PhD, University of Cincinnati, 2023, Engineering and Applied Science: Civil Engineering

Accelerated bridge construction (ABC) techniques have gained attention in recent years to improve the efficiency, safety, and durability of bridge construction. Prefabricated bridge elements and systems (PBES) play a crucial role in ABC by reducing on-site construction time, enhancing material quality, and improving work-zone safety. While precast/prestressed hollow core sections are commonly used for short to medium spans, longer spans require alternative solutions. Precast/prestressed deck bulb tee (DBT) sections offer a more suitable option for longer spans, but their widespread adoption is hindered by concerns about long-term connection performance. This research focuses on the design, detailing, and construction of longitudinal and transverse joints in DBT girder bridges utilizing ultra-high-performance concrete (UHPC) as a closure pour material. The study aims to develop guidelines and recommendations to ensure the strength and durability of these joints and facilitate accelerated construction. The variables considered include connection width, bar spacing, bar size, bar detailing, flange thickness. Ultra-high-performance concrete (UHPC) is explored as a viable option for improving joint durability due to its high bond strength to concrete and shorter development length requirements for reinforcing bars. To achieve the research objectives, a literature review was conducted to identify challenges and current practices in DBT bridge construction. Full-scale experimental testing was performed on systems of three girders to evaluate the performance of longitudinal UHPC joints under thermal and cyclic load and differential camber. Additionally, the transverse joint between two girders was tested using UHPC. Finite element analysis was employed to assess the behavior of longitudinal UHPC joints subjected to thermal loads and camber leveling forces. The findings of this research (open full item for complete abstract)

Committee: Richard Miller Ph.D. (Committee Chair); Eric Steinberg Ph.D (Committee Member); Bahram Shahrooz Ph.D. (Committee Member); Rachel Chicchi Ph.D. (Committee Member) Subjects: Civil Engineering

MARCH, University of Cincinnati, 2023, Design, Architecture, Art and Planning: Architecture

Urban spaces contain layers of development in a city's quest for evolution and expansion, however, perceived triumphs of development such as highways have created downfalls in cities' structures and history. Highway systems are an infrastructure that threads cities and states in an accessible line of transportation. Suburban communities have gained direct access to cities at the cost of urban communities being severed from the urban core. While interstates are integral to the vitality of a city's success, there are opportunities to reevaluate the form of interstates to minimize the divide created by their location and structure. One of these opportunities is to utilize interstate capping, building over interstates in order to expand the development potential of cities and help to positively affect these severed communities. In the process of investigating highway capping, the West End of Cincinnati will be analyzed in order to find opportune locations existing in the layout of I-75 and I-71 to be able to locate caps that would have the most impact. Along with analyzing this portion of the city, it is important to analyze the history of the neighborhood and its history of being undervalued by local government and city planners. Through this experiment, there is an opportunity to bring a positive effect to the West End community and help to mend the residual disappointment leaders and planners have inflicted on the community. Evaluating the current infrastructure can also allow for Downtown to expand, breaking through the current gridlock confines. With the proposed design, highway capping can create positive, sustainable, public spaces that can rebuild areas of neighborhoods that have been lost due to the creation of the highway and allow for city centers to expand.

Committee: Elizabeth Riorden M.Arch. (Committee Member); Michael McInturf M.Arch. (Committee Chair) Subjects: Architecture

MS, University of Cincinnati, 2022, Engineering and Applied Science: Civil Engineering

Bridges play a vital role in the nation's road network providing safety in crossing obstacles. The components of the bridges are subjected to continuous loads and severe weather conditions. Compared to the other elements of a bridge, a bridge deck is subjected to the direct impact of the traffic loads and has a more extensive contact area exposed to precipitation and temperatures. The condition rating is a metric that shows the bridge's (or its components) condition and is given on a scale of 0 through 9 by bridge inspectors after physical inspections. Prediction of the condition ratings helps the owner agencies in critical decision-making while saving time and preventing unnecessary investments in bridge maintenance by eliminating human errors. It is a proven fact that machine learning models can make accurate predictions given appropriate historical data. The research presented in this report uses a machine-learning-based KNN Classification algorithm to predict the bridge deck condition ratings for the bridge network located in Hamilton County, Ohio State. The data is obtained from the NBI database, which is considered the legit source for bridge inventory. Using different input variables and the KNN algorithm, multiple attempts were made to predict bridge deck condition ratings to obtain higher model prediction accuracy. This research identified nine input variables from the raw data that are more impactful than the other variables. Three engineered variables were introduced as input variables along with the existing variables. The three new engineered variables are developed using the NBI data, and the procedure and considerations were thoroughly discussed in this report. The model accuracies for different 'k' values were calculated with the help of a 'confusion matrix' and 'classification reports. The results showed that higher accuracies are possible with the simple form of machine learning algorithms by introducing new input variables which can be develop (open full item for complete abstract)

Committee: Sara Khoshnevisan Ph.D. (Committee Member); George Okere Ph.D. (Committee Member); Hazem Elzarka Ph.D. (Committee Member) Subjects: Civil Engineering

Master of Science (MS), Ohio University, 2022, Civil Engineering (Engineering and Technology)

This research reviewed the current and future uses of Ultra-High Performance Concrete (UHPC) for bridge applications in the state of Ohio. Since most designers, owners and contractors are unfamiliar with the material and only a small percentage of all bridges utilize it, UHPC is still considered a relatively new material. Monitoring and understanding its performance in current applications will undoubtedly provide useful insights for future applications. Advantages of UHPC discussed include rapid strength gain that can be utilized in Accelerate Bridge Construction, fiber content which provides post cracking strength, high bond strength which shortens development lengths of reinforcement, and the flowable material which allows UHPC to better penetrate tighter spaces. Disadvantages of UHPC such as material cost, increased labor and time are also discussed. In addition, recommendations for future UHPC applications are provided that would benefit designers, owners and contractors through valuable insight that was gained during these research objectives. The first objective was to review the performance of UHPC in the Sollars Road adjacent prestressed concrete box beam bridge in Fayette County. The design of the UHPC longitudinal joint (shear keys) included dowel bars but eliminated intermediate diaphragms, transverse post-tensioning, and a composite deck. Comparing truck loading data from 2014 shortly after bridge construction was completed and 2017 during this study, the load distribution has improved to some extent and the bridge is responding to loading in a similar manner which implies minimal to no cracking of the UHPC shear keys. This simplified design may be a realistic alternative to solve the typical issue of cracking in the longitudinal joints (shear keys) and associated reflective cracking in composite decks for adjacent prestressed concrete box beam bridges. This improved behavior with UHPC joints may result i (open full item for complete abstract)

Committee: Eric Steinberg Ph.D. P.E. (Advisor) Subjects: Civil Engineering

Doctor of Philosophy, University of Akron, 2021, Civil Engineering

Orthotropic steel decks have, over the years, demonstrated practical, economical and weight advantages over other deck types, particularly for long span bridges. That has led to the replacement of a number of original concrete bridge decks with by orthotropic steel decks. However, several orthotropic steel decks have suffered from localized fatigue cracking, primarily related to welded connections between the deck plate/panel to web, as well as deck to diaphragm welds. In this study, a new design concept for an orthotropic steel deck using closed-rib built-up sections, that provide further advantages to traditional steel decks and minimize past performance issues, including improved installation, performance and durability, is presented and investigated. Analysis and design tools were developed and implemented to generate optimal built-up deck alternatives for several existing bridges including the Benjamin Franklin Bridge, the Bronx-Whitestone Bridge, the George Washington Bridge and the Throgs Neck Bridge. Comprehensive comparisons between built-up designs and the actual bridge decks were conducted using a series of finite element simulations. Moreover, representative volume element (RVE) specimens of a single-rib, built-up deck were experimentally tested under static and dynamic loading conditions. Experimental results were compared and fatigue S-N curves developed. Finally, scanning electron microscopy (SEM) images were taken of fatigue cracks as well as panel to web welded connections of selected specimens.

Committee: Craig Menzemer (Advisor); David Roke (Committee Member); Ping Yi (Committee Member); Xiaosheng Gao (Committee Member); Jun Ye (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy (PhD), Ohio University, 2020, Civil Engineering (Engineering and Technology)

The long-term performance of a bridge deck depends on its resistance to bridge cracking. Most of these cracks are initiated at the early age. Early age cracking of bridge decks is a typical issue in the U.S. that reduces bridge service life. Therefore, internally cured concrete (ICC) has been used in some states to reduce or eliminate the development of cracks in reinforced concrete decks. In this study, the early age behavior of ICC deck and the effect of the internal curing on the long-term behavior of the bridge was measured and evaluated in the laboratory and field for newly adjacent constructed bridge, which were located on Route 271 in Mayfield, Ohio. Two different types of concrete mixtures were utilized for the decks: conventional concrete (CC) and internally cured concrete (ICC). Firstly, the ICC and CC mixtures were examined in the laboratory in terms of a mechanical properties test, a plastic shrinkage test, a free shrinkage test, and a restrained shrinkage test. Second, the field behavior of an ICC deck and an adjacent CC deck during their early age and long-term performance were evaluated. Also, the shrinkage development for both decks was examined during the very early age. Instrumentation was used to measure the concrete and reinforcement strains and the temperature in both bridges. The instrumentation and results for both bridges are discussed. Laboratory results indicated that using pre-wetted lightweight concrete in the concrete mixture led to decreased density, coefficient of thermal expansion, and free shrinkage strain, and increased tensile strength and cracking time of concrete compared to conventional concrete. In the field, from the early age test, it was observed that the time to develop concrete shrinkage was approximately 5-6 hours after casting the deck of the ICC and the CC. The results indicated that the majority of shrinkage occurred during the first week after concrete placement. However, the deck with ICC experienced less longitud (open full item for complete abstract)

Committee: Eric Steinberg Professor (Advisor) Subjects: Civil Engineering

Doctor of Philosophy (PhD), Ohio University, 2020, Civil Engineering (Engineering and Technology)

The primary types of deterioration in skewed composite adjacent box beam bridges are cracking in the deck and longitudinal reflective cracking above the shear keys. Possible causes include early age conditions, temperature, and traffic loads. Eliminating or reducing these types of damage is expected to lead to increased service life and reduced maintenance costs for this type of bridge. In this research, a skewed composite adjacent box beam bridge built in November 2015 on Dry Creek Road in Granville, Licking County, Ohio, was instrumented with embedded and attached sensors, including strain gauges, thermocouples, and linear variable differential transformers (LVDTs). These sensors were then monitored during the construction of the bridge on-site, and service, including during arranged field tests with a controlled vehicle load. The bridge was also analyzed using a validated threedimensional finite element model (FEM). Non-uniform temperature through the bridge superstructure and shrinkage cause high tensile strains at the bottom surface of the deck during the early aging of the concrete. The highest measured strains were near the supports and parallel to the skewed angle. Radial cracks were observed at the concrete deck ten months after bridge construction. Measurements made at the box beam fabrication facility showed a lack of uniformity in beam dimensions. Even if the variation in the beam dimensions was within tolerance, there was contact between adjacent beams at isolated spots where thermal expansion led to compressive stress at contact areas. Placing box beams at a slight angle to create a transverse slope and facilitate drainage also creates potential contact areas along the bottom edges of adjacent beams. The FEM showed that under uniform temperature and temperature gradient conditions, the stresses exceeded the concrete design strength at certain contact points along the beams' length. The skew geometry had a significant effect on the distribution of stre (open full item for complete abstract)

Committee: Shad Sargand (Advisor); Davydov Alexei (Committee Member); Eric Steinberg (Committee Member); Khoury Issam (Committee Member); Yu Xiong (Committee Member) Subjects: Civil Engineering; Engineering; Transportation

Doctor of Philosophy, The Ohio State University, 2019, Aero/Astro Engineering

Over the last 80 years, high-performance military aircraft have relied on increasingly sophisticated jet engine technologies to enable performance and fulfill mission requirements. To satisfy these engineering demands, several reliable technologies are often combined into one composite engine configuration. Although the behavior of these composite configurations is fairly well known at the engineering level, their rapid advancement is constrained by a lack of knowledge of the fundamental fluid dynamics, particularly the dominant unsteady turbulent mechanisms. This has in turn limited the effectiveness of design tools. Nozzle designs are also becoming more exotic as they conform to increasingly complicated emerging engine architectures, such as variable-cycle engines, whose flowfields are inherently complex due to the multitude of compressible shear layers that evolve in the presence of pressure gradients. The flowfield complexity is further exacerbated for supersonic flight where the engine is integrated into the airframe, and the turbulent, high-speed, shock-containing exhaust interacts with proximal surfaces of the aircraft. In this work, high-fidelity Large-Eddy Simulations are employed to examine the fluid dynamics of a nozzle configuration relevant to emerging airframe-integrated variable-cycle engine architectures. The nozzle comprises two rectangular streams; the upper (core) Mach 1.6 single-sided expansion ramp stream is separated by a splitter plate from a sonic, lower (deck) stream issuing in a wall-jet arrangement over an aft-deck. Simulation results are validated with available experimental measurements performed at Syracuse University, and are probed using a variety of techniques to characterize the composite flowfield. Even at design conditions, the asymmetry induced by the single-sided expansion and the aft-deck results in a highly three-dimensional shock train, whose interactions with the bounding shear layers influence numerous aspects of the flo (open full item for complete abstract)

Committee: Datta Gaitonde PhD (Advisor); Jen-Ping Chen PhD (Committee Member); Mei Zhuang PhD (Committee Member) Subjects: Aerospace Engineering

Master of Science in Engineering, Youngstown State University, 2018, Department of Civil/Environmental and Chemical Engineering

The Lincoln Parking Deck at Youngstown State University has been serving as one of the most important structures on campus since the 1970s. It is a multi-level parking deck consisting of two entries and exit points from Lincoln Ave and Arlington St. Due to aggressive environmental conditions in Northeast Ohio, this structure has undergone deterioration, which ranges from mild in some places to extreme in certain locations. This research delves into the potential decrease in the safety of the structure due to corrosion in reinforcement and other structural damages. Even after undergoing routine maintenance checks, the structure shows signs of corrosion within the embedded concrete, which are now visible from the outside. This research mainly focuses on detecting the causes of corrosion in reinforcement and suggesting remediation to overcome corrosion in both new and existing structures. Use of advanced non-destructive techniques, such as Ground Penetrating Radar and the Profoscope, has revealed crucial details that could help understand corrosion in various structures. Visual inspection also led to the discovery of corrosion on the deck which was not mentioned in the renovations. The data obtained from the structural drawings were incorporated into probabilistic equations to determine the present condition of the parking deck using corrosion modelling. A structural analysis was performed on the parking deck to evaluate the strength of the materials and the results obtained were found to be satisfactory. The results indicate the parking garage to be structurally adequate at the time of the experiments. Based on the findings, appropriate remedial measures were suggested to avoid further corrosion. Detecting corrosion and undertaking proper rehabilitation would help YSU on maintenance. It may also help commuters use the parking deck with ease and comfort. A considerable number of students and staff use the Lincoln Parking Deck daily. If the corrosion becomes severe, (open full item for complete abstract)

Committee: AKM Anwarul Islam PhD (Advisor); Richard. A. Deschenes PhD (Committee Member); Jai. K. Jung PhD (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy, University of Akron, 2018, Civil Engineering

Cracking on decks is one of the major concerns for bridges located all over the United States, affecting the durability and service life of the bridge. The CSS (Continuous Span Structural Slab) bridges, without stringers and are the most commonly used bridges in counties over the streams. Several CSS bridges in Ohio were surveyed to inspect crack widths on the bridge decks; and it was found that the crack widths over the negative moment regions were as wide as 0.125 inches. Such wide cracks exceed the recommended limit by ACI 224R-01 on bridges exposed to deicing salts by a factor of over 15. The permanently opened cracks act as pathways to the chlorides from the de-icing salts, allowing them to reach the reinforcement, causing aggressive environment around the embedded steel. This causes corrosion of the embedded reinforcing bars leading to severe section loss in steel. It was observed in the past, that epoxy-coated bars caused wider cracks compared to conventional black steel when used in reinforced concrete flexural applications. These wider cracks allow chlorides to penetrate the slab and directly attack the steel exposed due to the damage caused by epoxy coating during its handling. The corrosion of the epoxy coated bars leads to peeling off due to poor adhesion of the coating to the base steel. This causes a loss of bond with the surrounding concrete and loss in flexural capacity, which is of critical concern for the service life of the bridge. These cracks not only open and close under traffic loading, but widen over time due to the action of freeze-thaw effect and continuous fatigue due to vehicular loading. Experimental program was designed to reduce cracking using alternative reinforcing bars, with better bond characteristics as well better corrosion resistance. Prism tests with various corrosion resistant bars which include epoxy-coated bars, hot-dipped galvanized bars, stainless steel bars, CGR-UAR bars, MMFX bars revealed that epoxy coated bars caused w (open full item for complete abstract)

Committee: Anil Patnaik Dr. (Advisor); Craig Menzemer Dr. (Committee Member); Ping Yi Dr. (Committee Member); Xiaosheng Gao Dr. (Committee Member); Nao Mimoto Dr. (Committee Member) Subjects: Civil Engineering

Master of Science, The Ohio State University, 2017, Civil Engineering

Deterioration is among the primary concerns regarding the structural performance and functionality of bridges and their components. In light of annual budget constraints, infrastructure agencies, such as state Departments of Transportation (DOTs) in the US, prioritize their bridge maintenance needs. To make trade-offs across bridges and over time, key inputs to the prioritization and decision making process are bridge condition assessments and predictions. In this study, a Bayesian updating procedure is proposed to estimate a Markov Chain based concrete deck deterioration model in a manner that combines condition data collected over two inspection cycles and the deterioration information available prior to the collection of these condition data. Single period (one year) transition probabilities are estimated using Bayesian updating and maximum likelihood estimation, where in the case of the latter only the collected condition data over two inspection cycles are used. A dataset of 357 bridge deck condition assessments based on AASHTO condition state definitions collected by a state infrastructure agency spanning two years is used to evaluate the performance of the two methods. Training and validation datasets are selected from the original dataset where the former is used for estimation and the latter for prediction and evaluation. An experimental design is conceived where five bridges with distinctively different deterioration are considered to belong to the two sets or neither in various combinations. The evaluation is based on measuring the degree of similarity between reported condition states and those predicted based on the estimated transition probabilities using the two methods. While updating transition probabilities as new data are collected is found to be advantageous for many cases, this advantage is highly dependent on the deterioration nature of the bridge decks reflected in the training dataset. Finally, directions for future research are discussed. (open full item for complete abstract)

Committee: Abdollah Shafieezadeh (Advisor); Rabi Mishalani (Advisor); Mark McCord (Committee Chair) Subjects: Civil Engineering

Master of Science (MS), Ohio University, 2016, Civil Engineering (Engineering and Technology)

The infiltration of water and road salts from the cracking of concrete bridge decks is a problem throughout the country. This process is likely to accelerate the corrosion of the reinforcement embedded within the deck. The corrosion could promote further escalation of cracking and other damaging effects to the bridge decks. Cool-crete is a new liquid admixture which decreases the hydration heat and hence should achieve better shrinkage cracking performance than conventional concrete in bridge decks. Two slabs, the first containing an Ohio Department of Transportation (ODOT) Job Mix Formula (JMF) and the second using the same JMF but with the addition of the Cool-crete additive, were studied. The internal temperatures and strains were measured in the slabs which simulated portions of a bridge deck. The control slab was also subjected to a thermal gradient and analyzed using a finite element model. The data collected showed that there were higher internal temperatures and strains within the control slab and the Cool-crete slab had lower internal temperatures and strains.

Committee: Eric Steinberg (Advisor) Subjects: Civil Engineering

Doctor of Philosophy (PhD), Wright State University, 2015, Engineering PhD

While aircraft pilots must attain awareness of both pertinent spatial and temporal navigation information in the Next Generation Air Transportation System, current flight decks present spatial and temporal information separately. This research explored display design to enhance situation awareness (SA) while conducting navigation with spatial and temporal constraints (space-time navigation). For Experiment 1, static maps were developed for space-time navigation including scheduled/estimated time of arrival for passengers at bus stops on public bus routes. The maps varied time status representation and format of indicated time into four conditions. To examine SA, the test program provided 23 non-pilot participants with the maps and different questions asking about the spatial and/or temporal statuses. Participants answered questions faster and more accurately when the time formats of question and map were compatible. Also, time length format was as effective as exact time format, and the text + graphics maps showed a benefit. For Experiment 2, flight deck displays composed of a navigation display (ND) and a control display unit (CDU) were developed varying display proximity between space and time information. Compared with the traditional standard pilot displays, display proximity manipulation included adding required/estimated time of arrival text on the ND, adding temporal conformance graphic bars on the CDU, and integrating all temporal texts and conformance graphics on the ND. Fifteen pilots participated in queries about the spatial and/or temporal status to evaluate their SA during autopilot simulation in four display conditions. The increased display proximity conditions were as good or better with respect to pilot speed and accuracy and subjectively were perceived less difficult to answer compared with the traditional condition. In Experiment 3, 14 pilots flew a simulated flight, and their compliance of spatial and temporal requirements at scheduled waypoints (open full item for complete abstract)

Committee: Jennie J. Gallimore Ph.D. (Advisor); Yan Liu Ph.D. (Committee Member); Pratik J. Parikh Ph.D. (Committee Member); Pamela P. Tsang Ph.D. (Committee Member); Michael E. Miller Ph.D. (Committee Member) Subjects: Cognitive Psychology; Design; Engineering; Technology; Transportation

Doctor of Philosophy, University of Akron, 2014, Civil Engineering

Bridge deck cracking is a common problem throughout the United States, and it affects the durability and service life of concrete bridges. Several departments of transportation (DOTs) in the United States prefer using continuous three-span solid structural slab bridges without stringers over typical four-lane highways. Recent inspections of such bridges in Ohio revealed cracks as wide as 0.125 in. These measured crack widths are more than ten times the maximum limit recommended in ACI 224R-01 for bridge decks exposed to de-icing salts. Measurements using digital image correlation revealed that the cracks widened under truck loading, and in some cases, the cracks did not fully close after unloading. This dissertation includes details of an experimental investigation of the cracking behavior of structural concrete. Prism tests revealed that the concrete with epoxy-coated bars (ECB) develops the first crack at smaller loads, and develops larger crack widths compared to the corresponding specimens with uncoated (black) bars. Slab tests revealed that the slabs with longitudinal ECB developed first crack at smaller loads, exhibited wider cracks and a larger number of cracks, and failed at smaller ultimate loads compared to the corresponding test slabs with black bars. To develop a preventive measure, slabs with basalt and polypropylene fiber reinforced concrete were also included in the test program. These test slabs exhibited higher cracking loads, smaller crack widths, and higher ultimate loads at failure compared to the corresponding slab specimens without fibers. Merely satisfying the reinforcement spacing requirements given in AASHTO or ACI 318-11 is not adequate to limit cracking below the ACI 224R-01 recommended maximum limit, even though all the relevant design requirements are otherwise met. Addition of fiber to concrete without changing any steel reinforcing details is expected to reduce the severity and extent of cracking in reinforced concrete bridge decks. (open full item for complete abstract)

Committee: Anil Patnaik Dr. (Advisor); Craig Menzemer Dr. (Committee Member); William Schneider Dr. (Committee Member); Nao Mimoto Dr. (Committee Member); Xiaosheng Gao Dr. (Committee Member) Subjects: Engineering

Master of Science in Civil Engineering, Cleveland State University, 2014, Washkewicz College of Engineering

Pavement patching is a common maintenance activity in the state of Ohio, due to numerous freeze-thaw cycles. The Ohio Department of Transportation (ODOT) has a need for durable, more permanent high performing pavement and bridge deck materials that allow for a faster repair and for user safety. New or proprietary products were chosen, installed, and monitored in order to specify for use in future ODOT construction, based on the field performance of the products. The objective of this study was to document the investigation, installation, and field testing of the previously chosen high performance patching materials. The investigation determined the proper field testing criteria used throughout this project. The installation of the patches was performed in both winter and summer weather conditions. Observations regarding the different products installed, and the installation process, were documented throughout the installations in order to determine which products are easier to install, and in order to document the potential problems that could arise throughout a future patching project. Field testing and visual inspections were performed throughout the project as well, in order to determine the overall performance of the products being tested. The proper installation and testing of these new products will assist in determining the overall performance of these patching products.

Committee: Norbert Delatte PhD (Advisor); Stephen Duffy PhD (Committee Chair); Mehdi Jalalpour PhD (Committee Chair) Subjects: Civil Engineering

MS, University of Cincinnati, 2014, Engineering and Applied Science: Civil Engineering

The use of precast/prestressed concrete as a structural building system became prominent in the 1950s especially for bridges. The design of the bridge structures was done as simply supported then. In 1969, an analysis and design method for `continuous for live load' bridges was developed. Extensive research has been conducted since then to study the behavior of `continuous for live load' precast/prestresed bridges and various modifications have been proposed. The current analysis method fails to predict the behavior of the continuous precast/prestressed bridge accurately because of the complex loads such as creep and shrinkage. The experimental procedure to determine the behavior of structures due to creep and shrinkage needs time and lot of resources. The motivation behind the current research is to provide a concept where finite element method can be employed to study the behavior of such structures. This research focuses on studying the behavior of single-span precast prestressed bridge due to long-term loading such as creep and shrinkage. The general purpose finite element program, ABAQUS 6.11-2 is used for analysis in the current project. The concept developed from the current research can be applied to multi-span bridge continuous structure in the future. The effect of creep and shrinkage on the overall system is studied. The results obtained from the analyses conform to the observed behavior in the field. It can be said that the analyses procedure for `continuous for live load' bridges needs to account for the cracking of the deck slab to predict an accurate behavior of the structure.

Committee: Richard Miller Ph.D. (Committee Chair); Gian Rassati Ph.D. (Committee Member); Ala Tabiei Ph.D. (Committee Member) Subjects: Engineering

MS, University of Cincinnati, 2003, Engineering : Civil Engineering

Bridges B-0071, and B-0171 in Hamilton County, Ohio have been in service for about fifty years. They are short span bridges with prestressed concrete girders. Until late 2001, they had conventional reinforced concrete decks. On November third of that year the ribbon was cut to reopen the bridges, now with Fiber Reinforced Polymer Decks. One of the bridges also had the girders replaced. These are the only bridges in existence that have FRP decking on concrete girders. The Hamilton County Engineers Office contracted with the Civil Engineering Department at the University of Cincinnati to perform research on these bridges. Information gained from this research will seek to confirm the safety of the new technology, approve construction and design techniques with reference to the FRP deck, and determine overall performance of the bridge to provided understanding of the system. The 50-year-old prestressed concrete girders were subjected to destructive load testing. The girders showed little loss of strength or stiffness from aging. The information on the performance of the girders was used in the analysis of the bridge system. Two of the bridges were subjected to nondestructive load testing. A three-dimensional finite element model was then created to replicate the performance of the bridges. Data from the bridge tests provided enough information to create an accurate model of the bridge girders, but not the deck. Using the finite element model, a Load Rating was performed. The bridges were found to be sufficiently strong to resist the loads that may be applied to them. The deck showed no signs of separation from the concrete girders as was previously suspected. The bridge system acted as a fixed end beam because of the semi-integral end abutments for the range of loads tested. The deck was not adding any strength tot the girders through composite action. The load transfer from one girder to another was not provided by the deck as was assumed in the design process, but by (open full item for complete abstract)

Committee: Dr. James Swanson (Advisor) Subjects: Engineering, Civil

Master of Science in Civil Engineering, University of Toledo, 2009, Civil Engineering

An experimental study was conducted concerning the use of bridge heating technology on a Fiber-Reinforced Polymer Honeycomb (FRPH) bridge deck. The main objective of the study was to determine whether heating in an FRPH application is feasible. Testing demonstrated that not only were there no adverse effects from heating the FRPH, but that less energy is required to heat a FRPH bridge deck than a concrete deck.A test setup was created to determine approximate values of the thermal conductivity of the FRP used in the bridge deck flange and the polymer concrete used in the deck wearing surface. The calculated values suggest that conduction upward to the deck surface should offer the path of least resistance for heat flow from the deck heaters. An exploration of the environmental sustainability issues surrounding FRP construction was conducted. The results of this study suggest that FRPH construction has less environmental impact than concrete construction. Small specimens (20”x28”) were outfitted with electrical heating cables and numerous temperature sensors to simulate a bridge deck application. Specimens were created out of both FRPH and concrete and operated under controlled thermal conditions to determine the compatibility of heating systems with FRPH and to compare the energy requirements to that of heated concrete decks. The systems were operated in an assumed worst-case scenario: from a cold start with a layer of ice on the surface. Results showed that the FRPH behaved well in a heating situation and should prove promising in specialty applications.

Committee: Douglas Nims (Advisor); Cyril Masiulaniec (Committee Member); Defne Apul (Committee Member) Subjects: Civil Engineering

Master of Science (MS), Ohio University, 2001, Civil Engineering (Engineering)

Evaluation of performance of composite bridge deck panels under static and dynamic loading and environmental conditions

Committee: Shad Sargand (Advisor) Subjects: Engineering, Civil

Master of Public Administration (MPA), Bowling Green State University, 2007, Public Administration

Low voter turnout has been a characteristic of several recent national-level elections and referenda throughout the world. Scholarly literature has also documented declining turnout as a continuing trend in wealthy, advanced industrial democracies such as the United States and the United Kingdom. Yet, scholarly research using individual-level data has shown that wealthy, better educated people are more likely to vote than those with low income and/or low educational attainment. This study attempts to answer the question: Does economic growth lead to decreased voter turnout? This work uses aggregate-level data for 86 countries to explain voter turnout in lower house elections and employs a hot-deck imputation technique to fill in missing observations. Regression analysis of data from the World Bank, the International Institute for Democracy and Electoral Assistance, and the Polity IV project reveals little evidence to support the claim that economic growth affects voter turnout. Only one multiple regression model of countries in the Latin American and Caribbean region gives evidence supporting the principal hypothesis of this study that economic growth produces a decline in voter turnout. The literature review and null findings of this research establish that quantitative, scholarly research on voter turnout is more concerned with explaining voter turnout in industrial democracies than in developing countries. In the current context of globalization, future research must be grounded in a more encompassing theory if voter turnout is to be treated as a universal characteristic of all democratic elections.

Committee: Melissa Miller (Advisor) Subjects: