A foamed concrete and a method of making and using the same

Abstract

The application discloses a kind of foamed concrete and its preparation method and application.This foamed concrete includes the following components: cementing material and foam;Wherein, cementing material includes cement, hollow glass microsphere and water;Foam is prepared by foaming foaming agent composition;Foaming agent composition includes surface hydrophilic modified nanoparticle, surfactant, regulator and water.The application uses the foaming agent composition of pre-treatment to nanoparticle to carry out foaming, the performance of obtained foam is stable and low in cost, to this foam and using hollow glass microsphere to prepare foamed concrete, the performance of foamed concrete can be improved, can effectively increase the compressive strength of foamed concrete, and market application prospect is wide.

Description

Technical Field

[0001] This invention relates to the field of concrete technology, and in particular to a foamed concrete, its preparation method, and its application. Background Technology

[0002] Foamed concrete, also known as aerated concrete, is a new type of lightweight thermal insulation material containing a large number of closed pores. It is made by fully foaming a foaming agent using a foaming machine, uniformly mixing the foam with cement slurry, and then pouring it on-site or molding it with molds and allowing it to cure naturally.

[0003] Currently, foaming agents used in foamed concrete generally suffer from problems such as large dosage and instability. Common foaming agents tend to cause bubble aggregation during preparation, leading to increased size and thus unstable foam. Furthermore, high-performance foaming agents are mostly imported products, which not only increases the cost of foamed concrete but also hinders large-scale production and application.

[0004] Furthermore, the limited compressive strength of existing foamed concrete hinders its widespread application in many fields. Improving the compressive strength and mechanical properties of foamed concrete would allow it to better meet the application needs of a wider range of sectors.

[0005] Therefore, how to provide a low-cost, environmentally friendly, and high-performance foamed concrete has become a technical problem that researchers in the industry urgently need to solve. Summary of the Invention

[0006] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a foamed concrete; a second objective is to provide a method for preparing such foamed concrete; and a third objective is to provide applications of such foamed concrete.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A first aspect of the present invention provides a foamed concrete comprising the following components: a cementitious material and foam;

[0009] The cementitious material includes cement, hollow glass microspheres, and water;

[0010] The foam is prepared by foaming a foaming agent composition;

[0011] The foaming agent composition comprises surface-hydrophilic modified nanoparticles, surfactants, regulators, and water.

[0012] According to some embodiments of the foamed concrete of the present invention, the ratio of the cementitious material to the foam is 1g:(0.4~0.6)mL.

[0013] According to some embodiments of the foamed concrete of the present invention, the ratio of the cementitious material to the foam is 1g:(0.45~0.55)mL.

[0014] According to some embodiments of the foamed concrete of the present invention, the mass percentage of surface-hydrophilic modified nanoparticles in the foaming agent composition is 0.04% to 0.07%.

[0015] According to some embodiments of the foamed concrete of the present invention, the mass percentage of surface-hydrophilic modified nanoparticles in the foaming agent composition is 0.04% to 0.06%.

[0016] According to some embodiments of the foamed concrete of the present invention, the surfactant in the foaming agent composition is 0.06% to 0.1% by mass.

[0017] According to some embodiments of the foamed concrete of the present invention, the surfactant in the foaming agent composition is 0.07% to 0.09% by mass.

[0018] According to some embodiments of the foamed concrete of the present invention, the mass percentage of the regulator in the foaming agent composition is 0.15% to 0.3%.

[0019] According to some embodiments of the foamed concrete of the present invention, the mass percentage of the regulator in the foaming agent composition is 0.18% to 0.28%.

[0020] According to some embodiments of the foamed concrete of the present invention, the surface-modified hydrophilic nanoparticles include at least one of nano-silica, nano-titanium dioxide, nano-alumina, nano-zinc oxide, nano-zirconia, nano-cerium oxide, nano-iron oxide, nano-attapulgite, nano-kaolin, nano-montmorillonite, and nano-bentonite.

[0021] According to some embodiments of the foamed concrete of the present invention, the surface-modified hydrophilic nanoparticles include at least one of nano-attapulgite, nano-kaolin, nano-montmorillonite, and nano-bentonite. These types of nanoparticles are widely available and inexpensive. Using surface-modified hydrophilic nanoparticles can stabilize the foam, ensuring that the produced concrete has small-sized, uniformly dispersed pores, thereby improving the performance of the foamed concrete.

[0022] In this invention, the method for hydrophilic modification of the nanoparticle surface is a conventional method in the art, such as soaking or coating the nanoparticles with a surfactant. The surfactant used for hydrophilic modification can be selected from silane coupling agents and / or polyethers.

[0023] According to some embodiments of the foamed concrete of the present invention, the surfactant includes at least one of sulfate surfactants, sulfonate surfactants, and fatty alcohol polyoxyethylene ethers. These types of surfactants have the advantages of high foaming efficiency and good performance.

[0024] According to some embodiments of the foamed concrete of the present invention, the surfactant includes at least one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, AEO-7, and AEO-9.

[0025] According to some embodiments of the foamed concrete of the present invention, the regulator includes polymeric materials, foam stabilizers, and reinforcing agents.

[0026] According to some embodiments of the foamed concrete of the present invention, the polymer material includes at least one of polyacrylamide, polyethyleneimine, polyvinyl alcohol, and polyvinylpyrrolidone. Polyacrylamide can react with cement, and due to the chemical bonding between polyacrylamide and cement, the interface's load-bearing capacity is improved, thereby enhancing the interface's toughness and fracture resistance, resulting in good physical and mechanical properties, and also facilitating the formation of micro-, closed-cell structures. The nitrogen atoms on the polyethyleneimine molecular chain are grafted with a certain amount of corresponding hydrophobic chains, shielding some of the amine groups on the molecular chain. Therefore, polyethyleneimine is internally hydrophilic and externally hydrophobic, which can enhance the compatibility of foam and cement slurry and improve the mechanical properties of foamed concrete. Polyvinylpyrrolidone, as a water-soluble polymer compound, has good solubilizing and coagulant properties, which is beneficial for stabilizing the foam.

[0027] According to some embodiments of the foamed concrete of the present invention, the polymer material includes at least one of polyacrylamide, polyethyleneimine, and polyvinylpyrrolidone.

[0028] According to some embodiments of the foamed concrete of the present invention, the mass percentage of polymeric material in the foaming agent composition is 0.05% to 0.1%.

[0029] According to some embodiments of the foamed concrete of the present invention, the mass percentage of polymeric material in the foaming agent composition is 0.06% to 0.08%.

[0030] According to some embodiments of the foamed concrete of the present invention, the foam stabilizer includes at least one selected from methylcellulose, hydroxypropyl methylcellulose, and hydroxyethylcellulose. These celluloses are chosen as foam stabilizers because their aqueous solutions have high viscosity, which allows the foaming agent solution to maintain sufficient viscosity and improves the stability of the foam.

[0031] According to some embodiments of the foamed concrete of the present invention, the foam stabilizer includes at least one of methylcellulose and hydroxypropyl methylcellulose.

[0032] According to some embodiments of the foamed concrete of the present invention, the foaming agent composition contains a foam stabilizer at a mass percentage of 0.1% to 0.3%.

[0033] According to some embodiments of the foamed concrete of the present invention, the foam stabilizer in the foaming agent composition is 0.15% to 0.2% by mass.

[0034] According to some embodiments of the foamed concrete of the present invention, the reinforcing agent includes at least one selected from triethanolamine, sodium chloride, magnesium chloride, sodium silicate, and calcium nitrate. Using these types of reinforcing agents can increase the stability of the foam, further improve the density of the internal structure of the foamed concrete, and enhance its mechanical properties.

[0035] According to some embodiments of the foamed concrete of the present invention, the reinforcing agent includes at least one of triethanolamine, sodium chloride, and magnesium chloride.

[0036] According to some embodiments of the foamed concrete of the present invention, the mass percentage of reinforcing agent in the foaming agent composition is 0.005% to 0.01%.

[0037] According to some embodiments of the foamed concrete of the present invention, the mass percentage of reinforcing agent in the foaming agent composition is 0.006% to 0.009%.

[0038] According to some embodiments of the foamed concrete of the present invention, the regulator may further include a water-reducing agent.

[0039] According to some embodiments of the foamed concrete of the present invention, the water-reducing agent includes at least one of lignin sulfonate water-reducing agents, naphthalene-based water-reducing agents, melamine-based water-reducing agents, aminosulfonate-based water-reducing agents, fatty acid-based water-reducing agents, and polycarboxylate-based water-reducing agents. The dosage of the water-reducing agent can be adjusted according to actual needs, which is a conventional technique in the art.

[0040] According to some embodiments of the foamed concrete of the present invention, the mass of hollow glass beads in the cementitious material is 3% to 20% of the total mass of cement and hollow glass microspheres.

[0041] According to some embodiments of the foamed concrete of the present invention, the mass of hollow glass beads in the cementitious material is 5% to 15% of the total mass of cement and hollow glass microspheres.

[0042] According to some embodiments of the foamed concrete of the present invention, the particle size of the hollow glass beads is 10 micrometers to 1000 micrometers.

[0043] According to some embodiments of the foamed concrete of the present invention, the cement in the cementitious material includes at least one of silicate cement, ordinary silicate cement, slag silicate cement, pozzolanic silicate cement, fly ash silicate cement, and composite silicate cement.

[0044] According to some embodiments of the foamed concrete of the present invention, the cement in the cementitious material has a strength of at least one of grades 32.5, 42.5, and 52.5.

[0045] According to some embodiments of the foamed concrete of the present invention, the density of cement in the cementitious material is 2.4 g / cm³. 3 ~2.7g / cm 3 .

[0046] According to some embodiments of the foamed concrete of the present invention, the density of cement in the cementitious material is 2.5 g / cm³. 3 ~2.6g / cm 3 .

[0047] According to some embodiments of the foamed concrete of the present invention, the wet density of the foamed concrete is 800 kg / m³. 3 ~1000kg / m 3 .

[0048] According to some embodiments of the foamed concrete of the present invention, the dry density of the foamed concrete is 500 kg / m³. 3 ~750kg / m 3 .

[0049] According to some embodiments of the foamed concrete of the present invention, the thermal conductivity of the foamed concrete is 0.05 W / m·K to 0.11 W / m·K.

[0050] A second aspect of the present invention provides a method for preparing foamed concrete according to the first aspect of the present invention, comprising the following steps:

[0051] Cement, hollow glass microspheres and water are mixed to obtain a cementitious material;

[0052] A foaming agent composition is obtained by mixing surface-hydrophilically modified nanoparticles, surfactants, regulators, and water.

[0053] The foaming agent composition is foamed to obtain foam, and then the foam is mixed with the cementitious material to obtain the foamed concrete.

[0054] According to some embodiments of the foamed concrete preparation method of the present invention, in the step of preparing the foaming agent composition, the mass ratio of the total mass of the surface-modified hydrophilic nanoparticles, surfactants and regulators to water is 1:(200-500).

[0055] According to some embodiments of the foamed concrete preparation method of the present invention, in the step of preparing the foaming agent composition, the mass ratio of the total mass of the surface-modified hydrophilic nanoparticles, surfactants and regulators to water is 1:(300-400).

[0056] According to some embodiments of the foamed concrete preparation method of the present invention, the foam is mixed with the cementitious material under stirring conditions.

[0057] A third aspect of the invention provides the application of foamed concrete according to the first aspect of the invention in the fields of construction, 3D printing, landfill, explosion protection, or ground barrier systems.

[0058] The beneficial effects of this invention are:

[0059] This invention uses a foaming agent composition that pre-treats nanoparticles for foaming, resulting in foam with stable performance and low cost. Using this foam and hollow glass microspheres to prepare foamed concrete can improve the performance of foamed concrete and effectively increase its compressive strength, with broad market application prospects.

[0060] Furthermore, compared with the prior art, the present invention has the following advantages:

[0061] 1) The foam used in the foamed concrete of this invention is made from a foaming agent that has undergone pretreatment of nanoparticles. This foam, based on the principle of nanoparticle stabilization, undergoes surface treatment, allowing nanoparticles to aggregate in a single layer on the surface of air bubbles, thus greatly reducing the amount of nanoparticles required. When the foam enters the alkaline environment of the cement mixture, the nanoparticles quickly bond together to form a protective film, ensuring that the air bubbles do not rupture. Therefore, the resulting foam is more stable and improves the performance of the foamed concrete.

[0062] 2) The foaming agent composition of the present invention contains a low content of nanoparticles, which can reduce costs and facilitate large-scale promotion and application.

[0063] 3) The process of preparing foamed concrete in this invention only requires simple blending, which is simple and convenient to operate and produces no pollutants, making it very environmentally friendly. Attached Figure Description

[0064] Figure 1 This is a scanning electron microscope image of foamed concrete from Embodiment 1 of the present invention;

[0065] Figure 2 This is a scanning electron microscope image of foamed concrete from Embodiment 2 of the present invention;

[0066] Figure 3 This is a scanning electron microscope image of foamed concrete in Embodiment 3 of the present invention. Detailed Implementation

[0067] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents or apparatus used in the embodiments and comparative examples can be obtained from conventional commercial channels or by existing technical methods.

[0068] Unless otherwise specified, the test or inspection methods are conventional methods in the art, such as those described in JG / T 266-2011 Foamed Concrete.

[0069] Example 1

[0070] The foamed concrete in this example consists of the following ingredients: 270g cement, 30g hollow glass beads, 160mL water and 230mL foam.

[0071] The cement in this example has a density of 2.59 g / cm³. 3 52.5 grade ordinary Portland cement.

[0072] The foaming agent composition in this example comprises the following raw materials in the following mass percentages: 0.06% silane coupling agent with hydrophilic surface-modified nano-attapulgite powder, 0.08% sodium dodecylbenzenesulfonate, 0.016% polyacrylamide, 0.016% polyethyleneimine, 0.04% polyvinylpyrrolidone, 0.18% methylcellulose, 0.008% triethanolamine, and the balance being water.

[0073] The preparation method of foamed concrete in this example includes the following steps:

[0074] Mix 285g of cement, 15g of hollow glass beads and 130mL of water to obtain a mixture.

[0075] A foaming agent composition is obtained by mixing surface-hydrophilically modified nano-attapulgite powder, sodium dodecylbenzenesulfonate, polyacrylamide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose and triethanolamine, and then mixing them with water at a mass ratio of 1:300.

[0076] The foaming agent composition is stirred and foamed to produce foam. Then, under stirring conditions, the mixture is mixed with 230 mL of foam to obtain foamed concrete.

[0077] Example 2

[0078] The only difference between the foamed concrete in this example and Example 1 is that the foamed concrete in this example includes the following raw materials in the following quantities: 285g cement, 15g hollow glass beads, 130mL water and 230mL foam, and the rest are the same as in Example 1.

[0079] Example 3

[0080] The only difference between the foamed concrete in this example and Example 1 is that the foamed concrete in this example includes the following raw materials in the following quantities: 255g cement, 45g hollow glass beads, 190mL water and 230mL foam, and the rest are the same as in Example 1.

[0081] Example 4

[0082] The only difference between the foamed concrete in this example and Example 1 is the composition of the foaming agent composition; otherwise, they are the same as in Example 1.

[0083] The foaming agent composition in this example comprises the following raw materials in the following mass percentages: 0.06% silane coupling agent with hydrophilic surface-modified nano-kaolin powder, 0.08% sodium dodecyl sulfate, 0.016% polyacrylamide, 0.016% polyethyleneimine, 0.04% polyvinylpyrrolidone, 0.18% methylcellulose, 0.008% triethanolamine, and the balance being water.

[0084] Example 5

[0085] The only difference between the foamed concrete in this example and Example 1 is the composition of the foaming agent composition; otherwise, they are the same as in Example 1.

[0086] The foaming agent composition in this example comprises the following raw materials in the following mass percentages: 0.06% silane coupling agent with hydrophilic surface-modified nano-bentonite powder, 0.08% AEO-9, 0.016% polyacrylamide, 0.016% polyethyleneimine, 0.04% polyvinylpyrrolidone, 0.18% methylcellulose, 0.008% triethanolamine, and the balance being water.

[0087] Comparative Example 1

[0088] The only difference between the foamed concrete in this example and Example 1 is that the foamed concrete in this example includes the following raw materials in the following quantities: 270g cement, 160mL water and 230mL foam, and the rest are the same as in Example 1.

[0089] Comparative Example 2

[0090] The only difference between the foamed concrete in this example and that in Example 1 is that the foaming agent used in this example is the commercially available HTW-1 type composite foaming agent (the main components of which are animal and plant protein foaming agents).

[0091] Comparative Example 3

[0092] The foamed concrete in this example differs from that in Example 1 in that it comprises the following amounts of raw materials: 270g cement, 160mL water and 230mL foam; the foam in this example is obtained by foaming with commercially available HTW-1 type composite foaming agent.

[0093] The foamed concrete prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests, and standard test blocks with a size of 40mm×40mm×40mm were made to test the performance. The test results are shown in Table 1.

[0094] Table 1. Test results of Examples 1-5 and Comparative Example 1

[0095]

[0096] The test results above show that the wet density of the foamed concrete provided in this embodiment of the invention is 850 kg / m³. 3 ~950kg / m 3 The dry density is 550 kg / m³ 3 ~721kg / m 3 It has the advantage of low density. The nanofoam prepared by foaming using the foaming agent composition of the present invention, when combined with cement and hollow glass microspheres to make foamed concrete, has a significantly higher compressive strength than Comparative Example 1 without hollow glass microspheres, and is also higher than the sample prepared using commercially available foaming agents.

[0097] Scanning electron microscope (SEM) images of foamed concrete from Examples 1, 2, and 3 are attached. Figure 1 , 2 3. From Figures 1-3 As can be seen, the foamed concrete in Examples 1 to 3 has a uniform distribution of pores.

[0098] In the foaming agent composition of this invention, the content of nanoparticles is only 0.06%, and its price is only 16 yuan / cubic meter, which is far lower than that of imported products. This can greatly reduce costs and make it highly competitive in the market. Moreover, the preparation of foamed concrete in this embodiment only requires simple blending, which is simple and convenient to operate, and produces no pollutants, making it very environmentally friendly and worthy of widespread application.

[0099] In addition, tests showed that the thermal conductivity of the foamed concrete prepared in Examples 1 to 5 was 0.056 W / m·K to 0.103 W / m·K, which indicates that it has good thermal insulation performance and is a high-performance thermal insulation material.

[0100] The foamed concrete provided by this invention has good performance and is a lightweight thermal insulation material with high compressive strength. It can be applied in the fields of construction, 3D printing, landfill, explosion protection, or ground barrier systems, and has broad market prospects.

[0101] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A type of foamed concrete, characterized in that: It is made from the following raw materials in the following proportions: 270g cement, 30g hollow glass beads, 160mL water and 230mL foam; or 285g cement, 15g hollow glass beads, 130mL water and 230mL foam. The cement is grade 52.5 ordinary Portland cement; The foam is prepared by foaming a foaming agent composition; The foaming agent composition comprises the following raw materials in the following mass percentages: 0.06% silane coupling agent surface-modified hydrophilic nano-attapulgite powder, 0.08% sodium dodecylbenzenesulfonate, 0.016% polyacrylamide, 0.016% polyethyleneimine, 0.04% polyvinylpyrrolidone, 0.18% methylcellulose, 0.008% triethanolamine, and the balance being water. The foamed concrete is prepared by a method including the following steps: Cement, hollow glass microspheres and water are mixed to obtain a cementitious material; A foaming agent composition is obtained by mixing silane coupling agent surface-modified hydrophilic nano-attapulgite powder, sodium dodecylbenzenesulfonate, polyacrylamide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, triethanolamine and water. The foaming agent composition is foamed to obtain foam, and then the foam is mixed with the cementitious material to obtain the foamed concrete.

2. A method for preparing foamed concrete according to claim 1, characterized in that: Includes the following steps: Cement, hollow glass microspheres and water are mixed to obtain a cementitious material; A foaming agent composition is obtained by mixing silane coupling agent surface-modified hydrophilic nano-attapulgite powder, sodium dodecylbenzenesulfonate, polyacrylamide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, triethanolamine and water. The foaming agent composition is foamed to obtain foam, and then the foam is mixed with the cementitious material to obtain the foamed concrete.

3. The application of the foamed concrete according to claim 1 in the fields of construction, 3D printing, landfill, explosion protection, or ground barrier systems.

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