Solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification and preparation method of solid waste-based 3D printing concrete material

Abstract

The invention discloses a solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification and a preparation method thereof.The solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification is prepared from a carbon dioxide mineralization material, a solid waste material and a 3D printing coarse aggregate ink material, the 3D printing coarse aggregate printing ink material comprises a 3D printing mortar printing ink material and printing ink materials with different particle sizes, the 3D printing mortar printing ink material is a mixture of the printing ink material, Portland cement, aggregate and water, and the printing ink material comprises the following components in percentage by weight: 6-7% of cement, 0.5-1.5% of fly ash and 0.5-1.5% of mineral powder. Compared with the prior art, the solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification and the preparation method thereof have the advantages that the advantages of a carbon dioxide mineralization technology, biochar modification and solid waste utilization are combined, and the purposes of greenness, low carbon and high performance of the material are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and specifically relates to a solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification and a preparation method thereof. Background Art

[0002] Existing 3D printing concrete materials are an emerging building material technology, but they still have some limitations and shortcomings in practical applications. First, traditional 3D printing concrete usually relies on printable materials such as cement gypsum, etc. The mixing uniformity of these materials is difficult to meet the requirements, which may cause pores or bubbles inside the structure, thus affecting the strength and durability of the final product. In addition, 3D printing technology is inefficient during the mixing process, and it often takes a long time to form a uniform concrete matrix, which poses a certain bottleneck for mass production scenarios.

[0003] Secondly, the application of 3D printing concrete in the existing technology faces some key problems in terms of environmental protection. First, the traditional 3D printing concrete process will generate a large amount of waste during the production process, which may cause pollution to the environment, especially the water and soil environment. In addition, the raw materials used in the traditional process are expensive and prone to waste during the production process, further increasing the demand for resources.

[0004] In addition, some traditional 3D printing concrete processes cause serious water pollution. During the concrete production process, if the operation is improper or there is a lack of effective sewage treatment measures, it may be directly discharged into the water, causing water quality degradation or even pollution accidents. This environmental risk limits the application of traditional processes in the field of environmental protection.

[0005] Therefore, in response to the above technical problems, it is necessary to provide a solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification and a preparation method thereof. Summary of the invention

[0006] The purpose of the present invention is to provide a solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification and a preparation method thereof, which can solve the problems raised in the above-mentioned background technology.

[0007] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0008] Solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification and preparation method thereof, the 3D printing concrete material includes carbon dioxide mineralization material, solid waste material and 3D printing coarse aggregate ink material, the 3D printing coarse aggregate ink material includes 3D printing mortar ink material and ink materials of different particle sizes.

[0009] In one or more embodiments of the present invention, the 3D printing mortar ink material is a mixture of ink material, silicate cement, aggregate and water.

[0010] In one or more embodiments of the present invention, the ink material includes the following components in weight percentage: 6% to 7% cement, 0.5% to 1.5% fly ash, 0.5% to 1.5% mineral powder, 0.5% to 1.5% silica fume and 0.1% to 1% gypsum.

[0011] In one or more embodiments of the present invention, the aggregate includes one or both of coarse aggregate and fine aggregate.

[0012] In one or more embodiments of the present invention, the particle size of the fine aggregate is less than 4.8 mm.

[0013] In one or more embodiments of the present invention, the solid waste material is one or both of fly ash and silica ash.

[0014] In one or more embodiments of the present invention, the carbon dioxide mineralization material is an inorganic salt product produced by reacting one or both of metal ions or alkaline substances in the 3D printing concrete material slurry with carbon dioxide.

[0015] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0016] A method for preparing solid waste-based 3D printing concrete materials based on carbon dioxide mineralization and biochar modification, the method comprising the following steps:

[0017] S1: Weigh cement, fly ash, mineral powder, silica fume, gypsum and water according to proportion and mix them to prepare ink material;

[0018] S2: mixing the ink material obtained in S1 with silicate cement, aggregate and water to obtain a 3D printing mortar ink material;

[0019] S3: placing the 3D printing mortar ink material obtained in S2 in an environment with a carbon dioxide concentration of ≥ 99%, controlling the pressure at 0.1 to 0.5 MPa, and the mineralization time at 2 to 24 hours.

[0020] S4: The 3D printing mortar ink material obtained in S3 is made into different particle sizes for use.

[0021] In one or more embodiments of the present invention, the detailed steps of S1 are:

[0022] (1) Preliminary mixing: Pour 6% to 7% of cement, 0.5% to 1.5% of fly ash, 0.5% to 1.5% of mineral powder, and 0.5% to 1.5% of silica fume weighed in proportion into a mixer and stir for more than 5 minutes until the mixture is uniform to obtain a dry powder mixture;

[0023] (2) Further mixing: take one portion of water, add one half of the water to the dry powder at a uniform speed, control the stirring speed between 17 and 23 times per minute, stir for 1 minute, and obtain a mixture;

[0024] (3) Final mixing: The remaining water is then added to the mixture at a uniform speed. An appropriate amount of retarder can be added as needed to extend the setting time. The stirring speed is controlled between 17 and 23 times per minute, and the mixture is stirred evenly to obtain a 3D printing concrete material.

[0025] In one or more embodiments of the present invention, in S2, the ink material, silicate cement and aggregate are first divided into three parts, one of the raw materials is poured into tap water and stirred until mixed evenly to obtain a first mixture, and then another part of the raw materials is poured into the first mixture and stirred evenly to obtain a second mixture, and the remaining raw materials are poured into the second mixture and stirred evenly.

[0026] Compared with the prior art, the solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification and the preparation method thereof of the present invention have the following advantages:

[0027] 1) Combining the advantages of carbon dioxide mineralization technology, biochar modification and solid waste utilization, it aims to achieve green, low-carbon and high-performance materials;

[0028] 2) Solid waste-based 3D printing concrete materials based on carbon dioxide mineralization and biochar modification are based on solid waste to reduce economic costs, impart environmental protection properties and improve structural performance. By introducing carbon dioxide mineralization and biochar modification technology, the performance of the material is effectively improved to a certain extent, and the negative impact on the environment is reduced. The utilization of solid waste helps to reduce resource consumption and waste emissions, reduce raw material costs to a certain extent, and minimize material waste. Carbon dioxide mineralization technology can capture and fix carbon dioxide in the atmosphere, which is conducive to reducing greenhouse gas emissions. The modification of biochar further enhances the physical and chemical properties of the material;

[0029] 3) Solid waste-based 3D printing concrete materials based on carbon dioxide mineralization and biochar modification have excellent printing performance and constructability, are more environmentally friendly, can reduce material waste to a certain extent, and do not require formwork. At the same time, they reduce costs to a certain extent, especially the coarse aggregate ink effectively reduces the use of cementitious materials; at the same time, various mechanical strength indicators are at the leading stage at home and abroad, and the overall structure has excellent seismic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of the structure of a 3D printing mortar ink material for solid waste-based 3D printing concrete materials based on carbon dioxide mineralization and biochar modification in the second embodiment of the present invention;

[0032] Figure 2 Schematic diagram of the structure of a 3D printing coarse aggregate ink material for a solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification in the first embodiment of the present invention;

[0033] Figure 3 Schematic diagram of the solid waste material structure of the solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification in the first embodiment of the present invention Figure 1 ;

[0034] Figure 4 Schematic diagram of the solid waste material structure of the solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification in the first embodiment of the present invention Figure 2 ;

[0035] Figure 5 This is a schematic diagram of the structure of a 3D printed ribbed wall of a solid waste-based 3D printed concrete material based on carbon dioxide mineralization and biochar modification in the first embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the structure of a 3D printed hollow wall of a solid waste-based 3D printed concrete material based on carbon dioxide mineralization and biochar modification in the first embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0038] In the first embodiment, the 3D printing concrete material includes a carbon dioxide mineralized material, a solid waste material and a 3D printing coarse aggregate ink material with high hardening performance, wherein the 3D printing coarse aggregate ink material includes a 3D printing mortar ink material with high printing performance and ink materials with different particle sizes.

[0039] Furthermore, solid waste materials reduce the use of natural sand and natural aggregate as much as possible. At the same time, due to the characteristics of recycled aggregate and sand powder, the constructability of concrete can be effectively improved, and the problems of construction waste accumulation and raw material shortage can be solved as much as possible. At the same time, various mechanical strength indicators can reach more than 80% of the strength of natural aggregate or sand powder.

[0040] Furthermore, the carbon dioxide mineralization material is an inorganic salt product produced by reacting one or two of the metal ions or alkaline substances in the 3D printing concrete material slurry with carbon dioxide. 2 Mineralization technology can convert carbon dioxide into valuable products, reducing CO 2 At the same time, this technology can also solve the problems of waste disposal and resource recycling as much as possible and promote sustainable development.

[0041] Based on the above-mentioned method for preparing solid waste-based 3D printing concrete materials based on carbon dioxide mineralization and biochar modification, the method comprises the following steps:

[0042] S1: Weigh cement, fly ash, mineral powder, silica fume, gypsum and water according to proportion and mix them to prepare ink material;

[0043] S2: mixing the ink material obtained in S1 with silicate cement, aggregate and water until the mixture is uniform to obtain a 3D printing mortar ink material;

[0044] S3: placing the 3D printing mortar ink material obtained in S2 in an environment with a carbon dioxide concentration of ≥ 99%, controlling the pressure at 0.1 to 0.5 MPa, and the mineralization time at 2 to 24 hours.

[0045] During the mineralization process, carbon dioxide reacts with active substances such as calcium and magnesium in the slurry to form carbonates, which fill the pores and increase the density and strength of the material.

[0046] S4: preparing the 3D printing mortar ink material obtained in S3 into different particle sizes;

[0047] S5: Load the mineralized concrete slurry into the 3D printing equipment and print according to the pre-designed model. During the printing process, the printing speed, layer thickness, extrusion pressure and other parameters must be controlled to ensure printing accuracy and molding quality.

[0048] Embodiment 2

[0049] Different from the first embodiment, the 3D printing mortar ink material is a mixture of ink material, silicate cement, aggregate and water. Various additives and admixtures are prepared into a 3D printing cement-based material "ink" through a specific mass ratio and processing production process, and then the "ink" is mixed with silicate cement and aggregate and stirred with water to make a 3D printing mortar ink with excellent printing performance. It can solve the technical problems such as high cost and shrinkage of the printed structure surface caused by excessive content of cement and other cementitious materials in 3D printing concrete to a certain extent.

[0050] Embodiment 3

[0051] Different from the first embodiment, the aggregate includes one or both of coarse aggregate and fine aggregate.

[0052] The particle size of fine aggregate is less than 4.8 mm.

[0053] Embodiment 4

[0054] Different from Example 1, the mixing step of S1 is detailed into three steps: S1.1 preliminary mixing: pour 6% to 7% cement, 0.5% to 1.5% fly ash, 0.5% to 1.5% mineral powder, and 0.5% to 1.5% silica fume weighed in proportion into a mixer and stir for more than 5 minutes until the mixture is uniform to obtain a dry powder mixture; S1.2 further mixing: add half of the water to the dry powder at a uniform speed, control the stirring speed between 17 and 23 times per minute, stir for 1 minute, and obtain a mixture; S1.3 final mixing: add the remaining half of the water to the mixture at a uniform speed, add an appropriate amount of retarder as needed to prolong the setting time, control the stirring speed between 17 and 23 times per minute, and stir until the mixture is uniform.

[0055] Embodiment 5

[0056] Different from Example 1, the mixing step in S2 is detailed as follows: first, the ink material, silicate cement and aggregate are divided into three parts, one part of the raw materials is poured into tap water and stirred until mixed evenly to obtain a first mixture, and then another part of the raw materials is poured into the first mixture and stirred evenly to obtain a second mixture, and the remaining raw materials are poured into the second mixture and stirred evenly.

[0057] During use, a 3D printing cement-based material ink material is prepared, and then the ink material is mixed with silicate cement and aggregate and stirred with water to obtain a new 3D printing concrete slurry with excellent printing performance. The 3D printing concrete slurry is pumped into the 3D printer equipment, and can be extruded and stacked layer by layer to print house buildings. After being extruded through the printing nozzle, no template curing is required. By adjusting the ratio of each component material and the equipment printing process parameters, excellent printability and constructability can be achieved, ensuring that the structure is safe, stable and durable.

[0058] Among them, the addition of recycled coarse aggregate makes the ink material have added value advantages such as low economic cost and high environmental value. The prepared concrete slurry is placed in an environment with a carbon dioxide concentration of ≥99%, and the pressure is controlled at 0.1-0.5MPa for 2-24 hours. During the mineralization process of carbon dioxide, carbon dioxide reacts with active substances such as calcium and magnesium in the slurry to form carbonates, filling the pores, which is beneficial to improve the density and strength of the material to a certain extent.

[0059] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0060] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. Solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification, characterized by: The 3D printing concrete material includes carbon dioxide mineralization material, solid waste material and 3D printing coarse aggregate ink material; The 3D printing coarse aggregate ink material includes a 3D printing mortar ink material and ink materials with different particle sizes.

2. The solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification according to claim 1, characterized in that: The 3D printing mortar ink material is a mixture of ink material, silicate cement, aggregate and water.

3. The solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification according to claim 1, characterized in that: The ink material comprises the following components by weight percentage: 6% to 7% cement, 0.5% to 1.5% fly ash, 0.5% to 1.5% mineral powder, 0.5% to 1.5% silica fume and 0.1% to 1% gypsum.

4. The solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification according to claim 2, characterized in that: The aggregate includes one or both of coarse aggregate and fine aggregate.

5. The solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification according to claim 4, characterized in that: The particle size of the fine aggregate is less than 4.8 mm.

6. The solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification according to claim 1, characterized in that: The solid waste material is one or both of fly ash and silica ash.

7. The solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification according to claim 1, characterized in that: The carbon dioxide mineralization material is an inorganic salt product produced by reacting one or two of metal ions or alkaline substances in the 3D printing concrete material slurry with carbon dioxide.

8. A method for preparing solid waste-based 3D printing concrete materials based on carbon dioxide mineralization and biochar modification, characterized in that: For preparing the solid waste-based 3D printing concrete material according to any one of claims 1 to 7, the method comprises the following steps: S1: Weigh cement, fly ash, mineral powder, silica fume, gypsum and water according to proportion and mix them to prepare ink material; S2: mixing the ink material obtained in S1 with silicate cement, aggregate and water to obtain a 3D printing mortar ink material; S3: placing the 3D printing mortar ink material obtained in S2 in an environment with a carbon dioxide concentration of ≥ 99%, controlling the pressure at 0.1 to 0.5 MPa, and the mineralization time at 2 to 24 hours. S4: The 3D printing mortar ink material obtained in S3 is made into different particle sizes for use.

9. The method for preparing the solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification according to claim 8, characterized in that: The detailed steps of S1 are: S1.1: Preliminary mixing: Pour 6% to 7% of cement, 0.5% to 1.5% of fly ash, 0.5% to 1.5% of mineral powder and 0.5% to 1.5% of silica fume weighed in proportion into a mixer and mix evenly to obtain a dry powder mixture; S1.2: Further mixing: Take one portion of water, add half of the water to the dry powder at a uniform speed, control the stirring speed between 17 and 23 times per minute, stir for 1 minute, and obtain a mixture; S1.3: Final mixing: Add the remaining water into the mixture at a uniform speed. If necessary, add an appropriate amount of retarder to prolong the setting time. The stirring speed is controlled between 17 and 23 times per minute. Stir evenly to obtain 3D printing concrete material.

10. The method for preparing the solid waste-based 3D printing concrete material based on carbon dioxide mineralization and biochar modification according to claim 8, characterized in that: In S2, the ink material, silicate cement and aggregate are first divided into three parts, one of which is poured into tap water and stirred until uniformly mixed to obtain a first mixture, and then another part of the raw material is poured into the first mixture and stirred uniformly to obtain a second mixture, and the remaining raw material is poured into the second mixture and stirred uniformly.

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