Construction waste recycling assembly type whole body planting component and preparation method thereof

Abstract

This invention provides a prefabricated, fully-vegetated component made from recycled construction waste and its preparation method. The component comprises 45%–55% slag, 30%–40% recycled aggregate from waste concrete, 3%–5% coconut fiber powder, 10%–15% wastewater from recycled sand and gravel from waste concrete, and 1% grass seeds by mass of the total materials. The wastewater is first collected, then pumped into a shear disperser containing coconut fiber powder for one hour of thorough dispersion. It is then introduced into a concrete mixer and mixed with the slag, aggregate, and grass seeds. The mixture is then vibrated and pressed into shape in a brick-making machine, the recycled blank is covered with a film, and the grass seeds germinate and grow on the surface of the blank, resulting in the finished fully-vegetated component. Except for the grass seeds, all other raw materials in this invention are construction waste and agricultural / forestry waste. The product is self-vegetating and can be assembled into concrete frames for slope protection or directly laid in green belts. It is easy to assemble and disassemble, reusable, simple, economical, and environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of construction waste recycling and vegetation material preparation technology. More specifically, it relates to a prefabricated, fully-vegetated component made from recycled construction waste and its preparation method. Background Technology

[0002] The amount of waste generated in the early stages of construction projects is enormous: First, the demolition of existing buildings or structures, foundation excavation, underground engineering tunneling, soft soil foundation excavation, or tunnel boring all generate large amounts of slag and excavated soil. Second, temporary supporting concrete retaining structures are often erected in the early stages of construction for underground transportation or tunnel construction. Before the permanent supporting retaining structures are built, these temporary supporting concrete retaining structures need to be cut and demolished, which also generates a large amount of waste concrete. Third, the wet recycling process for waste concrete discharges large amounts of wastewater and sludge. For slag and excavated soil, dumping and landfilling are the main disposal methods. Resource recovery methods include backfilling roadbeds and manufacturing sintered bricks and non-fired bricks, but these products all suffer from high costs, low economic added value, and low cost-effectiveness. The disposal of waste concrete from the cutting and demolition of temporary supporting concrete retaining structures mainly involves processing recycled coarse and fine aggregates, but this also has the problem of excessively affecting the workability, mechanical properties, and durability of fresh concrete or mortar. The wet process for recycling waste concrete produces sand and gravel with good particle shape and low mud / powder content. However, the wet process consumes a lot of water and generates a large amount of wastewater. The wastewater is mostly separated into solid and liquid components using sedimentation, flocculation, and filter press separation processes. The water is recycled, while the filter press sludge is transported to landfills. It is evident that the solid waste generated in the early stages of construction projects is diverse and often difficult to treat and dispose of.

[0003] In the later stages of construction, after the main project is completed, ancillary works increase, such as backfilling of excavated areas, culverts, and trenches, slope reinforcement and greening, and vegetation planting in public areas. This leads to a surge in demand for backfill materials and ecological vegetation materials. Slag and recycled sand and gravel from waste concrete can both be used as backfill materials, and theoretically, they can also be used as ecological vegetation materials. However: on the one hand, slag contains a high clay content, which can provide a suitable soil environment for plant growth, but its permeability and aeration are extremely poor after compaction, making plant growth difficult; on the other hand, recycled sand and gravel from waste concrete are still highly alkaline, preventing many plants from developing and growing normally. Furthermore, the wastewater from the production of recycled sand and gravel from waste concrete is essentially unusable. Currently, slope reinforcement and greening, as well as vegetation planting in public areas, often use methods such as direct backfilling with vegetation soil or sprayed cement soil. These methods have poor early-stage consolidation capacity and weak water and soil retention, making them highly susceptible to erosion by rainwater, causing landslides. In particular, if some areas are damaged or plants cannot grow, large-scale demolition and rework are necessary.

[0004] In view of this, it is necessary to design a prefabricated, fully-planted component made from recycled construction waste and its preparation method. Summary of the Invention

[0005] To address the shortcomings of existing technologies, one objective of this invention is to solve one or more problems existing in the prior art by providing a prefabricated, fully-vegetated component made from recycled construction waste and its preparation method. Firstly, it can utilize a large quantity of various construction wastes; secondly, the component is self-supporting and self-vegetating; and thirdly, it is assembleable, easy to install and dismantle. Furthermore, it provides a simple, economical, environmentally friendly, and convenient method for utilizing construction solid waste and preparing ecologically vegetated components.

[0006] To achieve the above objectives, one aspect of the present invention provides a prefabricated, fully vegetated component made from recycled construction waste, comprising: 45% to 55% slag, 30% to 40% recycled crushed stone from waste concrete, 3% to 5% coconut fiber powder, 10% to 15% wastewater from recycled sand and gravel from waste concrete, and 1% grass seeds by weight of the total materials.

[0007] Furthermore, in the aforementioned prefabricated fully-vegetated components made from recycled construction waste, the slag is waste soil generated during the foundation and tunnel excavation process, which is passed through a 5 mm sieve and then naturally dried to a natural moisture content of approximately 10%.

[0008] Furthermore, in the aforementioned prefabricated, fully-vegetated components made from recycled construction waste, the recycled crushed stone from waste concrete is crushed stone with a size of 10.0~31.5 mm obtained after crushing the temporary support concrete of the construction project.

[0009] Furthermore, in the above-mentioned prefabricated whole-body planted components made from recycled construction waste, the coconut shell fiber powder is a mixture of fiber and debris made from crushed coconut shells, with a fiber radial dimension ≤10cm and a debris size ≤2mm.

[0010] Furthermore, in the aforementioned prefabricated, fully-planted components made from recycled construction waste, the wastewater from the recycled sand and gravel produced from waste concrete is wastewater discharged during the wet process of producing recycled sand and gravel for temporary support concrete in construction projects, with a solid content of approximately 3%.

[0011] Furthermore, in the aforementioned prefabricated, fully-vegetated components made from recycled construction waste, the grass species are conventional landscaping grass species.

[0012] Another aspect of the present invention provides a method for preparing prefabricated, fully vegetated components made from recycled construction waste, comprising the following steps: S1 collecting and filtering wastewater from recycled sand and gravel from waste concrete; S2 pumping the filtered wastewater from step S1 into a shear disperser containing coconut shell fiber powder and dispersing it thoroughly for 1 hour; S3 dry mixing slag, recycled crushed stone from waste concrete, and grass seeds in a concrete mixer for 10 minutes; S4 introducing the wastewater containing dispersed coconut shell fiber powder obtained in step S2 into the concrete mixer of step S3 and continuing to mix evenly to obtain a mixture; S5 spreading the mixture in a mold and vibrating and pressing it in a brick-making machine to obtain a green blank of a component with a set size and specifications; S6 covering the green blank with a film and storing it for 7 days; S7 removing the curing film and continuing to store it until the grass seeds germinate and grow on the surface of the green blank, thus obtaining the finished product of the recycled prefabricated, fully vegetated components.

[0013] Furthermore, after the regenerated prefabricated whole-body planted components are stacked and cured for 7 days, the compressive strength is ≥0.8 MPa.

[0014] The beneficial effects of this invention are as follows:

[0015] (1) Construction waste soil serves as a binder, binding coconut fiber powder, waste retarded concrete, and recycled crushed stone into a whole; it also acts as a growth substrate and nutrient source for grass seeds. At the same time, the active SiO2 and Al2O3 in the waste soil can undergo hydration reactions with the unhydrated cement and hydration product Ca(OH)2 in the waste concrete recycled crushed stone and recycled sand and gravel production wastewater. On the one hand, this provides cementing capacity, and on the other hand, it reduces the alkalinity of the system, making the system more suitable for plant growth.

[0016] (2) Waste concrete recycled crushed stone can serve as a supporting framework and provide large pile gaps. Slag, coconut fiber powder and grass seeds are dispersed in the pile gaps of recycled crushed stone. Grass seeds develop and germinate in slag and coconut fiber powder, and then grow along the pile gap channels. Its root system develops and grows in the pile gaps, which will not affect the integrity of the component. In the later stage, it will be able to fix slag and coconut fiber powder and maintain the long-term shape stability of the recycled prefabricated plant component.

[0017] (3) The compacted soil has good compaction properties, but its dense structure has poor water and gas permeability. Grass seeds that are directly fixed in the soil cannot fully absorb water and air, thus they cannot grow. However, this invention introduces coconut shell fiber powder, which is relatively loose when mixed with the soil. Therefore, it can improve the water permeability and air permeability of the solidified soil. In addition, coconut shell fiber powder also has a good water and fertilizer retention effect, which is conducive to the long-term stable growth of vegetation.

[0018] (4) The wastewater from the recycled sand and gravel produced by waste concrete of this invention has a solid content of about 3%, mainly containing unhydrated cement particles and cement hydration products, and is alkaline. Coconut shell fiber powder is pre-mixed with the wastewater and sheared and dispersed. In an alkaline environment, the cellulose and sugars in the coconut shell fiber powder dissolve, while Ca ions enter the coconut shell structure through ion exchange. On the one hand, the surface modification of the coconut shell fiber powder is achieved, making it easier to disperse; secondly, the long-term stability of the coconut shell fiber powder is improved; finally, the leached cellulose and sugars can also act as soil binders.

[0019] (5) Coconut shell fiber powder has good water absorption and retention properties, and it can improve soil permeability. When mixed with slag soil, it achieves mutual modification and alteration, making the mixture similar to vegetated soil.

[0020] (6) The raw materials for the recycled prefabricated whole-body vegetation components are all construction waste and agricultural and forestry solid waste, which fully reflects the characteristics of ecological and environmental protection. In particular, the vegetation components are self-supporting and self-growing, can be assembled, and are easy to install and dismantle. The vegetation components are only finished after the grass seeds germinate and grow on the surface, which also avoids the problem of poor vegetation effect and large-scale dismantling required by traditional vegetation methods. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention. Example 1

[0022] A prefabricated, fully vegetated component made from recycled construction waste comprises, by weight percentage: 45% slag, 35% recycled crushed stone from waste concrete, 5% coconut fiber powder, 15% recycled sand and gravel wastewater from waste concrete, and 1% grass seeds by weight of the above materials.

[0023] The preparation method of prefabricated, fully-planted components made from recycled construction waste is as follows:

[0024] Wastewater collection and filtration from recycled sand and gravel made from waste concrete;

[0025] The filtered wastewater is pumped into a shear disperser containing coconut shell fiber powder and dispersed for 1 hour.

[0026] Slag, recycled gravel from waste concrete, and grass seeds are dry-mixed in a concrete mixer for 10 minutes.

[0027] Wastewater containing dispersed coconut shell fiber powder is introduced into a concrete mixer and mixed with slag, recycled crushed stone from waste concrete, and grass seeds. The mixture is then stirred until homogeneous to obtain a final mixture.

[0028] The mixture is spread in a mold and vibrated and pressed in a brick-making machine to form green blanks of a set size and specification;

[0029] The green blanks are covered with film and stacked for curing for 7 days;

[0030] After removing the growing film, continue to pile the grass until the grass seeds germinate and grow on the surface of the raw material, thus obtaining the finished product of the regenerated assembled whole planted component.

[0031] After being stacked and cured for 7 days, the compressive strength of the recycled prefabricated whole-body planted components is 0.88 MPa. Example 2

[0032] A prefabricated, fully vegetated component made from recycled construction waste comprises, by weight percentage: 45% slag, 40% recycled crushed stone from waste concrete, 3% coconut fiber powder, 12% recycled sand and gravel wastewater from waste concrete, and 1% grass seeds by weight of the above materials.

[0033] The preparation method of prefabricated, fully-planted components made from recycled construction waste is as follows:

[0034] Wastewater collection and filtration from recycled sand and gravel made from waste concrete;

[0035] The filtered wastewater is pumped into a shear disperser containing coconut shell fiber powder and dispersed for 1 hour.

[0036] Slag, recycled gravel from waste concrete, and grass seeds are dry-mixed in a concrete mixer for 10 minutes.

[0037] Wastewater containing dispersed coconut shell fiber powder is introduced into a concrete mixer and mixed with slag, recycled crushed stone from waste concrete, and grass seeds. The mixture is then stirred until homogeneous to obtain a final mixture.

[0038] The mixture is spread in a mold and vibrated and pressed in a brick-making machine to form green blanks of a set size and specification;

[0039] The green blanks are covered with film and stacked for curing for 7 days;

[0040] After removing the growing film, continue to pile the grass until the grass seeds germinate and grow on the surface of the raw material, thus obtaining the finished product of the regenerated assembled whole planted component.

[0041] After 7 days of curing, the compressive strength of the recycled prefabricated whole-body planted components is 0.93 MPa. Example 3

[0042] A prefabricated, fully vegetated component made from recycled construction waste comprises, by weight percentage: 50% slag, 35% recycled crushed stone from waste concrete, 3% coconut fiber powder, 12% recycled sand and gravel wastewater from waste concrete, and 1% grass seeds by weight of the above materials.

[0043] The preparation method of prefabricated, fully-planted components made from recycled construction waste is as follows:

[0044] Wastewater collection and filtration from recycled sand and gravel made from waste concrete;

[0045] The filtered wastewater is pumped into a shear disperser containing coconut shell fiber powder and dispersed for 1 hour.

[0046] Slag, recycled gravel from waste concrete, and grass seeds are dry-mixed in a concrete mixer for 10 minutes.

[0047] Wastewater containing dispersed coconut shell fiber powder is introduced into a concrete mixer and mixed with slag, recycled crushed stone from waste concrete, and grass seeds. The mixture is then stirred until homogeneous to obtain a final mixture.

[0048] The mixture is spread in a mold and vibrated and pressed in a brick-making machine to form green blanks of a set size and specification;

[0049] The green blanks are covered with film and stacked for curing for 7 days;

[0050] After removing the growing film, continue to pile the grass until the grass seeds germinate and grow on the surface of the raw material, thus obtaining the finished product of the regenerated assembled whole planted component.

[0051] After 7 days of curing, the compressive strength of the recycled prefabricated whole-body planted components is 0.98 MPa. Example 4

[0052] A prefabricated, fully vegetated component made from recycled construction waste comprises, by weight percentage: 50% slag, 30% recycled crushed stone from waste concrete, 5% coconut fiber powder, 15% recycled sand and gravel wastewater from waste concrete, and 1% grass seeds by weight of the above materials.

[0053] The preparation method of prefabricated, fully-planted components made from recycled construction waste is as follows:

[0054] Wastewater collection and filtration from recycled sand and gravel made from waste concrete;

[0055] The filtered wastewater is pumped into a shear disperser containing coconut shell fiber powder and dispersed for 1 hour.

[0056] Slag, recycled gravel from waste concrete, and grass seeds are dry-mixed in a concrete mixer for 10 minutes.

[0057] Wastewater containing dispersed coconut shell fiber powder is introduced into a concrete mixer and mixed with slag, recycled crushed stone from waste concrete, and grass seeds. The mixture is then stirred until homogeneous to obtain a final mixture.

[0058] The mixture is spread in a mold and vibrated and pressed in a brick-making machine to form green blanks of a set size and specification;

[0059] The green blanks are covered with film and stacked for curing for 7 days;

[0060] After removing the growing film, continue to pile the grass until the grass seeds germinate and grow on the surface of the raw material, thus obtaining the finished product of the regenerated assembled whole planted component.

[0061] After being stacked and cured for 7 days, the compressive strength of the recycled prefabricated whole-body planted components is 0.85 MPa. Example 5

[0062] A prefabricated, fully vegetated component made from recycled construction waste comprises, by weight percentage: 50% slag, 35% recycled crushed stone from waste concrete, 4% coconut fiber powder, 11% recycled sand and gravel wastewater from waste concrete, and 1% grass seeds by weight of the above materials.

[0063] The preparation method of prefabricated, fully-planted components made from recycled construction waste is as follows:

[0064] Wastewater collection and filtration from recycled sand and gravel made from waste concrete;

[0065] The filtered wastewater is pumped into a shear disperser containing coconut shell fiber powder and dispersed for 1 hour.

[0066] Slag, recycled gravel from waste concrete, and grass seeds are dry-mixed in a concrete mixer for 10 minutes.

[0067] Wastewater containing dispersed coconut shell fiber powder is introduced into a concrete mixer and mixed with slag, recycled crushed stone from waste concrete, and grass seeds. The mixture is then stirred until homogeneous to obtain a final mixture.

[0068] The mixture is spread in a mold and vibrated and pressed in a brick-making machine to form green blanks of a set size and specification;

[0069] The green blanks are covered with film and stacked for curing for 7 days;

[0070] After removing the growing film, continue to pile the grass until the grass seeds germinate and grow on the surface of the raw material, thus obtaining the finished product of the regenerated assembled whole planted component.

[0071] After 7 days of curing, the compressive strength of the recycled prefabricated whole-body planted components is 1.13 MPa. Example 6

[0072] A prefabricated, fully vegetated component made from recycled construction waste comprises, by weight percentage: 55% slag, 30% recycled crushed stone from waste concrete, 5% coconut fiber powder, 10% recycled sand and gravel wastewater from waste concrete, and 1% grass seeds by weight of the above materials.

[0073] The preparation method of prefabricated, fully-planted components made from recycled construction waste is as follows:

[0074] Wastewater collection and filtration from recycled sand and gravel made from waste concrete;

[0075] The filtered wastewater is pumped into a shear disperser containing coconut shell fiber powder and dispersed for 1 hour.

[0076] Slag, recycled gravel from waste concrete, and grass seeds are dry-mixed in a concrete mixer for 10 minutes.

[0077] Wastewater containing dispersed coconut shell fiber powder is introduced into a concrete mixer and mixed with slag, recycled crushed stone from waste concrete, and grass seeds. The mixture is then stirred until homogeneous to obtain a final mixture.

[0078] The mixture is spread in a mold and vibrated and pressed in a brick-making machine to form green blanks of a set size and specification;

[0079] The green blanks are covered with film and stacked for curing for 7 days;

[0080] After removing the growing film, continue to pile the grass until the grass seeds germinate and grow on the surface of the raw material, thus obtaining the finished product of the regenerated assembled whole planted component.

[0081] After 7 days of curing, the compressive strength of the recycled prefabricated whole-body planted components is 1.02 MPa.

[0082] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for preparing a prefabricated, fully-planted component made from recycled construction waste, characterized in that, By mass percentage, the component comprises: 45% to 55% slag, 30% to 40% recycled crushed stone from waste concrete, 3% to 5% coconut fiber powder, 10% to 15% wastewater from recycled sand and gravel from waste concrete, and 1% grass seeds by mass of the above materials. The preparation method includes the following steps: S1 Wastewater collection and filtration from recycled sand and gravel made from waste concrete; Step S2: Pump the filtered wastewater from step S1 into a shear disperser containing coconut shell fiber powder and disperse it thoroughly for 1 hour. S3 slag, recycled gravel from waste concrete and grass seeds are dry-mixed in a concrete mixer for 10 minutes; S4. The wastewater containing coconut shell fiber powder obtained in step S2 is introduced into the concrete mixer in step S3 and stirred evenly to obtain a mixture. S5 mixture is spread in a mold and vibrated and pressed in a brick making machine to form green blanks of a set size and specification. S6 parts are coated and stacked for curing for 7 days; S7 Remove the growing film and continue to pile until the grass seeds germinate and grow on the surface of the raw material, thus obtaining the finished product of the regenerated assembled whole planted component; The excavated soil is waste soil generated during the foundation and tunnel excavation process. After being sieved through a 5 mm sieve, it is naturally dried to a natural moisture content of 10%. The recycled crushed stone from waste concrete is crushed stone with a size of 10.0~31.5mm obtained after crushing the temporary support concrete of the construction project; The coconut shell fiber powder is a mixture of fibers and debris produced by crushing and processing coconut shells, with a fiber radial dimension ≤10cm and a debris size ≤2mm; The wastewater from the production of recycled sand and gravel from waste concrete is the wastewater discharged during the wet process of producing recycled sand and gravel from temporary support concrete in construction projects, with a solid content of 3%. The grass species mentioned are conventional landscaping grass species; After the green parts are stacked and cured for 7 days, the compressive strength is ≥0.8 MPa; After the coconut shell fiber powder is pretreated with wastewater from recycled sand and gravel made from waste concrete, the cellulose on its surface dissolves and adsorbs Ca²⁺, forming modified fibers that improve the permeability and water retention of the slag.