Date of Award
Doctor of Philosophy (PhD)
Materials and Infrastructure Systems
As the world is moving to provide a better and cleaner environment for future generations, there is a critical need to quantify and try to reduce the environmental emission footprints of various industries. The construction industry, which emits a large amount of carbon dioxide (CO₂ ), is one of the targeted industries to decrease these emissions. Underground utility installations, especially in the development of residential communities in urban areas, are one of the largest construction projects across North America and, consequently, one primary source of emissions. Most of the pipelines in the U.S. are rapidly reaching the end of their useful service life. Now they need replacing or rehabilitating. In general, the selection of a pipeline installation method is currently solved by selecting the lowest cost method. However, with an increase in the public concerns about reducing emissions into the environment generated by human activities, other factors should be taken into account while choosing the pipe material and the installation method for a new pipeline; namely social cost, and environmental impact. The common three greenhouses gases (GHG) are CO2, methane (C𝐻4), and nitrous oxide (N₂ O). CO₂ is the GHG responsible for the greatest amount of environmental impact.
This parametric study and analysis focuses on the environmental impact (quantitative analysis the CO₂ emissions) for different pipeline materials during the lifecycle of pipeline and develops a framework which will help engineers and decisionmakers to choose the most environmentally friendly pipe material with low emission installation or rehabilitation methods. The life-cycle of a pipeline can be categorized into four phases: fabrication, installation, operation, and disposal. This study focuses on four commonly used types of pipe and liners: pre-stressed concrete cylinder pipe (PCCP), polyvinyl chloride (PVC) pipe, cured-in-place pipe (CIPP) liner, and high-density polyethylene (HDPE). The energy consumed in the fabrication phase includes base material extraction, material production material processing, and pipe manufacturing. The major construction activities in the installation stage are transporting pipes and equipment to a job-site, excavation, loading, backfilling, compaction, and repaving. For this study, the pipeline installation analysis and consideration of CO₂ emissions have been made for three different installation methods: open cut with PCCP, pipe bursting with PVC and HDPE, and CIPP lining. The energy consumed in the operation phase includes pumping energy and pipe cleaning for maintenance. For the disposal phase, the study will consist of the energy consumed for disposing of the material of the pipes, which cannot be recycled. The objective of this study was to first quantify the carbon footprint, which has never been done for this application, and then to analyze the environmental sustainability of a 100-foot segment of pipeline during the installation, operation, and disposal phases. This study focused on a large-diameter 36-inch sewer pressure pipe operating at 100 psi internal pressure for 100-years life operation. The results show that the PVC pipe has the lowest environmental impact compared to PCCP, HDPE, or CIPP during the life-cycle of pipeline phases before and after the optimization.
Alsadi, Alhossin, "" (2019). Dissertation. 37.