Carbon-emission calculation method during operation period based on asphalt pavement performance

The present study elucidates the comparison of thermal performance of pavement materials, namely asphalt and concrete. Albedo value of a material is considered to be a crucial parameter to evaluate thermal performance of engineering/natural materials. Experimental investigations reported in the literature suggest, albedo values of concrete pavement to be in the range of 0.25–0.4, whereas the values for asphalt pavement range from 0.05–0.10. The lower albedo value is associated with higher energy absorption and hence higher surface temperature. Based on the albedo values, it has been established that asphalt pavement exhibits higher surface temperature than PCC pavement. Through surface temperature, pavement materials also influence the energy consumption and carbon emissions. The present study highlights the recent advancements towards enhancing the thermal performance of asphalt and concrete pavement. The literature studies confirm that the enhancement in thermal performance of asphalt pavement has been mostly achieved by the application of additives in asphalt and/or utilization of high albedo aggregates. On the contrary, concrete pavement despite being superior in performance as compared to asphalt; fewer studies have attempted to improve the albedo values (viz., better thermal performance) of concrete pavement. The present review summarizes the current state of the art on the role of pavement materials on UHI effects and also suggests future direction towards making cities more sustainable, with lower UHI effects.KeywordsUrban heat islandPavement materialsAlbedoSurface temperatureConcreteAsphalt

An integrated construction station for an expressway is characterized by complex carbon emission sources and high carbon emission intensity. Conducting carbon emissions accounting makes possible a comprehensive understanding of these characteristics, enabling targeted and guided carbon reduction efforts, which is crucial for advancing the low-carbon development of expressway construction. This paper, based on an in-depth analysis of the carbon emission structure during the operational period of an integrated expressway construction station identifies, as calculation boundaries, eight categories: residential areas, station transportation, mixing stations, precast beams, steel bar yards, artificial carbon emissions, chemical reactions during construction, and construction conditions. The study adopts a “bottom-up” approach to carbon emission measurement and constructs a carbon emission model for the production and operational period of the integrated construction station, based on the carbon emission factor method. Using the SG-2 section of the Fengqiu to Xiuwu stretch of the Changxiu Expressway as an engineering case, carbon emissions accounting for each component of the integrated construction station’s operational period was conducted, and the results were compared with the station’s monitoring system. High-precision characterization and calculation of total carbon emissions, as well as emissions from each process and piece of equipment during the operational period, were achieved. The results indicate that: (1) the relative error between the overall calculation results and actual monitoring is 3.6%, verifying the model’s accuracy; (2) the monthly carbon emissions of the integrated construction station during the operational period reached 72.15 tons; (3) there is a significant difference in carbon emissions among the different processes, with the highest emissions coming from transportation and residential areas, accounting for 43.4% and 23.7%, respectively. Therefore, electrification of transportation equipment could significantly reduce the overall carbon emissions of the integrated construction station.

Expressways in mountainous plateau areas exhibit complex driving conditions and harsh climatic characteristics that continuously impact vehicle carbon emissions throughout their entire lifecycle and determine the carbon emission levels of expressways during the operational period. To study the carbon emission characteristics of expressways in the western Sichuan Plateau mountainous area, a coupling simulation analysis method combining CarSim/TruckSim simulation software and the Motor Vehicle Emissions Simulator (MOVES) was employed to analyze the spatial distribution characteristics of vehicle-specific power (VSP). This analysis was based on the alignment data and operational environment of the Wenchuan‒Barkam Expressway in the mountainous area of the western Sichuan Plateau. A conversion formula was established to calculate the cumulative VSP per second and total carbon emissions of each unit. Statistical analysis was conducted on the distribution of carbon emissions equivalent per kilometer across the different alignment units. Distribution ranges of carbon emissions equivalent per kilometer for light-duty vehicles (LDVs) and heavy-duty vehicles (HDVs) at each alignment unit were 60‒240 g and 100‒1600 g, respectively. The grey relational analysis method was used to quantify the relationship between the carbon emissions equivalent per kilometer of alignment units, circular curves radius, and average grade. Based on the vertical variations in climatic changes with altitude in the mountainous plateau area, a comparative analysis was performed on the trends in the effects of altitude, season, and vehicle starting frequency on carbon emissions. Frequent vehicle starts significantly impacted carbon emissions, and this impact was significantly higher in winter than in summer. Carbon emissions equivalent of the LDV and HDV starting twice on average in summer were approximately 1.09- and 1.04-times higher, respectively, than that when vehicles were started 0.5 times; whereas, in winter, they were 1.17- and 1.07-times higher, respectively.

ABSTRACTThe performance of asphalt pavement is highly affected by climate factors, such as temperature and precipitation. Different temperature and moisture conditions change the paving material properties, which consequently influence pavement performance. Considerable research has been conducted to study the effect of climate factors on pavement performance; however, there are no focused studies that have investigated the performance of asphalt pavements in cold regions. In this research, the effect of different design factors on asphalt pavement performance in cold regions is investigated utilising data extracted from the Long-Term Pavement Performance database. Only control sections with no historical maintenance or rehabilitation records were considered. The International Roughness Index (IRI) was adopted as the pavement performance measure. The IRI value is expected to increase gradually over time due to pavement deterioration. Initial screening of the data showed that most of the pavement sections experienced remarkable IRI increase followed by an unexpected decrease. An in-depth investigation revealed that frost heave was the main reason of this unexpected IRI trend as it was correlated in most of the cases to sudden monthly freezing index increases, especially for sections with no subsurface drainage and less layers thicknesses. An Artificial Neural Network with a Forward Sequential Feature Selection algorithm and regression analysis were employed to model pavement performance in cold regions and determine the most significant design factors prevailing in cold climate conditions. Moreover, a sensitivity analysis was performed to investigate the interrelation between the considered features and the IRI. As a result, several climate-related factors were found to have a significant impact on the performance of asphalt pavements in cold regions such as average temperature, freezing index, freeze/thaw, wind velocity and relative humidity.

An online carbon emission accounting method based on B/S structure for coal mines owned by the Coal Industry Group is proposed. Firstly, the carbon emission accounting method for coal mines owned by the Coal Industry Group is expounded, which is the basis of carbon emission accounting for coal mines. Secondly, an online accounting path of carbon emission for coal mines owned by the Coal Industry Group is proposed: The traditional top-down standalone accounting process of "carbon emission data acquisition, carbon emission calculation, carbon emission publication" is replaced by the bottom-up online accounting process of "carbon emission accounting tasks assignment, carbon emission data submission, carbon emission data audit, carbon emission calculation, carbon emission view", and the manual table lookup is replaced by system automatic table lookup to realize online calculation of carbon emissions. Then, taking Sql server as the database management system, ASP, C# as the development language, Dreamweaver, Visual Studio as the development platform, an online carbon emission accounting system based on B/S structure for coal mines owned by the Coal Industry Group is designed, which realizes online carbon emission accounting for coal mines owned by the Coal Industry Group. Finally, the application analysis results show that the method proposed in this paper can not only significantly improve the efficiency and accuracy of carbon emission accounting for coal mines owned by the Coal Industry Group, but also realize online sharing and comparison of accounting results, which is conducive for the Coal Industry Group to implement targeted monitoring and improvement of carbon emissions for coal mines owned by the Coal Industry Group.

To reduce carbon emissions during the construction period of roads, carbon emission calculations and carbon reduction suggestions for roads have been researched in this paper. The calculation method for carbon emissions and the key influencing factors of carbon emissions during the construction period have been presented and analyzed based on the Ningwu Expressway in Anhui Province. The research results show that the material production phase contributed over 90% of carbon emissions, making it the primary control object for engineering carbon reduction. Interchange engineering contributed the highest carbon emission amount and intensity, which seemed to be the key unit construction that needed control. Cement and steel have a significant carbon emissions impact on interchange engineering, with a proportion over 80% of carbon emissions. Energy carbon emissions mainly came from oil-electric hybrid construction facilities, nearly three times higher than the carbon emissions from electrical construction facilities. Suggestions have been proposed to reduce carbon emissions during the road construction period based on the research results, which aim to provide effective support for low-carbon construction and boost transformation development for roads in China.

Asphalt pavement, which is mainly made up of the asphalt mixture, exhibits complicated mechanical behaviors under the combined effects of moving vehicle loads and external service environments. Multi-scale numerical simulation can well characterize behaviors of asphalt materials and asphalt pavement, and the essential research progress is systematically summarized from an entire view. This paper reviews extensive research works concerning aspects of the design, characterization, and prediction of performance for asphalt materials and asphalt pavement based on multi-scale numerical simulation. Firstly, full-scale performance modeling on asphalt pavement is discussed from aspects of structural dynamic response, structural and material evaluation, and wheel-pavement interaction. The correlation between asphalt material properties and pavement performance is also analyzed, and so is the hydroplaning phenomenon. Macro- and mesoscale simulations on the mechanical property characterization of the asphalt mixture and its components are then investigated, while virtual proportion design for the asphalt mixture is introduced. Features of two-dimensional and three-dimensional microscale modeling on the asphalt mixture are summarized, followed by molecular dynamics simulation on asphalt binders, aggregates, and their interface, while nanoscale behavior modeling on asphalt binders is presented. Finally, aspects that need more attention concerning this study's topic are discussed, and several suggestions for future investigations are also presented.

Carbon emission calculation of prefabricated concrete composite slabs during the production and construction stages

Characterization of the emissions impacts of hybrid excavators with a portable emissions measurement system (PEMS)-based methodology

This study seeks to assess both environmental and economic effects associated with installing photovoltaic systems within construction waste landfills in Macau by employing an effective carbon emissions calculation methodology and benefit analysis method. Beginning by outlining characteristics and challenges associated with construction waste landfills, as well as photovoltaic systems used for this application in this paper. Here, we present a detailed outline of our methodology design, outlining its principles of life cycle analysis, data collection processes and the creation of carbon emissions calculation models. Subsequently, we examine photovoltaic systems within Macau's construction waste landfills by studying system design, component selection and operational strategies as well as carbon emission data collection during their operational time period. Under life cycle carbon emissions calculations, we assess the carbon emissions generated from photovoltaic systems as well as conduct an environmental and economic benefit analysis for carbon reduction benefit analysis purposes. This research incorporates sensitivity analysis and uncertainty consideration in order to conduct an extensive benefit analysis. The research results offer strong support for sustainable photovoltaic systems within Macau waste landfills as well as insights to inform planning and policy formation for similar future projects.

Thermal power industry is one of the six biggest carbon emissions industries in China. Researchers did innumerable studies in reducing carbon emissions of thermal power plants (TPP). However, most studies are focused on the calculation and prediction of China's total carbon emissions, while few studies are focused on specific TPP carbon emissions. There are 3 parts in developing this paper; first, the main ideas of the project life cycle’s calculation methods, construction periods and operation periods are summarized. Secondly, Intergovernmental Panel on Climate Change (IPCC) carbon emission factor mode, practical measurement mode, mass conservation mode and quantifying mode are discussed in detail. This paper aims to determine the optimal development path for thermal plants through the detailed discussion of the existing research results of a specific TPP project’s carbon emissions issue.

Carbon peaking and carbon neutrality goals are the focus of widespread attention at present, and reducing the carbon emission of power high-voltage transmission line projects becomes inevitable. In this paper, a carbon emission calculation method is proposed for overhead transmission line projects by investigating the relevant carbon emission accounting systems and calculation standards at home and abroad and comparing a variety of different carbon emission calculation methods. The construction process of the entire life cycle is broken down into four stages, which makes the calculation process clearer, through the analysis of the carbon emission sources in the construction process, the corresponding carbon emission factors are determined by the carbon emission factor table given, and the carbon emission of the whole life cycle is calculated by the relevant formula. Overhead transmission line construction processes and carbon emission factors for various activities are taken into account to improve the reliability of the results. Then, inducing by a practical case, the carbon emission is calculated for all stages. The complete results demonstrated that the carbon emission from the production phase account for 86.1% of the overall carbon emissions without considering the demolition phase. The method proposed in this paper can be used to calculate the carbon emissions of each stage of overhead transmission line construction project, and provide clear results for the carbon emissions of the whole project.

The power industry plays a crucial role in achieving the carbon reduction objectives and facilitating the transition towards a low-carbon economy and society. This study employed the IPCC carbon emission coefficient method to calculate the carbon emissions of the power industry in Fujian Province from 2001 to 2021. To predict the carbon emissions of the power industry in Fujian Province from 2022 to 2030, this article established a STIRPAT model based on ridge regression. Empirical research was carried out in this study to investigate the timing of carbon peaking and peak carbon emissions in the power industry of Fujian Province, considering various scenarios. The calculation of carbon emissions indicates that the overall carbon emissions in the electricity industry in Fujian Province showed an upward trend from 2001 to 2021. By 2021, the emissions reached 9.646×107 tons, and the carbon emissions peak has not been reached. Scenario simulation analysis shows that under the energy-saving scenario, the electricity industry in Fujian Province is projected to reach its carbon emissions peak in 2025, with a peak value of 9.687×107 tons. However, in the baseline and ideal scenarios, the carbon emissions in the electricity industry in Fujian Province are projected to not peak before 2030. By 2030, the emissions are estimated to be 9.853×107 tons and 1.067×108 tons, respectively. The article concludes by presenting a comprehensive analysis of the most effective approach towards achieving carbon peaking in the power industry within Fujian Province. This is accomplished by examining the issue from various angles, including government planning, power generation structure, industrial structure, and public awareness.

Purpose This study aims to explore the influencing factors of the spatial and temporal distribution of carbon emissions from the logistics industry in Northwestern provinces of China, so as to provide a policy basis and theoretical guidance for the logistics industry in these provinces to achieve carbon emission reduction goals. Design/methodology/approach Based on the calculation of carbon emissions from the logistics industry in Northwestern provinces of China during 2013–2023, this study analyzes their spatial and temporal differentiation characteristics. From the logistics-economy-society dimension, the Logarithmic Mean Divisia Index (LMDI) and Multi-Regional (M-R) decomposition models are used to investigate the influencing factors of carbon emissions. Findings The results indicate that economic development and logistics industry structure promote logistics carbon emissions, while energy intensity, energy structure, and employment scale restrain them. Temporally, total carbon emissions fluctuated upward from 2013 to 2019, dropped sharply in 2020, rose slightly in 2021, and then declined gradually. Spatially, in 2023, carbon emissions in Xinjiang and Gansu exceeded the regional average due to high energy intensity and unreasonable logistics structure; Xinjiang was also affected by its large employment scale. Carbon emissions in Shaanxi, Qinghai and Ningxia were below the regional average. Originality/value This study breaks through the application boundaries of the LMDI and M-R decomposition models and extends them to the regional industry research level; it reveals the specific causes of spatial and temporal differences in carbon emissions from the logistics industry in Northwestern provinces of China.

The whole life cycle carbon emission of buildings was calculated in this paper. Based on the whole life cycle evaluation theory, a carbon emission calculation model was established by using a single urban building as an example. The whole life cycle building of carbon emission calculation includes five stages: planning and design, building materials preparation, construction, operational maintenance, as well as dismantlement. It provides a reference for standardizing the calculation process of building carbon emissions by analyzed the carbon emissions and composition characteristics of each stage of the life cycle of the case house. The calculation results demonstrate that the carbon emission during the operational maintenance and building materials preparation stages in the whole life cycle of the building account for 78.05% and 20.59% respectively. These are the two stages with the greatest emission reduction potential.