Engineering Commons^™

In-Plane Behavior Of Strengthened Unreinforced Masonry Infill Walls With Alternative Wood-Fiber Fly Ash Material, Yosuke Tanizawa

Masters Theses

"This research investigates the potential for an alternative masonry product to use in masonry infill wall systems. The study also investigates the effects of an external fiber reinforced polymer (FRP) strengthening system on in-plane behavior of the alternative unreinforced masonry (URM) walls. The alternative masonry product is produced in a solid unit configuration and utilizes recycled white oak wood-fibers and an ASTM Class-C fly ash as its raw materials. The external strengthening system investigated consists of an elastomeric polyurea surface coating with and without integrated discrete chopped E-glass fibers which is directly sprayed on the URM wall surfaces. The alternative …

An Evolutionary Algorithm Approach To Actuated Signal Timing Optimization Under Lane-By-Lane Detection Condition, Eric G. Strack

Masters Theses

"Motivated by the need to reduce congestion on the nation's roadway network, this research seeks to determine when a new detection scheme at actuated signalized intersections may help. This new detection scheme is called lane-by-lane detection. It "looks" at traffic in all lanes individually to determine the traffic volume on the roadway. Specifically, the problems addressed are investigating alternate signal timings and investigating the traffic volume's effect on performance of the detection scheme. For the alternate signal timings, an Evolutionary Algorithm (EA) was employed to identify the optimal signal timing. This algorithm creates signal timings and tests them in the …

Anchorage And Bond Characteristics Of Externally Bonded Frp Laminates Used For Shear Strengthening Of Rc And Pc Girders, Carlos Andres Ortega Ordonez

Masters Theses

"In the last three decades, the use of fiber reinforced polymer (FRP) materials to strengthen structures externally has emerged as one of the most promising technologies in materials and structural engineering, and these materials have been gaining popularity in the civil engineering community. Externally bonded FRP sheets and laminates have been used successfully to increase flexural and shear capacity. The overall performance of the strengthened system depends heavily on the quality of the bond between the concrete and the FRP laminate. Low bond strength can cause delamination at the fiber-matrix interface and at the FRP laminate-concrete interface. As a result, …

An Integrated Damping And Strengthening Strategy For Performance-Based Seismic Design And Retrofit Of Highway Bridges, Kazi Rezaul Karim

Masters Theses

"In this study, a damping-enhanced strengthening (DES) strategy was introduced to retrofit bridge structures for multiple performance objectives. The main objectives of this study are (1) to numerically demonstrate the effectiveness of the anchoring mechanism of a constrained damping layer in the proposed DES system, and (2) to evaluate the performances of a highway bridge retrofitted with a DES retrofit technique of viscoelastic (VE) damping and carbon-fiber-reinforced-polymer (CFRP) strengthening components that are nearly independent under weak earthquakes but strongly coupled under strong earthquakes"--Abstract, page v.

Screw Connections Subject To Tension Pull-Out And Shear Forces, Ryan M. Francka

Masters Theses

"Currently, the behavior of screw connections subject to combined tension pull-out and shear forces is not well understood. An experimental study was conducted at Missouri University of Science and Technology to better understand the relationship or interaction between these forces. The test program evaluated four parameters that may influence the behavior of pure tension and pure shear in screw connections: the thickness of the sheet not in contact with the screw head, the ultimate strength of the steel, the ductility of the steel, and the screw diameter. This investigation extends the application of the pure pull-out and pure shear equations …

Seismic Behavior Of Circular Reinforced Concrete Bridge Columns Under Combined Loading Including Torsion, Suriya Prakash Shanmugam

Doctoral Dissertations

"Reinforced concrete (RC) columns of skewed and curved bridges with unequal spans and column heights can be subjected to combined loading including axial, flexure, shear, and torsion loads during earthquakes. The combination of axial loads, shear force, and flexural and torsional moments can result in complex failure modes of RC bridge columns. This study carried out experimental and analytical studies to investigate the seismic performance of circular RC columns under combined loading including torsion. The main variables considered here were (i) the ratio of torsion-to-bending moment (T/M), (ii) the ratio of bending moment-to-shear (M/V) or shear span (H/D), and (iii) …

Strain Sensitive Coax Cable Sensors For Monitoring Structures, Genda Chen, James L. Drewniak, Huimin Mu, David Pommerenke

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The invention provides increased structural monitoring systems that have sensitive continuous coaxial cable sensors. A preferred embodiment sensor cable of the invention includes an inner conductor, a dielectric jacket, and an outer conductor that is configured to passively deform responsively to strain in an associated structure. The deformation can be aided by the physical structure of the dielectric jacket, the outer conductor, or a combination of both. The deformation translates strain into a measurable change in a reflection coefficient associated with the outer conductor.

Determination Of Creep Compliance And Tensile Strength Of Hot-Mix Asphalt For Wearing Courses In Missouri, David Newton Richardson, S. M. Lusher

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Creep compliance and indirect tensile (IDT) strength of hot-mix asphalt (HMA) are the two primary inputs to the low-temperature or thermal cracking module in the new Mechanistic-Empirical Pavement Design Guide (M-E PDG) software. Creep compliance is defined as time-dependent strain per unit stress, while IDT strength is best defined as HMA strength when subjected to tension. AASHTO T 322 test protocol was used as reference for this work. However in preparation for the laboratory work performed at the Missouri University of Science and Technology many experts were consulted as to how IDT creep/strength testing and calculations are actually being performed. …

Rational Best-Value Model Based On Expected Performance, Magdy Abdelrahman, Tarek Zayed, Jay Hietpas, Ahmed Elwakil

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The best-value procurement strategy is gaining the interest of federal and state agencies. The strategy increases the value added to a project for each dollar added. A new concept of best value, that is, a rational and flexible model based on expected performance, is presented. The model's flexibility is obvious in the selection of parameters to be included in the contractor selection process and in the determination of their weights. The model's rationality will be achieved through relating all awarded scores to the agency's expected performance. The establishment of the best-value model relies on the past record of the contractor's …

Development Of Ballistic Limit Equations For Dual-Wall Spacecraft Shielding: A Concise History And Suggestions For Future Development, William P. Schonberg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

All earth-orbiting spacecraft are susceptible to impacts by orbital debris particles, which can occur at extremely high speeds and can damage flight- and mission-critical systems. The traditional damage mitigating shield design for this threat consists of a “bumper” that is placed at a relatively small distance away from the main “inner wall” of the spacecraft. The performance of a hypervelocity impact shield is typically characterized by its ballistic limit equation, which is typically drawn as a line of demarcation between regions of rear-wall perforation and no perforation; when graphically represented, it is often referred to as a ballistic limit curve. …

Estimation Of Earthquake Loss Due To Bridge Damage In The St. Louis Metropolitan Area: Part I - Direct Losses, Ronaldo Luna, David J. Hoffman, William T. Lawrence

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The risk associated with earthquake hazards on highway systems is dependent on the complexity of a network and its redundancy in providing traffic flow. Earthquake loss estimation studies can provide decision makers with an appreciation of the importance of having a highway network resistant to earthquakes and information to make the network resistant to these events. The direct economic loss was estimated for a major metropolitan area, St. Louis, for a series of earthquake scenarios. The primary component of the study was damage to bridges within the highway system. The study zone covers the St. Louis metropolitan area and its …

Electromagnetic Modeling Of Distributed Coaxial Cable Crack Sensors In Reinforced Concrete Members, Mei Wang

Masters Theses

"Distributed crack sensors were recently developed with coaxial cables that are composed of inner and outer conductors as well as dielectric layer in between. These sensors were designed based on the change in topology of the cable outer conductor structure under strain effects. Various tests of reinforced concrete (RC) beams and columns indicated that the newly designed sensors are 10~50 times more sensitive than commercial cables to the longitudinal elongation applied on their cable structures. The spatial resolution of the sensors is approximately 50 mm. Limited numerical simulations with the transmission line theory and the finite difference time domain model …

Performance Of Fire-Damaged Prestressed Concrete Bridges, Wendy Leann Moore

Masters Theses

"The purpose of this experimental program was to develop and analyze the effects of fire damage on prestressed concrete bridges. Flexural strength and serviceability of the bridge were measured by inputting fire damaged data into a parametric study spreadsheet consisting of a typical 3-span continuous prestressed concrete bridge. Data was obtained by exposing two types of specimens to different levels of elevated temperatures and then cooling them at room temperature to simulate fire damage. The two specimen types were prestressing strands which were tested in tension and concrete blocks with a single prestressing strand embedded in the center, which were …

Laboratory Analysis Of Small Strain Moduli In Compacted Silts, David M. Weidinger

Masters Theses

"Soil compaction quality control accounts for a significant portion of geotechnical practice. Often the performance of a roadway can be directly linked to the quality of the compacted subgrade. A poor subgrade can result in weak areas in the road causing excessive deflections at the surface, ultimately leading to a pot hole or uneven surface and an unpleasant ride for the travelers. Vehicles passing over a section of highway causes small strains in the founding soil. These strains accumulate over time. A better understanding of how the compacted soil responds at small strains could shed light on improving the quality …

Estimation Of Earthquake Loss Due To Bridge Damage In The St. Louis Metropolitan Area. Ii: Indirect Losses, David Lee Enke, Chakkaphan Tirasirichai, Ronaldo Luna

Engineering Management and Systems Engineering Faculty Research & Creative Works

An approach to estimate the indirect economic loss due to damaged bridges within the highway system from an earthquake event is presented. The indirect cost considered refers to the increased highway transportation cost only. The study zone covers the St. Louis metropolitan area and its surrounding suburban regions. An earthquake scenario centered in St. Louis, with a magnitude 7.0 is used. The direct earthquake loss was primarily damage to bridges, which causes an increase in travel time and distance within the transportation network. This information is then used as input for the indirect loss model. The indirect loss is examined …

Formation And Removal Of Pesticides And Pesticide Transformation Products During Water Treatment, Evelyn F. Chamberlain

Doctoral Dissertations

"A comprehensive suite of over 60 pesticides (herbicides, insecticides, and fungicides) representing a variety of classes at environmentally relevant concentrations (low µg/L) were screened for reactivity under typical drinking water conditions and dosages. The most common oxidants/transformation agents in water treatment systems were examined for reactivity including free and combined chlorine, chlorine dioxide, permanganate, ozone, hydrogen peroxide, ultraviolet radiation, and high pH (alkaline hydrolysis). Due to the broad nature of the study, pesticide compounds were analyzed as multiple mixes broken into two groups based on analytical methods, those analyzed by GC/ECD and those by LC/MS. Combinations of reactive disinfectant/oxidant and …

Development Of A Gis-Based Seismic Hazard Screening Tool, Andrew J. Wilding

Masters Theses

"Geotechnical earthquake engineering hazards have consequences that are difficult to mitigate, especially for infrastructure systems with multiple and distributed components. In the last few decades significant progress has been made to provide more accurate and useful methods to evaluate hazards for complex systems. One of these advances involves the application of spatial analysis and geographic information systems (GIS), for not only presenting data as maps, but also providing more practical and usable solutions, such as calculating the hazard potential with spatial distribution. This thesis studies the evaluation of geotechnical earthquake engineering hazards within a GIS environment, using borehole-specific data and …

A Laboratory Study Of Struvite Precipitation For Phosphorus Removal From Concentrated Animal Feeding Operation Wastewater, Sushmita Dhakal

Masters Theses

"Struvite precipitation occurs spontaneously in many wastewater treatment facilities as a nuisance. However, struvite precipitation is now being studied as a method to concurrently treat high phosphorus wastewaters and generate a valuable product. Many factors influence the precipitation of struvite such as component -ion molar ratios, pH, aeration, solubility, solids and mixing energy. In the present work, struvite precipitation in the actual swine wastewater was studied by strategically controlling aeration, pH, and mixing"--Abstract, page iv.

Hazards Assessment Of St. Charles County - Earthquakes And Floods, Amy Lynn Krauch

Masters Theses

"Located on the northernmost limits of the St. Louis metropolitan area, St. Charles County has been, and continues to be, one of the fastest-growing counties in the country. The county consists of several major cities featuring extensive industry, retail, and agriculture. Bounded by the Missouri River on the south and the Mississippi River on the north and east, St. Charles County is predominantly flat, low-lying terrain at great risk to periodic flooding. The county is also well within the area of influence for several local seismic zones, increasing the susceptibility to earthquake damage. Given the apparent risk to both flood …

Experimental Validation Of An Integrated Frp And Visco-Elastic Hardening, Damping, And Wave-Modulating System For Blast Resistance Enhancement Of Rc Columns, Brian Henry Wood

Masters Theses

"In today's society, terrorist attacks and accidental explosions pose a major threat to critical infrastructure. Vulnerable to blast loading, structures must be rehabilitated to ensure structural stability and protect human life. The goal of this study is to develop and validate a sandwich composite technology for column retrofitting. The new technology consists of an inner fiber reinforced polymer (FRP) sheet, an outer FRP sheet, and a visco-elastic (VE) layer sandwiched between the two FRP sheets. The inner FRP sheet is wrapped around an existing column for confinement, while the outer FRP sheet is for anchoring of the VE layer into …

Behavior Of Full-Scale Rc T-Beams Strengthened In Shear With Externally Bonded Frp Sheets, Antonio Brancaccio

Masters Theses

"Shear deficiencies in many bridges may be considered even more critical than flexural deficiencies since shear failures occur without advance warning and are more catastrophic. Deficiencies in shear can be due to insufficient shear reinforcement, use of outdated design codes, a reduction in the steel area due to corrosion, or an increase in the service load due to change of occupancy for the structure.

In recent years, many research studies have investigated the shear behavior of reinforced concrete (RC) beams strengthened with fiber-reinforced polymer (FRP) composites, however, most of them were conducted on small-scale specimens. Thus, analytical models and design …

Physical Modeling Of Railroad Ballast Using The Parallel Gradation Scaling Technique Within The Cyclical Triaxial Framework, Adam F. Sevi

Doctoral Dissertations

"Due to the difficulties involved with testing large particle granular materials such as rockfill and railroad ballast, several methods of testing scaled down model specimens have been introduced. Of these techniques, the parallel gradation model has been found to be most useful. The parallel gradation model states that a smaller grainsize distribution model granular material, of the same composition as the prototype material, can be used in triaxial testing at a scaled down grainsize, if the model materials grainsize is exactly parallel to the prototype material. Therefore, a model granular material composed of a smaller, but parallel, grainsize distribution can …

Performance Evaluation Of Existing Analytical Methods To Compute The Shear Contribution Provided By Externally Bonded Frp Sheets In Concrete Structures, Rocio Patricia Tumialan

Masters Theses

"External application of FRP composites has been adopted for strengthening and/or repair of concrete structures in many applications during the last two decades. However, the research into shear strengthening using FRP composites has not been widely conducted as compared to flexural strengthening and axial load capacity increase, and the results obtained thus far are scarce and sometimes controversial. This study presents a review of analytical studies and design guidelines on shear strengthening of concrete structures with externally-bonded FRP laminates, and their assessment with experimental data collected from the literature. The strengths and weaknesses of each model and design guidelines/codes/specifications are …

Static Evaluation Of The Out-Of-Plane Behavior Of Urm Infill Walls Utilizing Modern Blast Retrofit Systems, Trevor D. Hrynyk

Masters Theses

"Previous investigations have shown that the use of modern retrofit systems can significantly improve the behavior of URM infill walls subjected to variable out-of-plane loads. It has also been shown that the use of externally bonded retrofit systems can greatly reduce the amount of fragmentation and debris scatter that is found to occur in URM walls subjected to high intensity blast loads...The main objective of this study is to investigate, through static testing, the use of modern materials for the purpose of improving the behavior of URM walls subjected to blast loads. This study implemented externally bonded FRP grids and …

Análisis De Deslizamientos En La Ciudad Capital Utilizando Sistemas De Información Geográfica, Pedro Pablo Conlledo, Ronaldo Luna

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

En Guatemala, los daños ocasionados por deslizamientos de tierra son innumerables, y sin embargos son pocos los esfuezos que se han hecho a nivel nacional por estudiarlos. El principal objetivo de este trabajo fue utilizar Sistemas de lnformacion Geografica (SlG) para estudiar sistematicamente la ocurrencia de deslizamientos en el Departamento de Guatemala con la informacion disponible.

Analysis Of Soil Erosion Based On Soil Properties, Preetha Veeraraghavan

Masters Theses

"The objectives of this research were to identify the major soil parameter(s) that affect the erosion rate of soil and to estimate the erosion rate based on those soil parameters. Both prepared samples and natural samples were used in this research. The soil properties analyzed were the water content, unit weight, Atterberg limits, and soil cohesion. The erosion rate was determined using a rectangular flume and a linear relation between the erosion rate and shear stress was established from the flume experiment. The slope of the linear relation was a good indicator of the soil's erosion rate. The erosion rate …

Enhanced Electronic Conductivity In Si-Substituted Calcium Aluminate, Julia E. Medvedeva, Thomas O. Mason, Kenneth R. Poeppelmeier, Mariana I. Bertoni, Arthur J. Freeman

Physics Faculty Research & Creative Works

Improved conductivity has been achieved by controllable substitution of an ultraviolet electronic conductor. The transparent conducting oxide system, H-doped Ca12Al(14−x)SixO(33+x/2) with x=0−4, exhibits a conductivity strongly dependent on the substitution level. Four-point direct current conductivity increases with x from 0.15 to 0.61 S/cm at room temperature. The observed conductivity behavior is consistent with the predictions of our first principles density functional calculations for the Si-substituted system with x=0, 2, and 4. Furthermore, the Seebeck coefficient is composition dependent suggesting the existence of an activated mobility associated with small polaron conduction. ©2007 American Institute of Physics

Visual Traffic Movement Counts At Intersection For Origin-Destination (O-D) Trip Table Estimation, S. Lee, Hojong Baik, J. Park

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Origin-destination (O-D) trip table is necessary information for transportation planning and traffic impact study. However, current O-D estimations rely on estimated directional traffic counts at intersections, which obviously diminish reliability in the table. A video-based vehicle tracking system that utilizes wide view-angle lenses has been studied [26] to provide accurate direction traffic counts. The system expands the area covered by a single camera and uses a particle filtering method to handle environmental changes as well as geometric distortion caused by those lenses. This paper shows tracking capability of the system and also shows how to incorporate the directional traffic counts …

Field And Laboratory Investigation Of Ozone-Indoor Surface Reactions: Secondary Emissions Inventory And Implications For Indoor Air Quality, Hong Wang

Doctoral Dissertations

"Interfacial chemistry greatly influences human exposure to reactants and products in indoor environments. Emissions of volatile organic compounds, as a result of ozone-surface interactions, can lower an occupant's exposure to ozone, but increase indoor concentrations of odorous and carcinogenic compounds. Therefore, investigation of ozone-surface interactions are necessary for better understanding and controlling exposure to ozone and the products of indoor surface chemistry. In this dissertation, field experiments were conducted in five homes in three seasons to quantify ozone-initiated secondary emission rates (SERs), yields surface reaction probabilities and study their temporal trends"--Abstract, page iv.

Innovative Solutions In Bridge Construction, Rehabilitation, And Structural Health Monitoring, Fabio Matta

Doctoral Dissertations

"This dissertation includes three technical papers that investigate the development of innovative technologies for bridge construction, rehabilitation, and structural health monitoring, respectively, at different stages of the technology transfer process...The research impact is twofold: first is the introduction of promising innovative technologies in development and implementation projects with the direct involvement of forward-thinking industry partners; second is the demonstration of the validity of these technologies on the basis of a rigorous scientific approach"--Abstract, page iv.