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Articles 11551 - 11580 of 39794

Full-Text Articles in Civil and Environmental Engineering

Effect Of Mixing On Monochloramine Formation Through In-Line Injection Of Chemicals In Water Disinfection Process, Farhikhteh Samadi Aug 2019

Effect Of Mixing On Monochloramine Formation Through In-Line Injection Of Chemicals In Water Disinfection Process, Farhikhteh Samadi

Civil Engineering Dissertations - Archive

Addition of chlorine and ammonia to water for monochloramine formation in the secondary disinfection process in treatment plants has some challenges. Monochloramine formation as the only desirable product of the chloramination process is affected by several factors. These factors are pH, chlorine to nitrogen ratio and chemical mixing. In this study an investigation was conducted to measure the effect of mixing on monochloramine formation through direct injection of chemicals in a pipeline when keeping the other factors constant. In this study two sets of experiments were conducted. In the first study a tracer salt testing was used to find a …

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On The Concept Of Synthetic Fiber Reinforced Thin-Walled Concrete Pipes, Arash Emami Saleh Aug 2019

On The Concept Of Synthetic Fiber Reinforced Thin-Walled Concrete Pipes, Arash Emami Saleh

Civil Engineering Dissertations - Archive

This research investigates the structural and industrial possibility to create a new type of concrete pipes called synthetic fiber reinforced thin-walled concrete pipes, which would be lighter, cheaper, and more durable than what is currently in use while still providing a pipe product much less dependent upon installation conditions than the very flexible metal and plastic pipes in the American market. The idea is to reduce the thickness and reinforcement of the current reinforced concrete pipes to increase their deflection before failure and control the crack formation and width by using synthetic fibers. The flexibility of these pipes will enable …

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Development Of A Framework For Design And Installation Of Cementitious Spray Applied Pipe Linings In Renewal Of Corrugated Metal Culverts, Seyedmohammadsadegh Jalalediny Korky Aug 2019

Development Of A Framework For Design And Installation Of Cementitious Spray Applied Pipe Linings In Renewal Of Corrugated Metal Culverts, Seyedmohammadsadegh Jalalediny Korky

Civil Engineering Dissertations - Archive

Millions of culverts under road embankments provide drainage for U.S. transportation network system and are in need of maintenance, repair, and renewal. Over time culverts, like any other asset, deteriorate due to many factors. Spray applied pipe lining (SAPL) is one of the trenchless technology methods applicable for culverts renewal. In the SAPL method, polymers or cementitious materials are sprayed by machine or manually in different lifts to achieve required thickness based on the design criteria. The scope of this dissertation includes reinforced concrete pipe and corrugated metal pipe (RCP and CMP) culverts renewal with cementitious and polymer SAPLs. The …

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Rainfall Simulation For Investigating Hydrologic Responses To Storm Characteristics And Facilitating Frequency Analysis, Shang Gao Aug 2019

Rainfall Simulation For Investigating Hydrologic Responses To Storm Characteristics And Facilitating Frequency Analysis, Shang Gao

Civil Engineering Dissertations - Archive

Hydrologic and Hydraulic practices depend on the characterization of extreme precipitation that is rare in nature. Despite the advancement in sensing technology, the observation record of extreme rainfall with good spatio-temporal resolution has not reached a sufficient length. Furthermore, rainfall observation may never be sufficient in a non-stationary climate. Towards solutions to these issues, rainfall simulation was explored in this study (1) to investigate hydrologic responses to storm characteristics and (2) to facilitate rainfall frequency analysis. To that end, this study initially employed storm transposition plus hydrologic simulation for generating possible rainfall-runoff scenarios which further reveal relationships between storm characteristics …

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Utilizing The State Of Art Technologies To Assess And Address Urban Flooding, Daniel Li Aug 2019

Utilizing The State Of Art Technologies To Assess And Address Urban Flooding, Daniel Li

Civil Engineering Dissertations - Archive

Today, 55% of the world’s population lives in urban area, a proportion that is expected to increase to 60% by 2050. Projections show that urbanization, the gradual shift in residence of the human population from rural to urban areas, combined with the overall growth of the world’s population could add another 2.5 billion people to urban areas by 2050. With growing opportunities, there are great challenges. One of the challenges that urban communities are facing is the increasing flood risks. In U.S., over the past decade, extreme storm events have wreaked havoc on many urban areas. Aging and inadequate infrastructure, …

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Investigation Of Dsr Test Methods To Determine Binder Low Temperature Properties, Kommidi Santosh, Yong-Rak Kim Aug 2019

Investigation Of Dsr Test Methods To Determine Binder Low Temperature Properties, Kommidi Santosh, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

The low temperature rheology of bituminous binders is of great interest because low temperature cracking is one of the primary asphalt pavement failure modes observed in cold-climate places such as Nebraska. Low temperature binder characterization/grading has been primarily conducted using the bending beam rheometer (BBR), while the dynamic shear rheometer (DSR) can alternatively be used to characterize the low temperature properties of binders with the recent advancement of DSR equipment that can cover a wide range of testing temperatures. This study investigates alternative testing-analysis methods using the DSR to determine low temperature asphalt binder properties that have been measured by …

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Performance Evaluation Of Inverted Tee (It) Bridge System, Garrett P. Martindale, Daniel Watson, Antony Mohsen Kamal Masoud Kodsy, Mostafa Abo El-Khier, Richard L. Wood, George Morcous Aug 2019

Performance Evaluation Of Inverted Tee (It) Bridge System, Garrett P. Martindale, Daniel Watson, Antony Mohsen Kamal Masoud Kodsy, Mostafa Abo El-Khier, Richard L. Wood, George Morcous

Nebraska Department of Transportation: Research Reports

The Inverted Tee (IT) girder bridge system was originally developed in 1996 by the University of Nebraska–Lincoln (UNL) researchers and Nebraska Department of Transportation (NDOT) engineers. This bridge system currently accounts for over 110 bridges in Nebraska used for both state highways and local county roads. Extensive longitudinal and transverse deck cracking have been observed and noted in numerous bridge inspection reports. Since the IT girder bridge system is relatively new, limited data and knowledge exist on its structural performance and behavior. This study evaluates the IT girder bridge system by conducting twenty field observations as well as recording accelerometer, …

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Design And Predicting Performance Of Carbon Nanotube Reinforced Cementitious Materials : Mechanical Properties And Dispersion Characteristics., Mahyar Ramezani Aug 2019

Design And Predicting Performance Of Carbon Nanotube Reinforced Cementitious Materials : Mechanical Properties And Dispersion Characteristics., Mahyar Ramezani

Electronic Theses and Dissertations

Recently, Carbon Nanotubes (CNTs) are drawing considerable attention of researchers for reinforcing cementitious materials due to their excellent mechanical properties and high aspect ratio (length-to-diameter ratio). However, CNTs might not disperse well within the cement matrix, resulting in little improvement or even degradation of concrete properties. The uncertainty in producing the consistent results in different studies might be attributed to multiple interactions between the experimental variables affecting the nanotube dispersion and the final properties of CNT-cement nanocomposites. Therefore, this research mainly focused on proposing equations that can reliably capture these interactions in order to correlate CNT dispersion with the mechanical …

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Developing High Performance Magnesium Phosphate Cement Composite Bipolar Plates For Fuel Cells, Wenbin Hao, Hongyan Ma, Guoxing Sun, Zongjin Li Aug 2019

Developing High Performance Magnesium Phosphate Cement Composite Bipolar Plates For Fuel Cells, Wenbin Hao, Hongyan Ma, Guoxing Sun, Zongjin Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this work, we report a comprehensive study on developing high performance magnesium phosphate cement (MPC) composite bipolar plates for fuel cells. The MPC composite bipolar plates composed of MPC with partial replacement of fly ash as the binding matrix phase and multiple carbon-based materials (including graphite, carbon fiber and multi-walled carbon nanotubes) as the conductive phase. A simple hot-press process was applied to produce the MPC composite. After the optimization on the formula and the structure of the MPC composite and the processing parameters, all the US DOE 2015 technical targets, including electrical conductivity, flexural strength, corrosion resistance were …

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The Influence Of Incorporation Of Mn On The Pitting Corrosion Performance Of Crfeconi High Entropy Alloy At Different Temperatures, H. Torbati-Sarraf, Mitra Shabani, Paul D. Jablonski, Garrett J. Pataky, A. Poursaee Aug 2019

The Influence Of Incorporation Of Mn On The Pitting Corrosion Performance Of Crfeconi High Entropy Alloy At Different Temperatures, H. Torbati-Sarraf, Mitra Shabani, Paul D. Jablonski, Garrett J. Pataky, A. Poursaee

Publications

The electrochemical behavior and susceptibility to pitting corrosion of CrFeCoNi and CrMnFeCoNi high entropy alloys were studied in a 0.1 M NaCl solution at temperatures ranging from 25 to 75 °C. Electrochemical measurements revealed that CrMnFeCoNi is more susceptible to oxide film breakdown and localized corrosion compared to CrFeCoNi. Post corrosion microscopic observations showed severe pitting corrosion for CrMnFeCoNi in higher temperatures compared to CrFeCoNi. Based on in-depth XPS profile measurements on the remaining oxide films, this behavior was attributed to the depletion of Cr in the oxide film and detrimental presence of Mn in the matrix solid solution of …

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Elimination Of Empirical, Ineffective And Expensive Pg Plus Tests To Characterize Modified Binders, Zahid Hossain, Ashraf Elsayed, Mm Tariq Morshed, Mohammad Hassan Aug 2019

Elimination Of Empirical, Ineffective And Expensive Pg Plus Tests To Characterize Modified Binders, Zahid Hossain, Ashraf Elsayed, Mm Tariq Morshed, Mohammad Hassan

Publications

For characterizing the polymer modified binders, different state Departments of Transportation (DOTs) use different time consuming and empirical Performance Grade (PG) Plus test methods. Furthermore, the PG Plus tests are silent when asphalt binders are modified with chemicals such as polyphosphoric acid (PPA). But, the effects of the elastomeric or plastomeric polymer are not accurately identified through these conventional tests such as Elastic Recovery (ER) and tenacity. Thus, the main research goal of this study is to recommend alternative test method(s), which can possibly be pursued by using a commonly available device, a Dynamic Shear Rheometer (DSR). Three PG binders …

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Use Of Rice Husk Ash (Rha) In Flowable Fill Concrete Mix Material, Zahid Hossain, Kazi Tamzidul Islam Aug 2019

Use Of Rice Husk Ash (Rha) In Flowable Fill Concrete Mix Material, Zahid Hossain, Kazi Tamzidul Islam

Publications

In the way of finding sustainable development, the flowable fill is a relatively new construction technology. Flowable fill is a self-compacting material, which has been developed in recent years. Flowable fill has been used for different applications such as backfilling walls, sewer trenches, bridge abutments, conduit trenches, pile excavations, and retaining walls. This study examines the potential uses of Rice Husk Ash (RHA) as a sustainable cementitious material (SCM) in the preparation of flowable fill concrete. (RHA is an agricultural by-product of the rice milling process. This study has evaluated the usage of RHA in producing low strength and self-consolidating …

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Self-Healing Concrete Using Encapsulated Bacterial Spores In A Simulated Hot Subtropical Climate, Marwa Hassan, Jose Milla, Tyson Rupnow, Ahsennur Soysal Aug 2019

Self-Healing Concrete Using Encapsulated Bacterial Spores In A Simulated Hot Subtropical Climate, Marwa Hassan, Jose Milla, Tyson Rupnow, Ahsennur Soysal

Publications

Bacterial concrete has become one of the most promising self-healing alternatives due to its capability to seal crack widths through microbial induced calcite precipitation (MICP). In this study, two bacterial strains were embedded at varying dosages (by weight of cement) in concrete. Beam specimens were used to identify the maximum crack-sealing efficiency, while cylinder samples were used to determine their effects on the intrinsic mechanical properties, as well as its stiffness recovery over time after inducing damage. The concrete specimens were cured in wet-dry cycles to determine their feasibility in Region 6. The results showed that the specimen groups with …

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Karst Sinkhole Detecting And Mapping Using Airborne Lidar, Su Zhang, Shirley Baros, Susan Bogus Aug 2019

Karst Sinkhole Detecting And Mapping Using Airborne Lidar, Su Zhang, Shirley Baros, Susan Bogus

Publications

The focus of this study is to detect sinkhole hazards using airborne light detection and ranging (LiDAR) data. The premise is sinkholes, particularly those close to transportation infrastructure assets, could cause substantial damages to infrastructure assets, and therefore, being able to accurately and rapidly detect them is essential. However, it is expensive, time-consuming, labor-intensive, and unsafe to survey sinkholes using conventional ground observation methods. This research project was focused on developing accurate and rapid airborne LiDAR-based sinkhole detection and mapping methods, and transfer the technologies to transportation engineers for implementation and workforce development. The project team also identified best practices …

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Decision-Making Tool For Road Preventive Maintenance Using Vehicle Vibration Data, Changbum Ahn, Chao Wang, Jing Du Aug 2019

Decision-Making Tool For Road Preventive Maintenance Using Vehicle Vibration Data, Changbum Ahn, Chao Wang, Jing Du

Publications

Automated and timely road pavement damage inspection is critical to the preventive maintenance and the long-term sustainability and resilience of roads in Region 6. Current road inspection practices rely heavily on a manual process. Sensor-based methods (e.g., LiDAR scanning) are promising but can be too expensive for a wider adoption. This study employs a crowdsourcing approach of using the vibration patterns of regular vehicles in inferring specific types of road damages. A cloud-based smart phone app and system was developed to collect real-time vehicle vibrations, location data, and road damage images for training the detection model. However, there is a …

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Strategies For Prioritizing Needs For Accelerated Construction After Hazard Events, Fernando Moreu, Chao Wang, Xinxing Yuan, Laleh Ghanbari, Claudia Garrido Aug 2019

Strategies For Prioritizing Needs For Accelerated Construction After Hazard Events, Fernando Moreu, Chao Wang, Xinxing Yuan, Laleh Ghanbari, Claudia Garrido

Publications

There is a need for rapid and responsive infrastructure repair and construction after natural disaster events such as hurricanes, wildfires, and tornadoes. These natural disasters often shut down basic infrastructure systems, as experienced recently in several Region 6 states as well as in other states around the country. Accelerated construction practices are often used in these situations to speed up the traditional, and often slow, project delivery process. However, after a natural disaster, several and different types of transportation infrastructure components are in need of inspection, rehabilitation or reconstruction, and transportation agencies are challenged with the task of prioritizing these …

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Augmented Reality Enhancing The Inspections Of Transportation Infrastructure: Research, Education, And Industry Implementation, Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Xinxing Yuan Aug 2019

Augmented Reality Enhancing The Inspections Of Transportation Infrastructure: Research, Education, And Industry Implementation, Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Xinxing Yuan

Publications

Transportation infrastructure needs continuous monitoring that is conducted by field inspectors regularly in the field. Currently, infrastructure inspectors climb, measure, and photograph structures annually to inform repair needs and prioritize decisions. In order to promote and accelerate early learner's expertise in decision-making capabilities during infrastructure inspections, this research project developed various software applications using augmented reality (AR) as an inspection tool for bridges and bridge management, more specifically. By objectively quantifying infrastructure field inspections, inspectors can make more accurate field assessments and managers can make better-informed decisions. This project collaborated with stakeholders, national laboratories, DOT agencies such as NCHRP and …

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Workforce Development Symposiums For Uhpc, Brad Weldon, Craig Newtson, Grace Mcmurry, Leticia Davila Aug 2019

Workforce Development Symposiums For Uhpc, Brad Weldon, Craig Newtson, Grace Mcmurry, Leticia Davila

Publications

Ultra-high performance concrete (UHPC) is a cementitious material with a dense microstructure that contributes to high compressive strengths as well as enhanced durability properties. UHPC also possesses significant post-cracking strength and ductility due to the addition of fibers. These characteristics produce a material that provides advantages over conventional concrete; however, high costs attributed to materials and production, lack of industry familiarity and knowledge, and the absence of standardized design procedures have impeded its widespread use. To help disseminate knowledge on UHPC, two workforce development symposiums on UHPC were held in Las Cruces, New Mexico. The symposiums consisted of presentations and …

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Syntroph Diversity And Abundance In Anaerobic Digestion Revealed Through A Comparative Core Microbiome Approach, Masanori Fujimoto, Daniel Elliott Carey, Daniel Zitomer, Patrick J. Mcnamara Aug 2019

Syntroph Diversity And Abundance In Anaerobic Digestion Revealed Through A Comparative Core Microbiome Approach, Masanori Fujimoto, Daniel Elliott Carey, Daniel Zitomer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Anaerobic digestion is an important biotechnology treatment process for conversion of waste to energy. In this study, a comparative core microbiome approach, i.e., determining taxa that are shared in functioning digesters but not shared in non-functioning digesters, was used to determine microbial taxa that could play key roles for effective anaerobic digestion. Anaerobic digester functions were impaired by adding the broad-spectrum antimicrobial triclosan (TCS) or triclocarban (TCC) at different concentrations, and the core microbiomes in both functioning and non-functioning anaerobic digesters were compared. Digesters treated with high (2500 mg/kg) or medium (450 mg/kg) TCS and high (850 mg/kg) …

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Assessment Of Some Of The Common Practices Used In Scheduling Highway Projects, Jennifer Reyes Aug 2019

Assessment Of Some Of The Common Practices Used In Scheduling Highway Projects, Jennifer Reyes

Theses and Dissertations

There are several factors documented in the literature that can affect the accuracy of estimated project durations in highway construction, such as weather, location, and soil conditions. Recently, the Texas Department of Transportation (TxDOT) raised a concern regarding some of the practices used when estimating the contract time for projects. This research presents an assessment of the effect that two practices identified have on the estimated project duration. These two practices include: 1) the estimated lead/lag times in project schedules and 2) scheduling with only critical or controlling activities. The effect of these practices is measured, primarily, by using four …

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Evaluation And Enhancement Of Carbon Sequestration Potential Of Existing Vegetation Along Roadsides, Vikram Kapoor, Jeffrey Hutchinson, Samer Dessouky Aug 2019

Evaluation And Enhancement Of Carbon Sequestration Potential Of Existing Vegetation Along Roadsides, Vikram Kapoor, Jeffrey Hutchinson, Samer Dessouky

Publications

The objectives of this study were to evaluate the vegetative composition and carbon sequestration potential of vegetation along a major roadway in Texas. Soil and vegetation were evaluated along IH-35 within Bexar County for composition and carbon content. Three 20 m transects were placed at each site and percent vegetative cover was estimated and above ground plant biomass, and soil was collected from three 0.25 m2 subplots along each transect. Plant and soil samples were analyzed for carbon content. Two non-native grasses, bermudagrass and King Ranch bluestem, were the dominant cover at all sites accounting for > 90% coverage at several …

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Development Of Metals Corrosion Maps Of Arkansas And Maintenance Of Cross-Drains, Zahid Hossain, Ashraf Elsayed, Mdariful Hasan Aug 2019

Development Of Metals Corrosion Maps Of Arkansas And Maintenance Of Cross-Drains, Zahid Hossain, Ashraf Elsayed, Mdariful Hasan

Publications

Corrosion potential of metallic structures in alluvial soils is governed by chemical and electromagnetic properties of the soils. Geotechnical engineers are generally more concerned about different types of soils and their physical and mechanical properties than the chemical aspects. The main objective of this study is to analyze the geotechnical, electrochemical and electromagnetic properties of soils in Arkansas. Important parameters (e.g., soil resistivity) related to corrosion potential of metal culverts have been predicted through neural network (NN) models. The developed NN models have been trained and verified by using laboratory test results of soil samples collected from Arkansas Department of …

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Assessing The Impacts Of Super Storm Flooding In The Transportation Infrastructure – Case Study: San Antonio, Texas, Marcio Giacomoni, Francisco Olivera, Cesar Do Lago Aug 2019

Assessing The Impacts Of Super Storm Flooding In The Transportation Infrastructure – Case Study: San Antonio, Texas, Marcio Giacomoni, Francisco Olivera, Cesar Do Lago

Publications

Flooding are likely to increase worldwide due to climate change. Large storms, referred here as superstorms, defined as events with return period equal or larger than 100 years, can lead to an increase of property damages and loss of life. The ability to predict and plan for the impacts of superstorms on transportation infrastructure is key to mitigate future damages and losses. This study analyzed 51 combinations of future projections for representative concentration pathways (RCP) 4.5 and 8.5 scenarios, which were used to calculate future 1st and 3rd quartiles, median, minimum and maximum intensity-duration-frequency curves (IDF). A HEC-HMS and GSSHA …

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Use Of Bagasse Ash As A Concrete Additive For Road Pavement Application, Gabriel Arce, Marwa Hassan, Maria Gutierrez, Michele Barbato Aug 2019

Use Of Bagasse Ash As A Concrete Additive For Road Pavement Application, Gabriel Arce, Marwa Hassan, Maria Gutierrez, Michele Barbato

Publications

The objective of this study was to evaluate the use of sugarcane bagasse ash (SCBA) as a partial replacement of cement in concrete for road pavement application. The study explored the pozzolanic activity of SCBA produced from three different processing methodologies (i.e., raw SCBA, controlled SCBA and post-processed SCBA). The experimental results revealed that SCBA produced by the controlled burning of sugarcane bagasse fiber (SBF) at 650°C and grinding (C-650), presented the maximum pozzolanic activity. However, this SCBA production process was deemed challenging for large-scale industrial application due to low SCBA yield (i.e., 3 to 6%). On the other hand, …

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Developing Implementable Climatic Input Data And Moisture Boundary Conditions For Pavement Analysis And Design, Rifat Bulut, Amir Hossein Javid Aug 2019

Developing Implementable Climatic Input Data And Moisture Boundary Conditions For Pavement Analysis And Design, Rifat Bulut, Amir Hossein Javid

Publications

The main objective of this study is to develop a practical and implementable numerical model for predicting the moisture (suction) regime within the pavement subgrade system. The research quality and uniformly-dispersed climate data over short distances from Oklahoma Mesonet and the Mitchell based moisture (suction) prediction methods establish the main background of the research study. The study involved numerical modeling and statistical analysis of climatic weather data. The proposed moisture variation model predicts the suction distribution throughout the soil subgrade by solving the diffusion equation and incorporates the measured suction from the Oklahoma Mesonet to estimate the diffusion coefficient. The …

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A Comprehensive Framework For Life-Cycle Cost Assessment Of Reinforced Concrete Bridge Decks, Mohamed Soliman, Samir Ahmed, Ligang Shen Aug 2019

A Comprehensive Framework For Life-Cycle Cost Assessment Of Reinforced Concrete Bridge Decks, Mohamed Soliman, Samir Ahmed, Ligang Shen

Publications

Various environmental and mechanical stressors cause deterioration of concrete bridge decks. Normal wear and tear, freeze and thaw cycles, and chloride penetration due to deicing salts can cause aggressive deterioration that usually require frequent interventions during the life-cycle of the bridge. These interventions include deck maintenance and repairs (e.g., application of sealers or overlay placement) as well as bridge deck replacement. The quantification of the life-cycle cost of bridge decks considering maintenance and repair activities represents a significant challenge facing local and state transportation agencies. The life-cycle maintenance activities not only increase the direct life-cycle cost of the bridge, but …

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Portable Roadway High Water Detection System For Driver Safety And Infrastructure Assessment, Hatim Sharif, Samer Dessouky Aug 2019

Portable Roadway High Water Detection System For Driver Safety And Infrastructure Assessment, Hatim Sharif, Samer Dessouky

Publications

The state of Texas, local governments, and community groups are adopting several initiatives to address this problem. The main goal of this project is to develop an approach to enhance prediction and detection of roadway flooding and help efforts to prevent driving into flood roadways. The motivation of this work was initiated by the alarming number of vehicle related flood fatalities in Texas, mostly at low-water crossings. Texas leads the nation in the number of flood fatalities and about 77% of flood fatalities in Texas are motor vehicle-related. This percentage is much higher than the national percentage reported in several …

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Disaster Resilient And Self-Assessing Multifunctional Transportation Structures, Ibrahim Karaman, Darren Hartl Aug 2019

Disaster Resilient And Self-Assessing Multifunctional Transportation Structures, Ibrahim Karaman, Darren Hartl

Publications

This research designs and characterizes multifunctional materials, in particular inexpensive shape memory alloys, for transportation structures that possess excellent mechanical properties and self-sensing capabilities for strengthening and health monitoring. The properties are the Fe-SMAs are sensitive to part size in that the grain size of the material, which can be grown to several inches, should exceed the smallest dimension of the part. In the current work, maximum part size of the large dimension Fe-SMA rods were determined through detailed microstructural investigations. Samples were subjected to abnormal grain growth heat treatments and found out that part size be increased up to …

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Structural Vulnerability Of Coastal Bridges Under Extreme Hurricane Conditions, Arturo Montoya, Adolfo Matamoros, Firat Testik, Reza Nasouri, Adnan Shahriar, Arsalan Majlesi Aug 2019

Structural Vulnerability Of Coastal Bridges Under Extreme Hurricane Conditions, Arturo Montoya, Adolfo Matamoros, Firat Testik, Reza Nasouri, Adnan Shahriar, Arsalan Majlesi

Publications

This work presents the results of a numerical study evaluating the response of coastal bridges due to hurricane-induced waves. The analyses were conducted using the Coupled Eulerian-Lagrangian (CEL) approach, available on the commercial finite element software Abaqus, which allows modeling the interaction between water and the bridge. The work concentrated on (1) establishing an approach for modeling the desired wave characteristics (i.e., wave height, and frequency) within the CEL simulation, (2) conducting simulations using actual bridge dimensions of historically damaged bridges, (3) analyzing a range of foundation flexibilities to determine its effect on the uplift and shear forces acting on …

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Displacement Derived Energy Levels For Harvard Miniature Compaction, Ana Laura Errigo, Julia Loshelder Aug 2019

Displacement Derived Energy Levels For Harvard Miniature Compaction, Ana Laura Errigo, Julia Loshelder

Civil Engineering Undergraduate Honors Theses

Previously, the amount of energy provided by the Harvard Miniature tamper was adjusted by changing the number of blows per lift or the number of lifts or was not adjusted at all. However, this research was conducted to investigate the effect of adjusting the displacement of the spring (increased or decreased) to change the potential energy of the spring and therefore change the compacive effort with a specific type of soil. Thus, the objective was to match the compaction energies using the Harvard miniature method with the compaction energies obtained using the Proctor method. Specifically, the goal was to show …

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