A bamboo fiber reinforced extruded cement sound barrier board and a preparation method thereof

Abstract

The application discloses a kind of bamboo fiber reinforced extruded cement sound barrier plate and preparation method thereof, belong to prefabricated component technical field, by cement matrix and bamboo fiber composite is formed, wherein, cement matrix water glue ratio is 0.20-0.24;Cement matrix includes following raw materials by weight parts: cement 850-950 parts, silica fume 100-200 parts, quartz sand 900-1100 parts, plasticizer 18-23 parts, lubricant 8-12 parts, retarder 0.3-0.5 parts;Bamboo fiber content is 1% to 2% of the volume of cement matrix.The preparation method of the bamboo fiber reinforced extruded cement sound barrier plate described above is used, not only inherits the core advantage of traditional ECP, such as fire resistance, weather resistance, high strength, but also significantly improves the sound absorption performance, impact toughness and light weight level, realizes the upgrading from "single structural material" to "structure-function integrated green building material".

Description

Technical Field

[0001] This invention relates to the field of precast component technology, and in particular to a bamboo fiber reinforced extruded cement sound barrier board and its preparation method. Background Technology

[0002] Bamboo fiber reinforced ECP sound barrier panels arose from the convergence of two major problems: the limited functionality and susceptibility to secondary pollution of traditional sound barriers, and the technological bottlenecks inherent in natural fiber-reinforced cement-based materials. Traditional sound barriers, such as ordinary extruded cement boards, primarily offer sound insulation but lack sound absorption capabilities; sound barriers filled with glass wool or rock wool are prone to pulverization, generating dust and causing secondary pollution. This has prompted the market to seek a new material that combines sound absorption and insulation while being environmentally friendly and pollution-free. Meanwhile, although bamboo fiber has been studied as a reinforcing material for some time, it faces two major challenges: first, substances such as sugars in bamboo fiber inhibit cement hydration, leading to poor interfacial bonding and reduced board strength; second, the alkaline environment of the cement matrix causes long-term hydrolysis and mineralization of bamboo fibers, affecting the durability of its reinforcing effect. Furthermore, applying this type of material to extrusion molding processes requires addressing the issue of fiber dispersion. Summary of the Invention

[0003] The purpose of this invention is to provide a bamboo fiber reinforced extruded cement sound barrier board and its preparation method. This invention incorporates bamboo fiber into the extruded cement board, utilizing the bamboo fiber to enhance its mechanical and sound absorption properties, and optimizes its proportions and preparation process to produce a bamboo fiber reinforced extruded cement sound barrier board with excellent mechanical properties and sound absorption performance. This sound barrier board not only inherits the core advantages of traditional ECP (Extruded Cement Board) such as fire resistance, weather resistance, high strength, dimensional stability, and industrial production feasibility, but also significantly improves sound absorption performance, impact resistance, lightweighting, and environmental friendliness, achieving an upgrade from a "single structural material" to a "structure-function integrated green building material."

[0004] To achieve the above objectives, the present invention provides a bamboo fiber reinforced extruded cement sound barrier board, which is composed of a cement matrix and bamboo fiber. The cement matrix, by weight, includes the following raw materials: 850-950 parts cement, 100-200 parts silica fume, 900-1100 parts quartz sand, 18-23 parts plasticizer, 8-12 parts lubricant, 0.3-0.5 parts retarder, and water; the bamboo fiber content is 1%-2% of the volume of the cement matrix.

[0005] Preferably, the water-cement ratio (water:(cement + silica fume)) of the cement matrix is ​​0.20-0.24.

[0006] Preferably, the quartz sand has a mesh size of 40-200, and the bamboo fiber has a length of 4-8 mm and a diameter of 250 μm.

[0007] Preferably, the plasticizer is hydroxypropyl methylcellulose, the viscosity of a 2% aqueous solution of the plasticizer at 20°C is 200,000-30,000 mPa·s, the lubricant is magnesium stearate, and the retarder is sucrose.

[0008] This invention also provides a method for preparing bamboo fiber reinforced extruded cement sound barrier panels, comprising the following steps: S1. Raw material pretreatment: combing, cutting and drying bamboo fibers; S2. Dry material mixing: Cement, silica fume and quartz sand are put into a mixer and mixed to obtain dry material; S3. Wet mixing and fiber dispersion: Water is mixed with plasticizer, lubricant and retarder to obtain a mixture; the mixture is added to the dry material in S2 and stirred to obtain cement slurry; then the bamboo fiber pretreated in S1 is added and stirred to disperse the bamboo fiber evenly to obtain bamboo fiber cement-based composite material. S4. Vacuum extrusion: The bamboo fiber cement-based composite material is put into an extruder and vacuum extruded to obtain a slab; S5. Curing: Place the slab from S4 into a rapid curing box for curing to obtain bamboo fiber reinforced extruded cement sound barrier board.

[0009] Preferably, in S1, the specific drying steps are as follows: the combed and cut bamboo fibers are placed in an oven at 60°C and dried for 12 hours.

[0010] Preferably, in S2, the specific steps of mixing are as follows: cement, silica fume and quartz sand are put into a mixer and mixed at a low speed for 3 minutes, with the low speed mixing speed being 40 r / min.

[0011] Preferably, in S3, when preparing the mixture, the mixing is carried out for 1 minute; when preparing the cement slurry, the medium-speed mixing speed is 70 r / min and the mixing time is 3-4 minutes; after adding bamboo fiber, the high-speed mixing speed is 90 r / min and the mixing time is 4-6 minutes.

[0012] Preferably, in S4, the temperature of vacuum extrusion is 18-30℃ and the pressure is 3-5MPa.

[0013] Preferably, in S5, the specific curing steps include: after extrusion molding, covering with film, letting stand at room temperature for 2 hours, and then placing it in a rapid curing chamber for curing at a curing temperature of 80-90℃, a relative humidity of 90-95%, and a curing time of 12-36 hours.

[0014] Therefore, the present invention, employing the above-mentioned bamboo fiber reinforced extruded cement sound barrier board and its preparation method, has the following beneficial effects: (1) Excellent mechanical properties and toughness: The addition of bamboo fiber can significantly improve the mechanical properties of cement-based materials. The high tensile strength of bamboo fiber can effectively transfer the matrix stress, significantly improving the tensile strength and flexural strength of the material. At the same time, bamboo fiber plays a "bridging" role in the cement matrix. When the matrix cracks under stress, the fiber absorbs the fracture energy through pull-out or breakage, thereby effectively inhibiting the initiation and propagation of microcracks and greatly improving the toughness and impact resistance of the material.

[0015] (2) Significant cost advantages and green characteristics: As a natural, renewable, and low-cost plant fiber, bamboo fiber can effectively reduce material costs by replacing other fibers while ensuring or even improving the overall performance of components. At the same time, the energy consumption of bamboo fiber production is much lower than that of other fibers, and its application meets the requirements of energy conservation, emission reduction and sustainable development, thus improving the environmental friendliness of the products.

[0016] (3) Excellent acoustic performance: The addition of bamboo fiber and special extrusion process make countless tiny pores form inside the board. After the sound waves enter, they rub against the fiber pore walls and the energy is converted into heat energy and consumed, thus achieving efficient sound absorption. At the same time, the cement matrix provides sufficient surface density and rigidity, which can effectively block the penetration of sound.

[0017] (4) Lightweight and easy to construct: Bamboo fiber ECP usually has a lower density, making the product lighter. This reduces costs and hoisting difficulties during transportation and on-site installation; while ordinary ECP has a higher density, greater weight, and more stringent requirements for structural load-bearing capacity. At the same time, the prefabrication production method ensures the uniformity and stability of product quality, facilitates on-site installation, and greatly improves construction efficiency.

[0018] (5) The preparation process is highly feasible: By adopting a step-by-step feeding and a specific stirring process, this invention has successfully overcome the technical bottleneck of uniform dispersion of bamboo fiber in the matrix, overcomes the fiber agglomeration phenomenon, and significantly improves the consistency of the physical properties of the finished product; the method has excellent industrial adaptability and is convenient for standardized quality control in prefabrication production.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a SEM image of bamboo fiber and cement matrix in the bamboo fiber reinforced extruded cement sound barrier board and its preparation method according to the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention. Furthermore, it should be understood that after reading the contents of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims and are all within the protection scope of the present invention.

[0022] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0023] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0024] In this invention, unless otherwise specified, all other test materials and instruments are conventional test materials in the field and can be purchased through commercial channels.

[0025] Example 1 This invention provides a bamboo fiber reinforced extruded cement sound barrier panel with dimensions of 1960 mm in length, 500 mm in width, and 60 mm in thickness. The raw material proportions (by weight) include: 890 parts P·O42.5 silicate cement, 140 parts silica fume, 970 parts 40-200 mesh quartz sand, 20 parts hydroxypropyl methylcellulose, 10 parts magnesium stearate, 0.4 parts sucrose, and 225 parts water. The reinforcing fiber is bamboo fiber with a length of 6 mm and a diameter of 250 μm, added at 2% of the cement matrix volume.

[0026] SEM images of bamboo fiber and cement matrix are shown below. Figure 1 As shown, by Figure 1 It is known that the addition of bamboo fiber and the special extrusion process create countless tiny pores inside the board. When sound waves enter, they rub against the fiber pore walls, and the energy is converted into heat and dissipated, thus achieving efficient sound absorption. At the same time, the cement matrix provides sufficient surface density and rigidity, which can effectively block the penetration of sound.

[0027] The preparation method of bamboo fiber reinforced extruded cement sound barrier board specifically includes the following steps: (1) After combing and cutting the bamboo fiber to 6mm, dry it in an oven at 60℃ for 12h.

[0028] (2) Put cement, silica fume and quartz sand into a forced mixer and mix at low speed (40r / min) for 3 minutes until the powder is evenly mixed to obtain dry material.

[0029] (3) Mix hydroxypropyl methylcellulose, magnesium stearate, sucrose and water evenly to obtain a mixture. Slowly pour the mixture into a mixer to mix the dry materials with the mixture. Then, set the mixer to medium speed (70 r / min) and stir for 3 minutes to obtain cement slurry.

[0030] (4) Sprinkle bamboo fiber evenly into the mixer and stir at high speed (90r / min) for 5 minutes to obtain bamboo fiber cement-based composite material.

[0031] (5) The tested and qualified bamboo fiber cement-based composite material is put into a vacuum extruder for extrusion to obtain a slab. The slab is covered with a plastic film and left to stand at room temperature for 2 hours. Then it is placed in a rapid curing box for curing. The curing temperature is 80℃ and the relative humidity is 90% for 24 hours to obtain bamboo fiber reinforced extruded cement sound barrier board.

[0032] Example 2 The only difference between this embodiment and Embodiment 1 is that the amount of reinforcing fiber added is 1.5% of the matrix volume, while the other components and amounts, material preparation, mixing method, molding process and curing conditions are the same as in Embodiment 1.

[0033] Example 3 The only difference between this embodiment and Embodiment 1 is that the amount of reinforcing fiber added is 1.0% of the matrix volume, while the other components and amounts, material preparation, mixing method, molding process and curing conditions are the same as in Embodiment 1.

[0034] The bamboo fiber reinforced extruded cement sound barrier board prepared in Example 1 was tested, and the test items and standards are shown in Table 1.

[0035] Table 1. Test standards and results for Example 1

[0036] Comparative Example 1 The only difference between this embodiment and Embodiment 1 is that there is no reinforcing fiber, while the other components and dosages, material preparation, mixing method, molding process and curing conditions are the same as in Embodiment 1.

[0037] Comparative Example 2 The only difference between this embodiment and Embodiment 1 is that the reinforcing fiber is replaced with lignin fiber, and the dosage is added at 1.5% of the matrix volume. The other components and dosages, material preparation, mixing method, molding process and curing conditions are the same as in Embodiment 1.

[0038] The performance of the sound barrier panels prepared in Examples 1-3 and Comparative Examples 1-2 was tested, and the test results are shown in Table 2.

[0039] Table 2 Mechanical and acoustic performance tests

[0040] As shown in Table 2, bamboo fiber exhibits superior overall reinforcing effect compared to lignin fiber. Comparing Comparative Example 2 and Example 2 with the same dosage, the longitudinal flexural strength of the bamboo fiber specimen was 17.8 MPa, significantly higher than the 16.5 MPa of lignin fiber, representing an increase of approximately 7.9%. This demonstrates that bamboo fiber has a more effective bridging effect, better inhibiting crack propagation and improving bending toughness. Simultaneously, the weighted sound insulation of the bamboo fiber specimen was 36 dB, significantly better than the 31 dB of lignin fiber, and the noise reduction coefficient increased from 0.68 to 0.70, indicating that the internal porous structure formed by bamboo fiber is more conducive to sound energy absorption. Furthermore, the compressive strength and surface density of both are basically similar, indicating that bamboo fiber can balance mechanical and acoustic properties without increasing its own weight, making it a more ideal reinforcing material.

[0041] Secondly, the amount of bamboo fiber added is not necessarily better the higher it is; there is an optimal range. Comparing Examples 1, 2, and 3 with Comparative Example 1, it can be found that the group without bamboo fiber added has the highest compressive strength. In Example 3, 1% bamboo fiber can effectively bridge microcracks, enhance crack resistance, and thus improve compressive strength compared to Comparative Example 1. As the amount of bamboo fiber added increases, the compressive strength decreases, from 17.9 MPa in Example 2 to 17.7 MPa in Example 1. This may be because as the fiber content increases, fiber agglomeration occurs, leading to uneven fiber distribution, stress concentration points, and weakened compressive strength; longitudinal flexural strength increases with increasing fiber content. The flexural strength increased significantly from 15.1 MPa in the fiber-free group to 18.9 MPa in Example 1, indicating that the incorporation of bamboo fiber can effectively increase flexural strength. This is mainly because the presence of fiber allows stress to be more evenly distributed within the material, and during fracture, the deformation and pull-out of the fiber absorb a large amount of energy, thereby improving flexural strength. However, the surface density of the board decreased slightly with increasing incorporation, which is in line with the trend of lightweighting. However, the weighted sound insulation was 36 dB at incorporation levels of 1.0% and 1.5%, but decreased to 34 dB at 2%, showing a significant improvement compared to the fiber-free group. The noise reduction coefficient remained stable between 0.70 and 0.71 in the fiber-containing group, with little change, but it was still higher than that in the group without bamboo fiber. This fully demonstrates the superiority of bamboo fiber in the field of sound barriers.

[0042] Therefore, this invention employs the aforementioned method for preparing bamboo fiber reinforced extruded cement sound barrier panels. Bamboo fiber is incorporated into the extruded cement board, utilizing the bamboo fiber to enhance its mechanical and sound absorption properties. Furthermore, the formulation and preparation process are optimized to produce bamboo fiber reinforced extruded cement sound barrier panels with excellent mechanical properties and superior sound absorption performance. This not only inherits the core advantages of traditional ECP (Electronic Building Materials) such as fire resistance, weather resistance, and high strength, but also significantly improves sound absorption performance, impact resistance, lightweighting, and environmental friendliness, achieving an upgrade from a "single structural material" to a "structure-function integrated green building material."

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bamboo fiber reinforced extruded cement sound barrier board, characterized in that: It is composed of cement matrix and bamboo fiber. The cement matrix, by weight, includes the following raw materials: 850-950 parts cement, 100-200 parts silica fume, 900-1100 parts quartz sand, 18-23 parts plasticizer, 8-12 parts lubricant, 0.3-0.5 parts retarder, and water; the bamboo fiber content is 1%-2% of the volume of the cement matrix.

2. The bamboo fiber reinforced extruded cement sound barrier board according to claim 1, characterized in that: The water-cement ratio of the cementitious matrix is ​​0.20-0.

24.

3. The bamboo fiber reinforced extruded cement sound barrier board according to claim 1, characterized in that: The quartz sand has a mesh size of 40-200, and the bamboo fiber has a length of 4-8mm and a diameter of 250μm.

4. The bamboo fiber reinforced extruded cement sound barrier board according to claim 1, characterized in that: The plasticizer is hydroxypropyl methylcellulose, and the viscosity of a 2% aqueous solution of the plasticizer at 20°C is 200,000-30,000 mPa·s. The lubricant is magnesium stearate, and the retarder is sucrose.

5. A method for preparing a bamboo fiber reinforced extruded cement sound barrier board as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Raw material pretreatment: combing, cutting and drying bamboo fibers; S2. Dry material mixing: Cement, silica fume and quartz sand are put into a mixer and mixed to obtain dry material; S3. Wet mixing and fiber dispersion: Water is mixed with plasticizer, lubricant and retarder to obtain a mixture; the mixture is added to the dry material in S2 and stirred to obtain cement slurry; then the bamboo fiber pretreated in S1 is added and stirred to disperse the bamboo fiber evenly to obtain bamboo fiber cement-based composite material. S4. Vacuum extrusion: The bamboo fiber cement-based composite material is put into an extruder and vacuum extruded to obtain a slab; S5. Curing: Place the slab from S4 into a rapid curing box for curing to obtain bamboo fiber reinforced extruded cement sound barrier board.

6. The method for preparing a bamboo fiber reinforced extruded cement sound barrier board according to claim 5, characterized in that: In S1, the specific steps for drying are as follows: place the combed and cut bamboo fibers in an oven at 60℃ and dry for 12 hours.

7. The method for preparing a bamboo fiber reinforced extruded cement sound barrier board according to claim 5, characterized in that: In S2, the specific mixing steps are as follows: put cement, silica fume and quartz sand into the mixer and mix at a low speed for 3 minutes. The low speed mixing speed is 40 r / min.

8. The method for preparing a bamboo fiber reinforced extruded cement sound barrier board according to claim 5, characterized in that: In S3, when preparing the mixture, stir for 1 minute; when preparing the cement slurry, the medium-speed stirring speed is 70 r / min and the stirring time is 3-4 minutes; after adding bamboo fiber, the high-speed stirring speed is 90 r / min and the stirring time is 4-6 minutes.

9. The method for preparing a bamboo fiber reinforced extruded cement sound barrier board according to claim 5, characterized in that: In S4, the temperature of vacuum extrusion is 18-30℃ and the pressure is 3-5MPa.

10. The preparation method according to claim 5, characterized in that: In S5, the specific curing steps include: after extrusion molding, covering with film, letting stand at room temperature for 2 hours, and then placing it in a rapid curing chamber for curing. The curing temperature is 80-90℃, the relative humidity is 90-95%, and the curing time is 12-36 hours.

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