.

[0012] Preferably, the retarder is at least one of citric acid, tartaric acid, gluconic acid, molasses, borax, sodium tripolyphosphate, sodium fluoride, potassium fluoride, sucrose, xylose, barium chloride, lignin sulfonate and boric acid.

[0013] Preferably, the alkali metal silicate solution is a potassium silicate solution or a sodium silicate solution.

[0014] The present invention also provides a method for preparing geopolymer aerated concrete material based on active silica powder gasification, which is used for preparing factory-prefabricated geopolymer aerated concrete products or preparing geopolymer aerated concrete poured on construction sites.

[0015] Preferably, the preparation of the factory-prefabricated polymer aerated concrete product comprises the following steps:

[0016] 1) Add the powder component and the liquid component into a stirring device according to the proportion, add water at a water-to-solid ratio of 0.35-0.40, stir evenly, and obtain a pourable slurry;

[0017] 2) injecting the slurry into a mold, allowing it to stand to generate gas, solidifying and forming, and demolding to obtain a prefabricated porous geopolymer aerated concrete product;

[0018] 3) Curing the geopolymer aerated concrete product; the curing is natural curing or steam curing.

[0019] Preferably, the steam curing is specifically: performing steam curing at a temperature of 60-90° C. for 24-48 hours.

[0020] Preferably, the preparation of the construction site cast geopolymer aerated concrete comprises the following steps:

[0021] 1) At the construction site, add the powder component and the liquid component into the mixing equipment according to the proportion, add water at a water-solid ratio of 0.35-0.40, stir evenly, and obtain a pourable slurry;

[0022] 2) The slurry is pumped to the construction site through pumping equipment and cast in situ. The slurry is gasified and solidified in situ at the construction site;

[0023] 3) After the slurry solidifies and takes shape, natural curing is carried out.

[0024] Preferably, the geopolymer aerated concrete is used for thermal insulation construction of complex structures, such as roof insulation, wall insulation, and pipeline insulation.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] (1) The geopolymer aerated concrete material based on active silica powder gasification of the present invention adopts a high specific surface area (greater than 10m 2 / g) of active silica powder is used as a gas generating agent. The active silica powder has a gas generation induction period of 15-30 minutes and a volumetric gas generation rate of 3-8% / min in an alkaline environment. The gas generation induction period refers to the time interval from the contact of the active silica powder with the alkaline liquid to the start of obvious gas generation. The gas generation induction period allows the slurry to have sufficient operating time during the mixing and pouring process to avoid premature gas generation and affect the construction performance; at the same time, the gas generation induction period is also sufficient to ensure that the slurry is fully gasified before solidification to form a uniform pore structure. The volumetric gas generation rate refers to the percentage of the volume of gas generated per unit time to the total volume of the slurry, and this indicator is measured at 25°C and 1 standard atmosphere. By adjusting the components of geopolymer aerated concrete, the gas generation induction period and gas generation rate of the active silica powder can be controlled, the mildness and controllability of the reaction process can be ensured, and a uniform pore structure is finally formed, which is suitable for factory prefabrication and on-site cast-in-place construction.

[0027] (2) The geopolymer aerated concrete material based on activated silica powder gasification of the present invention improves the construction flexibility of geopolymer aerated concrete. The powder and liquid components of the present invention can be independently packaged and transported, providing dual construction options of factory prefabrication and on-site pouring. They can be mixed and stirred at the construction site to achieve instant pouring of the slurry and in-situ gasification solidification, significantly improving the flexibility and efficiency of construction.

[0028] (3) The geopolymer aerated concrete material based on active silica powder gasification of the present invention improves the adaptability of geopolymer aerated concrete, and the cast-in-place construction technology is particularly suitable for the insulation construction of complex structures such as roofs, walls, and pipes, and has good compatibility with other structural materials. Among them, roof insulation: the slurry can be directly pumped to the roof to form an insulation layer, which forms a good combination with the roof structure to avoid the generation of cold bridges and hot bridges. Wall insulation: It can be used to fill wall cavities, or as an external wall insulation material to improve the thermal insulation performance of the building. Pipeline insulation: It can be used to wrap pipes to prevent heat loss from the pipes, and is particularly suitable for insulation construction of special-shaped pipes and narrow spaces.

[0029] (4) The geopolymer aerated concrete material based on active silica powder gasification of the present invention can be prepared at room temperature and naturally cured at room temperature and pressure without high temperature and high pressure steam curing. The slurry temperature of ordinary aerated concrete generally needs to reach above 60°C, and the static gasification process generally requires an ambient temperature of about 50°C. Compared with traditional aerated concrete, the present invention greatly reduces energy consumption and carbon emissions.

[0030] (5) The geopolymer aerated concrete material based on active silica powder gasification of the present invention uses industrial waste residues, including fly ash, metakaolin, coal gangue, red mud, and tailings containing highly active silica and aluminum components. These tailings are rich in silica and aluminum components, SiO 2 and Al 2 O 3 The total mass fraction of is not less than 70%, which can effectively participate in the polymerization reaction, achieving cost-effectiveness and environmental sustainability.

[0031] (6) The geopolymer aerated concrete material based on active silica powder gasification of the present invention can optimize the slurry fluidity, strength and pore structure of the geopolymer aerated concrete by controlling the mixing ratio of the powder component and the liquid component, and can obtain geopolymer aerated concrete with excellent comprehensive performance, such as good mechanical properties, thermal insulation properties and construction performance.

[0032] (7) The geopolymer aerated concrete material based on active silica powder gasification of the present invention uses geopolymer as the matrix material. Geopolymer is a new type of inorganic polymer material with aluminosilicate minerals as the base material and is prepared through an alkali-activated curing process. It has the advantages of excellent mechanical properties, durability, fire resistance, corrosion resistance, etc., and the production process does not require high-temperature calcination, has low energy consumption and low carbon emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a microscopic photograph of the pore structure of the geopolymer aerated concrete based on active silica fume gas generation prepared in Example 1 of the present invention.

[0034] Figure 2 This is a microscopic photograph of the pore structure of the aerated concrete prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0036] Example 1

[0037] The geopolymer aerated concrete material based on active silica powder gasification of this embodiment includes a powder component and a liquid component; wherein:

[0038] 1. Powder components

[0039] Fly ash: 80wt%

[0040] Mineral powder: 20wt%

[0041] Active silicon powder: 0.08wt% (total weight of powder components), fineness 1200 mesh, specific surface area 15m 2 / g.

[0042] Retarder: 0.1wt% (accounting for the total weight of the powder component), using citric acid

[0043] 2. Liquid components

[0044] Sodium water glass: modulus is 1.8, solid content is 45wt%

[0045] Preparation method of geopolymer aerated concrete of this embodiment:

[0046] (1) The powder component and the liquid component are transported to the construction site, and the powder component and the liquid component are put into a mixing device at a mass ratio of 1:0.8, and water is added according to a water-to-solid ratio (0.36), and the mixture is stirred evenly to obtain a pumpable slurry.

[0047] (2) The slurry is transported to the roof construction site through a concrete pump. The slurry is gasified and solidified in situ on the roof and cured at room temperature for 7 days.

[0048] Example 2

[0049] The geopolymer aerated concrete material based on active silica powder gasification of this embodiment includes a powder component and a liquid component; wherein:

[0050] 1. Powder components

[0051] Metakaolin: 60wt%

[0052] Fly ash: 30wt%

[0053] Mineral powder: 10wt%

[0054] Active silicon powder: 0.06wt% (total weight of powder components), fineness 1000 mesh, specific surface area 12m 2 / g

[0055] Retarder: 0.4wt% (accounting for the total weight of the powder component), using tartaric acid

[0056] 2. Liquid components

[0057] Sodium water glass: modulus is 2.0, solid content is 50wt%

[0058] Preparation method of geopolymer aerated concrete of this embodiment:

[0059] (1) The powder component and the liquid component are put into a mixing device at a mass ratio of 1:0.6, water is added according to a water-to-solid ratio (0.38), and the mixture is stirred evenly to obtain a castable slurry.

[0060] (2) The slurry is injected into a mold, allowed to stand at room temperature to generate gas, solidified and formed, and demolded to obtain a prefabricated porous geopolymer aerated concrete product.

[0061] (3) Place the product in a steam curing room and steam cure it at 80°C for 36 hours.

[0062] Example 3

[0063] The geopolymer aerated concrete material based on active silica powder gasification of this embodiment includes a powder component and a liquid component; wherein:

[0064] 1. Powder components

[0065] Fly ash: 90wt%

[0066] Mineral powder: 10wt%

[0067] Active silicon powder: 0.1wt% (total weight of powder components), fineness 1100 mesh, specific surface area 13m 2 / g

[0068] Retarder: 0.2wt% (total weight of powder components), sodium gluconate

[0069] 2. Liquid components

[0070] Sodium water glass: modulus is 1.6, solid content is 35wt%

[0071] Preparation method of geopolymer aerated concrete of this embodiment:

[0072] (1) The powder component and the liquid component are transported to the construction site, and the powder component and the liquid component are put into a mixing device at a mass ratio of 1:1, and water is added according to a water-to-solid ratio (0.40), and the mixture is stirred evenly to obtain a pumpable slurry.

[0073] (2) The slurry is transported to the wall construction site through a mortar pump. The slurry is gasified and solidified in situ on the wall and cured at room temperature for 7 days.

[0074] Example 4

[0075] The geopolymer aerated concrete material based on active silica powder gasification of this embodiment includes a powder component and a liquid component; wherein:

[0076] 1. Powder components

[0077] Gangue: 70wt%

[0078] Fly ash: 20wt%

[0079] Mineral powder: 10wt%

[0080] Active silicon powder: 0.07wt% (total weight of powder components), fineness 1300 mesh, specific surface area 11m 2 / g

[0081] Retarder: 0.3wt% (accounting for the total weight of the powder component), using barium chloride

[0082] 2. Liquid components

[0083] Potassium water glass: modulus is 1.7, solid content is 40wt%

[0084] Preparation method of geopolymer aerated concrete of this embodiment:

[0085] (1) The powder component and the liquid component are put into a mixing device at a mass ratio of 1:0.9, water is added according to a water-to-solid ratio (0.37), and the mixture is stirred evenly to obtain a castable slurry.

[0086] (2) The slurry is injected into a mold, allowed to stand to generate gas, solidified and formed, and demolded to obtain a prefabricated geopolymer aerated concrete product.

[0087] (3) The geopolymer aerated concrete products are naturally cured for 7 days.

[0088] Example 5

[0089] The geopolymer aerated concrete material based on active silica powder gasification of this embodiment includes a powder component and a liquid component; wherein:

[0090] 1. Powder components

[0091] Iron ore tailings: 75wt%

[0092] Mineral powder: 25wt%

[0093] Active silicon powder: 0.08wt% (accounting for the total mass of powder components), fineness 1100 mesh, specific surface area 13m 2 / g

[0094] Retarder: 0.2wt% (accounting for the total weight of the powder component), using borax

[0095] 2. Liquid components

[0096] Sodium water glass: modulus is 1.9, solid content is 48wt%

[0097] Preparation method of geopolymer aerated concrete of this embodiment:

[0098] (1) The powder component and the liquid component are transported to the construction site, and the powder component and the liquid component are put into a mixing device at a mass ratio of 1:0.5, and water is added according to a water-to-solid ratio (0.37), and the mixture is stirred evenly to obtain a pumpable slurry.

[0099] (2) The slurry is transported to the roof construction site through a concrete pump. The slurry is gasified and solidified in situ on the roof and cured at room temperature for 7 days.

[0100] Example 6

[0101] The geopolymer aerated concrete material based on active silica powder gasification of this embodiment includes a powder component and a liquid component; wherein:

[0102] 1. Powder components

[0103] Phosphate ore tailings: 65wt%

[0104] Fly ash: 20wt%

[0105] Mineral powder: 15wt%

[0106] Active silicon powder: 0.07wt% (total weight of powder components), fineness 1300 mesh, specific surface area 11m 2 / g

[0107] Retarder: 0.3wt% (accounting for the total weight of the powder component), using sucrose

[0108] 2. Liquid components

[0109] Sodium water glass: modulus is 1.7, solid content is 40wt%

[0110] Preparation method of geopolymer aerated concrete of this embodiment:

[0111] (1) The powder component and the liquid component are put into a mixing device at a mass ratio of 1:0.7, water is added according to a water-to-solid ratio (0.40), and the mixture is stirred evenly to obtain a castable slurry.

[0112] (2) The slurry is injected into a mold, allowed to stand to generate gas, solidified into a shape, and demolded to obtain a prefabricated geopolymer aerated concrete product.

[0113] (3) Place the product in a steam curing room and steam cure it at 80°C for 36 hours.

[0114] Example 7

[0115] The geopolymer aerated concrete material based on active silica powder gasification of this embodiment includes a powder component and a liquid component; wherein:

[0116] 1. Powder components

[0117] Fly ash: 70wt%

[0118] Mineral powder: 30wt%

[0119] Active silicon powder: 0.07wt% (total weight of powder components), fineness 1200 mesh, specific surface area 14m 2 / g

[0120] Retarder: 0.2wt% (accounting for the total weight of the powder component), using sodium tripolyphosphate

[0121] 2. Liquid components

[0122] Potassium water glass: modulus is 1.8, solid content is 45wt%

[0123] Preparation method of geopolymer aerated concrete of this embodiment:

[0124] (1) The powder component and the liquid component are transported to the construction site, and the powder component and the liquid component are put into a mixing device at a mass ratio of 1:0.6, and water is added according to a water-to-solid ratio (0.38), and the mixture is stirred evenly to obtain a pumpable slurry.

[0125] (2) The slurry is transported to the wall construction site through a mortar pump. The slurry is gasified and solidified in situ on the wall and cured at room temperature for 7 days.

[0126] Comparative Example 1 (Conventional aerated concrete using Al powder for aeration)

[0127] The aerated concrete components of this comparative example are:

[0128] Fly ash: 67%

[0129] Lime: 17%

[0130] Cement: 13%

[0131] Gypsum: 3%

[0132] Foam stabilizer: 3%

[0133] Al powder: 0.08%

[0134] Water-solid ratio: 0.58

[0135] The preparation process of aerated concrete of this comparative example is as follows:

[0136] (1) Fly ash, lime, cement, gypsum and foam stabilizer are put into a mixing device and mixed evenly. Water is added according to the above water-solid ratio (0.58), and stirred evenly. Al powder is then added and stirred rapidly for 15 seconds to obtain a pourable slurry.

[0137] (2) The slurry is injected into a mold, left to stand in a 50°C environment to generate gas, solidified into a shape, and demolded to obtain a prefabricated aerated concrete product.

[0138] Comparative Example 2

[0139] The concrete components of this comparative example are:

[0140] Fly ash: 67%

[0141] Lime: 17%

[0142] Cement: 13%

[0143] Gypsum: 3%

[0144] Foam stabilizer: 3%

[0145] Active silica powder: 0.08%

[0146] Water-solid ratio: 0.58

[0147] The preparation process of aerated concrete of this comparative example is as follows:

[0148] (1) Fly ash, lime, cement, gypsum, foam stabilizer and activated silica powder are put into a mixing device and mixed evenly. Water is added according to the above water-to-solid ratio (0.58) and stirred evenly to obtain a pourable slurry.

[0149] (2) The slurry is injected into a mold, left to stand in a 50°C environment to generate gas, solidify into a shape, and demolded to obtain a prefabricated concrete product.

[0150] The induction period, gas evolution rate, porosity and sample compressive strength results measured in Examples 1 to 7 and Comparative Example 2 are shown in Table 1 below.

[0151] Table 1

[0152]

[0153] As can be seen from Table 1, by adjusting the components of geopolymer aerated concrete and utilizing the synergistic effect between the components, the gas induction period and gas evolution rate of the active silica powder can be controlled, the mildness and controllability of the reaction process can be ensured, and a uniform pore structure is finally formed, and the prepared geopolymer aerated concrete has a high compressive strength. Comparative Example 2, on the basis of Comparative Example 1 (conventional aerated concrete using Al powder for gasification), only uses active silica powder instead of aluminum powder as a gas generating agent, and the gas generation amount is small, and an aerated concrete sample cannot be prepared.

[0154] The pore structure of the geopolymer aerated concrete prepared in Example 1 and Comparative Example 1 was analyzed using a microscope. The results were as follows: Figure 1 , Figure 2As shown in the figure, compared with the conventional aerated concrete using Al powder for gasification, the geopolymer aerated concrete using active silicon as the gas generating agent in Example 1 has a smaller pore size and a more uniform pore distribution.

[0155] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A geopolymer aerated concrete material based on active silica fume gasification, characterized in that: including a powder component and a liquid component; The powder component comprises 70-100 parts by weight of silicon-alumina material, 0-30 parts by weight of mineral powder, active silicon powder and retarder; the active silicon powder accounts for 0.06-0.1% of the total weight of the powder component; the retarder accounts for 0-0.5% of the total weight of the powder component; the active silicon powder is a gas generating agent; The liquid component includes an alkali metal silicate solution with a modulus of 1.5-2.0 and a solid content of 30-50wt%; When in use, the powder component and the liquid component are mixed in a mass ratio of 1:(0.5-1.0).

2. The geopolymer aerated concrete material based on active silica fume gasification according to claim 1, characterized in that: The particle size of the active silicon powder is greater than 1000 mesh and the specific surface area is greater than 10m 2 / g.

3. The geopolymer aerated concrete material based on active silica fume gasification according to claim 1, characterized in that: The gas evolution induction period of the active silicon powder is 15-30 minutes, and the volumetric gas evolution rate is 3-8% / min.

4. The geopolymer aerated concrete material based on active silica fume gasification according to claim 3, characterized in that: The silicon-alumina material is at least one of fly ash, metakaolin, coal gangue, red mud, and tailings containing high-activity silicon-alumina components.

5. The geopolymer aerated concrete material based on active silica fume gasification according to claim 1, characterized in that: The retarder is at least one of citric acid, tartaric acid, gluconic acid, molasses, borax, sodium tripolyphosphate, sodium fluoride, potassium fluoride, sucrose, xylose, barium chloride, lignin sulfonate and boric acid.

6. The geopolymer aerated concrete material based on active silica fume gasification according to claim 1, characterized in that: The alkali metal silicate solution is a potassium silicate solution or a sodium silicate solution.

7. The method for preparing geopolymer aerated concrete material based on active silica fume gasification according to any one of claims 1 to 6, characterized in that: It is used for the preparation of factory-prefabricated geopolymer aerated concrete products or the preparation of geopolymer aerated concrete poured on the construction site.

8. The preparation method according to claim 7, characterized in that: The preparation of the factory-prefabricated geopolymer aerated concrete product comprises the following steps: 1) Add the powder component and the liquid component into a stirring device according to the proportion, add water at a water-to-solid ratio of 0.35-0.40, stir evenly, and obtain a pourable slurry; 2) injecting the slurry into a mold, allowing it to stand to generate gas, solidifying and forming, and demolding to obtain a prefabricated porous geopolymer aerated concrete product; 3) Maintain geopolymer aerated concrete products.

9. The preparation method according to claim 8, characterized in that: The curing is natural curing or steam curing.

10. The preparation method according to claim 7, characterized in that: The preparation of the construction site cast geopolymer aerated concrete comprises the following steps: 1) At the construction site, add the powder component and the liquid component into the mixing equipment according to the proportion, add water at a water-solid ratio of 0.35-0.40, stir evenly, and obtain a pourable slurry; 2) The slurry is pumped to the construction site through pumping equipment and cast in situ. The slurry is gasified and solidified in situ at the construction site; 3) After the slurry solidifies and takes shape, natural curing is carried out.

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