CN107265965A - A kind of aerogel foam concrete segment and preparation method thereof - Google Patents

Abstract

The invention discloses an airgel foam concrete block. It is characterized in that it is prepared from airgel foam concrete, the airgel foam concrete is composed of airgel powder and foam concrete, and the airgel powder is composed of an inner hydrophobic layer and a surface hydrophilic layer, The surface hydrophilic layer has a thickness of 0.1-100 μm. The preparation method of the airgel foam concrete block of the present invention comprises the following steps: (1) modifying the airgel powder; (2) dry mixing the airgel powder obtained in step (1) with the cementitious material, Then add water for wet mixing; (3) mix the wet mixture obtained in step (2) with a foaming agent, and stir; (4) shape the wet mixture obtained in step (3). The thermal insulation wall made of airgel foam concrete blocks disclosed by the present invention has more excellent tensile stress resistance performance, crack resistance performance and anti-leakage performance, and can be widely used in green buildings and ultra-low energy consumption and near zero energy consumption Building exterior walls, self-insulation walls and other fields.

Description

Airgel foam concrete block and preparation method thereof

technical field

The invention relates to a building material, in particular to an airgel foam concrete block and a preparation method thereof.

Background technique

With the progress of society, problems such as energy crisis and environmental degradation are becoming more and more serious. In 2006, the "Outline of the Eleventh Five-Year Plan for National Economic and Social Development" put forward the concept of "energy saving and emission reduction" for the first time. %, and the binding target of reducing the total discharge of major pollutants by 10%. "Energy saving" promotes "emission reduction". In the total energy consumption of domestic production, building energy consumption accounts for 33%. It can be seen that building energy saving is the top priority of energy saving and emission reduction. According to statistics, the heat loss of the wall structure is relatively the highest, and taking thermal insulation measures for the wall is a key step for building energy saving.

At present, most of the wall insulation measures are in the external wall insulation system, and there are many construction procedures. The commonly used external wall insulation materials are mostly organic combustible materials, such as foamed polyurethane and expanded polystyrene (EPS, XPS), which cannot be used at the same time as buildings. life, with safety hazards such as shedding and flammability. Therefore, airgel foam concrete blocks will occupy a place in the field of wall insulation.

Foam concrete has the advantages of high strength and low cost. Studies have shown that the thermal insulation performance and mechanical properties of foamed concrete are mutually restricted. How to greatly improve the thermal insulation performance of foamed concrete under the premise of ensuring the compressive strength is the key issue restricting the use of foamed concrete.

Airgel is a light inorganic solid material with a three-dimensional network skeleton structure and nano-scale pores. It has extremely high porosity, specific surface area, extremely low density and solid content, chemical inertness and non-combustibility, and exhibits excellent Lightweight, thermal insulation, fire prevention, sound insulation, shock absorption and energy absorption, etc., the thermal conductivity can be as low as 0.013W/m·K. It can be speculated that airgel has the ability to greatly improve the thermal insulation properties of foamed concrete.

Building blocks generally use right-angled hexahedral rectangular blocks, and the left and right adjacent blocks can only be bonded by the mortar in the vertical joints. The mortar in the vertical joints is easy to lose, which affects the bonding strength and reduces the leakage resistance of the wall. , tensile stress and other properties.

Contents of the invention

In view of the above technical problems, the present invention provides an airgel foam concrete block and a preparation method thereof.

An airgel foam concrete block is prepared from airgel foam concrete, the airgel foam concrete is composed of airgel powder and foam concrete, and the airgel powder is composed of an inner hydrophobic layer and The surface hydrophilic layer is formed, and the thickness of the surface hydrophilic layer is 0.1-100 μm.

In one embodiment, dovetail joints and dovetail grooves are symmetrically distributed on the left and right sides of the airgel foam concrete block.

In one of the embodiments, the inclination angle of the dovetail head and the dovetail groove is 0-90°.

A method for preparing an airgel foam concrete block, comprising the following steps:

(1) Airgel powder modification;

(2) dry-mixing the airgel powder obtained in step (1) with the gelling material, and then adding water to wet-mix;

(3) Mix the wet mixture obtained in step (2) with the foaming agent and stir;

(4) Forming the wet mixture obtained in step (3).

In one of the embodiments, the step (1) includes a hydrophobic modification step; the hydrophobic modification is to perform hydrophobic modification on the airgel powder in a closed gas-phase environment of a hydrophobic modifier; the hydrophobic modification The active agent is trimethylchlorosilane, hexamethyldisilazane, hexamethyldisiloxane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, two Methyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-glycidoxy)propyltrimethoxysilane, γ- One or more of methacryloxypropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

In one of the embodiments, the step (1) further includes a surface hydrophilic modification step; the surface hydrophilic modification is to use a surface hydrophilic modification solution to modify the surface of the hydrophobic airgel powder; the Described surface hydrophilic modification solution is the aqueous solution of surfactant and low surface tension solvent or the aqueous solution of low surface tension solvent; Described surfactant is anionic surfactant, cationic surfactant, amphoteric surfactant, non-ionic surfactant One or more of ionic surfactants; the anionic surfactants are fatty alcohol phosphate ester salts, fatty alcohol polyoxyethylene ether phosphate ester salts, alkyl sulfates, fatty alcohol polyoxyethylene ether sulfate salts , Glycerin Fatty Acid Ester Sulfate, Sulfated Ricinoleate, Naphthene Sulfate, Fatty Amide Alkyl Sulfate, Alkylbenzene Sulfonate, Alkyl Sulfonate, Fatty Acid Methyl Ester Ethoxylate Sulfonate , one or more of fatty acid methyl ester sulfonate, fatty alcohol polyoxyethylene ether carboxylate; the cationic surfactant is an aliphatic ammonium salt; the amphoteric surfactant is an alkyl amino acid, a carboxyl One or more of acid-based betaines, sultaines, phosphate betaines, and alkyl hydroxyamine oxides; the nonionic surfactants are aliphatic polyesters, alkylphenol polyoxyethylene ethers, Polyoxyethylene ethers of high-carbon fatty alcohols, polyoxyethylene fatty acid esters, fatty acid methyl ester ethoxylates, ethylene oxide adducts of polypropylene glycol, sorbitan esters, sucrose fatty acid esters, and alkyl ester amides One or more; The low surface tension solvent is one or more mixtures in acetone, n-hexane, n-pentane, n-heptane, ethanol, isopropanol, tert-butanol, propylene glycol, glycerin; The surface hydrophilic modification step also includes an external physical field action step; the external physical field action step is one of far-infrared radiation, stirring, ultrasonic treatment, and ball milling.

In one of the embodiments, the step (1) further includes a drying treatment step; the drying treatment step is far-infrared drying, spray drying, microwave drying, normal pressure drying, supercritical drying, subcritical drying, freeze drying kind of.

In one of the embodiments, phase change energy storage materials, lightweight aggregates, admixtures, fibers, flame retardants, wood powder, and admixtures can also be added in the step (2) and/or step (3) one or more of; the phase change energy storage material is one or more of microcapsule-coated inorganic water and salt, higher aliphatic hydrocarbons, polyhydric alcohols, and polyhydroxy carboxylic acids; the lightweight aggregate is One or more of ceramsite, slag, expanded vermiculite, volcanic stone, expanded perlite, vitrified microspheres, light sand, polyurethane foam particles, and polystyrene foam particles; the admixture is calcium-increased pulverized coal Ash, Class II fly ash, silica fume, finely ground slag powder, phosphorus slag powder; the fibers are polystyrene fibers, polypropylene fibers, lignin fibers, alkali-resistant glass fibers, steel one or more of fibers; the flame retardant is one or both of magnesium hydroxide and aluminum hydroxide; the additive is the surfactant, water reducer, water repellent, One or more of coagulant, retarder, thickener, foam stabilizer, preservative; the water reducer is polycarboxylate water reducer, lignosulfonate sodium salt water reducer, naphthalene One or more of water reducer, aliphatic water reducer, amino water reducer; the water repellent is one or more of hard sulfonate water repellent, silicone water repellent; The accelerator is one or more of sodium silicate, aluminum sulfate, sodium nitrate, calcium nitrate, sodium sulfate, sodium carbonate, lithium carbonate; the retarder is citric acid, sodium polyphosphate, bone glue One or more of protein and borax; the thickener is one of methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, bentonite, white carbon black, and starch or more; the foam stabilizer is one or more of polyacrylamide, polyvinyl alcohol, silicone resin polyether emulsion, lauryl dimethyl amine oxide, alkanolamide; the preservative For 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 1 , one or more of 3,5-tris(2-hydroxyethyl)-s-triazine and hexahydro-1,3,5-triethyl-triazine.

In one of the embodiments, the cementitious material is Portland cement, aluminate cement, sulfoaluminate cement, magnesium oxychloride cement, gypsum, lime, water glass, acrylic resin, polyurethane resin, epoxy resin , one or more of silicone resin, fluorocarbon resin; the foaming agent is rosin foaming agent, synthetic surfactant foaming agent, plant protein foaming agent, animal protein foaming agent, hydrogen peroxide One or more of foaming agent, ammonium bicarbonate foaming agent, azodicarbonamide foaming agent, aluminum powder foaming agent.

In one of the embodiments, the molding is cast molding and/or cutting molding.

The above-mentioned airgel foam concrete block has a thermal conductivity of 0.03~0.09 W/m·K, a compressive strength of 3.0~15.0MPa, and has more excellent tensile stress resistance, crack resistance, and anti-leakage performance. It can be widely used in the fields of green buildings and ultra-low energy consumption and near zero energy consumption buildings, such as exterior walls and self-insulation walls.

Description of drawings

Fig. 1 is the structural representation of a kind of airgel foam concrete block of the present invention;

Fig. 2 is a perspective view of an airgel foam concrete block of the present invention;

Fig. 3 is a schematic structural view of an airgel foam concrete block of the present invention.

Among them, 1 is a dovetail tenon head, 2 is a dovetail tenon groove, and 3 is an airgel foam concrete block.

detailed description

In order to make the above objects, features and advantages of the present invention more comprehensible, specific implementations of the present invention will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present invention, so the present invention is not limited by the specific implementations disclosed below.

An embodiment of the airgel foam concrete block of the present invention is prepared from airgel foam concrete, the airgel foam concrete is composed of airgel powder and foam concrete, and the airgel powder It is composed of an internal hydrophobic layer and a surface hydrophilic layer, and the thickness of the surface hydrophilic layer is 0.1-100 μm.

In this way, the present invention mixes the airgel powder with the foam concrete, so that the airgel powder is evenly distributed in the foam concrete, and the airgel powder still maintains a nanoporous structure; compared with the existing foam concrete on the market, The airgel foam concrete of the present invention can significantly improve the thermal insulation performance without reducing the mechanical performance.

In this embodiment, the dovetail tenons 1 and the dovetail tenon grooves 2 are symmetrically distributed on the left and right sides of the airgel foam concrete block.

Thus, compared with rectangular blocks, the airgel foam concrete blocks of the present invention have higher bonding strength and shear strength.

In this embodiment, the inclination angle of the dovetail tenon head 1 and the dovetail tenon groove 2 is 0-90°.

In this way, the dovetail tenon and the dovetail tenon groove of the present invention satisfy the following side length relationship: a>b>c>d, f>e, the dovetail tenon can be placed in the dovetail tenon groove, and the distance between the dovetail tenon head and the dovetail tenon groove can be adjusted , Block air convection heat transfer, improve masonry insulation performance. The airgel foam concrete block of the present invention is symmetrically distributed with dovetail tenons and dovetail tenon grooves on the left and right sides, and when the masonry is subjected to tension, the bond strength and shear strength between the block and the mortar are significantly higher than those of the rectangular protrusions The bond strength between the block and the grooved block, and the anti-leakage performance are also significantly increased.

A method for preparing an airgel foam concrete block, comprising the following steps:

(1) Airgel powder modification;

(2) dry-mixing the airgel powder obtained in step (1) with the gelling material, and then adding water to wet-mix;

(3) Mix the wet mixture obtained in step (2) with the foaming agent and stir;

(4) Forming the airgel foam concrete obtained in step (3).

In addition, airgel powders with a particle size of 1-10000 μm are suitable for the present invention.

In addition, the step (2) of the present invention can also be to dry mix the gelling material, then add water to wet mix, and add the airgel powder obtained in step (1) during wet mixing.

In this way, the preparation method of the airgel foam concrete block of the present invention has the advantages of simple process, short process cycle, waste utilization and environmental protection, and is very suitable for industrial production.

In this embodiment, the step (1) includes a hydrophobic modification step; the hydrophobic modification step is to perform hydrophobic modification on the airgel powder in a closed hydrophobic modifier gas phase environment; the hydrophobic modification The agent is trimethylchlorosilane, hexamethyldisilazane, hexamethyldisiloxane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyl Diethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-glycidoxy)propyltrimethoxysilane, γ-methyl One or more of acryloyloxypropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

In this way, due to the existing airgel preparation method, the precursor, the replacement solvent and the drying process have a great impact on the hydrophobicity of the airgel. If the contact angle between the surface of the airgel and water is greater than 90°, it is not necessary to Hydrophobic modification is carried out in advance, and the surface is directly modified to be hydrophilic; if the contact angle between the surface of the airgel and water is less than 90°, it is necessary to carry out hydrophobic modification in advance; Hydrophobic modification of rubber powder, in addition to significantly improving the modification effect of airgel powder and ensuring that the internal nanoporous structure is not damaged during subsequent hydrophilic modification, it also significantly improves modification efficiency and production efficiency, reducing production costs .

In this embodiment, the step (1) further includes a surface hydrophilic modification step; the surface hydrophilic modification step is to use a surface hydrophilic modification solution to modify the surface of the hydrophobic airgel powder; the The surface hydrophilic modification solution is an aqueous solution of a surfactant and a low surface tension solvent or an aqueous solution of a low surface tension solvent; the surfactant is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic One or more in type surfactant; Described anionic surfactant is fatty alcohol phosphate ester salt, fatty alcohol polyoxyethylene ether phosphate ester salt, alkyl sulfate, fatty alcohol polyoxyethylene ether sulfate, Glycerin Fatty Acid Ester Sulfate, Sulfated Ricinoleate, Naphthene Sulfate, Fatty Amide Alkyl Sulfate, Alkylbenzene Sulfonate, Alkyl Sulfonate, Fatty Acid Methyl Ester Ethoxylate Sulfonate, One or more of fatty acid methyl ester sulfonate, fatty alcohol polyoxyethylene ether carboxylate; the cationic surfactant is an aliphatic ammonium salt; the amphoteric surfactant is an alkyl amino acid, a carboxylic acid one or more of base betaine, sultaine, phosphate betaine, and alkyl hydroxyamine oxide; the nonionic surfactant is aliphatic polyester, alkylphenol polyoxyethylene ether, high One of carbon fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, fatty acid methyl ester ethoxylate, polypropylene glycol ethylene oxide adduct, sorbitan ester, sucrose fatty acid ester, alkyl ester amide one or more; the low surface tension solvent is one or more of acetone, n-hexane, n-pentane, n-heptane, ethanol, isopropanol, tert-butanol, propylene glycol, glycerin; the surface affinity The water modification step also includes an external physical field action step; the external physical field action step is one of far-infrared radiation, stirring, ultrasonic treatment, and ball milling.

In this way, the aqueous solution of surfactant and low surface tension solvent or the aqueous solution of low surface tension solvent has surface synergistic hydrophilic modification effect in the process of hydrophilic modification treatment on the surface of hydrophobic airgel powder, which can significantly improve The wetting and spreading rate of the surface hydrophilic modification solution on the surface of the airgel powder, and at the same time significantly slow down the wetting and spreading to the interior of the airgel powder. By adjusting the amount of the modification solution, the airgel can be accurately Control of the thickness of the hydrophilic layer on the surface of the powder. The low surface tension solvent not only has a surface synergistic hydrophilic modification effect with water and surfactants, but also can greatly reduce the hydrophilic modification that enters the nanopores on the surface of the airgel powder. The capillary force of the solution makes it easy to evaporate the hydrophilic modification solution in the nanopores on the surface of the airgel powder through the drying process without destroying its nanoporous structure, making the airgel powder internally hydrophobic and surface hydrophilic 1. The surface hydrophilic layer still retains the structural characteristics of nanoporous structure and the thickness of the surface hydrophilic layer is 0.1~100 μm, and has a good interface bonding with the gelling material; the external physical field can significantly improve the surface hydrophilic modification solution. Activity and contact probability with airgel powder, reduce the amount of surfactant, increase the surface hydrophilic modification rate of airgel powder, reduce cost, and improve production efficiency.

In this embodiment, the step (1) further includes a drying treatment step; the drying treatment step is one of far-infrared drying, spray drying, microwave drying, normal pressure drying, supercritical drying, subcritical drying, and freeze drying. kind.

In this way, if the airgel powder after hydrophilic modification is combined with the gelling material, the residual hydrophilic modification solution on the surface will affect the interface bonding, and it needs to be dried in advance; Under the premise that the nanopore structure of the surface layer of the body is not destroyed, the residual surface hydrophilic modification solution in the nanopores of the surface layer of the airgel powder is evaporated to improve the interface bonding strength between the airgel powder and the gelling material.

In this embodiment, one of phase change energy storage materials, lightweight aggregates, admixtures, fibers, flame retardants, wood powder, and additives can also be added to the step (2) and/or step (3). one or more; the phase change energy storage material is one or more of microcapsule-coated inorganic water and salt, higher aliphatic hydrocarbons, polyols, and polyhydroxy carboxylic acids; the lightweight aggregate is ceramsite , slag, expanded vermiculite, volcanic stone, expanded perlite, vitrified microspheres, light sand, polyurethane foam particles, polystyrene foam particles or one or more; the admixture is calcium-enhancing fly ash, One or more of Class II fly ash, silica fume, finely ground slag powder, and phosphorus slag powder; the fibers are polystyrene fibers, polypropylene fibers, lignin fibers, alkali-resistant glass fibers, and steel fibers. one or more of them; the flame retardant is one or both of magnesium hydroxide and aluminum hydroxide; , retarder, thickener, foam stabilizer, preservative in one or more; said water reducer is polycarboxylate water reducer, lignosulfonate sodium salt water reducer, naphthalene series water reducer One or more of water agent, aliphatic water reducer, amino water reducer; said water repellent is one or more of hard sulfonate water repellent, organosilicon water repellent; said The accelerator is one or more of sodium silicate, aluminum sulfate, sodium nitrate, calcium nitrate, sodium sulfate, sodium carbonate, lithium carbonate; the retarder is citric acid, sodium polyphosphate, bone glue protein, One or more in borax; The thickener is one or more in methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, bentonite, white carbon black, starch A kind; The foam stabilizer is one or more of polyacrylamide, polyvinyl alcohol, silicone resin polyether emulsion, lauryl dimethyl amine oxide, alkanolamide; The preservative is 1 ,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 1,3 , one or more of 5-tris(2-hydroxyethyl)-s-triazine and hexahydro-1,3,5-triethyl-triazine.

In this way, the phase change energy storage material can absorb or release a large amount of heat energy through phase change, and has the function of energy storage. The airgel foam concrete of the present invention is used in the building wall, which can adjust the indoor temperature of the building, improve the comfort of the building, and save energy. , and adding phase change energy storage materials can improve the freeze-thaw resistance of airgel foam concrete of the present invention; lightweight aggregate has low density, high compressive strength, good thermal insulation performance, adding lightweight aggregate can improve The mechanical properties and thermal insulation properties of airgel foam concrete do not significantly increase or decrease its density; the use of admixtures can improve the workability and cohesion of concrete, reduce the slump of concrete, and benefit the development of airgel foam concrete. The pore size distribution is uniform, thereby improving the mechanical properties and thermal insulation properties of airgel foam concrete; and the use of admixtures is conducive to the use of industrial waste, reducing the cost of airgel foam concrete, energy saving and waste utilization; adding fibers can improve air condensation The mechanical properties such as flexural resistance of rubber foam concrete; adding flame retardant can improve the fireproof grade of airgel foam concrete of the present invention, because flame retardants such as magnesium hydroxide, aluminum hydroxide meet fire and produce dehydration endothermic reaction, prolong matrix The rate of temperature rise; adding wood powder can improve the strength between airgel foam concrete and anchors and screws; adding surfactant can improve the wetting efficiency of cementitious materials on the surface of fibers, lightweight aggregates, etc., thereby improving The interface bonding strength between cementitious material and fiber, cementitious material and lightweight aggregate; adding water reducing agent can improve the fluidity and slump of concrete, reduce water consumption, and improve the mechanical properties of airgel foam concrete; adding water-repellent The agent can significantly reduce the water absorption of airgel foam concrete, especially the airgel foam concrete with through-hole structure, and improve the freeze-thaw resistance and weather resistance of airgel foam concrete; The curing rate can reduce the initial setting time of airgel foam concrete, reduce the pore size of airgel foam concrete, make the pore size distribution of airgel foam concrete uniform, and improve the mechanical properties and thermal insulation properties of airgel foam concrete; adding retarder can Slow down the curing rate of the cementitious material. When using gypsum, because the gypsum curing rate is too fast, it is necessary to add a retarder to adjust the hardening time; adding a thickener can increase the viscosity of the concrete, improve the stability and porosity of the foam concrete cells, The shape of airgel foam concrete cells is mostly regular spherical, thereby improving the mechanical properties and thermal insulation properties of airgel foam concrete; adding a foam stabilizer can improve the cell stability and porosity of airgel foam concrete , and then improve the mechanical properties and thermal insulation properties of the airgel foam concrete; adding preservatives can prevent the airgel foam concrete from mildewing and improve its service life and durability; the present invention adopts a two-step mixing process of dry mixing-wet mixing , solve the stratification caused by the large difference in specific gravity between airgel powder and other materials, realize the uniform mixing of modified airgel powder in concrete, and reduce the influence of airgel powder on the foaming process, It is beneficial to control the foaming quality and achieve low thermal conductivity.

In this embodiment, the cementitious material is Portland cement, aluminate cement, sulfoaluminate cement, magnesium oxychloride cement, gypsum, lime, water glass, acrylic resin, polyurethane resin, epoxy resin, organic One or more of silicone resin and fluorocarbon resin; the foaming agent is rosin foaming agent, synthetic surfactant foaming agent, vegetable protein foaming agent, animal protein foaming agent, hydrogen peroxide foaming agent One or more of foaming agent, ammonium bicarbonate foaming agent, azodicarbonamide foaming agent, aluminum powder foaming agent.

In this way, the type of foaming agent has a great influence on the pore shape, pore size distribution, water absorption, and thermal insulation performance of the airgel foam concrete. The present invention can prepare airgel foam concrete by physical foaming, or by chemical foaming The airgel foamed concrete is prepared by foaming, and the airgel foamed concrete or foamed concrete prepared by the invention has excellent thermal insulation, sound insulation and fireproof properties.

In this embodiment, the molding is casting molding and/or cutting molding.

In this way, the present invention can use the pre-prepared mold with dovetail tenon and dovetail tenon groove to prepare the airgel foam concrete block by pouring molding, and can also cut the airgel foam concrete block in the later stage to obtain the mold with dovetail tenon. and dovetail-groove airgel foam concrete blocks.

The above-mentioned airgel foam concrete block has a thermal conductivity of 0.03~0.09 W/m·K, a compressive strength of 3.0~15.0MPa, and has more excellent tensile stress resistance, crack resistance, and anti-leakage performance. It can be widely used in the fields of green buildings and ultra-low energy consumption and near zero energy consumption buildings, such as exterior walls and self-insulation walls.

The following is the specific embodiment part.

Example 1

The following steps were used to prepare _SiO2 airgel foam concrete blocks:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder to be treated and water, and the test result is 31°, then place the SiO ₂ airgel powder with a particle size of 88 μm in a vacuum heating In the furnace, place the weighed trimethylchlorosilane in a vacuum heating furnace with a container, heat and gasify, and perform hydrophobic modification for 1.5h to obtain hydrophobic _SiO2 airgel powder, and use a contact angle measuring instrument to detect hydrophobic SiO ₂ The contact angle between the airgel powder surface and water, the test result is 150°;

(2) At room temperature, weigh n-hexane, sodium alkylbenzenesulfonate and deionized water at a mass ratio of 1:0.5:1000, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is put into a container made of filter mesh, immersed in the surface hydrophilic modification solution together, and taken out after 1 min;

(4) Place the SiO ₂ airgel sheet containing the hydrophilic modification solution on the surface obtained in step (3) in a far-infrared drying oven, dry it at 120°C for 0.5h, and cool it down to below 50°C with the furnace Take it out, and detect the cross-section of the _SiO2 airgel powder, and the test results show that the thickness of the surface hydrophilic layer is 0.1 μm;

(5) Weigh the modified SiO ₂ airgel powder prepared in step (4), 425 ordinary Portland cement, ceramsite, redispersible latex powder, hydroxymethyl cellulose, polycarboxylic acid Class water reducer, sodium sulfate, carry out dry mixing, obtain dry mixture;

(6) adding water to the dry mixture obtained in step (5) for wet mixing to obtain a wet mixture;

(7) Use a foaming machine to foam the aqueous solution containing the animal protein foaming agent, and the volume ratio of the animal protein foaming agent to water is 1:20 to obtain a foam;

(8) Mix the wet mixture obtained in step (6) with the foam, and mechanically stir for 1 min to obtain _SiO2 airgel foam concrete;

(9) pour the wet material obtained in step (8) into a mold with a dovetail head and a dovetail groove, seal it, and demould after 24 hours;

(10) After the plastic film is sealed, it is naturally cured for 28 days under the conditions of 20°C temperature and 95% RH humidity to obtain SiO ₂ airgel foam concrete blocks. Table 1 is the performance index of the SiO ₂ airgel foam concrete blocks prepared in this example.

Table 1 Performance indicators of SiO ₂ airgel foam concrete blocks

Example 2

The following steps were used to prepare _SiO2 airgel foam concrete blocks:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder to be treated and water. The test result is 45°, and then place the SiO ₂ airgel powder with a particle size of 89 μm in a vacuum heating In the furnace, place the weighed hexamethyldisilazane in a vacuum heating furnace with a container, heat and gasify, and perform hydrophobic modification for 1.5h to obtain hydrophobic _SiO2 airgel powder, which is detected by a contact angle meter The contact angle between the surface of hydrophobic SiO ₂ airgel powder and water is 146°;

(2) At room temperature, weigh sodium alkylbenzenesulfonate, n-hexane and deionized water at a mass ratio of 1:0.8:120, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after mechanical stirring for 15 minutes, the rotating speed is 2000 rpm, and then filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a blast drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 6.0 μm;

(5) Weigh the modified SiO ₂ airgel powder prepared in step (4), 425 ordinary Portland cement, ceramsite, redispersible latex powder, starch, polycarboxylate water reducer in sequence according to the proportion , aluminum sulfate, carry out dry mixing, obtain dry mixture;

(6) adding water to the dry mixture obtained in step (5) for wet mixing to obtain a wet mixture;

(7) Foam preparation, using a foaming machine to foam the aqueous solution containing sodium lauryl sulfate foaming agent, the volume ratio of sodium lauryl sulfate foaming agent to water is 1:20, and the foam is obtained ;

(8) Mix the wet mixture obtained in step (6) with the foam, and mechanically stir for 1 min to obtain _SiO2 airgel foam concrete;

(9) Pour the wet material obtained in step (8) into a cubic mold, seal it, and demould it after 24 hours. After 5 days of natural curing, cut it into blocks with dovetail tenons and dovetail grooves, and continue curing for 23 days to obtain SiO ₂ Airgel foam concrete blocks. Table 2 is the performance index of the SiO ₂ airgel foam concrete blocks prepared in this embodiment.

Table 2 Performance indicators of SiO ₂ airgel foam concrete blocks

Example 3

The following steps were used to prepare _SiO2 airgel foam concrete blocks:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder with a particle size of 0.3 mm and water. If the test result is 148°, the SiO ₂ airgel powder is hydrophobic ;

(2) At room temperature, weigh fatty alcohol polyoxyethylene ether ammonium sulfate, n-hexane, ethanol and deionized water according to the mass ratio of 1:0.4:0.3:130, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after mechanical stirring for 15 minutes, the rotating speed is 2500 rpm, and then filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a far-infrared drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 11.1 μm;

(5) Weigh the modified SiO ₂ airgel powder prepared in step (4), 525 ordinary Portland cement, sulphoaluminate cement, ceramsite, redispersible latex powder, methylol Cellulose, polycarboxylate water reducing agent, sodium sulfate, carry out dry mixing, obtain dry mixture;

(6) adding water to the dry mixture obtained in step (5) for wet mixing to obtain a wet mixture;

(7) Mix the wet mixture obtained in step (6) with ammonium bicarbonate foaming agent, and stir mechanically for 2 minutes;

(8) Pouring the wet material obtained in step (7) into a mold with a dovetail head and a dovetail groove, foaming, sealing, and demoulding after 24 hours;

(9) After the plastic film is sealed, it is cut and formed, and naturally cured for 28 days to obtain SiO ₂ airgel foam concrete blocks. Table 3 is the performance index of the SiO ₂ airgel foam concrete blocks prepared in this embodiment.

Table 3 Performance indicators of SiO ₂ airgel foam concrete blocks

Example 4

The following steps were used to prepare _SiO2 airgel foam concrete blocks:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder to be treated and water, the test result is 45°, and then place the SiO ₂ airgel powder with a particle size of 67 μm in a vacuum heating In the furnace, place the weighed trimethylchlorosilane in a vacuum heating furnace with a container, heat and gasify, and perform hydrophobic modification for 1.5h to obtain hydrophobic _SiO2 airgel powder, and use a contact angle measuring instrument to detect hydrophobic SiO ₂ The contact angle between the surface of the airgel powder and water, the test result is 146°;

(2) At room temperature, weigh fatty alcohol polyoxyethylene ether sodium sulfate, sodium alkylbenzene sulfonate, n-hexane and deionized water according to the mass ratio of 1:1:1000, mix them evenly, and prepare the surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is put into a container made of filter mesh, immersed in the surface hydrophilic modification solution together, and taken out after 2 minutes;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a blast drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 1.3 μm;

(5) Weigh the modified SiO ₂ airgel powder prepared in step (4), 425 ordinary Portland cement, ceramsite, redispersible latex powder, hydroxyethyl cellulose, polycarboxylic acid Class water reducer, sodium nitrate, carry out dry mixing, obtain dry mixture;

(6) adding water to the dry mixture obtained in step (5) for wet mixing to obtain a wet mixture;

(7) Foam preparation, using a foaming machine to foam an aqueous solution containing a vegetable protein foaming agent, the volume ratio of the vegetable protein foaming agent to water is 1:20, and a foam is obtained;

(8) Mix the wet mixture obtained in step (6) with the foam, and mechanically stir for 1 min to obtain _SiO2 airgel foam concrete;

(9) pour the wet material obtained in step (8) into a mold with a dovetail head and a dovetail groove, seal it, and demould after 24 hours;

(10) After the plastic film is sealed, it is naturally cured for 28 days to obtain SiO ₂ airgel foam concrete blocks. Table 4 is the performance index of the SiO ₂ airgel foam concrete blocks prepared in this embodiment.

Table 4 Performance indicators of SiO ₂ airgel foam concrete blocks

Example 5

The following steps were used to prepare _SiO2 airgel foam concrete blocks:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder to be treated and water, and the test result is 31°, then place the SiO ₂ airgel powder with a particle size of 22 μm in a vacuum heating In the furnace, place the weighed hexamethyldisilazane in a vacuum heating furnace with a container, heat and gasify, and perform hydrophobic modification for 2.5 hours to obtain hydrophobic _SiO2 airgel powder, which is detected by a contact angle meter The contact angle between the surface of hydrophobic SiO ₂ airgel powder and water is 150°;

(2) At room temperature, weigh n-hexane, glycerin and deionized water at a mass ratio of 1:0.5:15, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is put into a container made of filter mesh, immersed in the surface hydrophilic modification solution together, and taken out after 1 min;

(4) Place the SiO ₂ airgel sheet containing the hydrophilic modification solution on the surface obtained in step (3) in a far-infrared drying oven, dry it at 120°C for 0.5h, and cool it down to below 50°C with the furnace Take it out, and detect the cross section of the _SiO2 airgel powder, and the test results show that the thickness of the surface hydrophilic layer is 99.2 μm;

(5) Weigh the modified SiO ₂ airgel powder prepared in step (4), 425 ordinary Portland cement, hemihydrate gypsum, polycarboxylate water reducer, sodium citrate, hydroxide Magnesium and microcapsules are coated with octadecane, and dry mixed to obtain a dry mixture;

(6) wet mixing the dry mixture obtained in step (5) with water and acrylic emulsion to obtain a wet mixture;

(7) Foam preparation, using a foaming machine to foam the foaming agent solution composed of foaming agent, acrylic emulsion and water, the volume ratio of animal protein foaming agent and water is 1:0.05:80, and the foam is obtained body;

(8) Mix the wet mixture obtained in step (6) with the foam, and mechanically stir for 1 min to obtain the SiO ₂ airgel foam concrete wet material;

(9) pour the wet material obtained in step (8) into a mold with a dovetail head and a dovetail groove, seal it, and demould after 24 hours;

(10) After the plastic film is sealed, it is naturally cured for 28 days to obtain SiO ₂ airgel foam concrete blocks. Table 5 is the performance index of the SiO ₂ airgel foam concrete blocks prepared in this embodiment.

Table 5 Performance indicators of SiO ₂ airgel foam concrete blocks

Example 6

The following steps were used to prepare _SiO2 airgel foam concrete blocks:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder with a particle size of 177 μm and water. If the test result is 141°, the SiO ₂ airgel powder is hydrophobic;

(2) At room temperature, weigh acetone and deionized water at a mass ratio of 1:100, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after ball milling for 25 minutes, it is taken out and filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a blast drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 6.5 μm;

(5) Weigh the modified SiO ₂ airgel powder, fly ash, redispersible latex powder, hydroxyethyl cellulose, polycarboxylate water reducer, poly Propylene fibers are dry mixed to obtain a dry mix;

(6) adding water glass and water to the dry mixture obtained in step (5) for wet mixing to obtain a wet mixture;

(7) Mix the wet mixture obtained in step (6) with the aluminum powder foaming agent, and stir mechanically for 5 minutes;

(8) Pouring the wet material obtained in step (7) into a mold with a dovetail head and a dovetail groove, foaming, sealing, and demoulding after 24 hours;

(9) After the plastic film is sealed, it is cut and formed, and naturally cured for 28 days to obtain SiO ₂ airgel foam concrete blocks. Table 6 is the performance index of the SiO ₂ airgel foam concrete blocks prepared in this embodiment.

Table 6 Performance indicators of SiO ₂ airgel foam concrete blocks

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. an airgel foam concrete building block, is characterized in that, is prepared from airgel foam concrete, and described airgel foam concrete is made of airgel powder and foam concrete, and described airgel powder The body is composed of an inner hydrophobic layer and a surface hydrophilic layer, and the thickness of the surface hydrophilic layer is 0.1-100 μm. 2. An airgel foam concrete block according to claim 1, characterized in that, dovetail tenon heads and dovetail tenon grooves are symmetrically distributed on the left and right sides of the airgel foam concrete block. 3. The airgel foam concrete block according to claim 1, wherein the inclination angle of the dovetail head and the dovetail groove is 0-90°. 4. A preparation method of airgel foam concrete block, is characterized in that, comprises the following steps: (1) Airgel powder modification; (2) dry-mixing the airgel powder obtained in step (1) with the gelling material, and then adding water to wet-mix; (3) Mix the wet mixture obtained in step (2) with the foaming agent and stir; (4) Forming the wet mixture obtained in step (3). 5. The method for preparing an airgel foam concrete block according to claim 4, wherein said step (1) includes a hydrophobic modification step; The airgel powder is hydrophobically modified in an agent gas phase environment; the hydrophobic modifier is trimethylchlorosilane, hexamethyldisilazane, hexamethyldisiloxane, methyltrimethoxysilane , Methyltriethoxysilane, Dimethyldimethoxysilane, Dimethyldiethoxysilane, γ-Aminopropyltrimethoxysilane, γ-Aminopropyltriethoxysilane, γ- (2,3-Glycidoxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxy One or more of the base silanes. 6. A method for preparing an airgel foam concrete block according to claim 4, wherein said step (1) also includes a surface hydrophilic modification step; said surface hydrophilic modification step is to use The surface hydrophilic modification solution modifies the surface of the hydrophobic airgel powder; the surface hydrophilic modification solution is an aqueous solution of a surfactant and a low surface tension solvent or an aqueous solution of a low surface tension solvent; the surfactant It is one or more of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants; the anionic surfactants are fatty alcohol phosphate ester salts, fatty alcohol polyoxygen Vinyl ether phosphate, alkyl sulfate, fatty alcohol polyoxyethylene ether sulfate, glycerin fatty acid ester sulfate, sulfated ricinoleate, naphthene sulfate, fatty amide alkyl sulfate, alkylbenzenesulfonate One or more of acid salts, alkyl sulfonates, fatty acid methyl ester ethoxylate sulfonates, fatty acid methyl ester sulfonates, fatty alcohol polyoxyethylene ether carboxylates; the cationic surface active The agent is aliphatic ammonium salt; the amphoteric surfactant is one or more of alkyl amino acids, carboxylate betaines, sultaines, phosphate betaines, and alkyl oxyamines; the non- Ionic surfactants are aliphatic polyesters, alkylphenol polyoxyethylene ethers, high-carbon fatty alcohol polyoxyethylene ethers, fatty acid polyoxyethylene esters, fatty acid methyl ester ethoxylates, and ethylene oxide addition of polypropylene glycol One or more in substance, sorbitan ester, sucrose fatty acid ester, alkyl ester amide; Described low surface tension solvent is acetone, n-hexane, n-pentane, n-heptane, ethanol, isopropanol One or more of , tert-butanol, propylene glycol, glycerol; in the surface hydrophilic modification step, also include an external physical field action step; the external physical field action step is far-infrared radiation, stirring, ultrasonic treatment , one of the ball mills. 7. A method for preparing an airgel foam concrete block according to claim 4, wherein said step (1) also includes a drying step; said drying step is far-infrared drying, spray drying, One of microwave drying, normal pressure drying, supercritical drying, subcritical drying, and freeze drying. 8. A method for preparing an airgel foam concrete block according to claim 4, characterized in that phase change energy storage materials, light bone One or more of materials, admixtures, fibers, flame retardants, wood flour, and additives; the phase change energy storage material is microcapsule-coated inorganic water and salt, higher aliphatic hydrocarbons, polyols, One or more of polyhydroxy carboxylic acids; the lightweight aggregate is ceramsite, slag, expanded vermiculite, volcanic stone, expanded perlite, vitrified microbeads, light sand, polyurethane foam particles, polystyrene foam One or more of particles; the admixture is one or more of calcium-increasing fly ash, class II fly ash, silica fume, ground slag powder, phosphorus slag powder; the fiber is poly One or more of styrene fibers, polypropylene fibers, lignin fibers, alkali-resistant glass fibers, and steel fibers; the flame retardant is one or both of magnesium hydroxide and aluminum hydroxide; the The admixture is one or more of the surfactant, water reducer, water repellent, coagulation accelerator, retarder, thickener, foam stabilizer, preservative; the water reducer is poly One or more of carboxylic acid water reducer, lignosulfonate sodium salt water reducer, naphthalene water reducer, aliphatic water reducer, amino water reducer; the water repellent is hard sulfonic acid One or more in salt water-repellent agent, organosilicon water-repellent agent; Described accelerator is one or more in sodium silicate, aluminum sulfate, sodium nitrate, calcium nitrate, sodium sulfate, sodium carbonate, lithium carbonate multiple; the retarder is one or more of citric acid, sodium polyphosphate, bone glue protein, borax; the thickener is methyl cellulose, ethyl cellulose, hydroxymethyl cellulose , hydroxyethyl cellulose, bentonite, white carbon black, starch in one or more; the foam stabilizer is polyacrylamide, polyvinyl alcohol, silicone resin polyether emulsion, lauryl dimethyl oxide One or more of amines and alkanolamides; the preservatives are 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazoline-3- Ketone, 2-methyl-4-isothiazolin-3-one, 1,3,5-tris(2-hydroxyethyl)-s-triazine, hexahydro-1,3,5-triethyl-triazine one or more of. 9. The preparation method of a kind of airgel foam concrete building block according to claim 4, is characterized in that, described cementitious material is portland cement, aluminate cement, sulphoaluminate cement, magnesium oxychloride One or more of cement, gypsum, lime, water glass, acrylic resin, polyurethane resin, epoxy resin, silicone resin, fluorocarbon resin; the foaming agent is rosin foaming agent, synthetic surfactant One or more of agent foaming agent, plant protein foaming agent, animal protein foaming agent, hydrogen peroxide foaming agent, ammonium bicarbonate foaming agent, azodicarbonamide foaming agent, aluminum powder foaming agent . 10 . The method for preparing an airgel foam concrete block according to claim 4 , wherein the molding is casting molding and/or cutting molding. 11 .