While various methodologies for quantifying carbon emissions of pavement construction are developed worldwide, adopting and promoting the existing tools to China's market is found fairly challenging due to institutional constraints. Therefore, the objectives of this study are to propose a methodology for measuring carbon emissions of pavement construction compatible with the fixed pricing systems prevalent in China; and develop an automatic tool for carbon estimations. The total carbon emissions are measured by aggregating emissions of energy consumption and materials used along with four stages, namely material manufacture, transportation, construction, and disposal. A set of composite carbon emission factors for energy and materials was calculated based on existing emission factors with the consideration of the boundaries concerned. The quantity of energy and materials used in pavement construction are obtained through bills of quantity and the fixed price system. The database of the emission factors for energy and materials was embedded into a C# based tool, and validated in a real case.Keywords: carbon emission calculation; pavement construction; China
BackgroundIt is predicted that, by 2020, carbon emission of infrastructure projects in China will reach 0.197 billion tons [1]. Pavement construction is one of the significant contributors. According to the China Statistical Yearbook (2012), the numbers of municipal projects including pavement projects under construction and planned were 47097 and 30079, respectively in 2011 [2]; and these numbers are still increasing along with the rapid urbanization. To reduce carbon emissions, quantifying them is of significant importance. While various methodologies are available for quantifying carbon emission of pavement construction worldwide, adopting and promoting the existing tools to China's market is found to be fairly challenging due to the institutional constraints. Research widely recognized that carbon emission calculation varies across different countries due to difference associated with parameters, data source, construction methods and regional conditions [3,4]. This renders the comparison between different countries complex and difficult [4]. Another hindrance to carbon emission estimation for pavement construction is the scarcity of reliable data [5]. It is worth noting that, recently, Wang et al.'s (2015) and Ma et al.'s (2016) studies presented a list of carbon emission factors for pavement construction in China [6,7]. However, uptake of these factors would face challenges as practitioners have to collect a separate panel of data for the calculation methodology.The objectives of this study are to develop a carbon emission calculation methodology with a customized database; and develop an automatic tool for carbon emission estimation. The customized database is compatible with the fixed pricing systems (Dinge) prevalent in China. Therefore, practitioners