Chowdhury, R (2009) Life cycle based analysis of various materials used in road construction. PhD thesis, University of Toledo, USA.
Abstract
Recently, various industrial byproducts are being used as a partial or full replacement of virgin materials such as natural aggregate, cement, lime and asphalt. However, industrial byproducts contain a certain amount of pollutants that may contaminate the underlying groundwater. On the other hand, during production of virgin materials a considerable amount of environmental loading of various pollutants is generated. Hence, to compare industrial byproducts with virgin materials an Excel based tool was developed using the life cycle assessment (LCA) approach. Both process based as well as economic input output based LCA were used for comparison purpose. Various base and embankment construction scenarios were analyzed and compared with respect to cost, energy consumption, global warming potential (GWP), acidification potential (AP) and various toxicity potentials. Mixed results were found from both embankment and base construction and no single scenario performed superiorly in all categories. Fly ash and bottom ash based embankment construction were found attractive in cost, GWP, and acidification potential categories whereas recycled concrete pavement (RCP) found attractive in toxicity categories. In the base construction, lime amended base course has the lowest toxicity compared to asphalt or cement based base courses. However, lime stabilized course has higher GWP and AP compared to asphalt. Uncertainty and sensitivity analysis for various characterization factors used for toxicity measurement were also performed using an Excel based statistical tool (@RISK). Uncertainty in data affected the results in toxicity categories and the results thus produced varied by 20–40 orders magnitude. A sensitivity analysis revealed that characterization factors for cadmium, cobalt, and copper were the most sensitive parameters for most of the industrial byproducts. EIOLCA based data and process based data were also compared for various base construction scenarios. It was observed that even though the system boundary for two types of LCA is different, the major processes which contribute to energy and various pollutants generation were similar in both types of LCA.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Thesis advisor: | Apul, D |
| Uncontrolled Keywords: | energy consumption; measurement; uncertainty; embankment; groundwater; pavement; replacement; life cycle; road construction |
| Index terms: | life cycle, copper, sensitivity analysis, global warming, energy consumption, life cycle assessment, embankment, pollutant, lime, replacement, road construction, fly ash, groundwater, aggregate, loading |
| Subjects: | environmental hazards, climate science, traditional and composite building materials, energy systems, building materials, environmental health, materials science, civil engineering, water management, infrastructure and transport systems, environmental impact, value management, construction operations |
| Topics: | Engineering Principles, Site Management, Project Management, Sustainability, Construction Materials |
| Descriptive scope: | 2 PC |
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