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Civil Engineering

Missouri University of Science and Technology

Theses/Dissertations

2012

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Discrete Fiber-Reinforced Polyurea Systems For Infrastructure Strengthening And Blast Mitigation, Natalia L. Carey Jan 2012

Discrete Fiber-Reinforced Polyurea Systems For Infrastructure Strengthening And Blast Mitigation, Natalia L. Carey

Doctoral Dissertations

"The research presented in this dissertation focused on evaluating the effectiveness of various blast mitigation materials and coating technologies to be used for enhancing blast resistance of structural members. Mechanical properties and blast mitigation performance of different discrete fiber-reinforced polyurea (DFRP) systems were investigated through experimental and analytical work. Four technical papers discuss the research efforts conducted within this dissertation.

The first paper examined the development and characterization of different DFRP systems for infrastructure strengthening and blast retrofit. The behavior of various systems which consisted of chopped E-glass fibers discretely integrated in with the polyurea matrix was evaluated through coupon …


Effects Of High Volume Fly Ash And Powder Activators On Plastic And Hardened Concrete Properties, Drew Alexander Davis Jan 2012

Effects Of High Volume Fly Ash And Powder Activators On Plastic And Hardened Concrete Properties, Drew Alexander Davis

Masters Theses

This study was performed to examine the effects of high volumes of Class C fly ash modified by powder activators upon the plastic and hardened properties of concrete. In a companion study, five Missouri area cements and five Class C fly ashes were examined for incompatibilities, with the most and least reactive combinations being scaled up to full scale concrete testing. Two baseline concrete mixtures were examined, the only difference in mixtures being the sources of portland cement and fly ash. Fly ash replacement was examined at 50% and 70% replacement (by total cementitious mass). Three powder activators were used …


Hardened Mechanical Properties And Durability Performance Of Specialized Concretes, Kyle Richard Holman Jan 2012

Hardened Mechanical Properties And Durability Performance Of Specialized Concretes, Kyle Richard Holman

Masters Theses

"Concrete is one of the most produced and utilized materials in the world. Due to the labor intensive and time consuming nature of concrete construction, new and innovative concrete mixes are being explored. Self-consolidating concrete (SCC) is one such method of improving the overall cost and time efficiency of concrete production. SCC is a highly flowable form of concrete. This characteristic drastically reduces the amount of labor and time needed to place the concrete. The highly flowable nature also allows for much easier placement in applications of highly congested reinforcement.

Another rising concern in today's construction industry is environmental responsibility. …


Characterization Of Soil Variability For Reliability-Based Design, Sitenikechukwu Onyejekwe Jan 2012

Characterization Of Soil Variability For Reliability-Based Design, Sitenikechukwu Onyejekwe

Doctoral Dissertations

"A very carefully planned Missouri-wide field exploration and laboratory investigation program, with a focus on fine-grained soils, was executed with the aim of characterizing the variability of geotechnical parameters statistically with a view to increasing the use of reliability-based design (RBD) among geotechnical engineers. Geotechnical parameters were characterized in terms of both their first and second statistical moments and their coefficient of variation (COV). Their probability distributions and their scale of fluctuation, θ, were also determined. Correlations between difficult-to-obtain parameters and more easily-obtained parameters were developed and the degree of fit of study data to published empirical correlations was investigated. …


Characterization Of Expanded Polystyrene (Eps) And Cohesive Soil Mixtures, Nicholas Thomas Rocco Jan 2012

Characterization Of Expanded Polystyrene (Eps) And Cohesive Soil Mixtures, Nicholas Thomas Rocco

Doctoral Dissertations

"Soils modified with expanded polystyrene (EPS) particulates could be used as lightweight fill in a variety of installations including slopes for improved stability, embankments over compressible soils, and to reduce earth pressures next to structures. The addition of low density EPS particulates into soil has a large effect on the mass and volumetric characteristics of these mixtures and their influence on mechanical properties is scarce in the literature. A laboratory characterization program using clay mixed with EPS particulates was conducted for different dosages of EPS. Soils were modified with up to 1.5% EPS by mass, which corresponds to approximately 45% …


Investigation Of The Effects Of Shrinkage, Creep, And Abrasion On Self-Consolidating Concrete And High Volume Fly Ash Concrete For Use In Transportation Related Infrastructure, Brian Timothy Tucker Jan 2012

Investigation Of The Effects Of Shrinkage, Creep, And Abrasion On Self-Consolidating Concrete And High Volume Fly Ash Concrete For Use In Transportation Related Infrastructure, Brian Timothy Tucker

Masters Theses

"Concrete specimens were fabricated for shrinkage, creep, and abrasion resistance testing. Variations of self-consolidating concrete (SCC), high volume fly ash concrete (HVFA), and conventional concrete were studied. The results were compared to previous similar testing programs and used to determine the adequacy of the materials for use in practice. These two concrete variations offer significant benefits when used as replacements to conventional concrete. Because of the respective properties of both types of concrete, both economic and environmental benefits are achieved with the use of both. The lower labor costs of SCC and the lower material cost of HVFA lead to …


Analysis Of Passive Louver Shading Systems And Impact On Interior Environment, Cory Joseph Brennan Jan 2012

Analysis Of Passive Louver Shading Systems And Impact On Interior Environment, Cory Joseph Brennan

Masters Theses

An installed passive louver shading systems can affect the heating, cooling, and lighting loads of any building, by altering the amount of solar energy, in the form of light and heat, from entering. The benefits of a louver system are derived from the application of solar geometry incident on the site and the climate within the area. By optimizing a passive louver system's design parameters, a building can reduce the total annual energy consumption due to artificial heating, cooling loads and artificial lighting. This research has implemented simulation modeling software, Energy Plus, to predict the effect of passive louver shades …


Effects Of High Volumes Of Fly Ash On Cement Paste, Karl Wehking Beckemeier Jan 2012

Effects Of High Volumes Of Fly Ash On Cement Paste, Karl Wehking Beckemeier

Masters Theses

"The study of high-volume fly ash (HVFA) concrete mixtures has become popular due to the significant environmental and economic benefits which the material may provide. By including fly ash at 50 percent or greater replacement levels, substantial benefits could be obtained. However, the inclusion of fly ash can have negative effects, including incompatibilities between constituents of a mixture. As the fly ash replacement level increases, the degree and likelihood of these problems increases.

In this study, paste mixtures were made, as part of a larger HVFA concrete study, in order to determine the degree to which varying levels of fly …


Self-Consolidating Concrete For Infrastructure Elements Shear Characteristics, Eric B. Sells Jan 2012

Self-Consolidating Concrete For Infrastructure Elements Shear Characteristics, Eric B. Sells

Masters Theses

"Because of its unique ability to maintain high flow-ability and remain homogeneous, self-consolidating concrete (SCC) has the potential to significantly reduce the costs associated with civil infrastructure; however, the use of higher paste and lower coarse aggregate volumes than non-SCC concretes raises concerns about shear strength of SCC mixes. This research focused on the components that contribute to the concrete's ability to provide shear by aggregate interlock. Variables investigated by push-off tests included concrete compressive strength, coarse aggregate type , and volumetric content level of the coarse aggregate portion . Post-failure digital imaging software was used to confirm fresh concrete …


Use Of High Volume Fly Ash-Wood Fiber And Polyurea Layers For Blast Mitigation, Anthony Francis Wulfers Jan 2012

Use Of High Volume Fly Ash-Wood Fiber And Polyurea Layers For Blast Mitigation, Anthony Francis Wulfers

Masters Theses

"This project is a continuation of research done by Natalia Carey and John Myers. The first part of Natalia's research was to develop and characterize an e-glass discrete fiber-reinforced polyurea (DFRP) system for infrastructure applications. She then recommended two polyurea systems (A and B) be further examined. These polyurea systems were then applied to plain reinforced concrete and steel fiber reinforced concrete panels (SFRC). Carey found that the SFRC panels sustained less overall damage. For this project SFRC was used as the base layer in combination with the DFRP systems. In addition to the DFRP and SFRC a high-volume fly …


Shear And Fracture Behavior Of High-Volume Fly Ash Reinforced Concrete For Sustainable Construction, Carlos Andres Ortega Ordonez Jan 2012

Shear And Fracture Behavior Of High-Volume Fly Ash Reinforced Concrete For Sustainable Construction, Carlos Andres Ortega Ordonez

Doctoral Dissertations

"Concrete is the most widely used man-made material on the planet. Unfortunately, producing Portland cement generates carbon dioxide (a greenhouse gas) at roughly a pound for pound ratio. High-volume fly ash (HVFA) concrete- concrete with at least 50% of the cement replaced with fly ash - offers a potential "green" solution. However, because it is still relatively new and has some disadvantages, there are still many questions that need to be answered. Most research to date has consisted only of the evaluation of the strength and durability of HVFA concrete mixtures, while only a limited number of studies have implemented …


Effect Of Side Edge Distance And Concrete Materials On Corrosion In Precast Prestressed Concrete Panels, Dayi Zhang Jan 2012

Effect Of Side Edge Distance And Concrete Materials On Corrosion In Precast Prestressed Concrete Panels, Dayi Zhang

Masters Theses

"This study involved the spalling problem found in some partial-depth precast prestressed bridge decks in the state of Missouri. Recently, panels of several bridges have exhibited corrosion of the prestressing steel tendons causing concrete spalling at the edges of panels. Some of the exposed tendons are corroded to the point of rupture. The effect of factors, namely concrete side edge distance and concrete material type, on steel corrosion in chloride-contaminated reinforced concrete was investigated in this study. Wet-dry cycle tests and accelerated corrosion tests were carried out on sixty-three specimens designed with three different side edge distances and three different …


Behavior Of Advanced Innovative Materials For Improved Long-Term Bridge Performance, Wei Zheng Jan 2012

Behavior Of Advanced Innovative Materials For Improved Long-Term Bridge Performance, Wei Zheng

Doctoral Dissertations

"The dissertation is to present the investigation results and comprehensive understanding of the long-term performance and behavior of innovative construction materials. The materials are applied in bridge engineering in order to either enhance the conventional materials or replace them. The dissertation consists of two major parts: structural steel coatings for corrosion mitigation and thermal behavior of concrete bridge.

In First Part, evaluation of advanced structural steel coatings was carried out through laboratory weathering tests (salt-fog resistance test and QUV weathering test), adhesion test, and electrochemical techniques. Fifteen coating systems were evaluated in this part, which covered both coating and recoating …


Nitrification Performance Of Activated Sludge Under Low Dissolved Oxygen Conditions, Guoqiang Liu Jan 2012

Nitrification Performance Of Activated Sludge Under Low Dissolved Oxygen Conditions, Guoqiang Liu

Doctoral Dissertations

"The combined effects of solids retention time (SRT) and dissolved oxygen (DO) concentration on nitrification, nitrifying bacterial communities, and aeration needs in the activated sludge process were studied. Nitrification was almost completed in the 10, 20, and 40-day SRT reactors with a minimum DO of 0.37, 0.25, and 0.16 mg/L, respectively. Under long-term low DO conditions, the endogenous decay of nitrifiers was slowed down and then nitirfier biomass concentration increased, thereby reducing the adverse effect of low DO on nitrification. Under long-term low DO conditions, the oxygen affinity of nitrite-oxidizing bacteria (NOB) increased significantly and as a result, NOB became …


A Progressive Collapse Evaluation Of Steel Structures In High Temperature Environment With Optical Fiber Sensors, Ying Huang Jan 2012

A Progressive Collapse Evaluation Of Steel Structures In High Temperature Environment With Optical Fiber Sensors, Ying Huang

Doctoral Dissertations

"In the process of a progressive failure of steel structures in a post-earthquake fire, real-time assessment and prediction of structural behaviors are of paramount significance to an emergency evacuation and rescue effort. However, existing measurement technologies cannot provide the needed critical data such as large strains at high temperature. To bridge this gap, a novel optical fiber sensor network and an adaptive multi-scale finite element model (FEM) are proposed and developed in this study. The sensor network consists of long period fiber gratings (LPFG) sensors and extrinsic Fabry-Perot interferometer (EFPI) sensors or their integration. Each sensor is designed with a …


Driver Mandatory Lane Change Behavior: Use Of Governing Gap In Critical Gap Estimation, Srinadh Kandada Jan 2012

Driver Mandatory Lane Change Behavior: Use Of Governing Gap In Critical Gap Estimation, Srinadh Kandada

Masters Theses

"This study analyzed the driver gap acceptance and rejection behavior during mandatory lane changes on a multilane freeway in congested and uncongested traffic conditions. During a lane change, drivers were more receptive to either the leading or the trailing gaps with vehicles in the target lane which governed the drivers' lane change and is termed as the governing gap. Drivers maneuvered till the governing gap was greater than the critical gap, accepted the gap and made a lane change. In this process, drivers reduced the non-governing gap to increase the length of the governing gap. The drivers as a result …


Bond Behavior Of High-Volume Fly Ash And Self-Consolidating Concrete, Trevor Jay Looney Jan 2012

Bond Behavior Of High-Volume Fly Ash And Self-Consolidating Concrete, Trevor Jay Looney

Masters Theses

"The main objective of this study was to determine the effect on bond performance of high-volume fly ash (HVFA) concrete and self-consolidating concrete (SCC). The HVFA concrete test program consisted of comparing the bond performance of two concrete mix designs with 70% cement replacement with Class C fly ash relative to a Missouri Department of Transportation (MoDOT) standard mix design. The SCC test program consisted of comparing the bond performance of normal and high strength SCC with their respective MoDOT standard mix designs.

Two test methods were used for bond strength comparisons. The first was a direct pull-out test based …


Bond, Transfer Length, And Development Length Of Prestressing Strand In Self-Consolidating Concrete, Krista Beth Porterfield Jan 2012

Bond, Transfer Length, And Development Length Of Prestressing Strand In Self-Consolidating Concrete, Krista Beth Porterfield

Masters Theses

"Due to its economic advantages, the use of self-consolidating concrete (SCC) has increased rapidly in recent years. However, because SCC mixes typically have decreased amounts of coarse aggregate and high amounts of admixtures, industry members have expressed concerns that the bond of prestressing strand in SCC may be compromised. While the bond performance of prestressing strand in a new material such as SCC is an important topic requiring investigation, the results are only applicable if the research is completed on strands with similar bond quality as the strands used in the field. Therefore, the objectives of this research program were …


Prediction And Performance Of Single Piles In Clay Soils Under Vibratory Loadings, Domenica Cambio Jan 2012

Prediction And Performance Of Single Piles In Clay Soils Under Vibratory Loadings, Domenica Cambio

Doctoral Dissertations

"This study developed a model for predicting the response, in terms of amplitude versus frequency of single piles under lateral vibratory loadings embedded in clay or fine silty soils. The model incorporates frequency dependent parameters and the effects of soil non-linearity through the relationship between soil shear modulus and damping with strain. A computer program, Dyna5, was used to generate the computed response of single piles using the Novak and El-Shamouby (1983) approach. Soil non-linearity was accounted for by incorporating spline interpolation routine into Dyna5. Sliding and coupled rocking vibrations were addressed. The computed responses were predicted and compared with …


Behavior Of Staged Externally Bonded Carbon Fiber Reinforced Polymer Sheets For Improved Ductility, Laura Marie Rathe Jan 2012

Behavior Of Staged Externally Bonded Carbon Fiber Reinforced Polymer Sheets For Improved Ductility, Laura Marie Rathe

Masters Theses

"Fiber reinforced polymers (FRP) has become increasingly used for the retrofit of aging structures for increased lifespans and for the rapid repair of damaged structures. It has many advantageous such as ease in rapid installation, high strength-to-weight ratio, and corrosion resistance. The main disadvantage of the material is brittle behavior with little warning of impending failures. The main objective of this study is to develop a new system of FRP that exhibits a more ductile behavior. To achieve this objective, separate sheets of FRP were applied at various staged levels and thus engaged at different loads. Ductile behavior was evaluated …