Development of the materials, construction, and maintenance phases of a life cycle assessment tool for pavements

Ferrebee, Eric

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https://hdl.handle.net/2142/72844 Copy

Description

Title

Development of the materials, construction, and maintenance phases of a life cycle assessment tool for pavements

Author(s)

Ferrebee, Eric

Issue Date

2015-01-21

Director of Research (if dissertation) or Advisor (if thesis)

Roesler, Jeffery R.

Department of Study

Civil & Environmental Eng

Discipline

Civil Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Life cycle assessment (LCA)
• environmental impact
• sustainability
• concrete pavement
• pavement
• continuously reinforced concrete pavement (CRCP)
• jointed plain concrete pavement (JPCP)
• supplementary cementitious materials (SCMs)

Abstract

The heightened interest in sustainability applied to the roadway industry has highlighted the need for suitable quantitative analysis tools for assessing the environmental impact of sustainability, including economic and societal impacts. At present, there are qualitative tools to assess sustainability, such as the Infrastructure Voluntary Evaluation Sustainability Tool (INVEST), and a few researchers are producing life cycle assessment (LCA) tools to quantitatively assess the environmental side of sustainability in terms of impacts such as global warming potential and total energy demand. This research study details the creation of a regionalized LCA tool, particularly for concrete pavements, focusing on the methodology of the construction and maintenance/rehabilitation phases with collaborative studies investigating the materials, use, and end-of-life phases. A tool verification study investigated the environmental impacts of the materials, construction, and maintenance/rehabilitation phases for a rigid pavement roadway. Cement, which had the highest impact for concrete in the materials phase, can be replaced with supplementary cementitious materials (SCMs) such as fly ash or ground granulated blast furnace slag (GGBFS) to reduce total energy and emissions by 14% to 29% for cement replacements of 35%. Construction impacts were relatively low compared to the materials phase, but practices such as two-lift paving can impact the materials phase and reduce total energy and global warming potential by 13.9% and 23.8%, respectively, when the bottom lift utilizes significant amounts of SCMs and recycled aggregates. The maintenance phase was found to be a significant contributor to the life cycle impacts, mainly because of the materials required for the activities, which accounted for 90% of the total energy and global warming potential, in the maintenance phase. Many of these results from the verification study were supported by previous findings reported in the literature. A hypothetical case study comparing continuously reinforced (CRCP) and jointed plain (JPCP) concrete pavements was performed to demonstrate the capabilities of the LCA tool in the materials, construction, and maintenance phases. The total energy and global warming potential were found to be 10.6% and 4.9% higher, respectively, for the CRCP design relative to the JPCP alternative, when considering the full life cycle, i.e., 78 and 62 year service life, respectively. When the results were annualized to a per year basis, the CRCP design was 12.5% and 19.6% lower than the JPCP design in terms of total energy and global warming potential, respectively. The results of this case study indicate that CRCP can be a sustainable pavement alternative relative to JPCP under certain design conditions. The use phase impacts should not be neglected as they have been shown to be a significant contributor in the life cycle. This LCA tool has been shown to provide a quantitative assessment of the environmental impacts of a roadway, in the materials, construction and maintenance phases, that can be used in conjunction with life cycle cost analysis to make more sustainable decisions.

Graduation Semester

2014-12

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http://hdl.handle.net/2142/72844

Copyright and License Information

Copyright 2014 Eric Ferrebee

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