ABSTRACT
The objective of this paper is to assess the technical and organizational challenges to extending the current Product Category Rule (PCR) for North American asphalt mixtures to include the asphalt pavement construction stage. The extant literature on pavement construction Life Cycle Assessment (LCA) tends to focus on assessing the environmental impacts of alternative designs emphasizing the life cycle accounting. There is limited consideration of the challenges a contractor encounters when reporting LCA outcomes using International Organization of Standardization (ISO) compliant documents. The organizational context defined by different project delivery scenarios, as well as how ISO defines “construction elements”, calls for a re-examination of the system boundary and other technical questions regarding cut-off and exclusions, thus determining the extent of data collection, and the relevant data quality requirements for a construction stage LCA. For instance, as per ISO Standard 21930, the asphalt pavement is considered to be a construction element, separate and independent of other construction elements and operations, and hence becomes a subset of the traditional construction stage system boundary. The paper also examines the effect of project delivery systems on construction project data reporting, the quality of available data, and its impact on the development of estimates, and their use with respect to actual reported project emissions. Scenarios in which contractors can use the PCR to improve their construction processes in addition to lowering environmental impacts are also identified. The outcomes of the analysis in this paper can inform the development of construction stage PCR for pavements while providing contractors practical guidance on reducing and reporting their environmental impacts.
