A 3D-printed photovoltaic sound barrier based on recycled solid waste materials and its preparation method

Abstract

This invention discloses a 3D-printed photovoltaic sound barrier based on recycled solid waste materials, and also discloses a method for preparing the 3D-printed photovoltaic sound barrier based on recycled solid waste materials. The sound barrier adopts a multi-layer composite structure, and the overall structure is constructed with multiple serrated teeth from top to bottom through 3D printing. It is then combined with a photovoltaic panel to form a 3D-printed photovoltaic sound barrier. The sound barrier of this invention has the advantages of high strength, efficient sound absorption and insulation, and multi-angle light reception. The serrated slope has a better noise reduction effect than a vertical plane. The serrated shape can act as ribs, enhancing the overall rigidity and buckling resistance of the barrier. This invention improves the utilization rate of solid waste by optimizing the proportion of solid waste materials. This invention also optimizes the tilt angle of the serrated slope where the photovoltaic panel is located through acoustic simulation, structural simulation, 3D printing feasibility test, and calculation of the total solar radiation on the serrated slope, thus combining environmental protection, functionality, and economy.

Description

Technical Field

[0001] This invention belongs to the field of building materials and construction technology, specifically relating to a 3D-printed photovoltaic sound barrier based on recycled solid waste materials, and also to a method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials. Background Technology

[0002] With the acceleration of urbanization, the amount of solid waste (such as construction waste, industrial slag, and tailings powder) generated in traffic arteries and industrial areas is increasing year by year. Traditional landfill or dumping methods not only occupy land resources but may also cause secondary pollution. At the same time, as a core facility for controlling traffic noise, sound barriers need to be exposed to the outdoor environment for a long time, requiring high standards for the weather resistance, structural strength, and sound absorption performance of the materials. Sound barriers are mostly made of precast concrete blocks, metal plates, or polymer composite materials, which have problems such as reliance on natural resources for raw materials, high energy consumption in production, and high transportation and installation costs.

[0003] Currently, the main defects of non-metallic sound barriers include surface honeycombing, concrete cracks, missing corners and chips, exposed rebar, and overall panel detachment. 3D-printed sound barriers offer advantages such as variable shape and structure, and integrated molding. By controlling the parameters related to the printing technology path, the shape and angle of the barrier can be actively and scientifically designed. This allows for adaptation to terrain conditions and the placement of photovoltaic panels on inclined surfaces with better sunlight exposure. Whether on east-west or north-south oriented highways, different serrated inclined surfaces will always have one that better faces the sun, significantly extending the effective power generation time and thus improving photovoltaic power generation efficiency.

[0004] While existing technologies employ recycled solid waste materials for 3D printing, the utilization rate of these materials is low. Furthermore, current technologies fail to integrate 3D-printed sound barriers with photovoltaic technology and lack methods for optimizing the angle of the photovoltaic surface. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in the prior art by providing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials, and also to provide a method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials.

[0006] The above-mentioned objectives of the present invention are achieved by the following technical means: A method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials includes the following steps: Step 1: Prepare solid waste recycled composite concrete material as a 3D printing material; Step 2: Conduct acoustic simulation, structural simulation, and 3D printing feasibility test on the sawtooth parameter variable combination of the sound barrier screen unit in sequence. Determine the optimal sawtooth parameter variable combination and tilt angle range through acoustic simulation. Then construct the sound barrier screen unit with the optimal sawtooth parameter variable combination. Conduct structural simulation and 3D printing feasibility test on the tilt angle of the sound barrier screen unit in sequence. Finally, take the intersection of the tilt angle range of acoustic simulation, the tilt angle range of structural simulation, and the tilt angle range of 3D printing feasibility test as the final tilt angle range. The sound barrier screen unit is configured as a multi-serrated structure from top to bottom, and the tilt angle is the angle between the serrated inclined surface of the sound barrier screen unit and the horizontal plane. Step 3: Calculate the total solar radiation on the sawtooth slope at different tilt angles within the final tilt angle range, and select the tilt angle that maximizes the total solar radiation on the sawtooth slope within the final tilt angle range as the final printing angle. Step 4: Print the sound barrier screen unit using a 3D printing device at the final printing angle.

[0007] As described above, acoustic simulation specifically includes the following steps: First, set the sawtooth parameter variable combination, which includes the tilt angle of the sawtooth slope, the sawtooth thickness, and the sawtooth period; second, set the sound source and the receiving point on both sides of the sound barrier, and set the noise of the target frequency band at the sound source; finally, perform parameter scanning: calculate the insertion loss under different sawtooth parameter variable combinations, and select the optimal sawtooth parameter variable combination with the largest insertion loss. Set the sawtooth thickness and sawtooth period to the optimal sawtooth parameter variable combination, perform acoustic simulation again, and select the tilt angle range in which the insertion loss of the target frequency band is greater than the set insertion loss value as the tilt angle range of the acoustic simulation. Insertion loss is the difference in sound pressure level before and after the sound barrier is installed.

[0008] The structural simulation described above specifically includes the following steps: Step 2.2.1: Construct the geometric model of the sound barrier screen unit based on the optimal combination of sawtooth parameter variables from the acoustic simulation, and import it into the finite element simulation software; Step 2.2.2: Calculate the wind pressure according to the specifications of the project location, and calculate the wet weight and dry weight of the 3D printed concrete. Set the anisotropic mechanical properties of the 3D printed concrete, including horizontal compressive strength, vertical compressive strength, interlayer bond strength, flexural strength, and crack resistance. Step 2.2.3: Check whether the maximum stress that the 3D printed concrete can withstand under the ultimate wind load specified in the local code of the project site exceeds the tensile strength and compressive strength, and whether the deformation of the 3D printed concrete is within the allowable range. Step 2.2.3: If the maximum stress borne by the 3D printed concrete exceeds the tensile strength or compressive strength, or the deformation of the 3D printed concrete exceeds the allowable range, then increase the tilt angle; if the maximum stress borne by the 3D printed concrete does not exceed the tensile strength or compressive strength, and the deformation of the 3D printed concrete does not exceed the allowable range, then decrease the tilt angle. Select the tilt angle range that meets the requirements under the ultimate wind load as the tilt angle range for structural simulation.

[0009] As mentioned above, the 3D printing feasibility test specifically includes the following steps: Step 2.3.1, Material Rheological Properties Test: The yield stress and thixotropy of the 3D printed material are measured using a rheometer to obtain the range of cantilever angles that allow the yield stress to reach the set threshold. Step 2.3.2, Printing test: Use 3D printing materials and printer to conduct cantilever printing test, find the critical angle that will not collapse, then the tilt angle should be greater than the critical angle; Step 2.3.4: Take the intersection of the overhang angle range in Step 2.3.1 and the tilt angle range greater than the critical angle in Step 2.3.2 to perform path planning verification: In the slicing software, check whether the printing path for the serrated shape is continuous and smooth, whether there are abrupt starts and stops and changes in direction, and whether the extrusion is smooth, to obtain the tilt angle range for the 3D printing feasibility test.

[0010] As described above, the solid waste recycled composite concrete material comprises the following components in parts by weight: 40-60 parts recycled aggregate, 20-30 parts cementitious material, 5-10 parts lightweight sound-absorbing filler, and 1-3 parts auxiliary additives. The recycled aggregate comprises waste concrete fragments and construction waste brick particles, with the waste concrete fragments accounting for 65% of the weight percentage of the recycled aggregate and the construction waste brick particles accounting for 35% of the weight percentage of the recycled aggregate. The cementitious material comprises slag powder, fly ash, steel slag powder, and water, with the slag powder accounting for 55% of the weight percentage of the cementitious material, the fly ash accounting for 25% of the weight percentage of the cementitious material, and the steel slag powder accounting for 20% of the weight percentage of the cementitious material. The auxiliary additives comprise silicate cement, water-reducing agent, fiber-reinforcing material, shrinkage-reducing agent, and retarder, with the silicate cement accounting for 30% of the weight percentage of the auxiliary additives, the water-reducing agent accounting for 30% of the weight percentage of the auxiliary additives, the fiber-reinforcing material accounting for 20% of the weight percentage of the auxiliary additives, the shrinkage-reducing agent accounting for 10% of the weight percentage of the auxiliary additives, and the retarder accounting for 10% of the weight percentage of the auxiliary additives. The recycled aggregate is pre-wetted to achieve a moisture content of 3%-5%. The water-cement ratio of the gelling material is 0.32-0.35, and the gelling material and auxiliary additives are mixed and stirred to form a printing paste.

[0011] As mentioned above, the slag powder is selected from S95 grade slag powder of industrial solid waste, with a specific surface area ≥400m² / kg; the fly ash is Class II fly ash; the steel slag powder is magnetically separated to remove iron and has an activity index ≥70%. The silicate cement is ordinary silicate cement with a strength grade of 42.5; the water-reducing agent is a polycarboxylate high-efficiency water-reducing agent; the fiber reinforcement material is polypropylene short fiber; the shrinkage reducing agent is an organosilicon; the retarder is sodium gluconate; and the lightweight sound-absorbing filler is expanded perlite particles.

[0012] As described above, step 4 specifically includes the following steps: Step 4.1: Feed recycled aggregate with a particle size ≤4.75mm and printing slurry into the main material bin of the 3D printing equipment. Simultaneously, supply lightweight sound-absorbing filler into the auxiliary material bin and mix it with the main material bin through pneumatic conveying. Finally, use the stirring screw device of the 3D printing equipment to mix the recycled aggregate, printing slurry and lightweight sound-absorbing filler evenly to obtain 3D printing material. Step 4.2: Test the printing status of the 3D printing material: When the 3D printing material is printed continuously without interruption and is stably stacked without collapse or deformation, proceed to step 4.3 to start printing; Step 4.3: Input the printing path parameters into the 3D printing equipment, move the print head of the 3D printer to the origin, and then start printing. Print in a layer-by-layer manner according to the preset printing path. The temperature range is controlled at 80-100℃ by the electric heating sleeve, and the expansion is controlled at ≥200mm. During the printing process, the layer thickness deviation is monitored in real time by the laser rangefinder, and the deviation is controlled at ≤±1mm. If local collapse or segregation occurs, the printing will be automatically paused and repair slurry will be sprayed.

[0013] A 3D-printed photovoltaic sound barrier based on recycled solid waste materials includes a sound barrier screen unit. The sound barrier screen unit has a multi-serrated serrated structure from top to bottom. The sound barrier screen unit includes a load-bearing layer, a functional layer, and a decorative layer. The load-bearing layer is located on the side of the sound barrier screen unit closest to the traffic road, and the decorative layer is located on the side of the sound barrier screen unit away from the traffic road. The functional layer is located between the load-bearing layer and the decorative layer. A concrete foundation is also provided at the bottom of the sound barrier screen unit. The load-bearing layer and the decorative layer are both provided with mounting grooves for photovoltaic panels on their sun-facing surfaces; The load-bearing layer is internally reinforced with I-shaped or honeycomb-shaped ribs; The functional layer includes alternating solid areas and porous areas. The porous areas are provided with arrayed pyramidal holes, which are filled with lightweight sound-absorbing filler. The openings of the pyramidal holes face the traffic road side. The outer surface of the decorative layer is an uneven, slightly curved surface or a near-flat surface, and is textured.

[0014] As described above, the photovoltaic panel and the sawtooth slope are connected by a photovoltaic panel support frame. The initial angle of the photovoltaic panel is set to be parallel to the sawtooth slope, and the intersection of any two sawtooth slopes on the load-bearing layer and the decorative layer is arc-shaped.

[0015] The sound barrier consists of multiple sound barrier panels connected sequentially along the road traffic direction. The sound barrier panels are provided with mortise and tenon joints and pipeline channels, and adjacent sound barrier panels are connected by mortise and tenon joints. The sound barrier also includes multiple H-shaped steel columns spaced at equal intervals along the traffic road. The H-shaped steel columns are fixed to the concrete strip base poured on the ground by anchor bolts. The sound barrier screen units are directly hoisted into the slots between the H-shaped steel columns, and adjacent sound barrier screen units are connected by mortise and tenon joints. The mortise and tenon joints are then fixed by bolts. The gaps between the sound barrier screen units are filled with elastic sealant.

[0016] Compared with the prior art, the present invention has the following advantages: (1) Environmental protection: This invention optimizes the proportion of solid waste recycled materials (such as waste concrete, industrial solid waste such as steel slag, fly ash, slag powder and other solid waste materials) to achieve a solid waste utilization rate of ≥70% (of which construction waste accounts for more than 50%), thereby reducing the mining of natural sand and gravel and the disposal of solid waste in landfills.

[0017] (2) Functionality: The sound barrier of the present invention has the advantages of high strength structural load-bearing, high efficiency sound absorption and insulation (comprehensive noise reduction coefficient NRC≥0.7) and weather resistance (design life≥20 years) and multi-angle light reception. The interior of the sound barrier is a high efficiency sound absorption cavity. Its tortuous surface can better scatter and absorb sound waves, and has a better noise reduction effect than a vertical plane. The sawtooth shape can act as a rib, enhancing the overall rigidity and buckling resistance of the screen. The cement structure is no longer passively receiving photovoltaic panels, but actively creating the best conditions for photovoltaic power generation.

[0018] (3) Economic efficiency: The cost of raw materials is reduced, and the installation angle of distributed photovoltaics is determined by 3D printing technology, eliminating the need for on-site angle adjustment and improving on-site installation efficiency by 50%.

[0019] (4) High efficiency: It supports personalized design and terrain adaptation, solves the core pain point of low power generation efficiency of vertical installation, and promotes the development of sound barriers from functional components to landscape functional integration.

[0020] (5) Convenient maintenance: If the photovoltaic panel has problems such as low efficiency conversion rate or damage, it can be replaced in time without angle adjustment. The installation skills of workers are low and maintenance is simple. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a side view of the sound barrier screen unit of the present invention; Figure 3 This is a schematic diagram of the connection between the photovoltaic panel and the sawtooth bevel of the present invention; Figure 4 This is a front view of the sound barrier screen unit of the present invention; Figure 5 This is a structural schematic diagram of the H-shaped steel column of the present invention; Figure labels and corresponding component names: 1-Sound barrier screen unit; 2-Photovoltaic panel; 3-Tilting angle; 4-Sawtooth bevel; 5-Functional layer; 6-Load-bearing layer; 7-Photovoltaic panel support frame; 8-Decorative layer; 9-H-shaped steel column; 10-Concrete foundation; 11-Installation groove. Detailed Implementation

[0022] To facilitate understanding and implementation of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to embodiments. The embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1:

[0023] like Figure 1 As shown, a method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials is presented. This embodiment takes a 3D-printed sound barrier along a highway as an example and includes the following steps: Step 1: 3D printing material formulation. Solid waste recycled materials are used to prepare solid waste recycled-based composite concrete materials that meet the load-bearing requirements of the sound barrier structure as 3D printing materials. The solid waste recycled-based composite concrete materials include the following components by weight: 60 parts recycled aggregate, 30 parts cementitious materials, 8 parts lightweight sound-absorbing filler, and 2 parts auxiliary additives.

[0024] The recycled aggregate includes waste concrete fragments and construction waste brick particles with a particle size of 5-20 mm. The waste concrete fragments and construction waste brick particles are crushed, screened to remove impurities (such as wood chips and plastics), and washed and dried to ensure that the surface is clean and free of organic residue. The waste concrete fragments account for 65% of the weight percentage of the recycled aggregate, and the construction waste brick particles account for 35% of the weight percentage of the recycled aggregate.

[0025] The cementing material includes slag powder, fly ash, and steel slag powder. The slag powder is selected from S95 grade industrial solid waste, with a specific surface area ≥ 400 square meters per kilogram (m² / kg), accounting for 55% of the weight percentage of the cementing material. Grade II fly ash is selected, accounting for 25% of the weight percentage of the cementing material. The steel slag powder needs to be magnetically separated to remove iron, and has an activity index ≥ 70%, accounting for 20% of the weight percentage of the cementing material. The cementing material improves the matrix density by utilizing its pozzolanic activity and micro-aggregate effect.

[0026] The auxiliary additives include silicate cement, water-reducing agent, fiber reinforcement material, shrinkage reducer, and retarder. The silicate cement can be ordinary silicate cement with a strength grade of 42.5 (PO 42.5) as the base binder, accounting for 30% of the weight percentage of the auxiliary additives, and this proportion can be gradually reduced as the activity increases. The water-reducing agent can be a polycarboxylate superplasticizer, accounting for 30% of the weight percentage of the auxiliary additives, used to improve fluidity. The fiber reinforcement material can be 12mm long polypropylene short fibers, accounting for 20% of the weight percentage of the auxiliary additives, used to improve crack resistance. The shrinkage reducer can be an organosilicon, accounting for 10% of the weight percentage of the auxiliary additives, used to inhibit drying shrinkage cracking. The retarder can be sodium gluconate, accounting for 10% of the weight percentage of the auxiliary additives, used to extend the initial setting time to 4-6 hours, ensuring sufficient time for the next layer to be stacked after the single-layer printing is completed (interlayer bonding quality is controllable).

[0027] Lightweight sound-absorbing fillers can be made of expanded perlite particles with a particle size of 2-5mm.

[0028] This invention is based on a cement-slag-fly ash ternary cementitious system. By adjusting the ratio of recycled aggregate to cementitious materials, utilizing the micro-expansion characteristics of steel slag powder to compensate for shrinkage, and using polypropylene short fibers to disperse stress at the crack tips, a high-strength, low-shrinkage, and durable solid waste recycled composite concrete material is finally formed.

[0029] Solid waste recycled composite concrete material meets the following requirements: 28-day compressive strength ≥30 MPa, meets the load-bearing requirements of sound barrier structure, sound absorption coefficient (average in 250-4000Hz frequency band) ≥0.6, softening coefficient ≥0.85 and mass loss ≤5% during freeze-thaw cycles (-15℃~20℃, 25 times) with the assistance of internal porous structure design.

[0030] Recycled aggregate and printing paste together constitute solid waste-based composite concrete. Recycled aggregate has a high water absorption rate (usually 1.5-2 times that of natural aggregate), so it needs to be pre-wetted to control the moisture content to 3%-5%. The printing paste consists of cementitious materials and auxiliary additives, and is used for extrusion molding from a nozzle. When adding water and mixing on site, an online humidity sensor is used for feedback. The water-cement ratio of the cementitious materials is 0.32-0.35.

[0031] Step 2: Perform acoustic simulation, structural simulation, and 3D printing feasibility test sequentially on the sawtooth parameter variable combination of the sound barrier screen unit 1. Determine the optimal sawtooth parameter variable combination and tilt angle range through acoustic simulation. Then construct the sound barrier screen unit 1 with the optimal sawtooth parameter variable combination. Perform structural simulation and 3D printing feasibility test sequentially on the tilt angle 3 of the sound barrier screen unit 1. Finally, take the intersection of the tilt angle ranges obtained from the acoustic simulation, structural simulation, and 3D printing feasibility test as the final tilt angle range. The specific steps include: The sound barrier screen unit 1 is configured with a multi-serrated serrated structure from top to bottom, and the tilt angle 3 is the angle between the serrated inclined surface 4 of the sound barrier screen unit 1 and the horizontal plane.

[0032] The sawtooth inclined plane 4 is essentially a cantilever structure. The smaller the angle between the sawtooth inclined plane 4 and the vertical direction, the larger the cantilever, and the greater the bending moment generated under gravity and wind load.

[0033] Step 2.1: Conduct acoustic simulation using the acoustic module of COMSOL Multiphysics (a multiphysics simulation software). The acoustic simulation includes the following steps: First, set the combination of sawtooth parameter variables, which includes tilt angle 3 (i.e., the angle between the inclined plane and the horizontal plane, in degrees (°)), sawtooth thickness (in millimeters (mm)), and sawtooth cycle (in units).

[0034] Secondly, sound sources and receiving points are set on both sides of the sound barrier, and noise of the target frequency band (such as 125Hz~4000Hz where traffic noise is significant) is set at the sound source.

[0035] Finally, a parameter scan is performed: the insertion loss (i.e., the sound pressure level difference before and after the sound barrier is installed) is calculated under different combinations of sawtooth parameter variables, and the optimal combination of sawtooth parameter variables with the largest insertion loss is selected.

[0036] Set the sawtooth thickness and sawtooth period as the optimal sawtooth parameter variable combination, and perform acoustic simulation again. Select the tilt angle range in which the insertion loss of the target frequency band is greater than the set insertion loss value as the tilt angle range of the acoustic simulation.

[0037] In this embodiment, the tilt angle 3, which meets the industry standard HJ / T90—2004 "Acoustic Design and Measurement Specifications for Sound Barriers", is 40°~60°.

[0038] Step 2.2: Use ANSYS Mechanical software (a finite element analysis software for structural mechanics and thermodynamics) to conduct structural simulation and verify the stability of the sound barrier. This includes the following steps: Step 2.2.1: Construct the geometric model of the sound barrier screen unit 1 based on the optimal combination of sawtooth parameter variables obtained from acoustic simulation, and import it into ANSYS Mechanical software.

[0039] Step 2.2.2: Calculate the wind pressure according to the specifications of the project location (such as (GB50009) "Code for Design of Building Structures"), and calculate the wet weight and dry weight of the 3D printed concrete; set the anisotropic mechanical properties of the 3D printed concrete, including horizontal compressive strength, vertical compressive strength, interlayer bond strength, flexural strength, and crack resistance. In this embodiment, the interlayer bond strength of the sound barrier screen unit 1 is lower than the strength of the main concrete.

[0040] Step 2.2.3: Check whether the maximum stress that the 3D printed concrete can withstand under the ultimate wind load specified in the local code of the project site exceeds the tensile strength and compressive strength, whether the deformation of the 3D printed concrete is within the allowable range, and whether there is a risk of local instability.

[0041] Step 2.2.4: If the maximum stress borne by the 3D printed concrete exceeds the tensile strength or compressive strength, or the deformation of the 3D printed concrete exceeds the allowable range, then increase the tilt angle 3; if the maximum stress borne by the 3D printed concrete does not exceed the tensile strength or compressive strength, and the deformation of the 3D printed concrete does not exceed the allowable range, then decrease the tilt angle 3. Select the tilt angle range that meets the requirements under the ultimate wind load as the tilt angle range for structural simulation.

[0042] In this embodiment, the acceptable tilt angle range under extreme wind load is 50°~90° (inclusive).

[0043] Step 2.3: Conduct 3D printing feasibility tests. These tests include material rheological property testing, printing experiments, and path planning verification. Specifically, they include the following steps: Step 2.3.1, Material Rheological Properties Test: The yield stress and thixotropy of the 3D printing material are measured by a rheometer. The higher the yield stress, the larger the cantilever angle that can be achieved. Finally, the range of cantilever angles that allow the yield stress to reach the set threshold is obtained.

[0044] Step 2.3.2, Printing Test: Conduct cantilever printing tests in the laboratory using 3D printing materials and a printer to find the critical angle that will not collapse and obtain the range of tilt angles greater than the critical angle.

[0045] Step 2.3.3: Take the intersection of the overhang angle range in Step 2.3.1 and the tilt angle range greater than the critical angle in Step 2.3.2 for path planning verification: In the slicing software, check whether the printing path for the serrated shape is continuous and smooth, whether there are abrupt starts and stops and changes in direction, and whether the extrusion is smooth. Obtain the tilt angle range that makes the printing path continuous and smooth, without abrupt starts and stops and changes in direction, and with smooth extrusion as the tilt angle range for the 3D printing feasibility test.

[0046] In this embodiment, the tilt angle range for the 3D printing feasibility test is 0~50° (inclusive).

[0047] The final tilt angle range is the intersection of the tilt angle ranges obtained from acoustic simulation, structural simulation, and 3D printing feasibility test. In this embodiment, the final tilt angle range is 40°~50° (inclusive of 40° and 50°).

[0048] Step 3: Calculate the total solar radiation on the sawtooth slope 4 at different tilt angles 3 within the final tilt angle range, and select the tilt angle 3 that maximizes the total solar radiation on the sawtooth slope 4 within the final tilt angle range as the final printing angle. This includes the following steps: Step 3.1: Based on local sunshine conditions, calculate the optimal average annual light-receiving angle of the sawtooth slope 4 using the following formula to maximize power generation. The total solar radiation on the sawtooth slope 4 is the sum of the direct solar radiation, the diffuse solar radiation, and the ground-reflected radiation. The total radiation of the sawtooth slope 4 is calculated using the following formula: (1); in, This represents the total solar radiation on the sawtooth inclined plane 4. This represents the amount of direct solar radiation on the sawtooth inclined plane 4. This represents the amount of solar scattered radiation on the sawtooth inclined plane 4. This represents the amount of ground-reflected radiation on the sawtooth slope 4. For the inclination angle 3 of the sawtooth inclined plane 4 to be determined, the total radiation on the inclined plane is... The derivative is used to determine the inclination angle 3 of the sawtooth slope 4.

[0049] Direct solar radiation on sawtooth slope 4 Calculated based on the following formula: (2); In the formula, This represents the amount of direct solar radiation on a horizontal surface. It is the ratio of the direct radiation on the sawtooth inclined plane 4 to that on the horizontal plane.

[0050] Solar scattered radiation on sawtooth slope 4 Calculated based on the following formula: (3); In the formula, This represents the amount of scattered radiation on a horizontal surface. This represents the amount of solar radiation on a horizontal surface outside the atmosphere.

[0051] Ground reflected radiation on sawtooth slope 4 Calculated based on the following formula: (4); In the formula, The total radiation on the horizontal surface (i.e., the direct solar radiation on the horizontal surface) Scattered radiation on the horizontal plane sum), For ground reflectivity, in this embodiment, according to Table 1, it can be taken as 0.25~0.3 for dry gray ground.

[0052] The ratio of the direct radiation on the serrated inclined plane 4 to that on the horizontal plane Calculated based on the following formula: (5); In the formula, The latitude of the location. The declination angle of the sun. The sunset angle on the horizontal plane. The sunset angle is on the inclined plane.

[0053] Table 1 shows the reflectance under different ground conditions. Step 3.2: Determine the final printing angle and record it. The total solar radiation is greatest on the sawtooth inclined plane 4 at that time, then if Within the range of 40° to 50°, the final printing angle is... ;like Less than 40°, and in The maximum value (i.e., the maximum value) is reached when the total solar radiation on the sawtooth slope 4 in the range of 40° to 50° is obtained. Decreasing the angle will result in a final printing angle of 40°; if Total solar radiation on sawtooth slope 4 within the range of 40° to 50° (greater than 50°) If the angle is increased, the final printing angle will be 50°.

[0054] Step 4: Print the sound barrier screen unit 1 at the final printing angle using a 3D printing device. This includes the following steps: Step 4.1: In this embodiment, a gantry-type 3D composite printer with a rotating nozzle (such as the CIICHC1009 from Huachuang Intelligent Manufacturing) is used to feed recycled aggregate with a particle size ≤4.75mm and printing paste into the main material hopper of the 3D composite printer. The auxiliary material hopper simultaneously supplies lightweight sound-absorbing filler expanded perlite particles, which are mixed with the main material hopper through pneumatic conveying. Then, the stirring screw device of the 3D composite printer is started, and the forced stirring mode is used to stir for more than 90 seconds to ensure that the recycled aggregate, printing paste and lightweight sound-absorbing filler are stirred evenly to obtain 3D printing material.

[0055] Step 4.2: Test the printing status of the 3D printing material: When the 3D printing material is printed continuously without interruption and is stably stacked without collapse or deformation, proceed to step 4.3 to start printing.

[0056] Step 4.3: Input the printing path parameters into the 3D printing equipment, move the print head of the 3D printer to the origin, and then start printing. Print in a layer-by-layer stacking manner according to the preset printing path. The print head integrates an electric heating sleeve, which controls the temperature range of 80-100℃, while ensuring the fluidity of the 3D printing material and controlling the expansion ≥200mm. During the printing process, the layer thickness deviation is monitored in real time by a laser rangefinder, and the deviation is controlled to ≤±1mm. If local collapse or segregation occurs, the printing will automatically pause and spray repair slurry.

[0057] The position of the sound-absorbing cavity is automatically adjusted to an extrusion speed of 12 mm / s. The extrusion head diameter of the 3D printer is 30 mm, and the horizontal printing speed of the printing equipment is 40 mm / s.

[0058] Step 4.4: The sound barrier screen unit 1 consists of two parallel 3D printed strips with serrated bevels 4 stacked together to form a bevel. The sound barrier screen unit 1 constructs a cavity and an overall external structure through a set path. The distance between the two parallel 3D printed strips with serrated bevels 4 in the cavity is 120mm. The single-layer extrusion height d is 5-10mm, and the extrusion thickness c is 50mm. The nozzle spacing is 120mm to ensure that the bonding strength between adjacent layers is ≥1.5MPa. The height of the sound barrier is 2m, and the width is 1.2m. The height of the base and the top plate is 0.5m. The thickness of the sound barrier screen unit 1 is 250mm, and all sharp corners are rounded with R=20mm.

[0059] The sound barrier panel unit 1 takes about 10 days of indoor curing to form. Once the strength reaches more than 70% of the design value, it can be hoisted, transported, and installed on site. Example 2:

[0060] like Figure 2 As shown, a 3D-printed photovoltaic sound barrier based on recycled solid waste materials includes a sound barrier screen unit 1. The sound barrier screen unit 1 is configured with a multi-serrated serrated structure from top to bottom, including multiple alternately arranged serrated inclined surfaces 4. The angle between the serrated inclined surfaces 4 and the horizontal plane is 50°. A photovoltaic panel 2 is connected to the serrated inclined surfaces 4 through a photovoltaic panel support frame 7. The initial angle of the photovoltaic panel 2 is set to be parallel to the serrated inclined surfaces 4 (e.g., ...). Figure 3 As shown, the photovoltaic panel support frame 7 also supports manual adjustment of the angle of the photovoltaic panel 2.

[0061] The sound barrier unit 1 is a multi-layer composite structure, including a load-bearing layer 6, a functional layer 5, and a decorative layer 8. The load-bearing layer 6 is located on the side of the sound barrier unit 1 closest to the traffic road, and the decorative layer 8 is located on the side of the sound barrier unit 1 furthest from the traffic road. The functional layer 5 is located between the load-bearing layer 6 and the decorative layer 8. A concrete foundation 10 is also provided at the bottom of the sound barrier unit 1.

[0062] The serrated structure of the sound barrier causes the incident sound waves to diffuse away from the sensitive area when reflected on the curved surface (the reflected sound attenuation is ≥5dB).

[0063] The load-bearing layer 6 and the decorative layer 8 are provided with mounting grooves 11 for photovoltaic panels 2, so that the photovoltaic panels 2 can receive sunlight better.

[0064] Functional layer 5 includes alternating solid areas (60%) and porous areas (40%) to ensure sound insulation (≥25dB). The porous areas are equipped with arrayed pyramidal holes (5-15mm in diameter, with a porosity of 30%-40%). The pyramidal holes are filled with lightweight sound-absorbing filler to specifically absorb mid-to-high frequency noise (increasing the sound absorption coefficient in the 2000-4000Hz frequency band to above 0.8). The openings of the pyramidal holes face the traffic road side to ensure that they receive vehicle noise as promptly and to the maximum extent.

[0065] The junction of any two inclined surfaces on the load-bearing layer 6 and the decorative layer 8 (i.e. the corner of the sawtooth) is rounded with a radius of 20mm, which can effectively reduce stress concentration.

[0066] The outer surface of the decorative layer 8 is an uneven, slightly curved surface or a near-flat surface, and is textured (such as a stone-like texture or a planter texture) for acoustic scattering.

[0067] The total thickness of the sound barrier screen unit 1 is 250mm, and the thickness of the load-bearing layer 6 is 80-100mm.

[0068] The load-bearing layer 6 has embedded I-shaped or honeycomb-shaped reinforcing ribs.

[0069] The sound barrier consists of multiple sound barrier screen units 1. Each sound barrier screen unit 1 is standardized to be 1.2m (width) × 2m (height) × 0.25m (thickness). The sound barrier screen units 1 are provided with mortise and tenon interfaces (concave and convex grooves are directly formed during printing) and pipeline channels (used to connect sound-absorbing material backing or sensors).

[0070] like Figure 4 and Figure 5 As shown, the sound barrier also includes multiple H-shaped steel columns 9 spaced evenly along the traffic road direction. The H-shaped steel columns 9 are fixed to the concrete foundation 10 by chemical anchors. The sound barrier screen unit 1 can be directly hoisted into the slots between the H-shaped steel columns 9 by a forklift or crane. Adjacent sound barrier screen units 1 are connected by mortise and tenon joints, and the mortise and tenon joints are then fixed by bolts. The gaps between the sound barrier screen units 1 are filled with elastic sealant, which can provide waterproofing and shock absorption.

[0071] It should be noted that the embodiments described in this invention are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains can make various modifications or additions to the described embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials, characterized in that, Includes the following steps: Step 1: Prepare solid waste recycled composite concrete material as a 3D printing material; Step 2: Perform acoustic simulation, structural simulation, and 3D printing feasibility test on the sawtooth parameter variable combination of the sound barrier screen unit (1) in sequence. Determine the optimal sawtooth parameter variable combination and tilt angle range through acoustic simulation. Then construct the sound barrier screen unit (1) with the optimal sawtooth parameter variable combination. Perform structural simulation and 3D printing feasibility test on the tilt angle (3) of the sound barrier screen unit (1) in sequence. Finally, take the intersection of the tilt angle range of acoustic simulation, the tilt angle range of structural simulation, and the tilt angle range of 3D printing feasibility test as the final tilt angle range. The sound barrier screen unit (1) is configured as a sawtooth structure with multiple serrations from top to bottom, and the tilt angle (3) is the angle between the sawtooth inclined surface (4) of the sound barrier screen unit (1) and the horizontal plane. Step 3: Calculate the total solar radiation on the sawtooth slope (4) at different tilt angles (3) within the final tilt angle range, and select the tilt angle (3) that maximizes the total solar radiation on the sawtooth slope (4) within the final tilt angle range as the final printing angle; Step 4: Print the sound barrier screen unit (1) using a 3D printing device at the final printing angle.

2. The method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials according to claim 1, characterized in that, The acoustic simulation is specifically Includes the following steps: First, set the sawtooth parameter variable combination, which includes the tilt angle (3) of the sawtooth inclined surface (4), the sawtooth thickness, and the sawtooth period; second, set the sound source and the receiving point on both sides of the sound barrier respectively, and set the noise of the target frequency band at the sound source; finally, perform parameter scanning: calculate the insertion loss under different sawtooth parameter variable combinations, and select the optimal sawtooth parameter variable combination with the largest insertion loss. Set the sawtooth thickness and sawtooth period to the optimal sawtooth parameter variable combination, perform acoustic simulation again, and select the tilt angle range in which the insertion loss of the target frequency band is greater than the set insertion loss value as the tilt angle range of the acoustic simulation. Insertion loss is the difference in sound pressure level before and after the sound barrier is installed.

3. The method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials according to claim 2, characterized in that, The structural simulation specifically includes the following steps: Step 2.2.1: Construct the geometric model of the sound barrier screen unit (1) based on the optimal combination of sawtooth parameters from the acoustic simulation, and import it into the finite element simulation software; Step 2.2.2: Calculate the wind pressure according to the specifications of the project location, and calculate the wet weight and dry weight of the 3D printed concrete. Set the anisotropic mechanical properties of the 3D printed concrete, including horizontal compressive strength, vertical compressive strength, interlayer bond strength, flexural strength, and crack resistance. Step 2.2.3: Check whether the maximum stress that the 3D printed concrete can withstand under the ultimate wind load specified in the local code of the project site exceeds the tensile strength and compressive strength, and whether the deformation of the 3D printed concrete is within the allowable range. Step 2.2.3: If the maximum stress borne by the 3D printed concrete exceeds the tensile strength or compressive strength, or the deformation of the 3D printed concrete exceeds the allowable range, then increase the tilt angle (3); if the maximum stress borne by the 3D printed concrete does not exceed the tensile strength or compressive strength, and the deformation of the 3D printed concrete does not exceed the allowable range, then decrease the tilt angle (3), and select the tilt angle range that meets the requirements under the ultimate wind load as the tilt angle range for structural simulation.

4. The method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials according to claim 3, characterized in that, The 3D printing feasibility test specifically includes the following steps: Step 2.3.1, Material Rheological Properties Test: The yield stress and thixotropy of the 3D printed material are measured using a rheometer to obtain the range of cantilever angles that allow the yield stress to reach the set threshold. Step 2.3.2, Printing test: Use 3D printing materials and printer to conduct cantilever printing test, find the critical angle that does not collapse, then the tilt angle (3) should be greater than the critical angle; Step 2.3.4: Take the intersection of the overhang angle range in Step 2.3.1 and the tilt angle range greater than the critical angle in Step 2.3.2 to perform path planning verification: In the slicing software, check whether the printing path for the serrated shape is continuous and smooth, whether there are abrupt starts and stops and changes in direction, and whether the extrusion is smooth, to obtain the tilt angle range for the 3D printing feasibility test.

5. The method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials according to claim 1, characterized in that, The solid waste recycled composite concrete material comprises the following components in parts by weight: 40-60 parts recycled aggregate, 20-30 parts cementitious material, 5-10 parts lightweight sound-absorbing filler, and 1-3 parts auxiliary additives. The recycled aggregate includes waste concrete fragments and construction waste brick particles, wherein the waste concrete fragments account for 65% of the weight percentage of the recycled aggregate, and the construction waste brick particles account for 35% of the weight percentage of the recycled aggregate. The cementing material includes slag powder, fly ash, and steel slag powder, wherein the slag powder accounts for 55% of the weight percentage of the cementing material, the fly ash accounts for 25% of the weight percentage of the cementing material, and the steel slag powder accounts for 20% of the weight percentage of the cementing material. The auxiliary additives include silicate cement, water-reducing agent, fiber-reinforcing material, shrinkage-reducing agent, and retarder. The silicate cement accounts for 30% of the weight percentage of the auxiliary additives, the water-reducing agent accounts for 30% of the weight percentage of the auxiliary additives, the fiber-reinforcing material accounts for 20% of the weight percentage of the auxiliary additives, the shrinkage-reducing agent accounts for 10% of the weight percentage of the auxiliary additives, and the retarder accounts for 10% of the weight percentage of the auxiliary additives. The recycled aggregate is pre-wetted to achieve a moisture content of 3%-5%. The water-cement ratio of the gelling material is 0.32-0.35, and the gelling material and auxiliary additives are mixed and stirred to form a printing paste.

6. The method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials according to claim 5, characterized in that, The slag powder is selected from S95 grade slag powder of industrial solid waste, with a specific surface area ≥400m² / kg; the fly ash is Class II fly ash; the steel slag powder is magnetically separated to remove iron and has an activity index ≥70%. The silicate cement is ordinary silicate cement with a strength grade of 42.5; the water-reducing agent is a polycarboxylate high-efficiency water-reducing agent; the fiber reinforcement material is polypropylene short fiber; the shrinkage reducing agent is an organosilicon; the retarder is sodium gluconate; and the lightweight sound-absorbing filler is expanded perlite particles.

7. The method for preparing a 3D-printed photovoltaic sound barrier based on recycled solid waste materials according to claim 6, characterized in that, Step 4 specifically includes the following steps: Step 4.1: Feed recycled aggregate with a particle size ≤4.75mm and printing slurry into the main material bin of the 3D printing equipment. Simultaneously, supply lightweight sound-absorbing filler into the auxiliary material bin and mix it with the main material bin through pneumatic conveying. Finally, use the stirring screw device of the 3D printing equipment to mix the recycled aggregate, printing slurry and lightweight sound-absorbing filler evenly to obtain 3D printing material. Step 4.2: Test the printing status of the 3D printing material: When the 3D printing material is printed continuously without interruption and is stably stacked without collapse or deformation, proceed to step 4.3 to start printing; Step 4.3: Input the printing path parameters into the 3D printing equipment, move the print head of the 3D printer to the origin, and then start printing. Print in a layer-by-layer manner according to the preset printing path. The temperature range is controlled at 80-100℃ by the electric heating sleeve, and the expansion is controlled at ≥200mm. During the printing process, the layer thickness deviation is monitored in real time by the laser rangefinder, and the deviation is controlled at ≤±1mm. If local collapse or segregation occurs, the printing will be automatically paused and repair slurry will be sprayed.

8. A 3D-printed photovoltaic sound barrier based on recycled solid waste materials, comprising a sound barrier screen unit (1), characterized in that, The sound barrier screen unit (1) is configured with a multi-serrated serrated structure from top to bottom. The sound barrier screen unit (1) includes a load-bearing layer (6), a functional layer (5), and a decorative layer (8). The load-bearing layer (6) is located on the side of the sound barrier screen unit (1) closest to the traffic road, and the decorative layer (8) is located on the side of the sound barrier screen unit (1) away from the traffic road. The functional layer (5) is located between the load-bearing layer (6) and the decorative layer (8). A concrete foundation (10) is also provided at the bottom of the sound barrier screen unit (1). The load-bearing layer (6) and the decorative layer (8) are both provided with mounting grooves (11) for photovoltaic panels (2) on their sun-facing surfaces. The load-bearing layer (6) is internally reinforced with I-shaped or honeycomb-shaped ribs; The functional layer (5) includes alternating solid areas and porous areas. The porous areas are provided with arrayed pyramidal holes, which are filled with lightweight sound-absorbing filler. The openings of the pyramidal holes face the traffic road side. The outer surface of the decorative layer (8) is an uneven, slightly curved surface or a near-flat surface, and is textured.

9. A 3D-printed photovoltaic sound barrier based on recycled solid waste materials according to claim 8, characterized in that, The photovoltaic panel (2) is connected to the sawtooth inclined surface (4) through the photovoltaic panel support frame (7). The initial angle of the photovoltaic panel (2) is set to be parallel to the sawtooth inclined surface (4). The intersection of any two sawtooth inclined surfaces (4) on the load-bearing layer (6) and the decorative layer (8) is arc-shaped.

10. A 3D-printed photovoltaic sound barrier based on recycled solid waste materials according to claim 9, characterized in that, The sound barrier includes multiple sound barrier screen units (1) connected sequentially along the road traffic direction. Tenon and mortise interfaces and pipeline channels are provided between the sound barrier screen units (1), and adjacent sound barrier screen units (1) are connected by tenon and mortise interfaces. The sound barrier also includes multiple H-shaped steel columns (9) set along the direction of the traffic road and spaced at the same intervals. The H-shaped steel columns (9) are fixed to the concrete strip base poured on the ground by anchor bolts. The sound barrier screen unit (1) is directly hoisted into the slot between the H-shaped steel columns (9), and adjacent sound barrier screen units (1) are connected by tenon and mortise joints. The tenon and mortise joints are then fixed by bolts. The gaps between the sound barrier screen units (1) are filled with elastic sealant.

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