Evaluation method for full-life-cycle carbon benefit of green low-carbon concrete

Abstract

The invention discloses a green low-carbon concrete full-life-cycle carbon benefit evaluation method, and relates to the technical field of energy conservation and environmental protection, and the method comprises the steps: dividing the full-life cycle of concrete into a plurality of stages, and calculating the carbon dioxide emission of each stage; determining life cycles of different types of concrete based on the plurality of stages; based on the life cycles of the different types of concrete and the carbon dioxide emissions of all the stages, the life cycle carbon dioxide emissions of the different types of concrete are calculated; and calculating the net carbon dioxide benefits of the recycled aggregate concrete and the carbonized and modified recycled aggregate concrete according to the carbon dioxide emissions of the different types of concrete in the life cycle. By establishing a perfect evaluation method system, the carbon emission and the carbon benefit of the whole life cycle of the green low-carbon concrete can be effectively calculated.

Description

Technical Field

[0001] The present application relates to the field of energy conservation and environmental protection technology, and in particular to a method for evaluating the carbon benefits of green and low-carbon concrete over its entire life cycle. Background Art

[0002] The sustainable development of the construction industry faces two practical problems: shortage of natural aggregates and disposal of construction waste. With the construction and development of cities, the demand for concrete is increasing. Coarse aggregate and fine aggregate account for about 3 / 4 of the total weight of concrete. As a non-renewable resource in the short term, natural aggregate is difficult to meet the growing demand. On the other hand, the concrete structures built in the early stage gradually reach the end of their service life, which will generate a large amount of construction waste. The increase in the amount of construction waste has a negative impact on the environment. Therefore, the research and application of green and low-carbon building materials has become an urgent task in the construction industry.

[0003] At present, the carbon emission assessment of concrete mainly focuses on the material production stage. The carbon emission and carbon benefit assessment methods of green and low-carbon concrete throughout its life cycle are not yet mature. The carbon emission boundaries, carbon emission calculation methods at different stages, and the influencing mechanisms of concrete strength and durability are still unclear. Summary of the invention

[0004] The purpose of this application is to provide an assessment method for the carbon benefits of green low-carbon concrete throughout its life cycle, and to effectively calculate the carbon emissions and carbon benefits of green low-carbon concrete throughout its life cycle by establishing a complete assessment method system.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] A method for evaluating the carbon benefits of green and low-carbon concrete over its entire life cycle, including:

[0007] Divide the whole life cycle of concrete into several stages and calculate the carbon dioxide emissions in each stage; the several stages include: raw material production, raw material transportation, carbon dioxide collection, carbon dioxide transportation, carbon dioxide maintenance, carbon dioxide solidification, concrete production, concrete transportation, construction, maintenance, demolition, waste transportation, waste treatment and landfill;

[0008] Based on the several stages, the life cycles of different types of concrete are determined; the different types of concrete include: natural aggregate concrete, recycled aggregate concrete and carbonized modified recycled aggregate concrete;

[0009] Calculating the life cycle carbon dioxide emissions of different types of concrete based on the life cycles of the different types of concrete and the carbon dioxide emissions at each stage;

[0010] The net CO2 benefits of recycled aggregate concrete and carbonation-modified recycled aggregate concrete were calculated based on the life cycle CO2 emissions of the different types of concrete.

[0011] Optionally, the life cycle of the natural aggregate concrete includes: raw material production, raw material transportation, concrete production, concrete transportation, construction, maintenance, demolition, waste transportation, waste disposal and landfill; the life cycle of the recycled aggregate concrete includes: raw material production, raw material transportation, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation; the life cycle of the carbonization modified recycled aggregate concrete includes: raw material production, raw material transportation, carbon dioxide collection, carbon dioxide transportation, carbon dioxide maintenance, carbon dioxide solidification, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation.

[0012] Optionally, the expression of the life cycle carbon dioxide emission of the natural aggregate concrete is:

[0013]

[0014] Among them, C NAC is the life cycle carbon dioxide emissions of natural aggregate concrete; M i is the mass of raw material i used in concrete per cubic meter per MPa; C Mi The carbon dioxide emissions generated to produce 1kg of raw material i; C Li The amount of carbon dioxide emissions generated by transporting 1kg of raw material i; L i is the transportation distance of raw material i; α f =1 / f cu is the coefficient considering the influence of concrete compressive strength, f cu is the compressive strength of concrete; C E is the carbon dioxide intensity of electricity; E mix For stirring 1m 3 Electricity consumption of concrete; C L Carbon dioxide emissions generated by transporting 1kg of concrete; L c is the transportation distance of concrete; M c C is the mass of concrete per cubic meter per MPa; con =M×S is the carbon dioxide emissions during the construction period, M=X+1.99 is the carbon dioxide emissions per square meter of building area, X is the number of floors above the ground, S is the building area; V c =v c ×S is the volume of concrete, v c C is the amount of concrete used per square meter of building area; h h is the carbon dioxide emissions from the materials used for maintenance; Y is the service life of the building; Tm is the maintenance interval; C dem,j is the carbon dioxide emission of demolition step j; Carbon dioxide emissions generated for transporting 1kg of demolition waste; L waste is the transportation distance of demolition waste; C diesel The amount of carbon dioxide emitted when consuming 1 liter of diesel; D process The amount of diesel required to process 1 kg of demolition waste; E process The electricity consumption for processing 1kg of demolition waste; D land is the amount of diesel required to landfill 1 kg of demolition waste; n is the total number of raw material types; l is the total number of material types used for repair; m is the total number of demolition steps.

[0015] Optionally, the expression of the life cycle carbon dioxide emission of the recycled aggregate concrete is:

[0016]

[0017] Among them, C RAC Life cycle CO2 emissions of recycled aggregate concrete.

[0018] Optionally, the expression of the life cycle carbon dioxide emission of the carbonized modified recycled aggregate concrete is:

[0019]

[0020] Among them, C CRAC Life cycle CO2 emissions of carbonation-modified recycled aggregate concrete; is the coefficient related to the carbon dioxide recovery efficiency; The amount of CO2 emissions generated for transporting 1kg of CO2; is the transport distance of carbon dioxide; is the mass of captured carbon dioxide, C RA is the mass of carbon dioxide captured per 1kg of recycled aggregate, M RA is the mass of recycled aggregate; V RAC 1m 3 The volume of recycled aggregate used in concrete; E cur For carbonization 1m 3 Power of recycled aggregate; T cur is the duration of CO2 curing.

[0021] Optionally, the net carbon dioxide benefit of the recycled aggregate concrete is expressed as:

[0022] NetCO2 Benefit RAC =C NAC -CRAC

[0023] Among them, NetCO2 Benefit RAC Net CO2 benefits of recycled aggregate concrete.

[0024] Optionally, the net carbon dioxide benefit of the carbonized modified recycled aggregate concrete is expressed as:

[0025] NetCO2 Benefit CRAC =C NAC -C CRAC

[0026] Among them, NetCO2 Benefit CRAC Net CO2 benefits of carbonation-modified recycled aggregate concrete.

[0027] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0028] The present application provides a method for evaluating the carbon benefits of green and low-carbon concrete over its entire life cycle. The method divides the entire life cycle of concrete into 14 stages, namely, raw material production, raw material transportation, carbon dioxide collection, carbon dioxide transportation, carbon dioxide maintenance, carbon dioxide solidification, concrete production, concrete transportation, construction, maintenance, demolition, waste transportation, waste treatment and landfill. The carbon dioxide emissions of each stage are calculated respectively, and the life cycle carbon dioxide emissions of different types of concrete are calculated based on their life cycles. The net carbon dioxide benefits of recycled aggregate concrete and carbonization-modified recycled aggregate concrete are determined, the carbon emission boundaries, the carbon emission calculation methods at different stages, and the influencing mechanism of concrete strength and durability are clarified, thereby achieving an effective evaluation of the carbon emissions and carbon benefits of green and low-carbon concrete over its entire life cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A flow chart of the method for assessing the carbon benefits of green low-carbon concrete throughout its life cycle provided for this application;

[0031] Figure 2 Flowchart of carbon emissions over the entire life cycle of green and low-carbon concrete provided for this application. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] Waste concrete can be screened, crushed, cleaned and graded to produce recyclable aggregates that can be used to replace natural aggregates in concrete. The application of recycled aggregate concrete (RAC) can solve the problem of natural aggregate shortage and recycle waste concrete. However, compared with natural aggregate concrete (NAC), the mechanical properties and durability of RAC are relatively poor. Therefore, it is recommended to carbonize the recycled aggregate, that is, to solidify the recycled aggregate in a high concentration of carbon dioxide (CO2). The Ca(OH)2 and CSH gel in the old mortar of the recycled aggregate can react with CO2 to generate CaCO3 and amorphous silica gel, which can fill the pores of the recycled aggregate and reduce the porosity of the concrete.

[0034] Therefore, the mechanical properties, durability and environmental benefits of carbonation modified recycled aggregate concrete (CRAC) have been studied. Existing studies have shown that carbonation of recycled aggregate is an effective method for fixing CO2, and that carbonation of recycled aggregate can improve the compressive and flexural strength of recycled concrete, and has a greater beneficial effect on the durability of recycled concrete. With the increase in strength, the volume of concrete can be reduced under the same bearing capacity, and with the improvement in the durability of concrete, the maintenance frequency can be reduced during the service life. Carbonation modification can achieve good environmental benefits for improving the strength and durability of concrete.

[0035] The application of CRAC can solve the problem of shortage of natural aggregates, reduce waste concrete, achieve good concrete mechanical properties and durability, and fix CO2 during the carbonation modification process, which is expected to achieve good positive net CO2 benefits. But the actual situation is not that simple. Existing studies have shown that considering that concrete waste needs to go through four steps of excavation, collection and two-phase crushing to produce recycled aggregates, the CO2 emissions in the production process of recycled aggregates are higher than those of natural aggregates. In addition, existing studies have also found that injecting or curing CO2 in concrete does not necessarily produce net carbon benefits, considering the energy consumption and CO2 emissions in the process of CO2 collection, CO2 transportation and CO2 solidification.

[0036] Compared with NAC, RAC has higher CO2 emissions during concrete production, but lower CO2 emissions during waste treatment and landfill. Carbonation modification increases CO2 emissions during CO2 collection, CO2 transportation, and CO2 curing, but it can fix CO2 and improve concrete strength and durability. Therefore, the application of recycled aggregates and carbonation modification have both advantages and disadvantages in generating net climate benefits. Whether CRAC does have a positive net CO2 benefit should be taken seriously and quantitatively analyzed.

[0037] This application can effectively calculate the carbon emissions and carbon benefits of green and low-carbon concrete throughout its life cycle by establishing a complete assessment method system.

[0038] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0039] In an exemplary embodiment, the present application provides a method for evaluating the carbon benefits of green low-carbon concrete throughout its life cycle. The method is executed by a computer device, which can be executed by a computer device such as a terminal or a server alone, or by a terminal and a server together. In the embodiment of the present application, Figure 1 As shown, the method includes the following steps S1 to S4.

[0040] Step S1: Divide the entire life cycle of concrete into several stages, and calculate the carbon dioxide emissions in each stage. The several stages include: raw material production P1, raw material transportation P2, carbon dioxide collection P3, carbon dioxide transportation P4, carbon dioxide maintenance P5, carbon dioxide solidification P6, concrete production P7, concrete transportation P8, construction P9, maintenance P10, demolition P11, waste transportation P12, waste treatment P13 and landfill P14. The carbon dioxide emissions in each stage are calculated as follows:

[0041] Phase 1: Raw material production.

[0042]

[0043] Where M i is the mass of raw material i used in concrete per cubic meter per MPa (kg / m 3 / MPa); C Mi is the carbon dioxide emissions generated by producing 1kg of raw material i (kg CO2 / kg); n is the total number of raw material types.

[0044] Phase 2: Transportation of raw materials.

[0045]

[0046] In the formula, C Li Carbon dioxide emissions generated by transporting 1kg of raw material i (kg CO2 / kg); L i is the transportation distance of raw material i (km).

[0047] Phase 3: CO2 capture (carbonation-modified recycled aggregate concrete only).

[0048]

[0049] In the formula, is a coefficient related to the carbon dioxide recovery efficiency.

[0050] Phase 4: CO2 transport (carbonation-modified recycled aggregate concrete only).

[0051]

[0052] In the formula, The amount of carbon dioxide emissions generated for transporting 1kg of carbon dioxide (kg CO2 / kg); is the transport distance of carbon dioxide (km); is the mass of captured carbon dioxide (kg), where C RA is the mass of carbon dioxide captured per 1kg of recycled aggregate, M RA is the quality of recycled aggregate.

[0053] Stage 5: Carbon dioxide curing (only for carbonation-modified recycled aggregate concrete).

[0054] P5=α f ·C E ·V RAC ·E cur ·T cur

[0055] In the formula, α f =1 / f cu is the coefficient considering the influence of concrete compressive strength, f cu is the compressive strength of concrete; C E is the carbon dioxide intensity of electricity (kg CO2 / kWh); V RAC 1m 3 The volume of recycled aggregate used in concrete; E cur For carbonization 1m 3 Power of recycled aggregate (kW / m 3 );T cur is the duration of carbon dioxide curing (hours).

[0056] Stage 6: CO2 absorption (carbonation-modified recycled aggregate concrete only).

[0057]

[0058] Phase 7: Concrete production.

[0059] P7=α f ·C E ·E mix

[0060] In the formula, E mix For stirring 1m 3 Electricity consumption of concrete (kWh / m 3 ).

[0061] Phase 8: Concrete transportation.

[0062] P8=C L ·L c ·M c

[0063] In the formula, C L Carbon dioxide emissions generated by transporting 1kg of concrete (kg CO2 / kg); L c is the transportation distance of concrete (km); M c is the mass of concrete per cubic meter per megapascal (kg / m 3 / MPa).

[0064] Phase 9: Construction.

[0065] P9=α f ·C con / V c

[0066] In the formula, C con =M×S is the carbon dioxide emissions during construction, M=X+1.99 is the carbon dioxide emissions per square meter of construction area (kg CO2 / m 2 ), X is the number of floors above the ground, S is the building area (m 2 );V c =v c ×S is the volume of concrete, v c The amount of concrete used per square meter of building area (kg / m 2 ).

[0067] Phase 10: Repair.

[0068]

[0069] In the formula, C hh is the carbon dioxide emissions of the materials used for maintenance; l is the total number of materials used for maintenance, and commonly used materials include concrete, steel bars, composite materials, structural adhesives, etc.; Y is the service life of the building; T m The maintenance interval time.

[0070] Phase 11: Demolition

[0071]

[0072] In the formula, C dem,j is the carbon dioxide emission of demolition step j; m is the total number of demolition steps, which generally includes two steps: component dismantling and crane transportation.

[0073] Phase 12: Waste transportation.

[0074]

[0075] In the formula, Carbon dioxide emissions generated by transporting 1kg of demolition waste (kg CO2 / kg); L waste The distance to transport demolition waste.

[0076] Stage 13: Waste disposal (natural aggregate concrete only).

[0077] P13=(C diesel ·D process +C E ·E process )·M c

[0078] Where D process The amount of diesel required to treat 1 kg of demolition waste (L / kg); E process The electricity consumption for processing 1kg of demolition waste; C diesel The amount of CO2 emitted for consuming 1 litre of diesel.

[0079] Stage 14: Landfill (natural aggregate concrete only).

[0080] P14=C diesel ·D land ·M c

[0081] Where D land The amount of diesel required to landfill 1kg of demolition waste (L / kg).

[0082] Step S2: Based on the several stages, determine the life cycle of different types of concrete. The different types of concrete include: natural aggregate concrete, recycled aggregate concrete and carbonized modified recycled aggregate concrete.

[0083] like Figure 2 As shown in the figure, the calculation of carbon emissions of green low-carbon concrete throughout its life cycle is divided into 14 steps. The first step is the production of raw materials, including the production of cement, coarse aggregate, recycled building materials (limited to recycled aggregate concrete and carbonized modified recycled aggregate concrete), sand, water, fly ash, slag, high-efficiency water reducer, etc.; the second step is the transportation of raw materials; the third to sixth steps are only for carbonized modified recycled aggregate concrete, including carbon dioxide collection, carbon dioxide transportation, carbon dioxide maintenance and carbon dioxide solidification; the seventh step is concrete production; the eighth step is concrete transportation; the ninth step is construction; the tenth step is maintenance, and the carbon emission calculation results of the maintenance stage of different types of concrete will vary due to differences in durability; the eleventh step is demolition; the twelfth step is waste transportation; the thirteenth and fourteenth steps are waste treatment and landfill, respectively, only for natural aggregate concrete.

[0084] Therefore, the life cycle of the natural aggregate concrete includes: raw material production, raw material transportation, concrete production, concrete transportation, construction, maintenance, demolition, waste transportation, waste treatment and landfill; the life cycle of the recycled aggregate concrete includes: raw material production, raw material transportation, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation; the life cycle of the carbonization-modified recycled aggregate concrete includes: raw material production, raw material transportation, carbon dioxide collection, carbon dioxide transportation, carbon dioxide maintenance, carbon dioxide solidification, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation.

[0085] Step S3: based on the life cycle of the different types of concrete and the carbon dioxide emissions in each stage, calculating the life cycle carbon dioxide emissions of the different types of concrete.

[0086] Based on the above calculation method, the life cycle carbon dioxide emissions of natural aggregate concrete are C NAC It can be determined according to the following formula, which includes P1, P2, P7, P8, P9, P10, P11, P12, P13 and P14.

[0087]

[0088] Life cycle CO2 emissions of recycled aggregate concrete RAC It can be determined according to the following formula, which includes P1, P2, P7, P8, P9, P10, P11 and P12.

[0089]

[0090] Life cycle carbon dioxide emissions of carbonized modified recycled aggregate concrete CRACIt can be determined according to the following formula, which includes P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11 and P12.

[0091]

[0092] Step S4: Calculate the net carbon dioxide benefits of recycled aggregate concrete and carbonation-modified recycled aggregate concrete according to the life cycle carbon dioxide emissions of the different types of concrete.

[0093] NetCO2 Benefit of Recycled Aggregate Concrete RAC The calculation is as follows.

[0094] NetCO2 Benefit RAC =C NAC -C RAC

[0095] NetCO2 Benefit of Carbonated Modified Recycled Aggregate Concrete CRAC The calculation is as follows.

[0096] NetCO2 Benefit CRAC =C NAC -C CRAC

[0097] This application can effectively evaluate the carbon emissions and carbon benefits of green low-carbon concrete throughout its life cycle through the above calculation method. It can be used in scenarios such as estimating the carbon emissions of concrete throughout its life cycle in structural design and evaluating the carbon emissions of existing building structures throughout their life cycle. Based on the calculation of carbon emissions of various green low-carbon concrete throughout its life cycle and the analysis results of the impact of various factors, it can also provide a reference for the formulation of policies in the construction, environment, new energy and other industries.

[0098] In an exemplary embodiment, the present application further provides a computer device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0099] In an exemplary embodiment, the present application further provides a computer-readable storage medium storing a computer program, which implements the steps in the above-mentioned method embodiments when executed by a processor.

[0100] In an exemplary embodiment, the present application further provides a computer program product, including a computer program, which implements the steps in the above-mentioned method embodiments when executed by a processor.

[0101] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant legal provisions.

[0102] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0103] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0104] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for evaluating the carbon benefits of green low-carbon concrete over its entire life cycle, characterized in that: include: Divide the entire life cycle of concrete into several stages and calculate the carbon dioxide emissions in each stage; The several stages include: raw material production, raw material transportation, carbon dioxide collection, carbon dioxide transportation, carbon dioxide maintenance, carbon dioxide solidification, concrete production, concrete transportation, construction, maintenance, demolition, waste transportation, waste treatment and landfill; Based on the several stages, the life cycles of different types of concrete are determined; the different types of concrete include: natural aggregate concrete, recycled aggregate concrete and carbonized modified recycled aggregate concrete; Calculating the life cycle carbon dioxide emissions of different types of concrete based on the life cycles of the different types of concrete and the carbon dioxide emissions at each stage; The net CO2 benefits of recycled aggregate concrete and carbonation-modified recycled aggregate concrete were calculated based on the life cycle CO2 emissions of the different types of concrete.

2. The method for evaluating the carbon benefits of green low-carbon concrete over its entire life cycle according to claim 1 is characterized by: The life cycle of natural aggregate concrete includes: raw material production, raw material transportation, concrete production, concrete transportation, construction, maintenance, demolition, waste transportation, waste treatment and landfill; The life cycle of recycled aggregate concrete includes: raw material production, raw material transportation, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation; The life cycle of the carbonized modified recycled aggregate concrete includes: raw material production, raw material transportation, carbon dioxide collection, carbon dioxide transportation, carbon dioxide maintenance, carbon dioxide solidification, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation.

3. The method for evaluating the carbon benefits of green low-carbon concrete over its entire life cycle according to claim 2 is characterized in that: The expression of the life cycle carbon dioxide emission of natural aggregate concrete is: Among them, C NAC is the life cycle carbon dioxide emissions of natural aggregate concrete; M i is the mass of raw material i used in concrete per cubic meter per MPa; C Mi The carbon dioxide emissions generated to produce 1kg of raw material i; C Li The amount of carbon dioxide emissions generated by transporting 1kg of raw material i; L i is the transportation distance of raw material i; α f =1 / f cu is the coefficient considering the influence of concrete compressive strength, f cu is the compressive strength of concrete; C E is the carbon dioxide intensity of electricity; E mix For stirring 1m 3 Electricity consumption of concrete; C L Carbon dioxide emissions generated by transporting 1kg of concrete; L c is the transportation distance of concrete; M c C is the mass of concrete per cubic meter per MPa; con =M×S is the carbon dioxide emissions during the construction period, M=X+1.99 is the carbon dioxide emissions per square meter of building area, X is the number of floors above the ground, S is the building area; V c =v c ×S is the volume of concrete, v c C is the amount of concrete used per square meter of building area; h h is the carbon dioxide emissions from the materials used for maintenance; Y is the service life of the building; T m is the maintenance interval; C dem,j is the carbon dioxide emission of demolition step j; Carbon dioxide emissions generated for transporting 1kg of demolition waste; L waste is the transportation distance of demolition waste; C diesel The amount of carbon dioxide emitted when consuming 1 liter of diesel; D process The amount of diesel required to process 1 kg of demolition waste; E process The electricity consumption for processing 1kg of demolition waste; D land is the amount of diesel required to landfill 1 kg of demolition waste; n is the total number of raw material types; l is the total number of material types used for repair; m is the total number of demolition steps.

4. The method for evaluating the carbon benefits of green low-carbon concrete over its entire life cycle according to claim 3 is characterized in that: The expression of the life cycle carbon dioxide emissions of the recycled aggregate concrete is: Among them, C RAC Life cycle CO2 emissions of recycled aggregate concrete.

5. The method for evaluating the carbon benefits of green low-carbon concrete over its entire life cycle according to claim 4 is characterized in that: The expression of the life cycle carbon dioxide emission of the carbonized modified recycled aggregate concrete is: Among them, C CRAC Life cycle CO2 emissions of carbonation-modified recycled aggregate concrete; is the coefficient related to the carbon dioxide recovery efficiency; The amount of CO2 emissions generated for transporting 1kg of CO2; is the transport distance of carbon dioxide; is the mass of captured carbon dioxide, C RA is the mass of carbon dioxide captured per 1kg of recycled aggregate, M RA is the mass of recycled aggregate; V RAC 1m 3 The volume of recycled aggregate used in concrete; E cur For carbonization 1m 3 Power of recycled aggregate; T cur is the duration of CO2 curing.

6. The method for evaluating the carbon benefits of green low-carbon concrete over its entire life cycle according to claim 4 is characterized in that: The net CO2 benefit of recycled aggregate concrete is expressed as: NetCO2 Benefit RAC =C NAC -C RAC Among them, NetCO2 Benefit RAC Net CO2 benefits of recycled aggregate concrete.

7. The method for evaluating the carbon benefits of green low-carbon concrete over its entire life cycle according to claim 5 is characterized in that: The net carbon dioxide benefit of the carbonation-modified recycled aggregate concrete is expressed as: NetCO2 Benefit CRAC =C NAC -C CRAC Among them, NetCO2 Benefit CRAC Net CO2 benefits of carbonation-modified recycled aggregate concrete.

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