Engineering Commons^™

Use Of Ultra-High Performance Concrete To Mitigate Impact And Explosive Threats, Julie Anne Willey

Masters Theses

"This study is a continuation of research conducted by Natalia Carey, Anthony Wulfers, and Dr. John Myers under the DHS ALERT Center. Carey investigated the use of polyurea coating systems to mitigate close range blast threats on wall panels. Wulfers continued this by using both polyurea coatings as well as a sacrificial wood fiber fly ash (WF-FA) layer to try to get increased performance. This research was aimed at the study of ultra-high performance concrete (UHPC) for the use in impact and blast mitigation. There is little information on the performance of UHPC under close range blast loading; therefore it …

Green Roof Water Quality Impacts And Physicochemical Stability, Grace Ella Harper

Masters Theses

"Green roofs can provide environmental benefits and conserve energy; this research evaluated green roof stormwater management, nutrient loading, and erosion prevention for two green roof media. During a pilot study, the runoff quantity and composition from green roof material was evaluated continuously under field conditions for two different media, both tested under planted and unplanted conditions. Water quantity results show over a 40% reduction in runoff from just the growing media and over 60% reduction in runoff with established plants in green roof media over the eight month study. Previous studies have reported a "first flush" of excess nutrients but …

Effect Of Mix Parameters On Longevity Of Bituminous Mixtures, Clayton Reichle

Masters Theses

"This study was performed to evaluate the effects of varying aggregate sources, aggregate gradations on the stripping and rutting potential of bituminous based plant mixes specified by the Missouri Department of Transportation. The different aggregate combinations included two different aggregate sources (Potosi Dolomite and Jefferson City Dolomite) including two variations for the Jefferson City Dolomite mix to simulate a marginally in-specification mix and an out-of-specification but in-field tolerance mix. The "field" mix simulated the marginal mix where field tolerance of high dust and low binder content were maximized. All three mixes were evaluated for stripping susceptibility using the Tensile Strength …

Phytoforensics On Energetics: Novel Plant Tissue Measure Approach And Modeling, Yuan Yuan

Doctoral Dissertations

"Explosives and energetics are common soil and groundwater pollutions. This research was to develop novel phytoforensics approaches on energetics. Four different plants species, including woody perennial trees and monocot grasses, were planted both in soil and sand reactors with continuous exposure to a mixture of explosives in the greenhouse. Time dependent assessments were carried out to determine kinetic mechanisms of uptake, transport and accumulation. Plant concentrations were analyzed by both traditional solvent extraction and novel sap analysis methods. A dynamic soil-plant system model was developed to quantify the relationship between tissue concentration and soil pore water concentration for non-volatile organic …

Numerical Analyses Of Long Carbon Fiber Reinforced Concrete Panels Exposed To Dynamic Loading, Zahra Sadat Tabatabaei

Doctoral Dissertations

"The purpose of this research was to evaluate impact and blast performance of long carbon fiber reinforced concrete experimentally and numerically. Experimental tests were conducted on plain concrete (PC), reinforced concrete, and four different types of long carbon fiber reinforced concrete (LCFRC). The results from each test were then compared to one another. This comparison indicates that adding long carbon fibers to concrete both increases the post-cracking behavior of concrete and decreases the spalls in either an impact or blast test. Among all of the fibers tested, Fiber Type B3 outperformed the other fibers, absorbing more energy during impact. Numerical …

Analysis Of Model Uncertainty In Hydraulic Modeling: The Bstem Application To The Osage River, Annabell Leigh Ulary

Masters Theses

"Uncertainty is inevitable when creating any kind of model. A model can be used in the most accurate way possible, if the uncertainties are understood. This study determines the level of uncertainty in the Bank Stability and Toe Erosion Model (BSTEM) of the Osage River downstream of Bagnell Dam between Lake Ozark, MO and Jefferson City, MO. The statistical analysis of the BSTEM model was performed using the aid of SAS statistical computer modeling software. There were 4 different analysis values used to determine the best fit model for all dependent variables. These values include the F-test, the coefficient of …

Distribution And Occurrence Of Escherichia Coli In Water And Sediments At Grand Glaize Beach In Lake Of The Ozarks State Park, Jordan Lee Wilson

Masters Theses

"Public swimming beaches at the Lake of the Ozarks State Park (LOSP) are popular vacationing spots for many Missourians; however, on several occasions Escherichia coli (E. coli) concentrations have exceeded standards set by the Missouri Department of Natural Resources (MDNR). Exceedances lead to beach closures which not only represent a potential public health threat but are also detrimental to the local economy and the public's perception of the lake's general water quality. In a collaborative effort between Missouri S&T, the United States Geological Survey (USGS) and the MDNR, an in-depth, two-summer study was conducted which included collection of …

Direct Shear Transfer Of Lightweight Aggregate Concretes With Non-Monolithic Interface Conditions, Dane Michael Shaw

Masters Theses

"This thesis describes the results of a study initiated to examine the influence of concrete unit weight on the direct shear transfer across an interface of concretes cast at different times. This type of interface is common with structural precast concrete connections, such as corbels, for which shear friction design provisions are commonly used. Increasing use of lightweight aggregate concretes prompted this investigation to determine the appropriateness of current shear friction design provisions with respect to all-lightweight and sand-lightweight concrete. The experimental investigation included thirty-six push-off test specimens, each of which was constructed with a cold-joint at the interface shear …

Monitoring Micropile Foundations Of Bridge During Construction, Devin Tavis Dixon

Masters Theses

"Information regarding the load transfer of micropiles during in-service construction has virtually never been monitored or documented. The primary objective of this research project was to monitor the load transfer versus the depth of production micropiles during construction. The micropiles being studied were used to support Bridge No. 2 of the Foothills Parkway in eastern Tennessee during construction. Two of the piers (1 & 2) were instrumented for the purpose of this study. Vibrating wire strain gages (VWSG) were installed on select micropiles within pile groups of twenty (20) micropiles. Seven vibrating wire strain gages were installed on each micropile …

Enamel Coated Steel Reinforcement For Improved Durability And Life-Cycle Performance Of Concrete Structures: Microstructure, Corrosion, And Deterioration, Fujian Tang

Doctoral Dissertations

"This study is aimed (a) to statistically characterize the corrosion-induced deterioration process of reinforced concrete structures (concrete cracking, steel mass loss, and rebar-concrete bond degradation), and (b) to develop and apply three types of enamel-coated steel bars for improved corrosion resistance of the structures. Commercially available pure enamel, mixed enamel with 50% calcium silicate, and double enamel with an inner layer of pure enamel and an outer layer of mixed enamel were considered as various steel coatings. Electrochemical tests were respectively conducted on steel plates, smooth bars embedded in concrete, and deformed bars with/without concrete cover in 3.5 wt.% NaCl …

Shear And Fracture Behavior Of High Performance Concretes, Mahdi Arezoumandi

Doctoral Dissertations

"Concrete is the most widely used man-made material in the world. Like other materials, it has been improved over time. Nowadays, with continued development of science and technology, a new generation of concretes is produced and is termed high performance concretes. A review of previously published work indicates that very few studies (in some cases none) have addressed the structural behavior of full-scale, high performance concrete elements. This study investigated the shear and fracture behavior of two types of high performance concrete - high-volume fly ash concrete (HVFAC) and self-consolidating concrete (SCC). The HVFAC incorporates up to 70% cement replacement …

Field Performance Of Alternative And Cost Efficient Cast In Place And Precast Prestressed Concrete Bridge Approach Slabs, Nathan Price Muncy

Masters Theses

"In December of 2010, the Missouri Department of Transportation (MoDOT) investigated alternative cost-efficient bridge approach slabs (BASs). New BAS designs were subsequently developed and had a projected cost savings up to twenty-four percent with anticipated equal or better structural performance. A precast-prestressed (PCPS) BAS was introduced as an alternative to traditional BASs that offers advantages such as rapid construction and improved long-term durability. The three new BAS designs were implemented into in-situ bridge projects by MoDOT and the field performance was evaluated within this research study.

Field testing of each BAS was performed using two MoDOT HS20 trucks. Various instrumentation …