Solid waste cementitious board sound barrier and preparation method

Abstract

This invention discloses a solid waste cemented board sound barrier and its preparation method. The solid waste cemented board sound barrier material is prepared from industrial solid wastes such as phosphogypsum, steel slag powder, and fly ash as the main raw materials, realizing the resource utilization of solid waste, significantly reducing raw material costs, and being environmentally friendly and low-carbon. The board production process has low energy consumption, simple and controllable technology, and is easy to mechanize for continuous production. The resulting material has high strength and stable performance, and is lightweight, fireproof, and corrosion-resistant. It does not crack or discolor under extreme climates, and its key indicators meet the requirements of highway sound barrier specifications. Based on its excellent strength, the solid waste cemented board sound barrier board prepared by this invention can be made into 4-5 meter long boards, suitable for installation with H-shaped steel columns spaced 4-5 meters apart. Compared with the traditional 2-meter boards, it can reduce the amount of column and foundation engineering, significantly reduce the overall cost, and has significant economic benefits and broad application prospects.

Description

Technical Field

[0001] This invention belongs to the technical field of highway sound barrier materials, and more specifically, relates to a solid waste cement board sound barrier and its preparation method. Background Technology

[0002] Noise barriers are core facilities for highway traffic noise control. Currently, mainstream products can be divided into two categories: metal panels and non-metal panels. Metal panels are prone to corrosion and difficult to clean, and the glass wool filling inside poses a risk of releasing harmful substances. Non-metal panels mostly adopt a foamed ceramic integrated sintering structure, which not only has high energy consumption and long preparation cycle in the production process, but its high brittleness also leads to insufficient bending strength, making the panels prone to microcracks or fractures during transportation and installation, thus affecting the durability and service life of the noise barrier.

[0003] To address the shortcomings of traditional sound barriers, existing technologies have explored the use of industrial solid waste in their fabrication. Patent CN118978382A discloses an environmentally friendly sound barrier utilizing slag and fly ash as raw materials, employing a composite structure of a cemented frame and a foamed sound-absorbing screen. However, this technology uses a step-by-step casting process, which is cumbersome and difficult to scale up into mechanized production. Furthermore, the raw materials include specialized chemical materials such as lightly calcined magnesium oxide and magnesium chloride, resulting in a complex formula and high procurement costs. Patent CN107572998B discloses a low-cost, high-strength porous sound-absorbing material and its manufacturing process, using steel slag and red mud as main raw materials. This material is prepared through foaming and can be used for highway sound barriers. While this technology achieves multi-source utilization of metallurgical solid waste, the product performance is still focused on sound absorption coefficient and compressive strength, without addressing the bending resistance required for sound barrier panels under complex outdoor conditions.

[0004] It is noteworthy that phosphogypsum, a major industrial solid waste generated by the phosphate chemical industry, has a huge annual emission volume, and its resource utilization has always been a challenge for the industry. Although phosphogypsum-based materials themselves possess the fire-resistant and corrosion-resistant properties of inorganic materials, their mechanical properties limit their application in the aforementioned scenarios. Unmodified phosphogypsum has low gelling activity and poor mechanical properties, and there are currently no publicly available technical solutions for its application in highway sound barrier panels. Highway sound barriers are subjected to complex outdoor conditions for extended periods, affected by wind pressure, vibration, and temperature changes; therefore, their resistance to bending fracture is a core indicator determining their service life and safety. None of the existing solid waste-based sound barrier materials mentioned above have been specifically designed for this indicator, making it difficult to meet the comprehensive requirements of highway engineering for sound barrier panels with high bending resistance, lightweight, and long service life. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a solid waste cemented board sound barrier and its preparation method. The solid waste cemented board sound barrier material is prepared using industrial solid wastes such as phosphogypsum, steel slag powder, and fly ash as main raw materials to achieve resource utilization of solid waste, significantly reducing raw material costs and promoting environmental protection and low carbon emissions. The board production process is energy-efficient, simple, controllable, and easily mechanized for continuous production. The resulting material has high strength and stable performance, possessing lightweight, fire-resistant, and corrosion-resistant properties. It does not crack or discolor under extreme weather conditions, and its key indicators meet the requirements of highway sound barrier specifications. Based on its excellent strength, the solid waste cemented board sound barrier panels prepared by this invention can be made into 4-5 meter long panels, suitable for installation with H-shaped steel columns spaced 4-5 meters apart. Compared to traditional 2-meter panels, this reduces the amount of column and foundation work, significantly lowering the overall cost and demonstrating significant economic benefits and broad application prospects.

[0006] To achieve the above objectives, according to a first aspect of the present invention, a method for preparing a solid waste cemented board sound barrier is provided, comprising the following steps: Step 1, Preparation of modified phosphogypsum: Phosphogypsum is microwave-treated, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and tetramethylammonium hydroxide aqueous solution are mixed and dried to obtain modified phosphogypsum. Step 2, Preparation of gelling material: Take the modified phosphogypsum obtained above and grind it with the auxiliary materials, mix them evenly, and obtain the gelling material; Step 3, prepare the mixture: Take the above-obtained cementitious material and put it into a mixer to dry mix with pulp fiber, quartz sand, fly ash and diatomaceous earth, then add water and continue mixing to obtain a uniform mixture; Step 4, Sound Barrier Molding and Curing: The above-obtained mixture is pressurized and extruded to make it dense and molded. The molded board is placed in a sealed curing room, first cured at low temperature, then cured with high temperature and high pressure steam. After cooling to room temperature, the sound insulation board of the solid waste cement board sound barrier is obtained.

[0007] Preferably, in step 1, the mass ratio of the phosphogypsum, alumina, attapulgite, sodium lignosulfonate, and tetramethylammonium hydroxide aqueous solution is 100:6~15:3~8:1~3:10~15.

[0008] Preferably, in step 1, the mass concentration of the tetramethylammonium hydroxide aqueous solution is 3-8%.

[0009] Preferably, in step 2, the modified phosphogypsum is 60-80 parts and the excipients are 20-40 parts.

[0010] Preferably, in step 2, the auxiliary material is one or more of steel slag powder, fly ash, lithium slag, and mineral slag.

[0011] Preferably, in step 3, the cementitious material comprises 40-50 parts, pulp fiber comprises 4-6 parts, quartz sand comprises 10-20 parts, fly ash comprises 10-20 parts, diatomaceous earth comprises 2-5 parts, and water comprises 2-5 parts.

[0012] Preferably, in step 4, the pressurization pressure is 10~20 MPa.

[0013] Preferably, in step 4, the low-temperature curing temperature is 60~90 ℃, and the curing time is 8~12 hours.

[0014] Preferably, in step 4, the high-temperature and high-pressure steam curing temperature is 180~200 ℃, the pressure is 1~2 MPa, and the time is 8~12 hours.

[0015] According to a second aspect of the present invention, a solid waste cementitious board sound barrier is provided, which is prepared by the method described above.

[0016] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. This invention uses industrial solid wastes such as phosphogypsum, steel slag powder, and fly ash as main raw materials to prepare cementitious materials. This not only realizes the resource utilization of solid waste and significantly reduces raw material costs, but also effectively reduces the environmental pollution caused by solid waste stockpiling. At the same time, the board production process has low energy consumption, simple and controllable technology, and is easy to achieve mechanized continuous production. From the source to the process, it meets the development requirements of green highways and low-carbon environmental protection.

[0017] 2. The solid waste cemented board sound barrier produced by this invention has high strength and stable performance. Its resistance to bending fracture load can reach 3.85 times its own weight, its compressive strength reaches 6.87 MPa, and its internal bond strength is ≥1.0 MPa. It also possesses lightweight, fire-resistant, and corrosion-resistant properties, and will not crack or discolor under extreme weather conditions, resulting in a long service life. In terms of acoustic performance, it achieves an average noise reduction of 6-8 decibels. Key indicators such as noise reduction coefficient, sound insulation, and wind pressure resistance all meet the requirements of highway sound barrier specifications, effectively controlling traffic noise pollution.

[0018] 3. The product obtained by this invention, based on the superior strength of the sheet material, can be manufactured into 4-5 meter long panels, perfectly adapting to the installation of H-shaped steel columns spaced 4-5 meters apart. Compared to traditional 2-meter long sound barrier panels, this design can reduce the amount of work required for one span of columns and the corresponding foundation, significantly reducing the overall cost. Furthermore, the surface of this panel is free from electrostatic adsorption, easy to self-clean, and supports various decorative processes such as sanding, embossing, and painting, combining practicality and aesthetics, resulting in significant economic benefits and broad application prospects. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the process flow for preparing the solid waste cement board sound barrier according to an embodiment of the present invention; Figure 2 This is a schematic cross-sectional view of the sound barrier panel of the solid waste cement board according to an embodiment of the present invention. Figure 3 This is a plan view of the sound barrier panel of the solid waste cement board according to an embodiment of the present invention.

[0020] Attached reference numerals: 1-Rivet; 2-Column head cap; 3-Mounting clip; 4-Steel plate; 5-Solid waste gelled sound insulation board; 6-H-shaped steel column; 7-Base steel plate. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] Example 1 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:6:3:1:10 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0023] (2) Preparation of cementitious material: Take 60 parts by weight of the above modified phosphogypsum and 20 parts by weight of steel slag powder, mix them, and grind them in a ball mill until the particle size is ≤100 μm to obtain cementitious material.

[0024] (3) Preparation of mixture: By weight, take 40 parts of cementitious material, 2 parts of water, 4 parts of pulp fiber, 10 parts of quartz sand, 10 parts of fly ash, and 2 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0025] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 10 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 60 ℃ for 12 hours. Then it is cured at a high temperature and high pressure of 180 ℃ and 1 MPa for 12 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0026] Example 2 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:10:5:2:12 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0027] (2) Preparation of cementitious material: Take 70 parts of the above modified phosphogypsum, mix with 15 parts of fly ash and 15 parts of slag by weight, put them into a ball mill and grind them until the particle size is ≤100 μm to obtain cementitious material.

[0028] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 5 parts of pulp fiber, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0029] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 75 ℃ for 10 hours. Then it is cured at a high temperature and high pressure of 190 ℃ and 1 MPa for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0030] Example 3 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:15:8:3:15 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0031] (2) Preparation of cementitious material: Take 80 parts by weight of the above modified phosphogypsum and 20 parts by weight of lithium slag, mix them, and grind them in a ball mill until the particle size is ≤100 μm to obtain cementitious material.

[0032] (3) Preparation of mixture: By weight, take 50 parts of cementitious material, 5 parts of water, 6 parts of pulp fiber, 20 parts of quartz sand, 20 parts of fly ash, and 5 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0033] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 20 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 90 ℃ for 8 hours. Then it is cured at a high temperature and high pressure of 200 ℃ and 1 MPa for 8 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0034] Example 4 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:3:2:0.5:8 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0035] (2) Preparation of cementitious material: Take 70 parts of the above modified phosphogypsum, mix with 15 parts of fly ash and 15 parts of slag by weight, put them into a ball mill and grind them until the particle size is ≤100 μm to obtain cementitious material.

[0036] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 5 parts of pulp fiber, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0037] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 75 ℃ for 10 hours. Then it is cured at a high temperature and high pressure of 190 ℃ and 1 MPa for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0038] Example 5 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:20:10:4:20 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0039] (2) Preparation of cementitious material: Take 70 parts of the above modified phosphogypsum, mix with 15 parts of fly ash and 15 parts of slag by weight, put them into a ball mill and grind them until the particle size is ≤100 μm to obtain cementitious material.

[0040] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 5 parts of pulp fiber, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0041] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 75 ℃ for 10 hours. Then it is cured at a high temperature and high pressure of 190 ℃ and 1 MPa for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0042] Example 6 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:10:5:2:5 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0043] (2) Preparation of cementitious material: Take 70 parts of the above modified phosphogypsum, mix with 15 parts of fly ash and 15 parts of slag by weight, put them into a ball mill and grind them until the particle size is ≤100 μm to obtain cementitious material.

[0044] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 5 parts of pulp fiber, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0045] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 75 ℃ for 10 hours. Then it is cured at a high temperature and high pressure of 190 ℃ and 1 MPa for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0046] Example 7 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:10:5:2:20 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0047] (2) Preparation of cementitious material: Take 70 parts of the above modified phosphogypsum, mix with 15 parts of fly ash and 15 parts of slag by weight, put them into a ball mill and grind them until the particle size is ≤100 μm to obtain cementitious material.

[0048] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 5 parts of pulp fiber, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0049] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 75 ℃ for 10 hours. Then it is cured at a high temperature and high pressure of 190 ℃ and 1 MPa for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0050] Comparative Example 1 (1) Preparation of phosphogypsum: Microwave the phosphogypsum and dry it in a drying oven until constant weight before use.

[0051] (2) Preparation of cementitious material: Take 70 parts of the above-mentioned dried phosphogypsum, mix it with 15 parts of fly ash and 15 parts of slag by weight, and grind it in a ball mill until the particle size is ≤100 μm to obtain cementitious material.

[0052] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 5 parts of pulp fiber, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0053] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 75 ℃ for 10 hours. Then it is cured at a high temperature and high pressure of 190 ℃ and 1 MPa for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0054] Comparative Example 2 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:10:5:2:12 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0055] (2) Preparation of cementitious material: Take 70 parts by weight of the above modified phosphogypsum and mix it with 30 parts of cement, put it into a ball mill and grind it until the particle size is ≤100 μm to obtain cementitious material.

[0056] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 5 parts of pulp fiber, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0057] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 75 ℃ for 10 hours. Then it is cured at a high temperature and high pressure of 190 ℃ and 1 MPa for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0058] Comparative Example 3 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:10:5:2:12 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0059] (2) Preparation of cementitious material: Take 70 parts of the above modified phosphogypsum, mix with 15 parts of fly ash and 15 parts of slag by weight, put them into a ball mill and grind them until the particle size is ≤100 μm to obtain cementitious material.

[0060] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0061] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing chamber and cured at a low temperature of 75 ℃ for 10 hours. Then it is cured at a high temperature and high pressure of 190 ℃ and 1 MPa for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0062] Comparative Example 4 (1) Preparation of modified phosphogypsum: Phosphogypsum was microwaved, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and 5% tetramethylammonium hydroxide aqueous solution were mixed evenly in a mass ratio of 100:10:5:2:12 and dried in a drying oven to constant weight to obtain modified phosphogypsum.

[0063] (2) Preparation of cementitious material: Take 70 parts of the above modified phosphogypsum, mix with 15 parts of fly ash and 15 parts of slag by weight, put them into a ball mill and grind them until the particle size is ≤100 μm to obtain cementitious material.

[0064] (3) Preparation of mixture: By weight, take 45 parts of cementitious material, 3 parts of water, 5 parts of pulp fiber, 15 parts of quartz sand, 15 parts of fly ash, and 3 parts of diatomaceous earth. First, put the cementitious material, pulp fiber, quartz sand, fly ash, and diatomaceous earth into a mixer and dry mix for 30 minutes. Then add water and continue mixing for 20 minutes to obtain a uniform mixture.

[0065] (4) Molding and curing: The mixture is fed into the board extrusion molding equipment and extruded into a strip hollow board under a pressure of 15 MPa. The molded board is placed in a sealed curing room and cured at a low temperature of 75 ℃ for 10 hours. After cooling to room temperature, the sound insulation board of solid waste cement board sound barrier is obtained.

[0066] Comparative Example 5 (1) Preparation of foamed ceramic sound barrier mixed slurry: Take 60 parts of ceramic waste, 20 parts of fly ash, 10 parts of clay, 3 parts of silicon carbide, 5 parts of feldspar powder and 8 parts of water. Put the ceramic waste, fly ash, clay and feldspar powder into a ball mill and dry grind for 30 min until the particle size is ≤150 μm. Then add water and silicon carbide and continue wet grinding for 20 min to obtain a uniform slurry.

[0067] (2) Plate forming and sintering: The slurry is injected into the mold and allowed to settle naturally. After settling, it is dried in an oven at 60 ℃ for 12 hours to remove free moisture. The dried green body is placed in a tunnel kiln, heated to 1150~1200 ℃, and held for 2~3 hours for foaming and sintering. After cooling to room temperature, foamed ceramic sound barrier plates are obtained.

[0068] Performance testing of solid waste cement board sound barrier materials The sound barriers prepared in Examples 1-7 were subjected to performance testing. The test items included bending fracture load, compressive strength, areal density, internal bond strength, and noise reduction coefficient. The bending fracture load was determined according to GB / T 17657-2013 "Test Methods for Physical and Chemical Properties of Wood-based Panels and Decorative Wood-based Panels", the compressive strength was determined according to GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", and the noise reduction coefficient was determined according to TB / T 3122-2010 "Technical Requirements and Test Methods for Acoustic Components of Railway Sound Barriers". The results are shown in Table 1.

[0069] Table 1 shows the performance test results of the sound barriers prepared in Examples 1-7. As shown in Table 1, the performance test results indicate that, compared with relevant technical requirements in the industry, the sound barriers prepared in Examples 1-7 exhibit superior performance in all indicators, with Example 2 showing the best overall performance. Changes in the proportion of each component in the modified phosphogypsum significantly affect the performance of the board. The formulation employing a multi-component solid waste synergistic approach outperforms the binary system, as the synergistic effect between its components effectively enhances the activity of the phosphogypsum and the comprehensive performance of the cementing material. Furthermore, the internal bond strength and noise reduction coefficient show a positive correlation. It is important to note that there is an optimal range for the raw material ratio; too low a ratio will lead to insufficient board strength, while too high a ratio may increase density, thereby reducing acoustic performance. This demonstrates that, by precisely controlling the component ratio of the modified phosphogypsum and the multi-component solid waste compound system of the cementing material, this invention can significantly optimize the acoustic performance of the board while ensuring its lightweight and high strength, achieving a synergistic improvement in the high-value utilization of industrial solid waste and the overall performance of the sound barrier.

[0070] Based on Example 2, which has the best overall performance, the modified phosphogypsum components, cementitious material ratio, mixture composition and curing process were adjusted respectively, and corresponding comparative examples 1-4 were set up to examine the influence of each factor on product performance. In addition, a comparative example 5 was set up to prepare foamed ceramic sound barriers using traditional methods. The specific test results are shown in Table 2.

[0071] Table 2 shows the test results of various performance aspects of the sound barriers prepared in Comparative Examples 1-5. As shown in Table 2, in Comparative Example 1, no modification was made to the phosphogypsum, resulting in a significant decline in the performance of all aspects of the sound barrier. The mechanical properties and noise reduction effect of the board were significantly reduced, confirming the key role of alumina, attapulgite, and tetramethylammonium hydroxide in activating the phosphogypsum. These modifiers effectively improve the bonding performance and interfacial compatibility of the cementitious material. In Comparative Example 2, although the performance met the standards after replacing fly ash and slag with cement, it was comprehensively inferior to Example 2, and the areal density increased, highlighting the advantages of multi-component solid waste synergy in achieving lightweight and high-strength materials. In Comparative Example 3, due to the lack of pulp fiber, the bending fracture load and compressive strength of the board decreased significantly, verifying the enhancing effect of pulp fiber on material toughness. In Comparative Example 4, due to the omission of high-temperature and high-pressure curing, the material strength indicators were significantly insufficient, demonstrating the necessity of the two-step process of low-temperature pre-curing and high-temperature steam curing. This indicates that the components and process steps in the technical solution of this invention are not simply superimposed, but rather form a significant synergistic effect mechanism through specific modification treatment, compounding of multiple solid wastes, fiber reinforcement, and two-step curing. Only under this complete technical system can the mechanical properties and acoustic characteristics of solid waste cementitious materials be synergistically improved, thereby obtaining a sound barrier product with comprehensive performance superior to that of traditional processes.

[0072] Table 2 shows that Comparative Example 5 represents the existing mainstream foamed ceramic sound barrier. Its performance test data shows that although the internal bond strength reaches 1.15 MPa, the maximum bending fracture load is only 1.2 times its own weight. Due to the material's inherent brittleness and weak deformation resistance, its performance indicators can only meet the safety requirements for a 2m span highway sound barrier. Under 4m span installation conditions, it is prone to bending deformation or even fracture due to outdoor loads such as wind pressure and vibration. Furthermore, its noise reduction performance is at a low level, making it difficult to meet the noise reduction needs of large-span projects. In contrast, the solid waste cementitious board sound barrier prepared in Example 2 of this invention has a bending fracture load of 3.85 times its own weight and an internal bond strength of 1.3 MPa. Its core mechanical properties far exceed those of existing foamed ceramic materials, fully meeting the outdoor safety requirements for a 4m span. It also possesses superior lightweight characteristics and noise reduction performance, achieving a triple breakthrough in large-span adaptability, mechanical performance, and noise reduction effect.

[0073] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a solid waste cementitious panel acoustic barrier, characterized by, Includes the following steps: Step 1, Preparation of modified phosphogypsum: Phosphogypsum is microwave-treated, and the treated phosphogypsum, alumina, attapulgite, sodium lignosulfonate and tetramethylammonium hydroxide aqueous solution are mixed and dried to obtain modified phosphogypsum. Step 2, Preparation of gelling material: Take the modified phosphogypsum obtained above and grind it with the auxiliary materials, mix them evenly, and obtain the gelling material; Step 3, prepare the mixture: Take the above-obtained cementitious material and put it into a mixer to dry mix with pulp fiber, quartz sand, fly ash and diatomaceous earth, then add water and continue mixing to obtain a uniform mixture; Step 4, Sound Barrier Molding and Curing: The above-obtained mixture is pressurized and extruded to make it dense and molded. The molded board is placed in a sealed curing room, first cured at low temperature, then cured with high temperature and high pressure steam. After cooling to room temperature, the sound insulation board of the solid waste cement board sound barrier is obtained.

2. The method for preparing a solid waste cementitious panel sound barrier according to claim 1, characterized in that, In step 1, the mass ratio of the phosphogypsum, alumina, attapulgite, sodium lignosulfonate, and tetramethylammonium hydroxide aqueous solution is 100:6~15:3~8:1~3:10~15.

3. The method for preparing a solid waste cementitious panel sound barrier according to claim 2, characterized in that, In step 1, the mass concentration of the tetramethylammonium hydroxide aqueous solution is 3-8%.

4. A method for preparing a solid waste cemented board sound barrier according to any one of claims 1-3, characterized in that, In step 2, the modified phosphogypsum is 60-80 parts and the excipients are 20-40 parts.

5. The method for preparing a solid waste cemented board sound barrier according to claim 4, characterized in that, In step 2, the auxiliary material is one or more of steel slag powder, fly ash, lithium slag, and mineral slag.

6. A method for preparing a solid waste cemented board sound barrier according to any one of claims 1-3, characterized in that, In step 3, the cementitious material consists of 40-50 parts, pulp fiber consists of 4-6 parts, quartz sand consists of 10-20 parts, fly ash consists of 10-20 parts, diatomaceous earth consists of 2-5 parts, and water consists of 2-5 parts.

7. A method for preparing a solid waste cemented board sound barrier according to any one of claims 1-3, characterized in that, In step 4, the pressurization pressure is 10~20 MPa.

8. The method for preparing a solid waste cemented board sound barrier according to claim 7, characterized in that, In step 4, the low-temperature curing temperature is 60~90 ℃, and the curing time is 8~12 hours.

9. The method for preparing a solid waste cemented board sound barrier according to claim 8, characterized in that, In step 4, the high-temperature and high-pressure steam curing temperature is 180~200 ℃, the pressure is 1~2 MPa, and the time is 8~12 hours.

10. A solid waste cemented board sound barrier, characterized in that, Prepared using the method described in any one of claims 1-9.

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