Anti-freezing thermal insulation concrete and preparation method thereof

Abstract

The invention discloses anti-freezing thermal insulation concrete and a preparation method thereof, and belongs to the technical field of building materials. The concrete is prepared from the following raw materials in parts by weight: 150 to 200 parts of cement, 90 to 110 parts of fly ash, 50 to 70 parts of silica fume, 12 to 18 parts of composite foaming agent, 200 to 300 parts of coarse aggregate, 100 to 200 parts of river sand, 30 to 50 parts of fiber, 2 to 5 parts of water reducing agent and 100 to 120 parts of water. The lightweight thermal insulation concrete prepared by using the composite foaming agent is uniform in pore structure, has good mechanical properties, low thermal insulation coefficient and good erosion resistance, and is excellent in comprehensive performance. Meanwhile, the waste animal feathers are effectively utilized, resources can be saved, the environment can be protected, and economic and social benefits are remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of lightweight concrete, and in particular relates to antifreeze and thermal insulation concrete and a preparation method thereof. Background Art

[0003] At present, flammable materials such as polystyrene foam board, extruded board, polyurethane, etc. occupy a large proportion of the entire insulation material market. These organic insulation materials generally have the advantages of low bulk density, good insulation performance, simple construction operation, and low water absorption. They can achieve good insulation effect when used for building exterior walls. But at the same time, they have defects that cannot be ignored, such as flammability, easy aging, and poor durability. In a fire, organic materials will melt very quickly, producing a large amount of toxic gases and smoke. Moreover, organic insulation materials cannot have the same lifespan as the building, and need to be replaced many times during the service life of the building, which not only wastes a lot of manpower, financial resources and material resources, but also brings environmental disasters such as white pollution caused by material replacement. Therefore, it is an inevitable trend of historical development and scientific and technological progress to replace organic insulation materials with inorganic insulation materials for building insulation.

[0004] Among the existing inorganic insulation materials, foam glass, foam aluminum, and foam ceramics are expensive and lack competitive advantages; while fiber insulation materials such as rock wool and mineral wool are slightly cheaper, but they are harmful to health; and they are not hard block materials, so they are difficult to use. The construction period of rock wool is long, and it takes about 2 years from the construction of the factory to the production. The current supply of rock wool in the market does not meet the requirements of use, which determines that they will not become the dominant material for building insulation; granular loose insulation materials such as expanded perlite and expanded vermiculite have high water absorption, and the products are not resistant to freezing and thawing, and they are loose and difficult to use, so they are also limited in application. Foam concrete raw materials are easy to obtain and low in price. It can realize rapid cast-in-place construction and make various products. At the same time, it has excellent fire resistance, sound insulation, earthquake resistance, and weather resistance. It is the most suitable material to replace organic foam plastics.

[0005] Foam concrete insulation material is a porous concrete material with a large number of closed pores inside, which is formed by introducing an appropriate amount of tiny bubbles into cement paste or cement mortar, mixing it evenly, and then pouring it to harden. Foam concrete contains a large number of bubbles inside, so compared with ordinary concrete, it has special properties such as light weight, heat preservation, heat insulation, and sound insulation; in addition, foam concrete also has a lower elastic modulus, good stress dispersion and shock absorption performance, so it can be competent for some occasions with special performance requirements and meet the needs of modern construction projects.

[0006] However, the current foam concrete materials still have many problems in terms of thermal insulation performance. The current foam concrete is prone to shrinkage and cracking if it is improperly maintained in the early stage or if water retention measures are insufficient, which will affect its thermal insulation effect. The poor pore structure inside the foam concrete makes it easy to cause volume shrinkage and surface cracking when water evaporates, and the mechanical properties are poor. At the same time, there is also the problem of poor anti-corrosion and anti-freeze-thaw performance.

[0007] Therefore, how to develop a lightweight foam insulation concrete with excellent comprehensive performance is a technical problem that needs to be solved urgently. Summary of the invention

[0008] The present invention aims at solving the problems existing in the prior art.

[0009] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0010] A frost-resistant thermal insulation concrete comprises the following raw materials in parts by weight: 150-200 parts of cement, 90-110 parts of fly ash, 50-70 parts of silica fume, 12-18 parts of composite foaming agent, 200-300 parts of coarse aggregate, 100-200 parts of river sand, 30-50 parts of fiber, 2-5 parts of water reducer and 100-120 parts of water.

[0011] Furthermore, the cement is P·O42.5 ordinary Portland cement.

[0012] Furthermore, the fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0013] Furthermore, the preparation method of the composite foaming agent is:

[0014] A. Place 10g of discarded animal feathers in a container, add 10mL of a 0.5-1% NaHSO3 solution, then add 500mL of water to soak for 5-8h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0015] B. Add 15g of glucose, 15g of tryptone and 6g of yeast extract powder to 100-120mL of distilled water and stir evenly. After high-temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48h to obtain an EM bacteria foaming agent;

[0016] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:1, 5% of sodium dodecyl sulfate and 3% of polyoxyethylene sorbitan fatty acid ester were added to the mixture, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0017] Furthermore, the amount of EM bacteria added in step B is 1-1.5% of the mass of the nutrient solution, and the number of effective live bacteria of the EM bacteria is not less than 20 billion / g. The EM bacteria can be commercially available products that meet the requirements. The EM bacteria in the embodiment of the present invention are purchased from Jinan Herui Biotechnology Co., Ltd., model EM-01.

[0018] Furthermore, the feathers used in step A are preferably poultry feathers from a large source, such as poultry such as chickens, ducks, geese, pigeons, etc.

[0019] Furthermore, the coarse aggregate is limestone crushed stone with a particle size of 5mm-25mm.

[0020] Furthermore, the fiber is a polymer fiber, which is one or more of polypropylene fiber and polyacrylonitrile fiber.

[0021] Furthermore, the water reducer is at least one of a polycarboxylic acid water reducer, a naphthalene water reducer and a fatty acid water reducer.

[0022] A method for preparing frost-resistant and thermal-insulating concrete comprises the following preparation steps:

[0023] (1) preparing a composite foaming agent;

[0024] (2) diluting the composite foaming agent and water in a mass ratio of 1:50-60 to prepare a foaming agent solution, and then preparing foam using a foaming machine;

[0025] (3) After cement, fly ash, silica fume, coarse aggregate, river sand and fiber are mixed evenly, a water reducer and water are added, and then the foam prepared in step (2) is added, mixed and stirred, and cast into shape. The molded test block is placed in a standard curing room for curing, and the mold is removed to obtain the final product concrete.

[0026] Traditional protein foaming agents have poor foam stability and are prone to breakage or loss of stability during use. The prepared concrete structure is uneven, and the strength and thermal insulation performance cannot meet the actual use requirements. At the same time, animal protein foaming agents rely on raw materials such as animal keratin, which are limited in source and expensive, limiting their large-scale development and application. In addition, although plant protein foaming agents have a wide range of raw material sources and low costs, their development is relatively lagging, and there are problems such as low foaming ability and poor anti-corrosion performance, which makes it difficult to meet the requirements of large-scale industrial applications.

[0027] General chemical foaming agents, such as rosin soap and rosin thermal polymer, have good compatibility but require heating treatment, and their foam stability is generally poor and prone to sedimentation. The use of chemical foaming agents may bring safety hazards and environmental problems.

[0028] Therefore, the present invention uses poultry discarded feathers as raw materials. Animal feathers are rich in keratin. Using NaHSO3 treatment can open more disulfide bonds between protein molecules and improve the hydrolysis rate of keratin. The prepared animal protein foaming agent has good foam stability and foaming ability, and is particularly suitable for producing ultra-low density foam concrete products. The obtained concrete has low density, closed and independent pores, and excellent anti-permeability and thermal insulation properties.

[0029] At the same time, EM bacteria are used to ferment and prepare microbial foaming agents. Microbial foaming agents produce carbon dioxide through fermentation to form a foam structure, thereby improving the microstructure of concrete. After being mixed with animal protein foaming agents in equal proportions, the resulting foam is more uniform and delicate, with better stability. After being added to concrete, it can form a more uniform pore structure, with closed and independent bubbles, and the concrete macroscopically presents excellent anti-permeability and thermal insulation properties. At the same time, EM bacteria can accelerate the hydration reaction of concrete, reduce water loss, and form a self-curing environment, thereby improving the corrosion resistance and durability of concrete.

[0030] Adding polymer fibers, such as polypropylene and polyacrylonitrile fibers, can significantly increase the air content of concrete, which helps capture air and form a more uniform pore structure, breaking up the large pores in the concrete into smaller uniform pores. On the one hand, it helps to improve the concrete's resistance to sulfate erosion and acid corrosion, and on the other hand, it helps to improve the concrete's thermal insulation performance.

[0031] Beneficial effects:

[0032] The lightweight thermal insulation concrete prepared by using the composite foaming agent of the present invention has uniform pore structure, good mechanical properties, low thermal insulation coefficient and good anti-corrosion performance, and has excellent comprehensive performance. At the same time, the discarded animal feathers are effectively utilized, which can save resources and protect the environment, and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a photo of the deterioration of the thermal insulation concrete surface after 80 freeze-thaw cycles of the specimen in Example 1;

[0034] Figure 2 The photos of the deterioration of the thermal insulation concrete surface after 80 freeze-thaw cycles of the specimens of comparative example 1-3;

[0035] Figure 3The photos of the deterioration of the thermal insulation concrete surface after 80 freeze-thaw cycles of the specimens of comparative example 4-6;

[0036] Figure 4 This is a diagram of the internal pore structure of the test piece of Example 1;

[0037] Figure 5 This is the internal pore structure diagram of the comparative example 1-6 specimens. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below in conjunction with specific embodiments, but is not limited thereto.

[0039] Example 1

[0040] A frost-resistant heat-insulating concrete comprises the following raw materials in parts by weight: 150 parts of cement, 90 parts of fly ash, 50 parts of silica fume, 12 parts of composite foaming agent, 200 parts of coarse aggregate, 200 parts of river sand, 30 parts of fiber, 2 parts of water reducer and 120 parts of water.

[0041] The cement is P·O42.5 ordinary Portland cement.

[0042] The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0043] The preparation method of the composite foaming agent is:

[0044] A. Place 10g of discarded animal feathers in a container, add 10mL of 0.5% NaHSO3 solution, then add 500mL of water to soak for 5h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0045] B. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 100 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0046] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:1, 5% of sodium dodecyl sulfate and 3% of polyoxyethylene sorbitan fatty acid ester were added to the mixture, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0047] The amount of EM bacteria added in step B is 1% of the mass of the nutrient solution, and the number of effective live bacteria of the EM bacteria is not less than 20 billion / g. The EM bacteria can be commercially available products that meet the requirements. The EM bacteria in this embodiment are purchased from Jinan Herui Biotechnology Co., Ltd., model EM-01.

[0048] The feathers used in step A are preferably poultry feathers from a large source, such as poultry such as chickens, ducks, geese, pigeons, etc.

[0049] The coarse aggregate is limestone crushed stone with a particle size of 5mm-25mm.

[0050] The fibers are polymer fibers, which are polypropylene fibers.

[0051] The water reducing agent is a polycarboxylic acid water reducing agent.

[0052] A method for preparing frost-resistant and thermal-insulating concrete comprises the following preparation steps:

[0053] (1) preparing a composite foaming agent;

[0054] (2) diluting the composite foaming agent and water in a mass ratio of 1:50 to prepare a foaming agent solution, and then preparing foam using a foaming machine;

[0055] (3) After cement, fly ash, silica fume, coarse aggregate, river sand and fiber are mixed evenly, a water reducer and water are added, and then the foam prepared in step (2) is added, mixed and stirred, and cast into shape. The molded test block is placed in a standard curing room for curing, and the mold is removed to obtain the final product concrete.

[0056] Example 2

[0057] A frost-resistant thermal insulation concrete comprises the following raw materials in parts by weight: 200 parts of cement, 100 parts of fly ash, 70 parts of silica fume, 15 parts of composite foaming agent, 250 parts of coarse aggregate, 200 parts of river sand, 40 parts of fiber, 3 parts of water reducer and 110 parts of water.

[0058] The cement is P·O42.5 ordinary Portland cement.

[0059] The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0060] The preparation method of the composite foaming agent is:

[0061] A. Place 10g of discarded animal feathers in a container, add 10mL of 0.8% NaHSO3 solution, then add 500mL of water to soak for 6h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0062] B. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 120 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0063] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:1, 5% of sodium dodecyl sulfate and 3% of polyoxyethylene sorbitan fatty acid ester were added to the mixture, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0064] The amount of EM bacteria added in step B is 1% of the mass of the nutrient solution, and the number of effective live bacteria of the EM bacteria is not less than 20 billion / g. The EM bacteria can be commercially available products that meet the requirements. The EM bacteria in this embodiment are purchased from Jinan Herui Biotechnology Co., Ltd., model EM-01.

[0065] The feathers used in step A are preferably poultry feathers from a large source, such as poultry such as chickens, ducks, geese, pigeons, etc.

[0066] The coarse aggregate is limestone crushed stone with a particle size of 5mm-25mm.

[0067] The fiber is polyacrylonitrile fiber.

[0068] The water reducer is a naphthalene-based water reducer.

[0069] A method for preparing frost-resistant and thermal-insulating concrete comprises the following preparation steps:

[0070] (1) preparing a composite foaming agent;

[0071] (2) diluting the composite foaming agent and water in a mass ratio of 1:60 to prepare a foaming agent solution, and then preparing foam using a foaming machine;

[0072] (3) After cement, fly ash, silica fume, coarse aggregate, river sand and fiber are mixed evenly, a water reducer and water are added, and then the foam prepared in step (2) is added, mixed and stirred, and cast into shape. The molded test block is placed in a standard curing room for curing, and the mold is removed to obtain the final product concrete.

[0073] Example 3

[0074] A frost-resistant heat-insulating concrete comprises the following raw materials in parts by weight: 180 parts of cement, 100 parts of fly ash, 60 parts of silica fume, 15 parts of composite foaming agent, 250 parts of coarse aggregate, 150 parts of river sand, 50 parts of fiber, 4 parts of water reducing agent and 100 parts of water.

[0075] The cement is P·O42.5 ordinary Portland cement.

[0076] The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0077] The preparation method of the composite foaming agent is:

[0078] A. Place 10g of discarded animal feathers in a container, add 10mL of 0.5% NaHSO3 solution, then add 500mL of water to soak for 8h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge and filter out the waste residue to obtain a clear feather protein solution;

[0079] B. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 120 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0080] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:1, 5% of sodium dodecyl sulfate and 3% of polyoxyethylene sorbitan fatty acid ester were added to the mixture, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0081] Furthermore, the amount of EM bacteria added in step B is 1% of the mass of the nutrient solution, and the number of effective live bacteria of the EM bacteria is not less than 20 billion / g. The EM bacteria can be commercially available products that meet the requirements. The EM bacteria in this embodiment are purchased from Jinan Herui Biotechnology Co., Ltd., model EM-01.

[0082] The feathers used in step A are preferably poultry feathers from a large source, such as poultry such as chickens, ducks, geese, pigeons, etc.

[0083] The coarse aggregate is limestone crushed stone with a particle size of 5mm-25mm.

[0084] The fiber is a polymer fiber, which is one or more of polypropylene fiber and polyacrylonitrile fiber.

[0085] The water reducing agent is a polycarboxylic acid water reducing agent.

[0086] A method for preparing frost-resistant and thermal-insulating concrete comprises the following preparation steps:

[0087] (1) preparing a composite foaming agent;

[0088] (2) diluting the composite foaming agent and water in a mass ratio of 1:55 to prepare a foaming agent solution, and then preparing foam using a foaming machine;

[0089] (3) After cement, fly ash, silica fume, coarse aggregate, river sand and fiber are mixed evenly, a water reducer and water are added, and then the foam prepared in step (2) is added, mixed and stirred, and cast into shape. The molded test block is placed in a standard curing room for curing, and the mold is removed to obtain the final product concrete.

[0090] Example 4

[0091] A frost-resistant thermal insulation concrete comprises the following raw materials in parts by weight: 200 parts of cement, 110 parts of fly ash, 70 parts of silica fume, 18 parts of composite foaming agent, 300 parts of coarse aggregate, 100 parts of river sand, 50 parts of fiber, 5 parts of water reducing agent and 100 parts of water.

[0092] The cement is P·O42.5 ordinary Portland cement.

[0093] The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0094] The preparation method of the composite foaming agent is:

[0095] A. Place 10g of discarded animal feathers in a container, add 10mL of 1% NaHSO3 solution, then add 500mL of water to soak for 8h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0096] B. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 100 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0097] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:1, 5% of sodium dodecyl sulfate and 3% of polyoxyethylene sorbitan fatty acid ester were added to the mixture, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0098] The amount of EM bacteria added in step B is 1.5% of the mass of the nutrient solution, and the number of effective live bacteria of the EM bacteria is not less than 20 billion / g. The EM bacteria can be commercially available products that meet the requirements. The EM bacteria in this embodiment are purchased from Jinan Herui Biotechnology Co., Ltd., model EM-01.

[0099] The feathers used in step A are preferably poultry feathers from a large source, such as poultry such as chickens, ducks, geese, pigeons, etc.

[0100] The coarse aggregate is limestone crushed stone with a particle size of 5mm-25mm.

[0101] The fibers are polymer fibers.

[0102] The water reducing agent is a polycarboxylic acid water reducing agent.

[0103] A method for preparing frost-resistant and thermal-insulating concrete comprises the following preparation steps:

[0104] (1) preparing a composite foaming agent;

[0105] (2) diluting the composite foaming agent and water in a mass ratio of 1:50 to prepare a foaming agent solution, and then preparing foam using a foaming machine;

[0106] (3) After cement, fly ash, silica fume, coarse aggregate, river sand and fiber are mixed evenly, a water reducer and water are added, and then the foam prepared in step (2) is added, mixed and stirred, and cast into shape. The molded test block is placed in a standard curing room for curing, and the mold is removed to obtain the final product concrete.

[0107] Comparative Example 1

[0108] A frost-resistant heat-insulating concrete comprises the following raw materials in parts by weight: 150 parts of cement, 90 parts of fly ash, 50 parts of silica fume, 12 parts of foaming agent, 200 parts of coarse aggregate, 200 parts of river sand, 30 parts of fiber, 2 parts of water reducing agent and 120 parts of water.

[0109] The preparation method of the foaming agent is:

[0110] A. Place 10g of discarded animal feathers in a container, add 10mL of 0.5% NaHSO3 solution, then add 500mL of water to soak for 5h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0111] B. Add 5% sodium dodecyl sulfate and 3% polyoxyethylene sorbitan fatty acid ester to the feather protein solution, and stir at room temperature for more than 12 hours using a stirrer to prepare a foaming agent.

[0112] Compared with Example 1, this comparative example is the same as Example 1 except that the foaming agent uses only feather protein as the raw material, and the other raw materials and preparation methods are the same as those of Example 1.

[0113] Comparative Example 2

[0114] A frost-resistant heat-insulating concrete comprises the following raw materials in parts by weight: 150 parts of cement, 90 parts of fly ash, 50 parts of silica fume, 12 parts of foaming agent, 200 parts of coarse aggregate, 200 parts of river sand, 30 parts of fiber, 2 parts of water reducing agent and 120 parts of water.

[0115] The preparation method of the foaming agent is:

[0116] A. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 100 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0117] B. Add 5% sodium dodecyl sulfate and 3% polyoxyethylene sorbitan fatty acid ester to the EM bacteria foaming agent, and stir at room temperature for more than 12 hours using a stirrer to prepare the foaming agent.

[0118] Compared with Example 1, this comparative example is the same as Example 1 except that only EM bacteria foaming agent is used as the foaming agent. Other raw materials and preparation methods are the same as those of Example 1.

[0119] Comparative Example 3

[0120] A frost-resistant heat-insulating concrete comprises the following raw materials in parts by weight: 150 parts of cement, 90 parts of fly ash, 50 parts of silica fume, 12 parts of composite foaming agent, 200 parts of coarse aggregate, 200 parts of river sand, 30 parts of fiber, 2 parts of water reducer and 120 parts of water.

[0121] The cement is P·O42.5 ordinary Portland cement.

[0122] The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0123] The preparation method of the composite foaming agent is:

[0124] A. Place 10g of discarded animal feathers in a container, add 10mL of 0.5% NaHSO3 solution, then add 500mL of water to soak for 5h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0125] B. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 100 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0126] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:1, add 3% of the volume of the mixed solution of polyoxyethylene sorbitan fatty acid ester, and stir at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0127] In this comparative example, except that sodium lauryl sulfate is not added in the preparation method of the composite foaming agent, the other raw materials and the preparation method are the same as those in Example 1.

[0128] Comparative Example 4

[0129] A frost-resistant heat-insulating concrete comprises the following raw materials in parts by weight: 150 parts of cement, 90 parts of fly ash, 50 parts of silica fume, 12 parts of composite foaming agent, 200 parts of coarse aggregate, 200 parts of river sand, 30 parts of fiber, 2 parts of water reducer and 120 parts of water.

[0130] The cement is P·O42.5 ordinary Portland cement.

[0131] The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0132] The preparation method of the composite foaming agent is:

[0133] A. Place 10g of discarded animal feathers in a container, add 10mL of 0.5% NaHSO3 solution, then add 500mL of water to soak for 5h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0134] B. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 100 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0135] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:1, 5% of the volume of the mixture was added with sodium dodecyl sulfate, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0136] In this comparative example, except that polyoxyethylene sorbitan fatty acid ester is not added in the preparation method of the composite foaming agent, the other raw materials and preparation method are the same as those of Example 1.

[0137] Comparative Example 5

[0138] A frost-resistant heat-insulating concrete comprises the following raw materials in parts by weight: 150 parts of cement, 90 parts of fly ash, 50 parts of silica fume, 12 parts of composite foaming agent, 200 parts of coarse aggregate, 200 parts of river sand, 30 parts of fiber, 2 parts of water reducer and 120 parts of water.

[0139] The cement is P·O42.5 ordinary Portland cement.

[0140] The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0141] The preparation method of the composite foaming agent is:

[0142] A. Place 10g of discarded animal feathers in a container, add 10mL of 0.5% NaHSO3 solution, then add 500mL of water to soak for 5h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0143] B. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 100 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0144] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 2:1, 5% of sodium dodecyl sulfate and 3% of polyoxyethylene sorbitan fatty acid ester were added to the mixture, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0145] In this comparative example, except that the volume ratio of the feather protein solution to the EM bacteria foaming agent is changed to 2:1 in the preparation method of the composite foaming agent, the other raw materials and the preparation method are the same as those in Example 1.

[0146] Comparative Example 6

[0147] A frost-resistant heat-insulating concrete comprises the following raw materials in parts by weight: 150 parts of cement, 90 parts of fly ash, 50 parts of silica fume, 12 parts of composite foaming agent, 200 parts of coarse aggregate, 200 parts of river sand, 30 parts of fiber, 2 parts of water reducer and 120 parts of water.

[0148] The cement is P·O42.5 ordinary Portland cement.

[0149] The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

[0150] The preparation method of the composite foaming agent is:

[0151] A. Place 10g of discarded animal feathers in a container, add 10mL of 0.5% NaHSO3 solution, then add 500mL of water to soak for 5h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution;

[0152] B. Add 15 g of glucose, 15 g of tryptone and 6 g of yeast extract powder into 100 mL of distilled water and stir evenly. After high temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48 hours to obtain an EM bacteria foaming agent;

[0153] C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:2, 5% of sodium dodecyl sulfate and 3% of polyoxyethylene sorbitan fatty acid ester were added to the mixture, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

[0154] In this comparative example, except that the volume ratio of the feather protein solution to the EM bacteria foaming agent is changed to 1:2 in the preparation method of the composite foaming agent, the other raw materials and the preparation method are the same as those in Example 1.

[0155] Performance Testing

[0156] Foam properties:

[0157] The composite foaming agent or foaming agent component prepared in the examples of the present invention and the comparative examples was subjected to performance tests. With reference to JC / T2199-2013 "Foaming Agent for Foamed Concrete", the foaming multiple of the foaming agent solution, the 1-hour settling distance of the obtained foam, and the 1-hour water bleeding rate were tested respectively.

[0158] Table 1 Comparison of foaming performance between examples and comparative examples

[0159] Foaming multiple 1h settlement distance / mm 1h water secretion rate / mL Foam stability / h Example 1 30 2.2 65.2 10.5 Comparative Example 1 25 8.5 75.1 5.5 Comparative Example 2 24 7.9 73.2 5.3 Comparative Example 3 26 7.0 70.5 5.0 Comparative Example 4 27 6.5 70.0 5.0 Comparative Example 5 28 4.0 68.5 6.5 Comparative Example 6 30 3.5 67.0 7.0 Standard requirements ＞20 ＜10 ＜80 ≥2

[0160] From the data in Table 1, we can see that the composite foaming agent prepared in Example 1 of the present invention has good foaming performance. The feather protein liquid and the microbial foaming agent interact with each other and exhibit good foaming and foam stabilizing properties after being mixed in equal proportions, and the bubble performance is good.

[0161] Concrete performance test:

[0162] Sample: The concrete prepared in Examples 1-4 and Comparative Examples 1-6 was poured into a test mold with a size of 100 mm × 100 mm × 100 mm, and demolded after 24 hours of molding. The demolded sample was placed in a standard curing box with a temperature of (20 ± 2) ° C and a relative humidity of > 95% for 28 days;

[0163] Pore ​​structure: The molded sample was cut vertically, and then the cross section was polished flat with a grinder. To prevent the cement powder generated during polishing from clogging the pores, the polished sample was oscillated and washed in an ultrasonic wave. After drying, a cross section with a clear pore structure was obtained. A VHX-600K ultra-depth microscope was used to construct a three-dimensional image of the cross section for easy observation.

[0164] The foamed concrete samples were tested according to JG / T266-2011 Foamed Concrete. The compressive strength of the specimens cured to the age was measured using the AG-X Shimadzu electronic universal testing machine. There were 3 specimens in each group, and the average value was taken.

[0165] The thermal conductivity of the sample was tested using a thermal conductivity meter DRRPL-3B; the rapid chloride ion migration coefficient method (RCM method) in GB / T50082-2009 "Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete" was used to test the chloride ion penetration resistance of the concrete.

[0166] The freeze-thaw cycle test was designed with reference to GB / T50082-2009, and the test was completed using a high-low temperature alternating humidity chamber. The test was performed in a (-19±4)℃ environment for 8 hours, and in a (18±4)℃ environment for 4 hours, with a total of 12 hours for one cycle. The number of cycles was 40 and 80. During the test, the freezing temperature at the center of the specimen was ensured to be greater than -10℃, and the time taken to heat from -20℃ to 20℃ was no more than 1.5 hours. The mass loss was also tested.

[0167] Table 2 Test results of comprehensive performance of concrete

[0168]

[0169] From the data in the table, we can see that the concrete sample of the embodiment of the present invention has good antifreeze and anti-corrosion performance, and at the same time has a low thermal conductivity and good thermal insulation performance. Figure 1-3 ) and hole structure diagram ( Figure 4-5) It can also be seen that after 80 cycles, the surface of the test piece of Example 1 of the present invention is flat and has no obvious falling objects, and the pore structure is uniform and dense. However, the comparative examples 1-6 with changed foaming agent components all showed different degrees of falling phenomena, and more through-hole macroporous structures appeared inside. This is due to the change in the composition of the foaming agent, the uneven pore structure and surface structure inside the concrete, resulting in uneven temperature conduction, and the macroscopic performance of the concrete is a decrease in comprehensive capabilities such as antifreeze and anti-corrosion.

[0170] It should be noted that the above embodiments are only partial embodiments of the preferred methods of implementing the present invention, rather than all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

Claims

1. A frost-resistant and thermal-insulating concrete, characterized in that: The invention comprises the following raw materials in parts by weight: 150-200 parts of cement, 90-110 parts of fly ash, 50-70 parts of silica fume, 12-18 parts of composite foaming agent, 200-300 parts of coarse aggregate, 100-200 parts of river sand, 30-50 parts of fiber, 2-5 parts of water reducing agent and 100-120 parts of water.

2. The antifreeze and thermal insulation concrete according to claim 1, characterized in that: The cement is P·O42.5 ordinary Portland cement.

3. The frost-resistant and thermal insulation concrete according to claim 1, characterized in that: The fly ash is Class I fly ash, and the specific surface area of ​​the fly ash is 400-500m 2 / kg.

4. The antifreeze and thermal insulation concrete according to claim 1, characterized in that: The preparation method of the composite foaming agent is: A. Place 10g of discarded animal feathers in a container, add 10mL of a 0.5-1% NaHSO3 solution, then add 500mL of water to soak for 5-8h, then add 50mL of 3% calcium hydroxide, heat to 90-95°C, adjust the pH value to 10-11, stir and react for 2h; after cooling, filter and adjust the pH to 7-8, centrifuge to remove the waste residue to obtain a clear feather protein solution; B. Add 15g of glucose, 15g of tryptone and 6g of yeast extract powder to 100-120mL of distilled water and stir evenly. After high-temperature sterilization, obtain a nutrient solution, inoculate EM bacteria, and then place the mixture in a constant temperature shaking incubator for 48h to obtain an EM bacteria foaming agent; C. After mixing the feather protein solution and the EM bacteria foaming agent in a volume ratio of 1:1, 5% of sodium dodecyl sulfate and 3% of polyoxyethylene sorbitan fatty acid ester were added to the mixture, and stirred at room temperature for more than 12 hours using a stirrer to prepare a composite foaming agent.

5. The antifreeze and thermal insulation concrete according to claim 4, characterized in that: The amount of EM bacteria added in step B is 1-1.5% of the mass of the nutrient solution, and the number of effective live bacteria of the EM bacteria is not less than 20 billion / g.

6. The antifreeze and thermal insulation concrete according to claim 1, characterized in that: The coarse aggregate is limestone crushed stone with a particle size of 5mm-25mm.

7. The thermal insulation concrete according to claim 1, characterized in that: The fiber is a polymer fiber, which is one or more of polypropylene fiber and polyacrylonitrile fiber.

8. The frost-resistant and thermal insulation concrete according to claim 1, characterized in that: The water reducer is at least one of a polycarboxylic acid water reducer, a naphthalene water reducer and a fatty acid water reducer.

9. A method for preparing the frost-resistant and thermal insulation concrete according to any one of claims 1 to 8, characterized in that: The method comprises the following preparation steps: (1) preparing a composite foaming agent; (2) diluting the composite foaming agent and water in a mass ratio of 1:50-60 to prepare a foaming agent solution, and then preparing foam using a foaming machine; (3) After cement, fly ash, silica fume, coarse aggregate, river sand and fiber are mixed evenly, a water reducer and water are added, and then the foam prepared in step (2) is added, mixed and stirred, and cast into shape. The molded test block is placed in a standard curing room for curing, and the mold is removed to obtain the final product concrete.

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