A plant fiber-based porous sound-absorbing material, preparation method thereof and application thereof

Abstract

The present invention belongs to the field of sound-absorbing materials and building materials, and specifically discloses a plant fiber-based porous sound-absorbing material, a preparation method thereof and an application thereof. The plant fiber-based porous sound-absorbing material provided by the present invention comprises the following raw materials: wheat straw, sunflower stem pith powder, styrene acrylic emulsion, sodium dodecylbenzene sulfonate, silica sol and water. The present invention improves the defect of poor strength of the plant fiber-based porous sound-absorbing material by compounding wheat straw with sunflower stem pith powder, and using silica sol to modify the above-mentioned plant-based compound, and prepares a new type of plant fiber-based porous sound-absorbing material by foam molding technology. The present invention also provides a preparation method of the above-mentioned plant fiber-based porous sound-absorbing material, laying a foundation for its industrial production. The present invention can be applied to the production and application fields of sound-absorbing materials and sound-absorbing concrete.

Description

Technical Field

[0001] The invention belongs to the field of sound absorbing materials and building materials, and in particular relates to a plant fiber-based porous sound absorbing material, a preparation method thereof and an application thereof. Background Art

[0002] With the rapid development of the global manufacturing industry, the problems caused by noise are becoming increasingly prominent. Noise is extremely harmful to the human body. Long-term exposure to noise can lead to hearing loss, and can also cause heart disease, high blood pressure, memory loss, mental inattention and other diseases. In addition, noise also has varying degrees of impact on surrounding organisms and buildings. Studies have shown that noise can aggravate the aging of building materials and machine parts, reduce the accuracy of equipment and instruments, and cause potential dangers and unnecessary maintenance costs. Therefore, solving the noise problem is urgent, and the development of new and efficient environmentally friendly sound-absorbing materials has attracted more and more attention from domestic and foreign research institutions and scholars. With the extensive use of petroleum-based materials, the earth's resources are gradually in short supply, which has a serious impact on the development of society. In order to solve the problem of resource shortage, it is urgent to develop environmentally friendly and sustainable sound-absorbing materials.

[0003] Plant fiber is the largest natural resource on earth. Rational development and utilization of such resources to prepare recyclable and degradable green materials can broaden the application prospects of biomass materials. However, traditional plant-based porous materials have low strength and poor thermal stability, which greatly limits their application development.

[0004] Building materials are the material basis of construction projects. Various materials are needed in the construction of buildings from the main structure to decoration and renovation. Since noise has become a major environmental pollution, the acoustic environment of buildings has received more and more attention and attention. Selecting appropriate materials to absorb and insulate buildings is one of the most commonly used and basic technical measures in building noise control projects. At present, most sound-absorbing and noise-reducing concretes focus on adding glass beads or lightweight aggregates to enhance the sound absorption performance of concrete. The aggregates used in their preparation are relatively insufficient compared to plant-based raw materials, and the performance of sound absorption and noise reduction needs to be improved. Summary of the invention

[0005] The purpose of the present invention is to provide a plant-based porous sound-absorbing material with relatively good strength and thermal stability by using recyclable and degradable plant materials;

[0006] The second object of the present invention is to provide a method for preparing the plant-based porous sound-absorbing material, and to provide an industrially scalable production method for its preparation and synthesis;

[0007] The third object of the present invention is to provide the use of the plant-based porous sound-absorbing material in sound-absorbing concrete;

[0008] Another object of the present invention is to provide a method for preparing the above-mentioned sound-absorbing concrete, which can be further used in the construction of sound-absorbing building walls.

[0009] In order to achieve the above-mentioned object of the invention, the embodiment of the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a plant fiber-based porous sound-absorbing material, which includes the following raw materials in parts by weight: 7 to 8 parts of wheat straw, 2 to 3 parts of sunflower stem pith powder, 31 to 35 parts of styrene acrylic emulsion, 0.7 to 0.9 parts of sodium dodecylbenzene sulfonate, 75 to 85 parts of silica sol and 540 to 570 parts of water.

[0011] In the context of green and sustainable development, scientific research and transformation applications based on the utilization of biomass resources can turn waste into treasure, becoming a priority support for the national development strategy and a hot spot for scientific research. Crops in northern my country, such as wheat straw, become the main waste resource after harvest. The main component of wheat straw is cellulose, which can be used to produce high-value chemicals.

[0012] Sunflower straw has a high degree of lignification, and the cellulose content of the sunflower stem pith is high, and the volume of this part occupies three quarters of the sunflower husk. Compared with the reported straw cores (sorghum straw cores and corn straw cores), the cellulose content of sunflower stem pith is significantly different. The study found that the sunflower stem pith has a high content of pectin (17.6% of dry weight) and ash (16.6%), low content of hemicellulose (4.4% of alkaline extraction) and lignin (3.2%), and the lower lignin and hemicellulose content makes the sunflower stem pith have a higher utilization value.

[0013] The present invention compounds wheat straw with sunflower stem pith powder, uses silica sol to modify the above plant-based compound, improves the defects of plant fiber-based porous sound-absorbing materials such as poor strength, corrosion resistance, and non-flame retardancy, and prepares a new type of plant fiber-based porous sound-absorbing material through foam molding technology. At the same time, it provides a reference for realizing the comprehensive utilization of wheat straw and sunflower straw, and can also improve the economic and social benefits of agricultural and sideline products.

[0014] Preferably, the silica sol is an alkaline silica sol with a pH value of 9-11 and a particle size of 10nm-15nm;

[0015] The particle size of the wheat straw is 60-100 meshes.

[0016] In a second aspect, the present invention provides a method for preparing the above-mentioned plant fiber-based porous sound-absorbing material, the preparation method comprising the following steps:

[0017] S1. Take wheat straw, sunflower stem pith powder, styrene acrylic emulsion, silica sol and water in parts by weight according to the above-mentioned plant fiber-based porous sound-absorbing material, mix well to obtain a foaming slurry;

[0018] S2. After the foaming slurry is dispersed, sodium dodecylbenzene sulfonate is added, the mixture is stirred for foaming, injection molded for dehydration, and dried for solidification.

[0019] Preferably, in step S1, the degassing time is 6 min to 8 min.

[0020] Preferably, in step S2, the stirring and foaming time is 8 min to 10 min and the rotation speed is 1500 rpm to 2200 rpm;

[0021] The drying and curing time is 1.5h~2h, and the temperature is 80℃~85℃.

[0022] In a third aspect, the present invention provides the use of the above-mentioned plant fiber-based porous sound-absorbing material in the preparation of sound-absorbing concrete.

[0023] In a fourth aspect, the present invention provides a sound-absorbing concrete comprising the following components in parts by weight: 68 to 70 parts of cement, 20 to 24 parts of water, 5 to 8 parts of fine sand, 3 to 5 parts of the plant fiber-based porous sound-absorbing material, 0.1 to 0.2 parts of a surfactant, and 0.7 to 1.5 parts of a reinforcing agent; wherein the surfactant comprises the following components in the following weight percentages: 30% to 35% of sodium α-olefin sulfonate, 25% to 35% of fatty alcohol polyoxyethylene ether, and 30% to 40% of nonylphenol polyoxyethylene ether.

[0024] Preferably, the enhancer comprises the following components in the following weight percentages: 20% to 35% sodium sulfate, 15% to 25% calcium chloride, 5% to 15% triethanolamine and 25% to 30% phenyl trimethicone.

[0025] The sound-absorbing concrete provided by the present invention improves the foam stabilizer of the surfactant through the synergistic effect of three surfactants, namely, sodium α-olefin sulfonate, fatty alcohol polyoxyethylene ether and nonylphenol polyoxyethylene ether, and also has the pore-opening performance for plant fibers. The sound-absorbing concrete prepared thereby has a sound absorption coefficient of 0.51-0.61 at a frequency of 250 Hz, a sound absorption coefficient of 0.72-0.79 at a frequency of 500 Hz, a sound absorption coefficient of 0.65-0.76 at a frequency of 1000 Hz, a sound absorption coefficient of 0.75-0.81 at a frequency of 2000 Hz, and a noise reduction coefficient of 0.68-0.78.

[0026] The prepared sound-absorbing concrete has the characteristics of being environmentally friendly, economical, lightweight, sound-absorbing, and non-combustible, and can be used as a wall material for sound absorption and noise reduction.

[0027] Surfactants are mainly used to reduce the surface tension of the system and improve the foaming ability of the system. Different surfactants have different effects. Since the present invention uses alkaline silica sol as a modifier, the surface of the sol particles has a negative charge, which will affect the foam system. The present invention achieves better foaming ability by optimizing surfactants with different surface charge properties.

[0028] In a fifth aspect, the present invention provides a method for preparing the above-mentioned sound-absorbing concrete, the preparation method comprising the following steps:

[0029] Step 1: Mix cement, reinforcing agent, fine sand and the plant fiber-based porous sound-absorbing material in proportion to prepare a dry material; add water and continue stirring to prepare a slurry;

[0030] Step 2: mixing the surfactant with the slurry to prepare a foaming slurry;

[0031] Step 3: pour the foaming slurry into a mold, vibrate, and let it stand to obtain a sound-absorbing concrete blank, and then perform mold curing, demoulding, and drying to obtain the sound-absorbing concrete.

[0032] The method for preparing the sound-absorbing concrete provided by the invention has a relatively simple process and is conducive to industrial production. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] It should be noted that the silica sol used in the present invention was purchased from Linyi Kehan ​​Silica Products Co., Ltd. and is a JN alkaline series silica sol with a pH of 9-11 and a particle size of 10-15 nm.

[0035] The wheat straw in the present invention refers to wheat straw which has been dried, dusted, impurity removed, and crushed to obtain a particle size of 60-100 meshes.

[0036] The preparation method of the sunflower stem pith powder of the present invention is as follows: the sunflower stems are crushed by hammer mill, and the crushed stems are passed through a sieve with a diameter of 180 cm and placed under a suction system. Since the density of the sunflower stem pith is lower than that of the sunflower stem outer skin particles (20-30 kg / m 3 ), the pith is recovered by a suction system and dried to obtain the sunflower stem pith powder raw material of the present invention.

[0037] Sound absorption test: The sound absorption coefficient and noise reduction coefficient of sound-absorbing concrete materials are determined according to the method described in TB / T 3122-2019.

[0038] Compressive strength and splitting strength: The sound-absorbing and noise-reducing concretes prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to compressive strength tests and splitting strength tests.

[0039] Example 1

[0040] The present embodiment provides a plant fiber-based porous sound-absorbing material, which includes the following raw materials: 35 g of wheat straw, 15 g of sunflower stem pith powder, 155 mL of styrene acrylic emulsion, 375 g of silica sol, 3.5 g of sodium dodecylbenzene sulfonate and 2700 mL of water.

[0041] The preparation method of the above-mentioned plant fiber-based porous sound-absorbing material is as follows:

[0042] S1 weighed wheat straw, sunflower stem pith powder, styrene acrylic emulsion, silica sol according to the above ratio, add 2700mL of water, mix well to obtain a foaming slurry;

[0043] S2. The foamed slurry is moved into a fiber decomposing machine for 6 minutes. The inner spiral line of the fiber decomposing machine used in this embodiment is 6.5×6.5-4 equal parts, and the leaf rotation frequency is 48.3 -1 , pour it into a foaming device after dispersion, add 3.5 g of sodium dodecylbenzene sulfonate, stir at a speed of 1500 rpm for 8 minutes, stir and foam, pour it into a molding device after foaming, inject and dehydrate, move the wet foam slurry into a drying oven, dry and cure it at 80°C for 2 hours, and obtain the plant fiber-based porous sound-absorbing material.

[0044] This embodiment also provides a sound-absorbing concrete, the raw materials of which include 6.8 kg of cement, 70 g of reinforcing agent, 0.5 kg of fine sand, 0.3 kg of the above-mentioned plant fiber-based porous sound-absorbing material, 10 g of surfactant and 3.4 kg of water. The surfactant used is composed of sodium α-olefin sulfonate, fatty alcohol polyoxyethylene ether and nonylphenol polyoxyethylene ether in a mass ratio of 35:35:30.

[0045] This embodiment also provides a method for preparing the above-mentioned sound-absorbing concrete, and the preparation method is specifically as follows:

[0046] Step 1: Preparation of slurry

[0047] Weigh 6.8 kg of cement, 70 g of reinforcing agent, 0.5 kg of fine sand, and 0.3 kg of the above-mentioned plant fiber-based porous sound-absorbing material and mix them evenly to make a dry material; add 2.0 kg of water and continue stirring to make a slurry;

[0048] Wherein: the cement used is 42.5 grade ordinary Portland cement; the reinforcing agent used is composed of sodium sulfate, calcium chloride, triethanolamine and phenyl polytrimethylsiloxane in a mass ratio of 20:25:15:40;

[0049] Step 2: Mix 10 g of surfactant with the above slurry to prepare a foaming slurry;

[0050] Step 3: pour the foaming slurry into a mold, vibrate, and let it stand to obtain a sound-absorbing concrete blank, which is then cured for 24 hours, demolded, and dried to obtain the sound-absorbing concrete, which is recorded as Concrete I.

[0051] Example 2

[0052] The present embodiment provides a plant fiber-based porous sound-absorbing material, which includes the following raw materials: 40 g of wheat straw, 10 g of sunflower stem pith powder, 175 mL of styrene acrylic emulsion, 425 g of silica sol, 4.5 g of sodium dodecylbenzene sulfonate and 2850 mL of water.

[0053] The preparation method of the plant fiber-based porous sound-absorbing material is as follows:

[0054] S1 weighed 40g wheat straw, sunflower stem pith powder 10g, styrene acrylic emulsion 175mL, silica sol 425g, add 2850mL water, mix well to obtain a foaming slurry;

[0055] S2. The foamed slurry is transferred into a fiber decompressor for decompression for 8 minutes, and then poured into a foaming device, 4.5 g of sodium dodecylbenzene sulfonate is added, and stirred at a speed of 2200 rpm for 10 minutes to stir and foam. After the foaming is completed, it is poured into a molding device for injection molding and dehydration, and the wet foam slurry is transferred into a drying oven and dried and cured at 85° C. for 1.5 hours to obtain the plant fiber-based porous sound-absorbing material.

[0056] This embodiment provides a sound-absorbing concrete, the raw materials of which include: 7kg cement, 150g reinforcing agent, 0.8kg fine sand, 0.5kg plant fiber-based porous sound-absorbing material, 20g surfactant and 3.6kg water. The surfactant used is composed of sodium α-olefin sulfonate, fatty alcohol polyoxyethylene ether and nonylphenol polyoxyethylene ether in a mass ratio of 30:30:40.

[0057] The preparation method of the above-mentioned sound-absorbing concrete is specifically as follows:

[0058] Step 1: Preparation of slurry

[0059] 7 kg of cement, 150 g of reinforcing agent, 0.8 kg of fine sand, and 0.4 kg of the above-mentioned plant fiber-based porous sound-absorbing material are mixed evenly to form a dry material; 2.4 kg of water is added and stirred continuously to form a slurry;

[0060] Wherein: the cement used is ordinary Portland cement of grade 52.5; the reinforcing agent used is composed of sodium sulfate, calcium chloride, triethanolamine and phenyl polytrimethylsiloxane in a mass ratio of 35:15:25:25;

[0061] Step 2: Mix 20 g of surfactant with the above slurry to prepare a foaming slurry;

[0062] Step 3: pour the foaming slurry into the mold, vibrate, and let it stand to obtain the sound-absorbing concrete blank, which is then cured for 36 hours, demolded, and dried to obtain the sound-absorbing concrete, which is recorded as Concrete II.

[0063] Example 3

[0064] The present embodiment provides a plant fiber-based porous sound-absorbing material, which includes the following raw materials: 35 g of wheat straw, 15 g of sunflower stem pith powder, 160 mL of styrene acrylic emulsion, 400 g of silica sol, 4.0 g of sodium dodecylbenzene sulfonate and 2750 mL of water.

[0065] The preparation method of the plant fiber-based porous sound-absorbing material is as follows:

[0066] S1 weighed 35g wheat straw, sunflower stem pith powder 15g, styrene acrylic emulsion 160mL, silica sol 400g, add 2750mL water, mix well to obtain a foaming slurry;

[0067] S2. The foamed slurry is transferred into a fiber decompressor for decompression for 7 minutes, and then poured into a foaming device, 4.0 g of sodium dodecylbenzene sulfonate is added, and stirred at a speed of 2000 rpm for 9 minutes to stir and foam. After the foaming is completed, it is poured into a molding device for injection molding and dehydration, and the wet foam slurry is transferred into a drying oven and dried and cured at 80° C. for 2 hours to obtain the plant fiber-based porous sound-absorbing material.

[0068] The present embodiment provides a sound-absorbing concrete, which includes the following raw materials: 7 kg of cement, 150 g of a reinforcing agent, 0.65 kg of fine sand, 0.4 kg of the above-mentioned plant fiber-based porous sound-absorbing material, 15 g of a surfactant and 3.5 kg of water; wherein the surfactant used is composed of sodium α-olefin sulfonate, fatty alcohol polyoxyethylene ether and nonylphenol polyoxyethylene ether in a mass ratio of 30:30:40.

[0069] The preparation method of the above-mentioned sound-absorbing concrete is specifically as follows:

[0070] Step 1: Preparation of slurry

[0071] 7 kg of cement, 150 g of reinforcing agent, 0.65 kg of fine sand, and 0.5 kg of the above-mentioned plant fiber-based porous sound-absorbing material are mixed evenly to form a dry material; 2.2 kg of water is added and stirred continuously to form a slurry;

[0072] Wherein: the cement used is ordinary Portland cement of grade 52.5R; the reinforcing agent used is composed of sodium sulfate, calcium chloride, triethanolamine and phenyl polytrimethylsiloxane in a mass ratio of 30:20:20:30;

[0073] Step 2: Mix 15 g of surfactant with the above slurry to prepare a foaming slurry;

[0074] Step 3: pour the foaming slurry into the mold, vibrate, and let it stand to obtain the sound-absorbing concrete blank, and then maintain it in the mold for 12 hours, demold, and dry to obtain the sound-absorbing concrete, which is recorded as concrete III.

[0075] Comparative Example 1

[0076] This comparative example provides a method for preparing sound-absorbing concrete, and its raw material composition, preparation method and preparation parameters are basically the same as those in Example 3, except that "35 g of wheat straw and 15 g of sunflower stem pith powder" are replaced by "50 g of wheat straw", and the other parameters are the same as those in Example 3. The obtained sound-absorbing concrete is recorded as Concrete Comparison I.

[0077] Comparative Example 2

[0078] This comparative example provides a method for preparing sound-absorbing concrete, and its raw material composition, preparation method and preparation parameters are basically the same as those in Example 3, except that "the surfactant is composed of sodium α-olefin sulfonate, fatty alcohol polyoxyethylene ether and nonylphenol polyoxyethylene ether in a mass ratio of 30:30:40" is replaced by "the surfactant is composed of sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide and polyvinyl alcohol in a mass ratio of 30:30:40", and the remaining parameters are the same as those in Example 3. The obtained sound-absorbing concrete is recorded as Concrete Comparison II.

[0079] Comparative Example 3

[0080] This comparative example provides a method for preparing sound-absorbing concrete. The raw material composition, preparation method and preparation parameters thereof are substantially the same as those of Example 3, except that “the surfactant is composed of sodium α-olefin sulfonate, fatty alcohol polyoxyethylene ether and nonylphenol polyoxyethylene ether in a mass ratio of 30:30:40” is replaced by “the surfactant is composed of sodium α-olefin sulfonate and fatty alcohol polyoxyethylene ether in a mass ratio of 50:50”, and the remaining parameters are the same as those of Example 3. The obtained sound-absorbing concrete is recorded as Concrete Comparison III.

[0081] Effect Example 1

[0082] According to the method described in TB / T 3122-2019, the sound absorption coefficient and noise reduction coefficient of the sound-absorbing concrete materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were measured. The specific results are shown in Table 1 below.

[0083] The sound-absorbing concretes prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to standing wave tube sound absorption tests at frequencies of 1000 Hz and 2000 Hz, and their sound absorption coefficients were measured for comparison.

[0084] Table 1 Statistics of sound absorption coefficient and noise reduction coefficient of different sound-absorbing concrete

[0085]

[0086] It can be seen from the data in Table 1 that compared with comparative examples 1 to 3, the sound absorption coefficient and noise reduction coefficient of the sound-absorbing concrete prepared in Examples 1 to 3 are both higher. From the data comparison of concrete III and concrete pair I, it can be seen that the sound absorption coefficient and noise reduction coefficient of the concrete prepared using wheat straw and sunflower stem pith powder as raw materials are significantly higher than the sound absorption effect of using only wheat straw, a plant fiber-based raw material. From the data comparison of concrete III, concrete pair II and concrete pair III, it can be seen that different compounded active agents have different noise reduction effects on sound-absorbing concrete. It is speculated that the reason may be that the surfactant can affect the structural stability of the foaming base by adjusting the surface tension of the slurry, thereby affecting the sound absorption and noise reduction.

[0087] Effect Example 2

[0088] The present invention measures the compressive strength and splitting strength of the sound-absorbing concrete materials prepared in Examples 1 to 3 and Comparative Example 1. The specific results are shown in Table 2 below.

[0089] Table 2 Statistics of compressive strength and splitting strength of different sound-absorbing concrete

[0090]

[0091] It can be seen from the data in Table 2 that compared with Comparative Example 1, the compressive strength and splitting strength of the sound-absorbing concrete prepared in Examples 1 to 3 are better, indicating that the use of wheat straw and sunflower stem pith powder as a raw material can make the prepared concrete more tightly bonded, which may be related to the addition of sunflower stem pith to enhance the cross-linking effect between plant cellulose.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A sound-absorbing concrete, characterized in that: It includes the following components in parts by weight: 68 to 70 parts of cement, 5 to 8 parts of fine sand, 3 to 5 parts of plant fiber-based porous sound-absorbing material, 0.1 to 0.2 parts of surfactant, 0.7 to 1.5 parts of reinforcing agent and 20 to 24 parts of water; Wherein, the surfactant comprises the following components in the following weight percentages: 30% to 35% of sodium α-olefin sulfonate, 25% to 35% of fatty alcohol polyoxyethylene ether and 30% to 40% of nonylphenol polyoxyethylene ether; The plant fiber-based porous sound-absorbing material comprises the following raw materials in parts by weight: 7 to 8 parts of wheat straw, 2 to 3 parts of sunflower stem pith powder, 31 to 35 parts of styrene-acrylic emulsion, 0.7 to 0.9 parts of sodium dodecylbenzene sulfonate, 75 to 85 parts of silica sol and 540 to 570 parts of water; The preparation method of the plant fiber-based porous sound-absorbing material comprises the following steps: S1. Take wheat straw, sunflower stem pith powder, styrene acrylic emulsion, silica sol and water in parts by weight and mix to obtain a foaming slurry; S2. After the foaming slurry is dispersed, sodium dodecylbenzene sulfonate is added, the mixture is stirred for foaming, injection molded for dehydration, and dried and solidified to obtain a plant fiber-based porous sound-absorbing material.

2. The sound-absorbing concrete according to claim 1, characterized in that: The silica sol is alkaline silica sol, with a pH value of 9-11 and a particle size of 10nm-15nm; and / or The particle size of the wheat straw is 60-100 meshes.

3. The sound-absorbing concrete according to claim 1, characterized in that: In step S1, the decongestion time is 6 minutes to 8 minutes.

4. The sound-absorbing concrete according to claim 1, characterized in that: In step S2, the stirring and foaming time is 8min~10min, and the rotation speed is 1500rpm~2200rpm; The drying and curing time is 1.5h~2h, and the temperature is 80℃~85℃.

5. The sound-absorbing concrete according to claim 1, characterized in that: The enhancer comprises the following components in the following weight percentages: 20% to 35% sodium sulfate, 15% to 25% calcium chloride, 5% to 15% triethanolamine and 25% to 30% phenyl trimethylsiloxane.

6. The method for preparing sound-absorbing concrete according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Step 1: Mix cement, reinforcing agent, fine sand, the plant fiber-based porous sound-absorbing material, surfactant and water in proportion to prepare slurry; Step 2: pour the slurry into a mold, vibrate, and let it stand to obtain a sound-absorbing concrete blank, and then perform mold curing, demoulding, and drying to obtain the sound-absorbing concrete.

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