Development and implementation of comprehensive regionalized pavement life-cycle assessment
The use of life-cycle assessment (LCA) to evaluate the environmental impacts of pavement systems is a topic that stakeholders in academia, industry, and government have actively engaged with in the last two decades. The LCA methodology aims to provide quantitative environmental metrics such as energy consumption and greenhouse gases regarding the cradle-to-grave impacts accumulated over the pavement’s life-cycle. While research progress has been made to improve the inventory data and models used in pavement LCA, the connectivity between development of the LCA, application of an LCA software, and interpretation of LCA results have not yet been thoroughly addressed. Thus, in order to further the practical utilization of pavement LCA, work must be done to evaluate how LCA consumers and decision makers can apply and interpret LCA results and how methodological issues may affect LCA results. The first portion of this dissertation concerns the compilation and application of regional life-cycle inventory data for initial pavement construction. Using data modeled to represent the Northern Illinois region, various pavement mixtures and pay item activities are evaluated for initial environmental impacts due to material production and construction processes. To address the limitations in possessing only partial LCA impacts, a scenario-based analysis is used to consider the effect of future pavement performance on life-cycle environmental impacts. In addition, economic impacts are also calculated for mixes and pay items, and a cost-effectiveness analysis is conducted to expand the pay item environmental assessment into a useful set of metrics for agencies. Building upon the inventory data compiled, a full LCA framework and software is then implemented. The roadway/roadside software is designed to consider each life-cycle stage (i.e., materials and construction, maintenance and rehabilitation, use, and end-of-life) of major roadway/roadside elements including drainage, landscape, lighting, pavement, and structures using pay items to facilitate agency utilization. A set of fourteen diverse pavement construction contracts are analyzed using the LCA software and their results are visualized and interpreted as relevant to transportation agencies. The final portion of this dissertation evaluates key interpretation issues related to pavement LCA. A series of sensitivity analyses are performed on major methodological choices to determine which decisions and parameters ultimately have a significant effect on the overall LCA results. Furthermore, two methods for incorporating uncertainty into the LCA are also implemented - one using a simplistic probabilistic approach and the other using an informed Bayesian updating approach. The effects of considering data uncertainty in LCA, especially for comparative analyses, are addressed.
Life-cycle assessment, Pavement, Highway construction, Environmental impacts
University of Illinois - Urbana-Champaign
Networked Digital Library of Theses and Dissertations
University of Illinois at Urbana-Champaign