A method for evaluating the carbon benefits of green and low-carbon concrete throughout its life cycle

Abstract

This application discloses a method for evaluating the carbon benefits of green and low-carbon concrete over its entire life cycle, which relates to the field of energy conservation and environmental protection technology. The method comprises: dividing the entire life cycle of concrete into several stages and calculating the carbon dioxide emissions of each stage; determining the life cycle of different types of concrete based on the several stages; calculating the life cycle carbon dioxide emissions of different types of concrete based on the life cycle of the different types of concrete and the carbon dioxide emissions of each stage; and calculating the net carbon dioxide benefits of recycled aggregate concrete and carbonization-modified recycled aggregate concrete based on the life cycle carbon dioxide emissions of the different types of concrete. By establishing a comprehensive evaluation method system, this application can effectively calculate the carbon emissions and carbon benefits of green and low-carbon concrete over its entire life cycle.

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 throughout its entire life cycle. Background Art

[0002] The sustainable development of the construction industry faces two real challenges: a shortage of natural aggregates and the disposal of construction waste. With the construction and development of cities, the demand for concrete continues to increase. Coarse and fine aggregates account for approximately three-quarters of concrete's total weight. Natural aggregates, as a non-renewable resource in the short term, are unable to meet this growing demand. Furthermore, as earlier concrete structures gradually reach the end of their service life, they generate significant amounts of construction waste. This increase in construction waste has a negative impact on the environment. Therefore, the research and application of green, low-carbon building materials has become a pressing task for 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 still immature. 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 evaluation method for the carbon benefits of green low-carbon concrete throughout its entire life cycle. By establishing a complete evaluation method system, the carbon emissions and carbon benefits of green low-carbon concrete throughout its entire life cycle can be effectively calculated.

[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 throughout its life cycle includes:

[0007] Divide the entire life cycle of concrete into several stages and calculate the CO2 emissions of each stage; the stages include: raw material production, raw material transportation, CO2 collection, CO2 transportation, CO2 curing, CO2 solidification, concrete production, concrete transportation, construction, maintenance, demolition, waste transportation, waste treatment and landfill;

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

[0009] Calculating 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 curing, carbon dioxide solidification, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation.

[0012] Optionally, the expression for the life cycle carbon dioxide emissions 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 amount of 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 The amount of carbon dioxide emissions generated by transporting 1kg of concrete; L c is the transportation distance of concrete; M c is the mass of concrete per cubic meter per MPa; C con =M×S is the carbon dioxide emissions during construction, M=X+1.99 is the carbon dioxide emissions per square meter of building area, X is the number of floors above the ground, and 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 emissions of demolition step j; Carbon dioxide emissions generated by 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 for the life cycle carbon dioxide emissions of the recycled aggregate concrete is:

[0016]

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

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

[0019]

[0020] Among them, C CRAC The life cycle CO2 emissions of carbonation-modified recycled aggregate concrete; is the coefficient related to the carbon dioxide recovery efficiency; The amount of carbon dioxide emissions generated for transporting 1kg of carbon dioxide; is the transport distance of carbon dioxide; is the mass of captured carbon dioxide, C RA M is the mass of carbon dioxide captured per 1 kg of recycled aggregate, 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 carbon dioxide 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 The net CO2 benefit 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 the life cycle of different types of concrete. 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 realizing 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 following briefly introduces the drawings required for use in the embodiments. 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 creative work.

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

[0031] Figure 2 A flow chart 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 this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0033] Waste concrete can be screened, crushed, cleaned, and graded to produce recyclable aggregate that can be used to replace natural aggregate 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 produce CaCO3 and amorphous silica gel, which can fill the pores of the recycled aggregate and reduce the porosity of the concrete.

[0034] Therefore, research has focused on the mechanical properties, durability, and environmental benefits of carbonization-modified recycled aggregate concrete (CRAC). Existing research indicates that carbonization of recycled aggregate is an effective method for CO₂ fixation. Carbonation of recycled aggregate can improve the compressive and flexural strength of recycled concrete, with a particularly beneficial impact on its durability. As strength increases, concrete volume can be reduced for the same load-bearing capacity, and as concrete durability improves, maintenance frequency can be reduced over its service life. Carbonation modification can improve both concrete strength and durability, resulting in significant environmental benefits.

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

[0036] Compared to NAC, RAC emits higher CO₂ during concrete production but lower CO₂ emissions during waste disposal and landfill. Carbonation modification increases CO₂ emissions during CO₂ collection, CO₂ transportation, and CO₂ curing, but it can sequester CO₂ and improve concrete strength and durability. Therefore, both the use of recycled aggregates and carbonation modification have advantages and disadvantages in generating net climate benefits. Whether CRAC truly has positive net CO₂ benefits warrants careful consideration and quantitative analysis.

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

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to 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 CO2 emissions for each stage. The stages include: raw material production P1, raw material transportation P2, CO2 collection P3, CO2 transportation P4, CO2 curing P5, CO2 solidification P6, concrete production P7, concrete transportation P8, construction P9, maintenance P10, demolition P11, waste transportation P12, waste treatment P13, and landfill P14. The CO2 emissions for 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] Where 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] Where, is a coefficient related to the carbon dioxide recovery efficiency.

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

[0051]

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

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

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

[0055] Where, 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: Carbon dioxide absorption (only for carbonized modified recycled aggregate concrete).

[0057]

[0058] Phase 7: Concrete production.

[0059] P7=α f ·C E ·E mix

[0060] Where, 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] Where 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 MPa (kg / m 3 / MPa).

[0064] Phase 9: Construction.

[0065] P9=α f ·C con / V c

[0066] Where 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] Where C hh is the carbon dioxide emissions from 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] Where 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] Where, 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 process 1 kg of demolition waste (L / kg); E process The electricity consumption for processing 1kg of demolition waste; C diesel The amount of carbon dioxide emitted for consuming 1 liter 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 plurality of stages, determining the life cycles of different types of concrete, including 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; steps 3 to 6 are only for carbonized modified recycled aggregate concrete, including carbon dioxide collection, carbon dioxide transportation, carbon dioxide curing and carbon dioxide solidification; step 7 is concrete production; step 8 is concrete transportation; step 9 is construction; step 10 is maintenance, and the carbon emission calculation results of the maintenance stage of different concrete types will vary due to differences in durability; step 11 is demolition; step 12 is waste transportation; steps 13 and 14 are waste treatment and landfill, respectively, which are 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 curing, carbon dioxide solidification, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation.

[0085] Step S3: Calculating the life cycle carbon dioxide emissions of the different types of concrete based on the life cycles of the different types of concrete and the carbon dioxide emissions at each stage.

[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 carbon dioxide 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: Calculating the net carbon dioxide benefits of the recycled aggregate concrete and the carbonization-modified recycled aggregate concrete based on the life cycle carbon dioxide emissions of the different types of concrete.

[0093] Net CO2 Benefit of Recycled Aggregate Concrete RAC The calculation is as follows.

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

[0095] Net CO2 Benefit of Carbonated Modified Recycled Aggregate Concrete CRAC The calculation is as follows.

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

[0097] This application uses the aforementioned calculation method to effectively assess the carbon emissions and carbon benefits of green, low-carbon concrete throughout its lifecycle. This method can be used in scenarios such as estimating carbon emissions throughout the lifecycle of concrete in structural design and assessing the carbon emissions of existing building structures throughout their lifecycles. Based on the calculations of carbon emissions throughout the lifecycle of various green, low-carbon concretes and the analysis of the impact of various factors, this method can also provide a reference for policy development in industries such as construction, environment, and new energy.

[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 will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. 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 memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may 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 may 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 databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may include, but are not limited to, general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic units, data processing logic units based on quantum computing, and the like.

[0104] The technical features of the above embodiments can 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 document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may 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 throughout its 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, CO2 collection, CO2 transportation, CO2 curing, CO2 solidification, concrete production, concrete transportation, construction, repair, demolition, waste transportation, waste treatment and landfill; Based on the several stages, determining the life cycles of different types of concrete; the different types of concrete include: natural aggregate concrete, recycled aggregate concrete, and carbonized modified recycled aggregate concrete; The life cycle of natural aggregate concrete includes: raw material production, raw material transportation, concrete production, concrete transportation, construction, repair, demolition, waste transportation, waste disposal and landfill; The expression of the life cycle carbon dioxide emissions of the 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 amount of 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 The amount of 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 construction, M=X+1.99 is the carbon dioxide emissions per square meter of building area, X is the number of floors above the ground, and 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 emissions of demolition step j; is the carbon dioxide emissions generated by transporting 1 kg of demolition waste; L waste C is the transportation distance of demolition waste; 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 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 materials used for repair; m is the total number of demolition steps 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, CO2 collection, CO2 transportation, CO2 curing, CO2 solidification, concrete production, concrete transportation, construction, maintenance, demolition and waste transportation; Calculating 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 throughout its life cycle according to claim 1 is characterized in that: The expression of the life cycle carbon dioxide emissions of the recycled aggregate concrete is: Among them, C RAC is the life cycle CO2 emissions of recycled aggregate concrete.

3. The method for evaluating the carbon benefits of green low-carbon concrete throughout its life cycle according to claim 2, characterized in that: The expression of the life cycle carbon dioxide emission of the carbonized modified recycled aggregate concrete is: Among them, C CRAC The life cycle CO2 emissions of carbonation-modified recycled aggregate concrete; is the coefficient related to the carbon dioxide recovery efficiency; The amount of carbon dioxide emissions generated for transporting 1kg of carbon dioxide; is the transport distance of carbon dioxide; is the mass of captured carbon dioxide, C RA M is the mass of carbon dioxide captured per 1 kg of recycled aggregate, 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 carbon dioxide curing.

4. The method for evaluating the carbon benefits of green low-carbon concrete throughout its life cycle according to claim 2, characterized in that: The net carbon dioxide benefit of recycled aggregate concrete is expressed as: NetCO2 Benefit RAC =C NAC -C RAC Among them, NetCO2Benefit RAC The net CO2 benefit of recycled aggregate concrete.

5. The method for evaluating the carbon benefits of green low-carbon concrete throughout its life cycle according to claim 3 is characterized in that: The net carbon dioxide benefit of the carbonized modified recycled aggregate concrete is expressed as: NetCO2 Benefit CRAC =C NAC -C CRAC Among them, NetCO2Benefit CRAC Net CO2 benefits of carbonation-modified recycled aggregate concrete.

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