Engineering Commons^™

Potential Impacts Of Climate Change On Water Resources And Water Quality Of Norris Lake, Tennessee, Yong-Gil Choi

Masters Theses

This study assessed the potential impacts of climate change on hydrology, water resources operation, and water quality of the Norris Lake area in Tennessee. To project future climate conditions, the simulation outputs for 2030s, 2050s, and 2070s from six general circulation models (GCMs) were extracted under two Intergovernmental Panel on Climate Change (IPCC) greenhouse gases emissions scenarios (A2 and B1 for high and low emissions, respectively) to consider the range of uncertainty. The outputs of the six GCMs were weighted by considering their accuracy to simulate the climate conditions observed from 1961 to 1990 to suggest an ensemble average. A …

Behavior Of Externally Fiber-Reinforced Polymer Reinforced Shrinkage-Compensating Concrete Beams, Qi Cao

Doctoral Dissertations

The major cause of cracking in bridge decks, concrete pavements, as well as slabs on grade, is restrained shrinkage of the concrete. The resulting steel corrosion problem causes tremendous increase of maintenance and replacement cost. Shrinkage-compensating concrete (SHCC) and fiber-reinforced polymer (FRP) are explored to develop a hybrid slab system as one possible method of delaying the cracking and eliminating corrosion. To achieve the objective, a hybrid FRP reinforced SHCC structural system was developmed, and short-term and long-term behavior of this hybrid FRP-SHCC beams were investigated in this dissertation.

In the first-stage development, a series of “coffee can” tests were …

Oceanic-Atmospheric And Hydrologic Variability In Long Lead-Time Forecasting, Abdoul Aziz Oubeidillah

Doctoral Dissertations

Water managers throughout the world are challenged with managing scarce resources and therefore rely heavily on forecasts to allocate and meet various water demands. The need for improved streamflow and snowpack forecast models is of the utmost importance. In this research, the use of oceanic and atmospheric variables as predictors was investigated to improve the long lead-time (three to nine months) forecast of streamflow and snowpack. Singular Value Decomposition (SVD) analysis was used to identify a region of Pacific and Atlantic Ocean SSTs and a region of 500 mbar geopotential height (Z500mb) that were teleconnected with streamflow and snowpack. The …

Bankfull Geomorphic Relationships And Reference Reach Assessment Of The Ridge And Valley Physiographic Province Of East Tennessee, James Brady Mcpherson

Masters Theses

Waterways have been geomorphically altered or disturbed by development, mining, agriculture and other human activities for many years. Section 404 of the Clean Water Act determined that these impacts to our waterways must be mitigated for channel alterations. Stream restoration has been one method to mitigate for these impacts to our water resources. Stream restoration is considered to be a measurable improvement to the channel stability, water quality, habitat or overall function of a degraded stream system. Practices of stream restoration have changed in the last 10 to 20 years with the introduction of natural channel design methods. Natural channel …

Comparison Of Two Methods For The Assessment Of Chloride Ion Penetration In Concrete: A Field Study, Eric William Ryan

Masters Theses

The currently accepted method for assessing the resistance of concrete to penetration of chloride ions is ASTM C1202, commonly known as the “Rapid Chloride Permeability (RCP) Test.” The test is time-consuming, laborious, has rather high variability, and, is to a degree, user sensitive, making it problematic for inclusion in a performance-based specification. A potential alternative to the RCP test is the “Surface Resistivity (SR) Test”, a method which is dramatically easier, faster, and has less variability than the RCP test. The research reported herein was directed toward determining a correlation between RCP and SR test measurements for Tennessee bridge deck …

Discrete Element Method (Dem) Analyses For Hot-Mix Asphalt (Hma) Mixture Compaction, Jingsong Chen

Doctoral Dissertations

Asphalt mixture compaction is an important procedure of asphalt mixture construction and can significantly affect the performance of asphalt pavement. Many laboratory compaction methods (or devices), have been developed to study the asphalt mixture compaction. Nevertheless, the whole process from the selection of aggregate to laboratory compaction is still time-consuming and requires significant human and material resources. In order to better understand asphalt mixture compaction, some researchers began to use finite element method (FEM) to study and analyze mixture compaction. However, FEM is a continuum approach and lacks the ability to take into account the slippage and interlocking of aggregates …

Investigating Properties Of Pavement Materials Utilizing Loaded Wheel Tester (Lwt), Hao Wu

Doctoral Dissertations

Loaded wheel tester (LWT) is a common testing equipment usually used to test the permanent deformation and moisture susceptibility of asphalt mixtures by applying moving wheel loads on asphalt mixture specimens. It has been widely used in the United States since 1980s and practically each Department of Transportation or highway agency owns one or more LWT(s). Compared to other testing methods for pavement materials, LWT features movable wheel loads that allow more realistic situations existing on the actual pavement to be simulated in the laboratory. Due to its potential of creating a condition of repetitive loading, the concept of using …