Method for reducing carbon emissions of 3D printed concrete in raw material production stage and construction stage, and method for calculating carbon emissions in construction stage

Abstract

The present invention relates to the technical field of concrete. Disclosed are a method for reducing carbon emissions of 3D printed concrete in a raw material production stage and a construction stage, and a method for calculating carbon emissions in the construction stage. In the present invention, carbon emissions in a raw material production stage corresponding to raw material consumption variations from -20% to +20% are calculated respectively, and sensitivity analysis is performed on the calculated carbon emissions in the raw material production stage; consumption variations in raw materials having a sensitivity >0.9 are adjusted within a range of -10% to 10% to obtain an appropriate mix proportion of the raw materials. Thus, the carbon emissions of 3D printed concrete in the raw material production stage are effectively controlled. The present invention perfects and enriches the carbon emission reduction evaluation system for concrete, offering specificity and guiding significance, provides a theoretical basis for evaluating the environmental impact of 3D printed concrete, and is conducive to the application of more environmentally friendly and lower-carbon materials in the technical field of concrete.

Description

A method for reducing carbon emissions from 3D printed concrete during the raw material production and construction phases, and a method for calculating carbon emissions during the construction phase. Technical Field

[0001] This invention relates to the field of concrete technology, and more specifically, to a method for reducing carbon emissions from 3D printed concrete during the raw material production and construction stages, as well as a method for calculating carbon emissions during the construction stage. Background Technology

[0002] With the continuous acceleration of industrialization and urbanization, greenhouse gas emissions are increasing day by day. Among them, greenhouse gas emissions from the transportation and construction sectors are the main sources of carbon emissions in the field of concrete technology. Calculating concrete carbon emissions is an important means of evaluating the environmental impact of products. Accurate carbon emission data can help engineering designers understand the environmental impact of transportation and construction during the manufacturing stage.

[0003] 3D printed concrete technology uses computer modeling and mechanical control to print concrete material layer by layer. Compared with ordinary concrete, it has the advantages of high efficiency, flexibility, no need for formwork, material saving, environmental friendliness, and economy, and has been widely promoted. However, existing research lacks systematic methods for preparing 3D printed concrete and quantitative data to evaluate the environmental impact of 3D printed concrete, and there is a lack of assessment of the environmental impact of using more environmentally friendly concrete materials in 3D printed structures.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for reducing carbon emissions during the raw material production and construction stages of 3D printed concrete, as well as a method for calculating carbon emissions during the construction stage, in order to solve the aforementioned technical problems.

[0006] This invention is implemented as follows:

[0007] In a first aspect, embodiments of the present invention provide a method for reducing carbon emissions in the raw material production stage of 3D printed concrete, comprising the following steps:

[0008] The carbon emissions from changes in raw material consumption of -20% to +20% during the raw material production stage were calculated, and a sensitivity analysis was performed on the calculated carbon emissions during the raw material production stage.

[0009] Adjust the consumption change of raw materials with sensitivity > 0.9 by -20% to 0 to obtain the appropriate raw material ratio.

[0010] Secondly, embodiments of the present invention provide a method for calculating the carbon emissions (C) of 3D-printed concrete during the construction phase, as described above. The calculation of the carbon emissions (C) during the construction phase is derived from the carbon emissions (C) during the raw material production phase, as described above. p ) and carbon emissions during the transportation of building materials (C t Carbon emissions during the construction phase (C) c The carbon emissions of the preparation method, C = C0, are obtained by summing the results. p +C t +C c .

[0011] Thirdly, embodiments of the present invention provide a method for reducing carbon emissions of 3D printed concrete during the construction phase, which includes the aforementioned method for reducing carbon emissions of 3D printed concrete during the raw material production phase or the aforementioned method for calculating carbon emissions of 3D printed concrete during the construction phase. Beneficial effects

[0012] This invention provides a method for reducing carbon emissions in the raw material production stage of 3D printed concrete. The method calculates the carbon emissions for changes in raw material consumption ranging from -20% to +20% during the raw material production stage, and performs sensitivity analysis on the calculated carbon emissions. By adjusting the raw material consumption change from -20% to 0 for those with a sensitivity > 0.9, the optimal raw material ratio is obtained, effectively controlling the carbon emissions of 3D printed concrete during the raw material production stage. The method for calculating and reducing the carbon emissions of 3D printed concrete during the construction stage provides a theoretical basis for evaluating the environmental impact of 3D printed concrete, and facilitates the application of more environmentally friendly and lower-carbon materials in the field of concrete technology. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 is a schematic diagram of the sensitivity analysis of carbon emissions of 3D printed concrete during the raw material production stage. Embodiments of the present invention

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0016] The IPCC National Greenhouse Gas Inventory is the most widely accepted and applied national-level greenhouse gas emissions inventory guideline to date, encompassing six major categories of greenhouse gases, primarily CO2. The emission factor method provided in the IPCC guideline is currently the most widely used method for calculating greenhouse gas emissions. This method combines information about the extent of human activity (referred to as "activity data"; AD) with a quantifiable factor for emissions or removals per unit of activity (i.e., the emission factor; EF), simply expressed as: E = AD × EF. Greenhouse gas emissions = Activity level × Emission factor.

[0017] Greenhouse gas emissions in the transportation and construction sectors primarily occur in the manufacturing and use phases. The manufacturing phase includes the extraction, transportation, and processing of raw materials, the production and transportation of materials, and the construction process. First, a survey of the carbon emission factors (CEF) of fossil fuels and electricity used in the manufacturing phase was conducted. Since carbon emission factor databases vary across different countries and regions, the IPCC Greenhouse Gas Inventory Guidelines and the Provincial Greenhouse Gas Inventory Compilation Guidelines were referenced. The final CEFs for various fossil fuels were selected: coal 2.624 kgCO2e / kg, oil 2.008 kgCO2e / kg, natural gas 1.532 kgCO2e / kg, and electricity (Jiangsu) 0.928 kgCO2e / (kW·h). This invention, based on the newly developed 3D printed concrete technology in the concrete field, studies the environmental impact of 3D printed concrete using quantitative data.

[0018] In a first aspect, embodiments of the present invention provide a method for reducing carbon emissions in the raw material production stage of 3D printed concrete, comprising the following steps:

[0019] The carbon emissions from changes in raw material consumption of -20% to +20% during the raw material production stage were calculated, and a sensitivity analysis was performed on the calculated carbon emissions during the raw material production stage.

[0020] Adjust the consumption of the most sensitive raw material by -20% to 20% to obtain the appropriate raw material ratio.

[0021] It should be noted that reducing the amount of highly sensitive raw materials used, or replacing them with similar materials that have lower carbon emission factors—that is, adjusting to more environmentally friendly and lower-carbon materials—will significantly reduce carbon emissions during the raw material production stage. In an optional embodiment of the present invention, solid waste concrete is used as the raw material for the reuse of waste materials, thereby reducing environmental pollution from solid waste while creating economic benefits.

[0022] In an optional embodiment of the present invention, the formula for calculating carbon emissions during the raw material production stage is as follows: (1), in equation (1), CM i The carbon emission factor per unit produced from the i-th raw material (kgCO2e / t); m i Let t be the amount (t) of the i-th raw material; n be the type of raw material.

[0023] Specifically, the carbon emissions of each raw material in the raw material production stage are obtained by multiplying the consumption of each raw material by its corresponding carbon emission factor. The carbon emissions of all raw materials are summed to obtain the carbon emissions of the raw material production stage.

[0024] In an optional embodiment of the present invention, in the sensitivity analysis of the raw material production stage, the change in raw material consumption is selected from at least one of -20%, -10%, 0, 10%, and 20%.

[0025] It should be noted that high consumption of raw materials or high carbon emission factors in the raw material production stage can significantly impact the carbon emissions of 3D-printed concrete, causing substantial environmental impact. Therefore, it is necessary to improve the proportions of raw materials in 3D-printed concrete to obtain an optimal ratio, reducing carbon emissions and thus mitigating environmental impact. In other optional embodiments of this invention, the amount of raw material consumed can be reasonably adjusted according to actual conditions, selecting other values ​​between -20% and +20%.

[0026] In an optional embodiment of the present invention, the sensitivity calculation formula for the sensitivity analysis in the raw material production stage is as follows: (2), in equation (2), S i The sensitivity of raw material i; ΔI i I represents the change in raw material i; i Let ΔT be the total amount of raw material i; i T represents the change in unit carbon emissions. i This represents the total amount of carbon emissions.

[0027] It should be noted that in the sensitivity analysis, the change in unit carbon emissions is linearly related to the change in raw material emissions. The slope of the line segment is used to determine the sensitivity of each raw material to the unit carbon emission result. Then, the consumption change of raw materials with sensitivity > 0.9 is adjusted from -10% to 10% to obtain the appropriate raw material ratio, thereby reducing the carbon emissions of 3D printed concrete in the raw material production stage and thus reducing the carbon emissions of 3D printed concrete. This provides a theoretical basis for evaluating the environmental impact of 3D printed concrete and is conducive to the application of more environmentally friendly and lower-carbon materials in the field of concrete technology.

[0028] In an optional embodiment of the present invention, the raw materials that generate carbon emissions during the raw material production stage include cementitious materials, water, fine aggregates, and additives; wherein, cementitious materials include cement, fine aggregates include recycled sand, and additives include admixtures.

[0029] It is important to note that cementitious materials play a crucial role in concrete. When mixed with water, they form a paste that fills the spaces between aggregates, acting as a bond and fixative. Cementitious materials significantly influence the strength of concrete by reducing capillary porosity in the hardened cement paste, improving the structure of hydration products, and increasing the structural strength of the cement paste, particularly the hardened paste at the aggregate interface. The mechanisms of action and specific applications of different types of cementitious materials, such as limestone powder, natural volcanic ash, and fly ash, also affect the strength and durability of concrete. Furthermore, different types of cementitious materials have varying carbon emissions, and the specific types used should be adjusted according to actual needs.

[0030] Fine aggregates primarily function as fillers in concrete, filling the voids between large-diameter aggregates to form a dense skeletal structure, thereby enhancing the compactness and strength of the concrete. By using appropriate particle size and gradation, the compactness and strength of the concrete are further improved, thus enhancing its overall performance. In other optional embodiments of the invention, the type of fine aggregate can be adjusted according to actual needs.

[0031] Concrete additives are an indispensable component of concrete, and their main functions are as follows: Additives can improve the physical properties of concrete, such as adjusting its fluidity, density, shrinkage, impermeability, and frost resistance; Additives can improve the strength, durability, crack resistance, and setting delay properties of concrete; The use of concrete additives can also reduce the production cost of concrete, such as using cement reducers to reduce the amount of cement used, thereby reducing the production cost of concrete.

[0032] In an optional embodiment of the present invention, a sensitivity analysis is performed on the carbon emissions of cement, recycled sand and admixtures in the raw materials.

[0033] In an optional embodiment of the present invention, among the raw materials that generate carbon emissions during the raw material production stage, the cementing material also includes fly ash and silica powder; the additives also include polypropylene fiber.

[0034] It should be noted that cement, recycled sand, and admixtures are materials with high consumption and high carbon emissions among raw materials. Therefore, analyzing their sensitivity is used to guide the adjustment of the appropriate ratio of raw materials to reduce the carbon emissions of 3D printed concrete in the raw material production stage.

[0035] In a preferred embodiment of the present invention, the carbon emission factors corresponding to the same material used to produce 1 t 3D printed concrete specimens are shown in Table 1. It should be noted that the carbon emission factors are affected by local conditions, and the survey data may vary. In the optional embodiments of the present invention, the survey data are all from Jiangsu Province; in other optional embodiments of the present invention, data from other provinces can be selected according to actual needs.

[0036] Table 1 Carbon emission factors of relevant raw materials in the raw material production stage

[0037]

[0038] Secondly, embodiments of the present invention provide a method for calculating the carbon emissions (C) of 3D-printed concrete during the construction phase, as described above. The calculation of the carbon emissions (C) during the construction phase is derived from the carbon emissions (C) during the raw material production phase, as described above. p ) and carbon emissions during the transportation of building materials (C t Carbon emissions during the construction phase (C) c The carbon emissions of the preparation method, C = C0, are obtained by summing the results. p +C t +C c .

[0039] In an optional embodiment of the present invention, the formula for calculating carbon emissions during the building materials transportation stage is as follows: (3), in equation (3), C ti Carbon emission factor per unit transport weight of the i-th raw material (kgCO2e / (t·km)); m i The amount (t) of the i-th raw material; D i The transportation distance (km) of the i-th raw material; wherein the means of transport that generates carbon emissions during the building material transportation stage is selected from at least one of railway, medium-sized gasoline truck and heavy-duty gasoline truck.

[0040] It should be noted that the carbon emissions generated during the building material transportation phase are mainly due to the electricity and fuel consumption of various mechanical equipment, and are numerically equal to the vehicle's carbon emission factor multiplied by the transportation distance. In other optional embodiments of the present invention, the transportation vehicles used during the building material transportation phase can be reasonably adjusted and replaced according to the actual construction site or the properties of the transported materials, and the transportation distance can be reasonably adjusted according to the actual situation.

[0041] In an optional embodiment of the present invention, the carbon emission factor of the transportation vehicle used to produce 1 t of 3D printed concrete specimens during the building material transportation stage is shown in Table 2. It should be noted that the carbon emission factor is affected by local conditions, and the survey data may vary. In an optional embodiment of the present invention, the survey data are all from Jiangsu Province; in other optional embodiments of the present invention, data from other provinces can be selected according to actual needs.

[0042] Table 2 Carbon emission factors of relevant transportation vehicles during the building materials transportation phase

[0043]

[0044] In an optional embodiment of the present invention, the formula for calculating carbon emissions during the construction phase is as follows: (4), in equation (4), C ei Let t be the carbon emission factor per hour for the i-th production process (kgCO2e / h); wi E represents the working time (h) for the i-th production process. ei P represents the hourly energy consumption (kW) of the i-th production process. n Energy or electricity carbon emission factor (kgCO2e / (kW·h) or kgCO2e / kg); mechanical equipment that generates carbon emissions during the construction phase includes 3D printers, mixers and cranes.

[0045] In this invention, the 3D printer, mixer, and crane are not particularly limited, and appropriate specifications of equipment can be selected according to actual needs. In optional embodiments of this invention, a vortex paddle mixer and a gantry crane are used.

[0046] It should be noted that the carbon emissions during the construction phase are the sum of the carbon emissions from each production process, including both construction equipment and labor. The total carbon emissions for the process are obtained by multiplying the carbon emissions per unit time of the production process, the working hours, and the energy or electricity carbon emission factor (labor carbon emission factor). All of these can be reasonably adjusted according to the actual situation.

[0047] In an optional embodiment of the present invention, the carbon emission factor of 1 t 3D printed concrete specimens during the construction stage is shown in Table 3. It should be noted that the carbon emission factor is affected by local conditions, and the survey data may vary. In an optional embodiment of the present invention, the survey data are all from Jiangsu Province; in other optional embodiments of the present invention, data from other provinces can be selected according to actual needs.

[0048] Table 3 Carbon emission factors of relevant machinery and equipment during the construction phase

[0049]

[0050] Thirdly, embodiments of the present invention provide a method for reducing carbon emissions of 3D printed concrete during the construction phase, which includes the aforementioned method for reducing carbon emissions of 3D printed concrete during the raw material production phase or the aforementioned method for calculating carbon emissions of 3D printed concrete during the construction phase.

[0051] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0052] Example 1

[0053] This embodiment provides a method for reducing carbon emissions during the raw material production stage of 3D printed concrete, as follows:

[0054] A maintenance work area produced a 3D printed sculpture (5t) from solid waste. The raw materials used included: cement, fly ash, silica fume, recycled sand, polypropylene fiber, water, and additives. The material ratio for making 1t of specimens is shown in Table 4, and the carbon emission factors corresponding to different materials are shown in Table 1.

[0055] Table 4 Material ratio of a 1t specimen of a 3D-printed sculpture made from solid waste

[0056]

[0057] (1) Calculate the carbon emissions (C) during the raw material production stage. p ):

[0058] From equation (1) Calculations show that the carbon emissions during the production stage of 3D printing concrete raw materials from solid waste are 166.04 kgCO2e / t. For the production of 5t of concrete products, the carbon emissions from the solid waste 3D printing process are 830.2 kgCO2e.

[0059] C p=211.5×735+126.9×19.1+84.6×14+148×0.17+423×3.68+0.846×1.03+5.076×1064) / 1000=166.04(kgCO2e / t).

[0060] (2) Sensitivity analysis:

[0061] Taking all factors into consideration, the sensitivity analysis selected cement, admixtures, and recycled sand, which have high consumption and carbon emissions, according to formula (2). The sensitivity of the above three raw materials was calculated, and the carbon emissions were analyzed when their consumption changed by -20%, -10%, 0%, 10%, and 20%, respectively. The data results are shown in Table 5, and the analysis diagram is shown in Figure 1.

[0062] Table 5. Carbon emissions (kgCO2) corresponding to different raw material consumption levels

[0063]

[0064] The change in unit carbon emissions is linearly related to the change in raw materials. The sensitivity of various inventory data to the unit carbon emission result can be judged based on the slope of the line segment.

[0065] As can be seen from Table 5 and Figure 1, formula (2) Calculations show that the sensitivity values ​​for cement, admixtures, and recycled sand are 0.935, 0.031, and 0.008, respectively, ranking from highest to lowest sensitivity as cement, admixtures, and recycled sand. Therefore, cement usage is the most sensitive component in raw material production, and reducing cement usage can lower carbon emissions throughout the entire life cycle.

[0066] S i The calculation is illustrated using a 20% change in cement consumption as an example:

[0067] Si= =0.935.

[0068] Example 2

[0069] This embodiment provides a method for reducing carbon emissions during the construction phase of 3D printed concrete, as detailed below:

[0070] A maintenance work area produced 5 tons of solid waste 3D printed sculptures. The raw materials used included: cement, fly ash, silica fume, recycled sand, polypropylene fiber, water, and additives. The material ratio for making 1 ton of specimens is shown in Table 4, and the carbon emission factors corresponding to different materials are shown in Table 1.

[0071] (1) Calculate the carbon emissions (C) during the raw material production stage. p ):

[0072] From equation (1) Calculations show that the carbon emissions during the production stage of 3D printing concrete raw materials from solid waste are 166.04 kgCO2e / t. For the production of 5t of concrete products, the carbon emissions from the solid waste 3D printing process are 830.2 kgCO2e.

[0073] (2) Calculate the carbon emissions (C) during the transportation of building materials. t ):

[0074] The transportation vehicles used in the transportation stage of 3D printed solid waste concrete include heavy-duty gasoline trucks, railways, and medium-duty gasoline trucks. The carbon emission factors of the transportation distance and transportation mode of 3D printed solid waste concrete are shown in Table 6.

[0075] Table 6. Relevant information on the transportation stage of 3D-printed solid waste concrete.

[0076]

[0077] According to equation (3) Calculations show that the carbon emissions during the transportation of 1 ton of raw materials are 32.14 kg CO2e / t, and the carbon emissions during the transportation of solid waste 3D printing raw materials for producing a total weight of 5 tons of concrete products are 160.7 kg CO2e.

[0078] C t =35×0.104+(40+10)×(0.01+0.104)×2+76×0.104+40×0.115×2=32.14 kgCO2e / t.

[0079] (3) Calculate the carbon emissions (C) during the construction phase. c ):

[0080] The machinery and equipment used in the production stage of 3D printed solid waste concrete include: 3D printer, vortex paddle mixer, gantry crane, and corresponding manpower. The working hours, hourly carbon emissions and carbon emission factors of the machinery and manpower used in 3D printed solid waste concrete are shown in Table 7.

[0081] Table 7. Relevant information on 3D-printed solid waste concrete during the construction phase.

[0082]

[0083] According to formula (4) The calculated carbon emissions of 3D-printed concrete during the construction phase are 361.5 kgCO2e.

[0084] C c=8.30×0.928×8+34.10×0.928×4+88.29×0.928×2+0.118×80=361.5 kgCO2e.

[0085] The carbon emissions of 3D-printed concrete during the construction phase have been calculated as C=C. p +C t +C c =830.2+160.7+361.5=1352.4kgCO2e.

[0086] Example 3

[0087] This embodiment provides a method for reducing carbon emissions from 3D printed concrete during the construction phase. In addition to the content in Embodiment 2, it also includes sensitivity analysis. The sensitivity analysis in this embodiment comprehensively considers the carbon emissions from the raw material production phase, the building material transportation phase, and the construction phase. Sensitivity analysis is performed on the carbon emissions from the raw material production phase, which has high consumption and high carbon emissions. Since the raw materials are the same, the sensitivity analysis is the same as that in Embodiment 1.

[0088] Comparative Example 1

[0089] This comparative example provides a method for making a sculpture (5t) using ordinary concrete. The raw materials used include cement, water, natural sand, and crushed stone. The material mix for making a 1t specimen is shown in Table 8, and the carbon emission factors corresponding to different materials are shown in Table 9.

[0090] Table 8 Material mix proportions for making 1t specimens from ordinary concrete

[0091]

[0092] Table 9 Carbon emission factors of ordinary concrete raw materials during the production stage

[0093]

[0094] (1) Calculate the carbon emissions (C) during the raw material production stage. p ):

[0095] From equation (1) Calculations show that the carbon emissions during the raw material production stage of ordinary concrete are 145.2 kgCO2e / t. For the production of 5t of concrete products, the carbon emissions from the ordinary concrete process are 726.0 kgCO2e.

[0096] (2) Calculate the carbon emissions (C) during the transportation of building materials. t ):

[0097] The main means of transportation used in the ordinary concrete transportation stage is heavy-duty gasoline trucks. The carbon emission factors of the transportation distance and transportation mode of ordinary concrete are shown in Table 10.

[0098] Table 10 Carbon emission factors during the transportation of raw materials for ordinary concrete

[0099]

[0100] According to equation (3) Calculations show that the carbon emissions during the transportation of 1 ton of raw materials are 16.22 kg CO2e / t, and the carbon emissions during the transportation of solid waste 3D printing raw materials for producing a total weight of 5 tons of concrete products are 81.1 kg CO2e.

[0101] (3) Calculate the carbon emissions (C) during the construction phase. c ):

[0102] The machinery used in the ordinary concrete production stage includes: vortex paddle mixer, concrete trowel, gantry crane, and corresponding manpower. The working hours, hourly carbon emissions, and carbon emission factors of ordinary concrete machinery and manpower are shown in Table 11.

[0103] Table 11 Carbon emission factors during ordinary concrete construction

[0104]

[0105] From equation (4) The calculated carbon emissions during the construction of ordinary concrete are 951.3 kgCO2e.

[0106] The total carbon emissions during the construction phase of ordinary concrete are calculated as C = C0. p +C t +C c =726.0+81.1+884.3=1691.4kgCO2e.

[0107] Ultimately, through quantitative calculations using carbon emission assessment methods, it was found that 3D-printed concrete reduced carbon emissions by 20.04% compared to conventional concrete.

[0108] In summary, 3D-printed concrete has a higher carbon emission rate than ordinary concrete, primarily due to the use of cement. However, introducing low-carbon materials such as recycled sand can effectively reduce carbon emissions from the aggregate component. Furthermore, 3D-printed concrete may include a wider variety of additives or modifiers in its mix design, which also increase carbon emissions during production and transportation, making its carbon emissions higher than ordinary concrete in this stage. However, compared to the carbon emissions generated during raw material production and transportation, the carbon emissions from electricity and labor consumption during the 3D printing process account for a more significant proportion. In actual production, the advantages of 3D printing technology lie in its ability to eliminate the need for templates and reduce labor hours, which is key to the energy conservation and emission reduction of 3D solid waste concrete. Future development of 3D printing technology in reducing carbon emissions during the raw material production stage should focus on further reducing cement usage, selecting raw materials appropriately based on local conditions, and ensuring performance stability.

[0109] In summary, this invention, by comparing the carbon emissions of different construction schemes, illustrates the characteristics of 3D printing carbon emissions, identifies the intrinsic factors affecting 3D printing carbon emissions, and demonstrates the carbon reduction potential of 3D printed concrete construction. The quantitative analysis of the entire construction process—from 3D printed solid waste concrete scheme design, raw material production, raw material transportation, to mixture production—improves and enriches the carbon emission reduction evaluation system for concrete, providing targeted guidance. It also provides a theoretical basis for evaluating the environmental impact of 3D printed concrete, facilitating the application of more environmentally friendly and lower-carbon materials in the field of concrete technology.

[0110] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of reducing carbon emissions of 3D printed concrete in the raw material production phase, characterized in that, It includes the following steps: The carbon emissions from changes in raw material consumption of -20% to +20% during the raw material production stage were calculated, and a sensitivity analysis was performed on the calculated carbon emissions during the raw material production stage. Adjust the consumption change of raw materials with sensitivity > 0.9 by -10% to 10% to obtain the appropriate raw material ratio.

2. The method of reducing carbon emissions of 3D printing concrete in the raw material production phase according to claim 1, characterized in that, The calculation formula of carbon emission of the raw material production stage is: (1), in formula (1), CM i is the unit carbon emission factor (kgCO2e / t) of the production of the ith raw material; m i is the amount (t) of the ith raw material; and n is the type of raw material.

3. The method of reducing carbon emissions of 3D printing concrete in the raw material production phase according to claim 1, characterized in that, In the sensitivity analysis of the raw material production stage, the change in raw material consumption is selected from at least one of -20%, -10%, 0%, 10%, and 20%.

4. The method of reducing carbon emissions of 3D printing concrete in the raw material production phase according to claim 1, characterized in that, In the sensitivity analysis of the raw material production stage, the calculation formula of sensitivity is: (2), in formula (2), S i is the sensitivity of raw material i; ΔI i is the change of raw material i; I i is the total amount of raw material i; ΔT i is the change of unit carbon emission; T i is the total amount of carbon emission.

5. The method of reducing carbon emissions of 3D printing concrete in the raw material production phase according to claim 1, characterized in that, The raw materials that generate carbon emissions during the raw material production stage include cementitious materials, water, fine aggregates, and additives; wherein, the cementitious materials include cement, the fine aggregates include recycled sand, and the additives include admixtures. Preferably, a sensitivity analysis is performed on the carbon emissions of cement, recycled sand, and admixtures in the raw materials.

6. The method of reducing carbon emissions of 3D printing concrete in the raw material production phase according to claim 1, characterized in that, Among the raw materials that generate carbon emissions during the raw material production stage, the cementing material also includes fly ash and silica powder; the additives also include polypropylene fiber.

7. A method for calculating the carbon emissions of a 3D printed concrete according to any one of claims 1-6 in a construction phase, characterized in that, The carbon emissions (C) during the construction phase are calculated based on the carbon emissions (C) during the raw material production phase as described in claim 2. p ) and carbon emissions during the transportation of building materials (C t Carbon emissions during the construction phase (C) c The carbon emissions of the preparation method, C = C0, are obtained by summing the results of the previous steps. p +C t +C c .

8. The method of claim 7, wherein the carbon emission amount is calculated based on the production method, wherein the production method is a method of producing a product by using a raw material, and the carbon emission amount is calculated based on the production method. The calculation formula of the carbon emission of the building material transportation stage is: (3), in formula (3), C ti The unit transportation weight carbon emission factor of the i th raw material (kgCO2e / (t·km)); i The amount of use of the i th raw material (t); D i The transportation distance of the i th raw material (km); The vehicles that generate carbon emissions during the building material transportation phase are selected from at least one of railways, medium-sized gasoline trucks, and heavy-duty gasoline trucks.

9. The method of claim 7, wherein the carbon emission amount is calculated based on the amount of carbon dioxide generated in the production process of the product, the amount of carbon dioxide generated in the production process of the raw material, and the amount of carbon dioxide generated in the production process of the intermediate product. The formula for calculating carbon emissions during the construction phase is as follows: (4), in formula (4), C ei is the carbon emission factor per hour (kgCO2e / h) for the i-th production process; t wi is the working time (h) for the i-th production process; E ei is the energy consumption per hour (kW) for the i-th production process; P n is the energy or power carbon emission factor (kgCO2e / (kW·h) or kgCO2e / kg). The mechanical equipment that generates carbon emissions during the construction phase includes 3D printers, mixers, and cranes.

10. A method of reducing carbon emissions of 3D printed concrete at the construction stage, characterized in that, It includes the method for reducing carbon emissions of 3D printed concrete in the raw material production stage as described in any one of claims 1-6, or the method for calculating carbon emissions of 3D printed concrete in the construction stage as described in any one of claims 7-9.

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