Engineering Commons^™

Assessment Of Seismic Damage Of Buildings And Related Environmental Impacts, Carley A. Feese

Dissertations, Master's Theses and Master's Reports - Open

Sustainable development has only recently started examining the existing infrastructure, and a key aspect of this is hazard mitigation. To examine buildings under a sustainable perspective requires an understanding of a building's life-cycle environmental costs, including the consideration of associated environmental impacts induced by earthquake damage. Damage repair costs lead to additional material and energy consumption, leading to harmful environmental impacts. Merging results obtained from a seismic evaluation and life-cycle analysis for buildings will give a novel outlook on sustainable design decisions. To evaluate the environmental impacts caused by buildings, long-term impacts accrued throughout a building's lifetime and impacts associated …

A Study Of The Impacts Of Freeze-Thaw On Cliff Recession At The Calvert Cliffs In Calvert County, Maryland, Bonnie Elizabeth Zwissler

Dissertations, Master's Theses and Master's Reports - Open

The Calvert Cliffs, which form much of the western coastline of the Chesapeake Bay in Calvert County, Maryland, are actively eroding and destabilizing, resulting in a critical situation for many homes in close proximity to the slope's crest. Past studies have identified that where waves directly interact with the toe of the slope, wave action controls cliff recession; however, where waves do not regularly interact with the slope toe, the past work identified that freeze-thaw controls recession. This study investigated the validity of this second claim by analyzing the recession rate and freeze-thaw behavior of six study sites along the …

An Investigation Of Waste Glass-Based Geopolymers Supplemented With Alumina, Mary U. Christiansen

Dissertations, Master's Theses and Master's Reports - Open

An increased consideration of sustainability throughout society has resulted in a surge of research investigating sustainable alternatives to existing construction materials. A new binder system, called a geopolymer, is being investigated to supplement ordinary portland cement (OPC) concrete, which has come under scrutiny because of the CO2 emissions inherent in its production.

Geopolymers are produced from the alkali activation of a powdered aluminosilicate source by an alkaline solution, which results in a dense three-dimensional matrix of tetrahedrally linked aluminosilicates. Geopolymers have shown great potential as a building construction material, offering similar mechanical and durability properties to OPC. Additionally, geopolymers have …

Performance-Based Engineering Framework For Earthquake And Fire Following Earthquake, Aerik Carlton

Dissertations, Master's Theses and Master's Reports - Open

The objective for this thesis is to outline a Performance-Based Engineering (PBE) framework to address the multiple hazards of Earthquake (EQ) and subsequent Fire Following Earthquake (FFE). Currently, fire codes for the United States are largely empirical and prescriptive in nature. The reliance on prescriptive requirements makes quantifying sustained damage due to fire difficult. Additionally, the empirical standards have resulted from individual member or individual assembly furnace testing, which have been shown to differ greatly from full structural system behavior. The very nature of fire behavior (ignition, growth, suppression, and spread) is fundamentally difficult to quantify due to the inherent …

The Laboratory Evaluation Of Bio Oil Derived From Waste Resources As Extender For Asphalt Binder, Xu Yang

Dissertations, Master's Theses and Master's Reports - Open

A shortage of petroleum asphalt is creating opportunities for engineers to utilize alternative pavement materials. Three types of bio oils, original bio oil (OB), dewatered bio oil (DWB) and polymer-modified bio oil (PMB) were used to modify and partially replace petroleum asphalt in this research. The research investigated the procedure of producing bio oil, the rheological properties of asphalt binders modified and partially replaced by bio oil, and the mechanical performances of asphalt mixtures modified by bio oil. The analysis of variance (ANOVA) is conducted on the test results for the significance analysis. The main finding of the study includes: …

Stilling Basin Scour Remediation Using Air Injection And Flat Plate Extension, Rachael Barlock

Dissertations, Master's Theses and Master's Reports - Open

The South Florida Water Management District (SFWMD) is responsible for managing over 2500 miles of waterways and hundreds of water control structures. Many of these control structures are experiencing erosion, known as scour, of the sediment downstream of the structure. Laboratory experiments were conducted in order to investigate the effectiveness of two-dimensional air diffusers and plate extensions (without air injection) on a 1/30 scale model of one of SFWMD gated spillway structures, the S65E gated spillway. A literature review examining the results of similar studies was conducted. The experimental design for this research was based off of previous work done …

Structural Control Of A Small-Scale Test-Bed Shaker Structure Using A Sponge-Type Magneto-Rheological Fluid Damper, Benjamin D. Winter

Dissertations, Master's Theses and Master's Reports - Open

Semi-active damping devices have been shown to be effective in mitigating unwanted vibrations in civil structures. These devices impart force indirectly through real-time alterations to structural properties. Simulating the complex behavior of these devices for laboratory-scale experiments is a major challenge. Commercial devices for seismic applications typically operate in the 2-10 kN range; this force is too high for small-scale testing applications where requirements typically range from 0-10 N. Several challenges must be overcome to produce damping forces at this level. In this study, a small-scale magneto-rheological (MR) damper utilizing a fluid absorbent metal foam matrix is developed and tested …

Determing The Effect Of Thermal Treatment Timing On Ultra-High Performance Concrete Beams, Christopher H. Mullen

Dissertations, Master's Theses and Master's Reports - Open

The loss of prestressing force over time influences the long-term deflection of the prestressed concrete element. Prestress losses are inherently complex due to the interaction of concrete creep, concrete shrinkage, and steel relaxation. Implementing advanced materials such as ultra-high performance concrete (UHPC) further complicates the estimation of prestress losses because of the changes in material models dependent on curing regime.

Past research shows compressive creep is "locked in" when UHPC cylinders are subjected to thermal treatment before being loaded in compression. However, the current precasting manufacturing process would typically load the element (through prestressing strand release from the prestressing bed) …

Evaluation Of Intelligent Compaction Control In The M-189 Reconstruction Project At Iron River, Michigan, Junhong Li

Dissertations, Master's Theses and Master's Reports - Open

This research evaluated an Intelligent Compaction (IC) unit on the M-189 highway reconstruction project at Iron River, Michigan. The results from the IC unit were compared to several traditional compaction measurement devices including Nuclear Density Gauge (NDG), Geogauge, Light Weight Deflectometer (LWD), Dynamic Cone Penetrometer (DCP), and Modified Clegg Hammer (MCH). The research collected point measurements data on a test section in which 30 test locations on the final Class II sand base layer and the 22A gravel layer. These point measurements were compared with the IC measurements (ICMVs) on a point-to-point basis through a linear regression analysis. Poor correlations …

Preliminary Investigation Of Ultra-High Performance Concrete Behavior At High Strain Rates Using The Split-Hopkinson Pressure Bar, Jacob Clark

Dissertations, Master's Theses and Master's Reports - Open

Ultra-high performance concrete (UHPC) displays several enhanced material properties compared to normal strength concrete (NSC). In past research, Split-Hopkinson pressure bar (SHPB) tests have been used for normal strength concrete to determine material behavior at high strain rates. The behavior of advanced concrete materials, such as UHPC, under high strain rates has not been thoroughly investigated. While it is generally accepted that concrete materials experience increases in compressive strength under increasing strain rates, a preliminary investigation was conducted to gain insight into the compressive behavior of UHPC under high strain rate SHPB testing.

In this research, 50 specimens were tested …