Alkali-activated foam concrete as well as preparation method and application thereof

Abstract

The invention discloses alkali-activated foam concrete as well as a preparation method and application thereof, and relates to the technical field of building materials. The alkali-activated foam concrete is prepared from the following raw materials in parts by mass: 45 to 70 parts of mineral powder, 1 to 3 parts of first alkali activator, 8 to 15 parts of second alkali activator, 5 to 10 parts of alkali sealing treatment agent, 0.5 to 1.0 part of fiber, 15 to 30 parts of water, 0.5 to 2.0 parts of foaming agent, 0.1 to 0.5 part of foam stabilizer and 0.1 to 0.5 part of water reducing agent. According to the technical scheme, ordinary Portland cement and special cement are replaced with mineral powder, the lightweight and high-strength foam concrete material is prepared according to the alkali excitation principle, the cracking phenomenon of foam concrete can be relieved and eliminated, the stability of the slope surface can be improved, and by means of the mixed alkali activator, the alkali sealing treatment agent and the low-alkali-amount formula, the slope surface is more stable. The alkalinity of the foamed concrete can be reduced, and the survival rate of slope plant cultivation can be improved, so that the problem that different plants are difficult to grow on the slope can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to an alkali-activated foamed concrete and a preparation method and application thereof. Background Art

[0002] As a high-carbon emission enterprise, cement is subject to restrictions by government departments. Reducing the use of cement in the foaming process and using alkali-activated mineral powder to make foaming materials can significantly reduce the use of cement and to a certain extent reduce the stacking of waste, thus realizing the resource utilization of construction waste. It is a feasible way to turn waste into treasure.

[0003] Slope greening is an important engineering measure aimed at improving the ecological environment, preventing soil erosion, and enhancing the landscape effect. It is combined with traditional engineering slope protection to effectively restore the ecological vegetation on the slope. However, some problems are often encountered during the implementation process, such as unstable slope materials, soil and matrix problems. The slope material is unstable and may be lost or cracked, which will affect the slope greening effect; the slope soil is often poor, has poor water retention capacity, and may contain substances that are not conducive to plant growth. If proper soil improvement and selection of suitable greening matrix are not carried out, the survival rate of vegetation will also be affected. Therefore, the existing slope greening process has the defects of poor slope stability and low plant survival rate, resulting in poor greening effect and difficulty in planting plants on the slope. Summary of the invention

[0004] The main purpose of the present invention is to propose an alkali-activated foam concrete and its preparation method and application, aiming to solve the problems of poor slope stability and low plant survival rate in existing slope greening processes, which make it difficult to plant plants on the slope.

[0005] To achieve the above-mentioned object, the present invention provides an alkali-activated foamed concrete, characterized in that, measured by mass, the raw materials of the alkali-activated foamed concrete include the following components: 45-70 parts of mineral powder, 1-3 parts of a first alkali activator, 8-15 parts of a second alkali activator, 5-10 parts of an alkali sealing agent, 0.5-1.0 parts of fiber, 15-30 parts of water, 0.5-2.0 parts of a foaming agent, 0.1-0.5 parts of a foam stabilizer, and 0.1-0.5 parts of a water reducer.

[0006] In one embodiment, the alkali-activated foamed concrete further includes quartz sand, and the mass ratio of the quartz sand to the mineral powder is (0.5-1):1.

[0007] In one embodiment, the mass ratio of the fly ash microbeads to the mineral powder is (0.5-1):1.

[0008] In one embodiment, the mass ratio of the silica fume to the mineral powder is (0.5-1):1.

[0009] In one embodiment, the first alkaline activator includes at least one of sodium hydroxide, sodium carbonate, and sodium sulfate.

[0010] In one embodiment, the second alkali activator comprises water glass, wherein the water glass is sodium water glass having a modulus of 1.5-3.

[0011] In one embodiment, at least one of silica sol, aluminum sol, alcohol solution of metal chloride and organic silicon water repellent is used.

[0012] In one embodiment, the foaming agent includes at least one of a plant-based protein foaming agent and an animal-based protein foaming agent.

[0013] The present invention provides a method for preparing alkali-activated foamed concrete, comprising the following steps:

[0014] S10, mixing the first alkaline activator and the second alkaline activator to prepare a mixed alkaline activator;

[0015] S20, mixing a mixed alkali activator, mineral powder, fly ash microspheres, silica fume, quartz sand, water and a water reducing agent to prepare a mixture;

[0016] S30, mixing a foaming agent with water to form foam, and adding the foam, foam stabilizer and fiber to the mixture to form a foaming slurry;

[0017] S40, placing the foaming slurry in a curing box for curing, and applying an alkali-sealing treatment agent on the surface to obtain alkali-activated foam concrete.

[0018] The present invention provides an application of the alkali-activated foamed concrete or the alkali-activated foamed concrete prepared by the preparation method in planting slope plants.

[0019] In one embodiment, the slope plants include at least one of Bermuda grass, Sedum dactylifera, Pueraria lobata, Rosa laevigata, Trachelospermum jasminoides, Vitex negundo, Ficus microcarpa, and Elaeagnus chinensis.

[0020] In one embodiment, the application comprises the following steps:

[0021] Using alkali-activated foamed concrete as a cultivation matrix layer for planting slope plants, wherein the angle between the cultivation matrix layer and the horizontal ground is (1:1.5) to (1:2);

[0022] The mass proportion of the alkali-activated foamed concrete in the cultivation substrate layer is 70% to 100%.

[0023] In one embodiment, after the step of using alkali-activated foamed concrete as a cultivation substrate layer for planting slope plants, the method further comprises:

[0024] Apply alkali-reducing agents during planting.

[0025] The technical solution of the present invention adopts mineral powder to replace ordinary silicate cement and special cement, and prepares light and high-strength foam concrete materials based on the alkali excitation principle, which can slow down and eliminate the cracking phenomenon of the foamed material, which is beneficial to improving the stability of the slope material, and to a certain extent reducing the stacking of waste materials, and realizing the resource utilization of construction waste. At the same time, the first alkali exciter and the second alkali exciter are mixed to obtain a mixed alkali exciter, and the mixed alkali exciter, the alkali sealing treatment agent and the low alkali amount formula are beneficial to reduce the amount of free hydroxide ions in the alkali exciter foam concrete, improve the water retention rate of the alkali exciter foam concrete, and thus improve the survival rate of slope plant cultivation, promote plant growth, and solve the problem that it is difficult for planted plants to grow on the slope. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0027] Figure 1 This is a preparation flow chart of Example 1 of the present invention.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in 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 creative work are within the scope of protection of the present invention.

[0030] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0031] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] As a high-carbon emission enterprise, cement is subject to restrictions by government departments. Reducing the use of cement in the foaming process and using alkali-activated mineral powder to make foaming materials can significantly reduce the use of cement and to a certain extent reduce the stacking of waste, thus realizing the resource utilization of construction waste. It is a feasible way to turn waste into treasure.

[0033] Slope greening is an important engineering measure aimed at improving the ecological environment, preventing soil erosion, and enhancing the landscape effect. It is combined with traditional engineering slope protection to effectively restore the ecological vegetation on the slope. However, some problems are often encountered during the implementation process, such as soil and substrate problems. The slope soil is often poor, has poor water retention capacity, and may contain substances that are not conducive to plant growth. If proper soil improvement and selection of suitable greening substrates are not carried out, the survival rate of vegetation will be affected; for example, the problem of unstable slope materials. When the slope materials are lost or cracked, the slope greening effect will also be affected. Therefore, the existing slope greening process has the defects of poor slope stability and low plant survival rate, resulting in poor greening effect and difficulty in planting plants on the slope.

[0034] In view of this, the present invention proposes an alkali-activated foamed concrete, characterized in that, measured by mass, the raw materials of the alkali-activated foamed concrete include the following components: 45-70 parts of mineral powder, 1-3 parts of a first alkali activator, 8-15 parts of a second alkali activator, 5-10 parts of an alkali sealing treatment agent, 0.5-1.0 parts of fiber, 15-30 parts of water, 0.5-2.0 parts of a foaming agent, 0.1-0.5 parts of a foam stabilizer, and 0.1-0.5 parts of a water reducer.

[0035] Using mineral powder to replace ordinary silicate cement and special cement, fly ash microbeads, silica fume, and quartz sand as fillers can greatly reduce the use of cement and reduce the stacking of waste to a certain extent, realizing the resource utilization of construction waste. Physical foaming is used for foaming, and lightweight and high-strength cement foaming materials are prepared based on the principle of alkali excitation. The formula can also be adjusted to adjust the pH and soil moisture content, so that the plants can be planted on the slope.

[0036] In an embodiment of the present invention, the alkali-activated foamed concrete further comprises quartz sand, and the mass ratio of the quartz sand to the mineral powder is (0.5-1):1. Good grading can reduce the void ratio, improve the density, strength and durability of the concrete, and help to keep the material light while providing good compressive strength. The quartz sand used in the technical solution of the present invention adopts the fuller formula, and the particle grading includes quartz sand of 40, 60, 200, 400 and 1250 mesh.

[0037] In an embodiment of the present invention, the alkali-activated foamed concrete further comprises fly ash micro-beads, and the mass ratio of the fly ash micro-beads to the mineral powder is (0.5-1):1. Fly ash is a siliceous-aluminous volcanic ash material, the glassy body of which contains soluble SiO2 and Al2O3, and can be activated by alkali components to produce gelling substances. The micro-bead effect of fly ash can improve the fluidity of the slurry, reduce the viscosity, and facilitate the entry of foam into the slurry, thereby reducing the density of the foaming material. In addition, due to the addition of fly ash micro-beads, the calcium oxide contained in the fly ash is conducive to hydration reaction with silicon dioxide to generate hydrated calcium silicate, thereby improving the flexural strength of the foaming material, and is also conducive to reducing the alkali content of the high-alkalinity slurry.

[0038] In an embodiment of the present invention, the alkali-activated foamed concrete further comprises silica fume. Due to its extremely high specific surface area and fineness, silica fume can be better filled in the pore structure of the foaming material to form a denser structure, thereby enhancing the overall strength and durability of the material and enhancing the fluidity of the material. In addition, silica fume also has water retention, which is also conducive to maintaining the stability of the foam, preventing the foam from breaking, and ensuring the uniformity of the foaming material.

[0039] In an embodiment of the present invention, the first alkali activator includes at least one of sodium hydroxide, sodium carbonate, and sodium sulfate. The first alkali activator includes at least one of sodium hydroxide, sodium carbonate, and sodium sulfate, that is, it can be any one of sodium hydroxide, sodium carbonate, and sodium sulfate, and can also contain two or more of sodium hydroxide, sodium carbonate, and sodium sulfate at the same time, all of which belong to the protection scope of the present invention. Preferably, the first alkali activator is sodium hydroxide.

[0040] In an embodiment of the present invention, the second alkali activator comprises water glass, wherein the water glass is sodium water glass with a modulus of 1.5 to 3. Using the first alkali activator to adjust the modulus of the water glass is beneficial to improving the foaming degree.

[0041] It should be noted that the first alkali activator and the second alkali activator are mixed to obtain a mixed alkali activator, which is beneficial to enhancing the activity of mineral powder at multiple points and will not produce excess alkaline substances. The combination of water glass and sodium hydroxide is beneficial to reducing the modulus of water glass, and the low alkali content is for the consideration of the subsequent growth environment of plants. If there is no alkali-sealing treatment agent, the conventional alkali content can be up to nearly 1 times higher than the current added amount. The role of the alkali-sealing treatment agent can not only eliminate the alkali content, but also reduce the porosity of the foaming material surface and enhance the density of the material surface.

[0042] Furthermore, the mixing of multiple components is beneficial to the generation of calcium silicate hydrate to improve the strength of the foamed material.

[0043] In an embodiment of the present invention, the alkali-sealing agent includes at least one of silica sol, aluminum sol, alcohol solution of metal chloride and organosilicon waterproofing agent. The alkali-sealing agent contains components that can react with alkaline substances, and can also block the surface pores of the foaming material to prevent the entry of impurities, so as to reduce the alkalinity of the foamed concrete, which is conducive to the growth of plants. The alkali-sealing agent can be purchased or homemade. The preparation steps of the alkali-sealing agent are as follows:

[0044] Weigh aluminum chloride powder and prepare it into an ethanol solution with a mass fraction of 30%. At the same time, add the same components of YC265 type silicone waterproofing agent and acidic silica sol. After the above components are evenly mixed and dispersed, they are evenly coated on the foamed concrete by brushing and spraying. Among them, the acidic silica sol uses Dezhou Jinghuo Technology Glass Co., Ltd., aluminum chloride uses Henan Zhongbang Environmental Protection Technology Co., Ltd. Article No.: ZB190372179, ethanol: Jiangsu Huating Biotechnology Co., Ltd. FK500, and the YC265 type silicone waterproofing agent uses the 265 type silicone fluorine waterproofing agent of Guangzhou Yuchuang Company.

[0045] It should be noted that, in the embodiment of the present invention, the fiber includes at least one of polypropylene fiber and glass fiber. By using the fiber, the toughness of the alkali-activated foam concrete is enhanced.

[0046] In an embodiment of the present invention, the foaming agent includes at least one of a plant protein foaming agent and an animal protein foaming agent. Both the plant protein foaming agent and the animal protein foaming agent are physical foaming agents, which adjust the pressure through a foaming machine, compress the volatilization of the liquid to form uniform foam, and form pores during the formation of the foaming slurry.

[0047] In an embodiment of the present invention, the foam stabilizer is at least one of hydroxypropyl methylcellulose ether, calcium stearate, and trisodium phosphate. The foam stabilizer is used to reduce the internal structure density difference of the foam concrete, make the pores evenly distributed, improve the pore structure, and enhance the strength of the foam concrete.

[0048] In an embodiment of the present invention, the reducing agent includes a polycarboxylate water reducing agent. The water reducing agent can increase the fluidity of the concrete, help the bubbles generated by the foaming agent to be more evenly distributed, obtain a foaming material with a more uniform structure, and can also improve the strength of the foaming.

[0049] The present invention provides a method for preparing alkali-activated foamed concrete, comprising the following steps:

[0050] S10, mixing the first alkaline activator and the second alkaline activator to prepare a mixed alkaline activator;

[0051] S20, mixing a mixed alkali activator, mineral powder, fly ash microspheres, silica fume, quartz sand, water and a water reducing agent to prepare a mixture;

[0052] S30, mixing a foaming agent with water to form foam, and adding the foam, foam stabilizer and fiber to the mixture to form a foaming slurry;

[0053] S40, placing the foaming slurry in a curing box for curing, and applying an alkali-sealing treatment agent on the surface to obtain alkali-activated foam concrete.

[0054] The present invention provides an application of the alkali-activated foamed concrete or the alkali-activated foamed concrete prepared by the preparation method in planting slope plants.

[0055] Porosity affects the growth and development of plants in the specimen. Plants with high porosity have faster root penetration speed and better foaming effect. Under the same volume, the lighter the foam specimen, the better the growth effect. Taking advantage of the lightweight and porous characteristics of alkali-activated foam concrete, alkali-activated foam concrete can be used as the cultivation matrix layer for planting slope plants.

[0056] In an embodiment of the present invention, the slope plants include at least one of Bermuda grass, Sedum dactylifera, Pueraria lobata, Rosa laevigata, Trachelospermum jasminoides, Vitex negundo, Ficus microcarpa, and Elaeagnus chinensis.

[0057] It should be noted that the planting of plants on the slopes must comply with the ecological habits of the plants. If the external environment cannot meet the ecological habits of the plants, the growth of the plants will be hindered. Environmental conditions should be comprehensively considered when selecting plants. Specifically, plants such as bermudagrass, sedum, kudzu vine, and golden cherry are planted on the top of the sunny slope, and plants such as trachelospermum, vitex negundo, Ficus microcarpa, and Elaeagnus chinensis are planted at the bottom of the sunny slope. Plant species with good alkali resistance, cold resistance, and heat resistance, such as bermudagrass, bahia grass, and apex grass, can be given priority for planting.

[0058] In an embodiment of the present invention, the application comprises the following steps:

[0059] Using alkali-activated foamed concrete as a cultivation matrix layer for planting slope plants, wherein the angle between the cultivation matrix layer and the horizontal ground is (1:1.5) to (1:2);

[0060] The mass proportion of the alkali-activated foamed concrete in the cultivation substrate layer is 70% to 100%.

[0061] Setting the angle between the cultivation substrate layer and the horizontal ground to (1:1.5) to (1:2) is beneficial to improving the stability of the slope and increasing the survival rate of plants on the slope.

[0062] It should be noted that setting the mass proportion of the alkali-activated foamed concrete in the cultivation substrate layer to 70% to 100% means that the alkali-activated foamed concrete can be combined with other suitable materials and used as the cultivation substrate layer material, or the alkali-activated foamed concrete can be used entirely as the cultivation substrate layer material.

[0063] In an embodiment of the present invention, after the step of using alkali-activated foamed concrete as a cultivation substrate layer for planting slope plants, the method further comprises:

[0064] Apply alkali-reducing agents during planting.

[0065] It should be noted that the alkalinity reducing agent can be one or more of citric acid, ferrous sulfate, superphosphate, and DPS agent.

[0066] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0067] In the following examples, the mineral powder (CaO 39.92%, SiO2 31.23%, Al2O3 14.12%, Fe2O3 0.78%, MgO 7.34%, SO3 2.23%) was purchased from Shijiazhuang Yitian Mineral Products Co., Ltd.;

[0068] The fly ash microbeads (SiO2 51.3%, Al2O3 26.8%, Fe2O3 7.15%, MgO1.29%, CaO2.86%, K2O1.47%, SO2 0.45%, Na2O 0.64%) were purchased from Shanghai Kaiyin Chemical Co., Ltd.;

[0069] The silica fume (more than 70% SiO2 and less than 30% CaO) was purchased from Xi'an Linyuan Microsilica Fume Co., Ltd.

[0070] The water glass (SiO2 31.8%, Na2O 14.1%, Be 50%, modulus 2.33) was purchased from Shenzhen Yoshida Chemical Co., Ltd.;

[0071] The water is ordinary tap water;

[0072] The fiber is polypropylene fiber purchased from Shandong Huahe New Materials Co., Ltd.

[0073] The foaming agent is a polypropylene microporous foam material purchased from Zhejiang Xinhengtai New Materials Co., Ltd.

[0074] The foam stabilizer is calcium stearate, purchased from Guangdong Nanhui New Materials Co., Ltd.

[0075] Example 1

[0076] An alkali-activated foamed concrete, wherein the alkali-activated foamed concrete raw materials contain the following components, measured by mass: 62 parts of mineral powder, 1.9 parts of a first alkali activator (sodium hydroxide), 13 parts of a second alkali activator (water glass), 8 parts of an alkali sealing treatment agent, 0.6 parts of fiber (polypropylene fiber), 21 parts of water, 0.6 parts of a foaming agent (polypropylene microporous foaming material), 0.4 parts of a foam stabilizer (calcium stearate), and 0.5 parts of a water reducer (polycarboxylic acid high-performance water reducer), wherein each part is 1 g.

[0077] Example 2

[0078] Compared with Example 1, the difference is that the mass fractions of each raw material are different, as shown in Table 1.

[0079] Example 3

[0080] Compared with Example 1, the difference is that the mass fractions of each raw material are different, as shown in Table 1.

[0081] Example 4

[0082] Compared with Example 1, the difference is that the mass fractions of each raw material are different, as shown in Table 1.

[0083] Example 5

[0084] Compared with Example 1, the alkali sealing agent is a hydrophobic silane-based powder shp-50, as shown in Table 1.

[0085] Example 6

[0086] A method for preparing alkali-activated foamed concrete comprises the following steps:

[0087] (1) 15 g of sodium hydroxide and 105 g of water glass were mixed to prepare a mixed alkali activator;

[0088] (2) 500 g of mineral powder, 100 g of fly ash microspheres, 100 g of silica ash and 100 g of quartz sand were mixed evenly by a mortar mixer, and the mixed alkali activator prepared in step (1), 10 g of water and 4 g of water reducing agent were added and stirred evenly to prepare a mixture;

[0089] (3) 10 g of a foaming agent was mixed with 90 g of water and a dense foam was prepared by an air compressor. The foam, 3 g of a foam stabilizer and 5 g of fiber were added to the mixture to prepare a foaming slurry.

[0090] (4) Pour the foaming slurry into the mold and place it in a curing box for curing. After curing for 3 days, apply an alkali-sealing treatment agent on the surface to obtain alkali-activated foam concrete. Figure 1 .

[0091] Example 7

[0092] A method for planting bermudagrass using alkali-activated foamed concrete comprises the following steps:

[0093] (1) preparing a foaming slurry according to the method of steps (1) to (3) in implementation 6;

[0094] (2) Pour the foaming slurry into a mold and place it in a curing box for curing. After curing for 3 days, place the Bermuda grass plant seeds in the pores of the foamed concrete for planting. After the plants are planted, add ordinary organic fertilizers and apply an alkali-sealing agent on the surface of the foaming slurry.

[0095] Comparative Example 1 (Comparative Example for Mixed Alkali Activator)

[0096] It does not contain the first base activator, as shown in Table 1.

[0097] Comparative Example 2 (Comparative Example for Sealing Alkali Treatment Agent)

[0098] It does not contain alkali-sealing agent, see Table 1 for details.

[0099] Comparative Example 3 (Comparative Example for Low Alkalinity)

[0100] The mass fraction of the first base activator is 5 parts, and the mass fraction of the second base activator is 18 parts, as shown in Table 1 for details.

[0101] Table 1 Mass fractions of raw materials in Examples 1-5 and Comparative Examples 1-3

[0102]

[0103] In Table 1, “-” means that the component is not contained.

[0104] Performance Testing

[0105] The density, compressive strength (curing for 28 days), pH value and water retention rate of the alkali-activated foamed concrete of Examples 1-5 and Comparative Examples 1-3 were tested.

[0106] Density: Dry density is tested in accordance with the relevant provisions of JG / T266-2011 "Foamed Concrete".

[0107] Compressive strength: The test method is in accordance with the "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" GB / T50081-2002, and the evaluation standard is in accordance with the "Technical Specifications for Application of Ecological Concrete" CECS361-2013 (greater than 5MPa). The test results are shown in Table 2.

[0108] pH value: Place the alkali-reduced foamed concrete in a container, add water to cover the surface of the sample; seal it for 24 hours, extract the upper, middle and lower soaking liquids, measure the pH with an acidity meter, and take the average pH of the upper, middle and lower soaking liquids. The test results are shown in Table 2.

[0109] Water retention capacity: obtained by multiplying the difference between the mass immersed in water and the mass after drying by the mass after drying by 100%, where (water absorption per unit mass) test results are shown in Table 2.

[0110] In order to evaluate the feasibility of using alkali-activated foamed concrete for planting slope plants, the alkali-activated foamed concrete of Examples 1-5 was used to plant Bermuda grass, and the root length of the plant grown for 28 days was tested. The test results are shown in Table 2.

[0111] Table 2 Performance test results of Examples 1-5, Comparative Examples 1-3 and existing concrete materials

[0112]

[0113] In Table 2, “-” means the item was not tested.

[0114]

[0115]

[0116] It should be noted that a too high pH value indicates that the alkaline content is too high, which is not conducive to the growth of plants. A pH value of about 8 is conducive to the growth of Bermuda grass plants.

[0117] As shown in Table 2, compared with conventional cement concrete, the alkali-activated foamed concrete of Examples 1-5 has a smaller density, and the compressive strength meets the application standard of ecological concrete (greater than 5MPa). As shown in Table 2, the pH values ​​of Examples 3-4 are all less than 10, the pH value of Example 3-4 is less than that of Example 1-2, and the water retention of Example 3-4 is greater than that of Example 1-2, indicating that the alkali-activated foamed concrete of Example 3-4 is more conducive to plant growth.

[0118] The proline content of the leaves of the Bermuda grass planted with the alkali-activated foam concrete of Example 7 was measured, and the proline content at 28 days was 60ug / g. It should be noted that proline can regulate water balance, maintain cell wall integrity, regulate metabolism and enhance photosynthesis during plant growth. Compared with the conventional content, the proline content in this example is lower, indicating that factors such as the porosity and alkalinity of the vegetation concrete are conducive to plant growth, and the nutrient status of the configured growth substrate meets the plant growth conditions, and has the dual functions of ecological protection and slope protection.

[0119] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An alkali-activated foamed concrete, characterized in that: The alkali-activated foamed concrete raw materials include the following components, measured by mass: 45-70 parts of mineral powder, 1-3 parts of a first alkali activator, 8-15 parts of a second alkali activator, 5-10 parts of an alkali-sealing agent, 0.5-1.0 parts of fiber, 15-30 parts of water, 0.5-2.0 parts of a foaming agent, 0.1-0.5 parts of a foam stabilizer, and 0.1-0.5 parts of a water reducer.

2. The alkali-activated foamed concrete according to claim 1, characterized in that: The alkali-activated foamed concrete also includes quartz sand, and the mass ratio of the quartz sand to the mineral powder is (0.5-1):

1.

3. The alkali-activated foamed concrete according to claim 1 or 2, characterized in that: The alkali-activated foamed concrete further comprises fly ash microbeads, and the mass ratio of the fly ash microbeads to the mineral powder is (0.5-1):

1.

4. The alkali-activated foamed concrete according to any one of claims 1 to 3, characterized in that: The alkali-activated foamed concrete also includes silica fume, and the mass ratio of the silica fume to the mineral powder is (0.5-1):

1.

5. The alkali-activated foamed concrete according to claim 1, characterized in that: The first alkaline activator comprises at least one of sodium hydroxide, sodium carbonate and sodium sulfate; and / or, The second alkali activator comprises water glass, wherein the water glass is sodium water glass with a modulus of 1.5 to 3; and / or, The alkali sealing agent comprises at least one of silica sol, aluminum sol, alcohol solution of metal chloride and organic silicon waterproofing agent; and / or, The foaming agent includes at least one of a plant-based protein foaming agent and an animal-based protein foaming agent.

6. A method for preparing alkali-activated foamed concrete, characterized in that: The following steps are involved: S10, mixing the first alkaline activator and the second alkaline activator to prepare a mixed alkaline activator; S20, mixing a mixed alkali activator, mineral powder, fly ash microspheres, silica fume, quartz sand, water and a water reducing agent to prepare a mixture; S30, mixing a foaming agent with water to form foam, and adding the foam, foam stabilizer and fiber to the mixture to form a foaming slurry; S40, placing the foaming slurry in a curing box for curing, and applying an alkali-sealing treatment agent on the surface to obtain alkali-activated foam concrete.

7. Use of the alkali-activated foamed concrete according to any one of claims 1 to 5 or the alkali-activated foamed concrete prepared by the preparation method according to claim 6 in planting slope plants.

8. The use according to claim 7, characterized in that The slope plants include at least one of Bermuda grass, Sedum scabra, Pueraria lobata, Rosa laevigata, Trachelospermum officinale, Vitex negundo, Ficus microcarpa, and Elaeagnus chinensis.

9. The use according to claim 7, characterized in that The application comprises the following steps: Using alkali-activated foamed concrete as a cultivation matrix layer for planting slope plants, wherein the angle between the cultivation matrix layer and the horizontal ground is (1:1.5) to (1:2); The mass proportion of the alkali-activated foamed concrete in the cultivation substrate layer is 70% to 100%.

10. The use according to claim 9, characterized in that After the step of using the alkali-activated foamed concrete as a cultivation substrate layer for planting slope plants, the method comprises: Apply alkali-reducing agents during planting.

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