Preparation method of waste wood recycled aggregate concrete

Abstract

The application discloses a preparation method of waste wood regenerated aggregate concrete, which comprises the following steps: (1) diluting glycerol with anhydrous ethanol to form a base solution, and then adding magnesium potassium phosphate cement, tricalcium silicate powder, sodium alginate powder and fly ash into the base solution to uniformly disperse and form a slurry; then, the slurry is coated on the surface of wood aggregate, and after being dried, modified wood aggregate is obtained; (2) mixing basalt fibers with an alkali solution and then performing heat preservation, and after completion, the basalt fibers are washed to obtain modified basalt fibers; then, the modified basalt fibers, the modified wood aggregate, ordinary Portland cement, gravel, sand, fly ash, a water reducing agent and mixing water are uniformly mixed to obtain a concrete slurry. The technical scheme of the application effectively improves the strength of the concrete containing wood aggregate, and is beneficial to promoting the popularization and application of waste wood in concrete.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete preparation, and particularly relates to a preparation method of waste wood recycled aggregate concrete. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of increasing an understanding of the general background of the application and does not necessarily constitute an admission by the patent applicant or the patent owner that this information constitutes prior art.

[0003] Wood is a natural plant material and an important resource in the construction of the national economy. A large amount of waste wood is generated in the process of urbanization, such as old district reconstruction, house relocation, logistics warehouse, conference and exhibition, etc. The utilization of these waste materials is of great significance for alleviating the shortage of forestry resources, reducing environmental pollution and saving resources. The application of waste wood in concrete is an effective way to realize resource utilization. Waste wood can be made into wood aggregate, wood fiber, wood powder, etc. and added to concrete to prepare lightweight concrete, thermal insulation wallboard and other products. For example, the patent document with the application number CN202011143363.2 discloses a wood fiber self-compacting concrete. The patent document with the application number CN202111367264.7 discloses a cement wood concrete, its preparation method and application. The patent document with the application number CN202111479350.7 discloses a vegetation concrete made of wood aggregate and its preparation method. Although the use of waste wood to prepare wood aggregate instead of sandstone aggregate can prepare lightweight concrete with thermal insulation effect, the strength of the concrete is significantly insufficient due to the low strength of wood itself. Therefore, the load bearing capacity of this type of concrete structure is significantly insufficient compared with ordinary concrete. In addition, wood is prone to water absorption and rot after being soaked, which shortens the service life of the concrete structure, which is one of the reasons affecting the popularization and application of wood aggregate in concrete. SUMMARY

[0004] The present application provides a preparation method of waste wood recycled aggregate concrete, which effectively improves the strength of concrete containing wood aggregate and is conducive to promoting the popularization and application of waste wood in concrete. Specifically, the technical solution of the present application is as follows.

[0005] A preparation method of waste wood recycled aggregate concrete, comprising the following steps:

[0006] (1) dilute glycerol with anhydrous ethanol to form a base solution, then add magnesium potassium phosphate cement (MKPC), tricalcium silicate (C3S) powder, sodium alginate powder, fly ash to the base solution to disperse uniformly to form a slurry. Then coat the slurry on the surface of the wood aggregate, and dry to obtain the modified wood aggregate.

[0007] (2) mix basalt fibers with lye, heat, wash the basalt fibers after completion, and obtain the modified basalt fibers. Then mix the modified basalt fibers, modified wood aggregate, ordinary Portland cement, gravel, sand, fly ash, water reducing agent, and mixing water uniformly to obtain a concrete slurry.

[0008] Further, in step (1), the volume ratio (v / v) of anhydrous ethanol to glycerol is 0.45-0.6:1. By diluting glycerol with anhydrous ethanol, the viscosity of glycerol can be reduced, making it easier to form a slurry with subsequent raw materials. At the same time, the hydration of the magnesium potassium phosphate cement is avoided.

[0009] Further, in step (1), the ratio of magnesium potassium phosphate cement, tricalcium silicate powder, sodium alginate powder, base solution is 40-55 parts by weight: 18-24 parts by weight: 7-10 parts by weight: fly ash 20-25 parts by weight, 34-41 parts by weight.

[0010] Further, in step (1), the wood aggregate is immersed in the slurry to make the surface of the wood aggregate uniformly coated with the slurry, then taken out and dried to obtain the modified wood aggregate. Alternatively, the drying is carried out at room temperature for 1-2 hours. Alternatively, the particle size of the wood aggregate is between 5-10 mm.

[0011] Further, in step (1), 0.5-1.1 parts by weight of an antibacterial agent is also included. Alternatively, the antibacterial agent includes at least one of nano-titanium dioxide, nano-copper oxide, nano-zinc oxide, calcium formate, etc. The antibacterial agent helps to improve the antibacterial ability of the wood aggregate and prevent the wood aggregate from rotting.

[0012] Further, in step (2), the ratio of basalt fibers to lye is 1g:10-20ml. Alternatively, the lye includes at least one of sodium hydroxide, potassium hydroxide, etc. The mass fraction of the lye is 5-15%. Alternatively, the length of the basalt fibers is 10-20mm.

[0013] Further, in step (2), the temperature of the heat preservation is 50-75℃, and the heat preservation time is 20-40min.

[0014] Further, in step (2), after the heat preservation is completed, the basalt fibers are separated and washed with clean water for 2-4 times to remove residual alkali liquor, thereby obtaining modified basalt fibers.

[0015] Further, in step (2), the raw materials are as follows: ordinary Portland cement 110-185 parts by weight, modified wood aggregate 60-80 parts by weight, gravel 95-160 parts by weight, sand 205-280 parts by weight, fly ash 30-50 parts by weight, modified basalt fibers 4.5-8 parts by weight, water reducing agent 2.5-3.5 parts by weight, and mixing water 56-92 parts by weight.

[0016] Optionally, the water reducing agent includes any one of polycarboxylic acid water reducing agent, lignin sulfonate water reducing agent, amino sulfonate water reducing agent, naphthalene series water reducing agent, etc.

[0017] Compared with the prior art, the technical scheme provided by the application has at least the following beneficial effects:

[0018] The present application firstly takes the viscous liquid obtained by diluting glycerol with anhydrous ethanol as a base liquid, which is convenient for adding potassium magnesium phosphate cement, tricalcium silicate, sodium alginate powder and fly ash to form a slurry and then coated on the surface of wood aggregate. Moreover, the slurry does not contain water, which can prevent the hydration of the potassium magnesium phosphate cement, thereby forming an unhydrated potassium magnesium phosphate cement-based coating layer on the surface of the wood aggregate. When the modified wood aggregate of the present application encounters mixing water in concrete, the glycerol in the coating layer dissolves, allowing the mixing water to fully enter the coating layer. The potassium magnesium phosphate cement hydrates after being exposed to water, and the hydration product of the potassium magnesium phosphate cement has the characteristics of high strength and strong adhesion, which can tightly bond the wood aggregate with the concrete matrix, overcoming the problem of weak bonding between the wood aggregate and the concrete matrix, which causes a significant decrease in the strength of the concrete. However, the hydration product of the potassium magnesium phosphate cement, k-struvite (potassium magnesium phosphate hexahydrate), has insufficient water resistance, and dissolves when exposed to water during the service of the concrete, which destroys the bonding between the wood aggregate and the concrete matrix, resulting in a decrease in the service life of the concrete structure. The sodium alginate in the slurry effectively overcomes the above problems, because the sodium alginate dissolves and distributes in the coating layer when it encounters mixing water. At the same time, the tricalcium silicate releases calcium ions after hydration, and the sodium alginate crosslinks under the action of calcium ions to form an organic film with waterproof function attached to the surface of the hydration product of the potassium magnesium phosphate cement, thereby improving the water resistance of the coating layer. In addition, the sodium alginate also has a retarding effect, which can reduce the hydration rate of the potassium magnesium phosphate cement and prolong the hydration reaction time, facilitating the synchronous hydration of the tricalcium silicate, which has a slower hydration rate than the potassium magnesium phosphate cement. On the one hand, it is convenient to use the tricalcium silicate to release calcium ions to start the crosslinking reaction of the sodium alginate, making the organic film and the hydration product of the potassium magnesium phosphate cement interpenetrate and interweave, thereby improving the water resistance of the coating layer. On the other hand, the waterproof coating layer also helps to prevent the internal wood aggregate from rotting. Further, the strength of the modified wood aggregate cannot reach the level of natural aggregates such as sand and gravel, and the addition of the modified wood aggregate results in insufficient strength of the prepared concrete. Therefore, the present application adds modified basalt fibers, the main components of which are silicon dioxide, aluminum oxide, etc. to form silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra. After treatment with the alkaline solution, the silicon-oxygen bonds and aluminum-oxygen bonds in the silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra are depolymerized and broken. In the hydration process, these bonds and the hydration product of tricalcium silicate, calcium hydroxide, in Portland cement undergo secondary hydration reactions, thereby forming hydrated calcium silicate cementitious products.Thus, the part of the modified basalt fiber in the concrete matrix is tightly combined with the matrix by the cementitious product formed by the secondary hydration reaction, and the part of the modified basalt fiber in contact with the modified wood aggregate is tightly combined with the modified wood aggregate by the cementitious product formed by the secondary hydration reaction of calcium hydroxide in the coating layer, so as to further enhance the interfacial bonding force between the modified wood aggregate and the concrete matrix, and improve the mechanical strength of the concrete. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the application and are incorporated herein for illustrative purposes. The illustrative embodiments of the present application and their description serve the purpose of explanations and are not meant to limit the present application. Detailed description of the embodiments of the present application will be given hereinafter with reference to the drawings.

[0020] Figure 1 Sample image of the modified wood aggregate prepared for the following Example 1.

[0021] Figure 2 Compressive strength test image of the test piece prepared for the following Example 1. DETAILED DESCRIPTION

[0022] The present application will be further described with reference to the following specific examples. It is to be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods not specifically mentioned in the following examples are generally performed according to the conventional conditions or according to the conditions recommended by the manufacturers.

[0023] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by one of ordinary skill in the art. The reagents or materials used in the present application can be purchased through conventional channels. Unless otherwise specified, the reagents or materials used in the present application are used according to the conventional methods in the art or according to the product instructions. In addition, any method and material similar or equivalent to those described can be used in the present application. The preferred methods and materials described in the present application are only used for demonstration.

[0024] Example 1

[0025] A preparation method of a waste wood recycled aggregate concrete, comprising the following steps:

[0026] (1) Mix anhydrous ethanol and glycerol in a volume ratio of 0.5:1 and stir until uniform, to obtain a base solution. Then add magnesium phosphate cement, tricalcium silicate powder, sodium alginate powder, and fly ash to the base solution and disperse uniformly to form a slurry, wherein: magnesium phosphate cement, tricalcium silicate powder, sodium alginate powder, fly ash, base solution = 48 parts by weight: 20 parts by weight: 8.5 parts by weight: 23 parts by weight: 37 parts by weight. Then immerse the aggregate prepared from waste wood (particle size distribution between 5-10 mm) in the slurry to uniformly coat the surface of the aggregate, then take out the aggregate and air dry at room temperature for 1.5 hours, to obtain modified wood aggregate (as shown in Figure 1 ).

[0027] (2) Mix basalt fibers with a length of 20 mm and a 10% by mass sodium hydroxide solution in a ratio of 1 g:15 ml, heat to 60°C for 30 min, then filter out the basalt fibers, and then wash with clean water 3 times to remove residual lye, to obtain modified basalt fibers, for use.

[0028] (3) Take the following raw materials: 150 parts by weight of 42.5 ordinary Portland cement, 68 parts by weight of the modified wood aggregate prepared in this embodiment, 140 parts by weight of crushed stone, 260 parts by weight of sand, 40 parts by weight of Class II fly ash, 6.0 parts by weight of the modified basalt fibers prepared in this embodiment, 3.0 parts by weight of polycarboxylic acid water reducer (water reducing rate 25%), and 76 parts by weight of mixing water. Mix and stir the above raw materials until uniform, to obtain a concrete slurry.

[0029] Performance test:

[0030] 1. According to the "Standard Test Methods for Physical and Mechanical Properties of Concrete" (GB / T 50081-2019), test the 28d compressive strength of the test piece made of the concrete slurry prepared in this embodiment (reference Figure 2 ), and the result is 53.27 MPa.

[0031] 2. According to the "Test Methods for Long-Term Performance and Durability of Concrete" (GB / T 50082-2009), test the water resistance. The specific method is: immerse the test piece made of the concrete slurry prepared in this embodiment in water for 28d, then test the compressive strength, and record it as A. Another part of the test piece prepared in the same way is cured in air for 28d, then test the compressive strength, and record it as B. The strength retention rate = A / B, the higher the strength retention rate, the better the water resistance. The result is: the strength retention rate = 92.14%.

[0032] Example 2

[0033] A method for preparing a waste wood recycled aggregate concrete, comprising the following steps:

[0034] (1)Mix anhydrous ethanol and glycerol in a volume ratio of 0.45:1, and stir until uniform, to obtain a base solution. Then add magnesium potassium phosphate cement, tricalcium silicate powder, sodium alginate powder, fly ash and nano titanium dioxide to the base solution and disperse uniformly to form a slurry, wherein: magnesium potassium phosphate cement, tricalcium silicate powder, sodium alginate powder, fly ash, nano titanium dioxide, base solution = 55 parts by weight: 24 parts by weight: 10 parts by weight: 25 parts by weight: 1.1 parts by weight: 41 parts by weight. Then immerse the aggregate prepared from waste wood (particle size distribution between 5-10 mm) in the slurry to uniformly coat the surface of the aggregate, then take out the aggregate and air dry at room temperature for 2 hours, to obtain modified wood aggregate, for use.

[0035] (2)Mix basalt fibers with a length of 10 mm with a 5% mass fraction of potassium hydroxide solution in a ratio of 1 g:10 ml, heat to 50°C for 40 min, then filter out the basalt fibers, and then wash with clean water for 2 times to remove residual lye, to obtain modified basalt fibers, for use.

[0036] (3)Take the following raw materials: 42.5 ordinary Portland cement 110 parts by weight, the modified wood aggregate prepared in this embodiment 60 parts by weight, crushed stone 95 parts by weight, sand 205 parts by weight, grade II fly ash 30 parts by weight, the modified basalt fibers prepared in this embodiment 4.5 parts by weight, polycarboxylic acid water reducer (water reducing rate 25%) 2.5 parts by weight, and mixing water 56 parts by weight. Mix and stir the above raw materials until uniform, to obtain a concrete slurry.

[0037] Performance test:

[0038] 1. According to the "Standard Test Methods for Physical and Mechanical Properties of Concrete" (GB / T 50081-2019), test the 28d compressive strength of the test piece made of the concrete slurry prepared in this embodiment, and the result is 50.61 MPa.

[0039] 2. According to the "Test Methods for Long-Term Performance and Durability of Concrete" (GB / T 50082-2009), test the water resistance. The specific method is: immerse the test piece made of the concrete slurry prepared in this embodiment in water for 28d, then test the compressive strength, and record it as A. Another part of the test piece prepared in the same way is cured in air for 28d, then test the compressive strength, and record it as B. The strength retention rate = A / B. The result is: the strength retention rate = 93.37%.

[0040] Example 3

[0041] A method for preparing a waste wood recycled aggregate concrete, comprising the following steps:

[0042] (1) The anhydrous ethanol and glycerol are mixed in a volume ratio of 0.6:1 and stirred uniformly to obtain a base solution. Then the magnesium potassium phosphate cement, tricalcium silicate powder, sodium alginate powder, fly ash and nano titanium dioxide are added to the base solution and dispersed uniformly to form a slurry, wherein: magnesium potassium phosphate cement, tricalcium silicate powder, sodium alginate powder, fly ash, nano copper oxide, base solution = 40 parts by weight: 18 parts by weight: 7 parts by weight: 20 parts by weight, 0.5 parts by weight: 34 parts by weight. Then the aggregate prepared from waste wood (particle size distribution between 5-10 mm) is immersed in the slurry to make its surface uniformly coated with the slurry, and then the aggregate is taken out and dried at room temperature for 1 hour, to obtain modified wood aggregate, ready for use.

[0043] (2) The basalt fiber with a length of 10 mm is mixed with a 15% mass fraction of sodium hydroxide solution in a ratio of 1 g:20 ml, heated to 75°C for 20 min, filtered out after completion, and then washed with water 4 times to remove residual lye, to obtain modified basalt fiber, ready for use.

[0044] (3) Take the following raw materials: 42.5 ordinary Portland cement 185 parts by weight, the modified wood aggregate prepared in this embodiment 80 parts by weight, gravel 160 parts by weight, sand 280 parts by weight, grade II fly ash 50 parts by weight, the modified basalt fiber prepared in this embodiment 8 parts by weight, lignin sulfonate water reducer (water reducing rate 20%) 3.5 parts by weight, and mixing water 92 parts by weight. Mix and stir the above raw materials uniformly to obtain a concrete slurry.

[0045] Performance test:

[0046] 1. The 28d compressive strength of the test piece made of the concrete slurry prepared in this embodiment is tested according to the "Standard Test Methods for Physical and Mechanical Properties of Concrete" (GB / T 50081-2019), and the result is 49.88 MPa.

[0047] 2. The water resistance test is carried out according to the "Test Methods for Long-Term Performance and Durability of Concrete" (GB / T 50082-2009). The specific method is: the test piece made of the concrete slurry prepared in this embodiment is soaked in water for 28d, and then the compressive strength is tested, recorded as A. Another part of the test piece prepared by the same method is cured in air for 28d, and then the compressive strength is tested, recorded as B. The strength retention rate = A / B. The result is: the strength retention rate = 95.02%.

[0048] Example 4

[0049] A preparation method of a waste wood recycled aggregate concrete, comprising the following steps:

[0050] (1) The anhydrous ethanol and glycerol are mixed in a volume ratio of 0.5:1 and stirred uniformly to obtain a base solution. Then the magnesium potassium phosphate cement, tricalcium silicate powder and fly ash are added to the base solution and dispersed uniformly to form a slurry, wherein: magnesium potassium phosphate cement, tricalcium silicate powder, fly ash, base solution = 48 parts by weight: 20 parts by weight: 23 parts by weight: 37 parts by weight. Then the aggregate prepared from waste wood (particle size distribution between 5-10 mm) is immersed in the slurry to make its surface uniformly coated with the slurry, and then the aggregate is taken out and dried at room temperature for 1.5 hours to obtain modified wood aggregate, which is ready for use.

[0051] (2) The basalt fiber with a length of 20 mm is mixed with a 10% sodium hydroxide solution in a mass fraction of 1g:15ml, heated to 60°C for 30min, filtered out after completion, and then washed with water 3 times to remove residual lye, to obtain modified basalt fiber, ready for use.

[0052] (3) Take the following raw materials: 42.5 ordinary Portland cement 150 parts by weight, the modified wood aggregate prepared in this embodiment 68 parts by weight, gravel 140 parts by weight, sand 260 parts by weight, grade II fly ash 40 parts by weight, the modified basalt fiber prepared in this embodiment 6.0 parts by weight, polycarboxylic acid water reducer (water reducing rate 25%) 3.0 parts by weight, and mixing water 76 parts by weight. Mix and stir the above raw materials uniformly to obtain a concrete slurry.

[0053] Performance test:

[0054] 1. The 28d compressive strength of the test piece made of the concrete slurry prepared in this embodiment is tested according to the "Standard Test Methods for Physical and Mechanical Properties of Concrete" (GB / T 50081-2019), and the result is 52.74MPa.

[0055] 2. The water resistance test is carried out according to the "Test Methods for Long-Term Performance and Durability of Concrete" (GB / T 50082-2009). The specific method is as follows: the test piece made of the concrete slurry prepared in this embodiment is soaked in water for 28d, and then the compressive strength is tested, recorded as A. Another part of the test piece prepared by the same method is cured in air for 28d, and then the compressive strength is tested, recorded as B. The strength retention rate = A / B. The result is: the strength retention rate = 70.46%.

[0056] Example 5

[0057] A preparation method of a waste wood recycled aggregate concrete, comprising the following steps:

[0058] (1) The anhydrous ethanol and glycerol are mixed in a volume ratio of 0.45:1 and stirred uniformly to obtain a base solution. Then, the magnesium potassium phosphate cement, sodium alginate powder, fly ash and nano titanium dioxide are added to the base solution and dispersed uniformly to form a slurry, wherein: magnesium potassium phosphate cement, sodium alginate powder, fly ash, nano titanium dioxide, base solution = 55 parts by weight: 10 parts by weight: 25 parts by weight: 1.1 parts by weight: 41 parts by weight. Then, the aggregate prepared from waste wood (particle size distribution between 5-10 mm) is immersed in the slurry to make its surface uniformly coated with the slurry, and then the aggregate is taken out and dried at room temperature for 2 hours, to obtain modified wood aggregate, which is ready for use.

[0059] (2) The basalt fiber with a length of 10 mm is mixed with a 5% potassium hydroxide solution in a mass fraction of 1g:10ml, heated to 50°C for 40min, then the basalt fiber is filtered out, and then washed with water for 2 times to remove the residual lye, to obtain modified basalt fiber, which is ready for use.

[0060] (3) The following raw materials are taken: 110 parts by weight of 42.5 ordinary Portland cement, 60 parts by weight of the modified wood aggregate prepared in this embodiment, 95 parts by weight of crushed stone, 205 parts by weight of sand, 30 parts by weight of grade II fly ash, 4.5 parts by weight of the modified basalt fiber prepared in this embodiment, 2.5 parts by weight of polycarboxylic acid water reducer (water reducing rate 25%), and 56 parts by weight of mixing water. The above raw materials are mixed and stirred uniformly to obtain a concrete slurry.

[0061] Performance test:

[0062] 1. The 28d compressive strength of the test piece made of the concrete slurry prepared in this embodiment is tested according to the "Standard Test Methods for Physical and Mechanical Properties of Concrete" (GB / T 50081-2019), and the result is 45.04MPa.

[0063] 2. The water resistance test is carried out according to the "Test Methods for Long-Term Performance and Durability of Concrete" (GB / T 50082-2009). The specific method is as follows: the test piece made of the concrete slurry prepared in this embodiment is soaked in water for 28d, and then the compressive strength is tested, which is recorded as A. Another part of the test piece prepared by the same method is cured in air for 28d, and then the compressive strength is tested, which is recorded as B. The strength retention rate = A / B. The result is: the strength retention rate = 87.19%.

[0064] Example 6

[0065] A preparation method of a waste wood recycled aggregate concrete, comprising the following steps:

[0066] (1) The anhydrous ethanol and glycerol are mixed in a volume ratio of 0.5:1 and stirred uniformly to obtain a base solution. Then, the magnesium potassium phosphate cement, tricalcium silicate powder, sodium alginate powder, and fly ash are added to the base solution and dispersed uniformly to form a slurry, wherein: magnesium potassium phosphate cement, tricalcium silicate powder, sodium alginate powder, fly ash, base solution = 48 parts by weight: 20 parts by weight: 8.5 parts by weight: 23 parts by weight: 37 parts by weight. Then, the aggregate prepared from waste wood (particle size distribution between 5-10 mm) is immersed in the slurry to uniformly coat the surface of the aggregate, and then the aggregate is taken out and dried at room temperature for 1.5 hours to obtain modified wood aggregate, which is ready for use.

[0067] (2) Basalt fibers with a length of 20 mm are mixed with water in a ratio of 1 g: 15 ml, heated to 60°C for 30 min, and then filtered to obtain modified basalt fibers, which are ready for use.

[0068] (3) The following raw materials are taken: 42.5 ordinary Portland cement 150 parts by weight, the modified wood aggregate prepared in this embodiment 68 parts by weight, gravel 140 parts by weight, sand 260 parts by weight, grade II fly ash 40 parts by weight, the modified basalt fibers prepared in this embodiment 6.0 parts by weight, polycarboxylic acid water reducer (water reducing rate 25%) 3.0 parts by weight, and mixing water 76 parts by weight. The above raw materials are mixed and stirred uniformly to obtain a concrete slurry.

[0069] Performance test:

[0070] 1. The 28d compressive strength of the test piece made of the concrete slurry prepared in this embodiment is tested according to the "Standard Test Methods for Physical and Mechanical Properties of Concrete" (GB / T 50081-2019), and the result is 44.15 MPa.

[0071] 2. The water resistance test is carried out according to the "Test Methods for Long-Term Performance and Durability of Concrete" (GB / T 50082-2009). The specific method is as follows: the test piece made of the concrete slurry prepared in this embodiment is soaked in water for 28 days, and then the compressive strength is tested, recorded as A. Another part of the test piece prepared by the same method is cured in air for 28 days, and then the compressive strength is tested, recorded as B. The strength retention rate = A / B. The result is: the strength retention rate = 91.83%.

[0072] Example 7

[0073] A preparation method of a waste wood recycled aggregate concrete, comprising the following steps:

[0074] Take the following raw materials: 42.5 ordinary Portland cement 185 parts by weight, waste wood prepared aggregate (particle size distribution between 5-10 mm) 80 parts by weight, gravel 160 parts by weight, sand 280 parts by weight, grade II fly ash 50 parts by weight, modified basalt fiber prepared according to the method of Example 3 8 parts by weight, lignin sodium sulfonate water reducing agent (water reducing rate 20%) 3.5 parts by weight, and mixing water 92 parts by weight. After mixing the above raw materials, stir evenly to obtain the concrete slurry.

[0075] Performance test:

[0076] 1. According to the test method for physical and mechanical properties of concrete (GB / T 50081-2019), the 28d compressive strength of the test piece prepared from the concrete slurry prepared in this example was tested, and the result was 30.34MPa.

[0077] 2. According to the test method for long-term performance and durability of concrete (GB / T50082-2009), the water resistance test was carried out. The specific method is as follows: the test piece prepared from the concrete slurry prepared in this example was soaked in water for 28d, and then the compressive strength was tested, recorded as A. Another part of the test piece prepared by the same method was cured in air for 28d, and then the compressive strength was tested, recorded as B. The strength retention rate = A / B. The result is: the strength retention rate = 84.21%.

[0078] Example 8

[0079] A preparation method of waste wood recycled aggregate concrete, comprising the following steps:

[0080] Take the following raw materials: 42.5 ordinary Portland cement 110 parts by weight, modified wood aggregate prepared according to the method of Example 2 above 60 parts by weight, gravel 95 parts by weight, sand 205 parts by weight, grade II fly ash 30 parts by weight, polycarboxylic acid water reducing agent (water reducing rate 25%) 2.5 parts by weight, and mixing water 56 parts by weight. After mixing the above raw materials, stir evenly to obtain the concrete slurry.

[0081] Performance test:

[0082] 1. According to the test method for physical and mechanical properties of concrete (GB / T 50081-2019), the 28d compressive strength of the test piece prepared from the concrete slurry prepared in this example was tested, and the result was 30.34MPa.

[0083] 2. The water resistance was tested according to the "Test Method for Long-term Performance and Durability of Concrete" (GB / T50082-2009). The specific method was as follows: the test piece prepared from the concrete slurry of the present example was immersed in water for 28 days, and then the compressive strength was tested, recorded as A. Another part of the test piece prepared by the same method was cured in air for 28 days, and then the compressive strength was tested, recorded as B. The strength retention rate = A / B. The result was: the strength retention rate = 93.06%.

[0084] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will still be able to modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing concrete using recycled waste wood aggregate, characterized in that, Includes the following steps: (1) Glycerol is diluted with anhydrous ethanol to form a base liquid, wherein the volume ratio of anhydrous ethanol to glycerol is 0.45~0.6:1; then potassium magnesium phosphate cement, tricalcium silicate powder, sodium alginate powder, and fly ash are added to the base liquid and dispersed evenly to form a slurry; then the slurry is coated onto the surface of the wood aggregate and dried to obtain modified wood aggregate; the ratio of potassium magnesium phosphate cement, tricalcium silicate powder, sodium alginate powder, fly ash, and base liquid is 40~55 parts by weight: 18~24 parts by weight: 7~10 parts by weight: 20~25 parts by weight: 34~41 parts by weight; (2) After mixing basalt fiber with alkaline solution, keep it at 50~75℃ for 20~40 minutes. After completion, wash the basalt fiber to obtain modified basalt fiber. Then mix the modified basalt fiber, modified wood aggregate, ordinary silicate cement, crushed stone, sand, fly ash, water reducing agent and mixing water evenly to obtain concrete slurry.

2. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, In step (1), the wood aggregate is immersed in slurry to make its surface evenly coated with slurry, and then taken out and dried to obtain the modified wood aggregate.

3. The method for preparing waste wood recycled aggregate concrete according to claim 2, characterized in that, The drying process is carried out at room temperature for 1 to 2 hours.

4. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, In step (1), the particle size of the wood aggregate is between 5 and 10 mm.

5. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, Step (1) also includes 0.5 to 1.1 parts by weight of antibacterial agent.

6. The method for preparing waste wood recycled aggregate concrete according to claim 5, characterized in that, The antibacterial agent includes at least one of nano-titanium dioxide, nano-copper oxide, nano-zinc oxide, and calcium formate.

7. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, In step (2), the ratio of basalt fiber to alkaline solution is 1g:10~20ml.

8. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, In step (2), the alkaline solution includes at least one of sodium hydroxide and potassium hydroxide.

9. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, In step (2), the mass fraction of the alkaline solution is 5-15%.

10. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, In step (2), the length of the basalt fiber is 10~20mm.

11. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, In step (2), after the heat preservation is completed, the basalt fiber is separated and washed with water 2 to 4 times to obtain the modified basalt fiber.

12. The method for preparing waste wood recycled aggregate concrete according to claim 1, characterized in that, In step (2), the raw materials are as follows: 110-185 parts by weight of ordinary silicate cement, 60-80 parts by weight of modified wood aggregate, 95-160 parts by weight of crushed stone, 205-280 parts by weight of sand, 30-50 parts by weight of fly ash, 4.5-8 parts by weight of modified basalt fiber, 2.5-3.5 parts by weight of water-reducing agent, and 56-92 parts by weight of mixing water.

13. The method for preparing waste wood recycled aggregate concrete according to any one of claims 1-12, characterized in that, The water-reducing agent includes any one of polycarboxylate water-reducing agents, lignin sulfonate water-reducing agents, aminosulfonate water-reducing agents, and naphthalene water-reducing agents.

Images