Civil and Environmental Engineering Commons^™

Molecular Dynamics Modeling And Simulation Of Bitumen Chemical Aging, Farshad Fallah

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Chemical aging of asphalt binder leads to significant changes in its mechanical and rheological properties, resulting in poor pavement behavior and distress. Various laboratory methods have been used to simulate asphalt aging during the service life of the pavement. However, controversy exists regarding the capability of these methods to predict field aging, as various factors interact with the pavement during service and the mechanism behind aging is not fully understood. The two main outcomes of chemical aging are oxidation of asphalt molecules, and change in asphalt SARA (saturate, aromatic, resin, and asphaltene) fractions. Reaction of oxygen with asphalt components forms …

Cement Improved Highly Weathered Phyllite For Highway Subgrades: A Case Study In Shaanxi Province., Xuesong Mao, Carol Jean Miller, Longqi Liu

Civil and Environmental Engineering Faculty Research Publications

In a cost-saving move, the soft rocks composed of highly-weathered phyllites available onsite were used to fill the subgrade in the eastern Ankang section of the expressway of Shiyan to Tianshui, China. Cement admixture was used to improve the performance of the weathered phyllites. In order to determine the best mix ratio, values corresponding to compaction performance, unconfined compressive strength, and the California bearing ratio (CBR) were analyzed for variable cement content weight percentages (3%, 4%, 5%, and 6%) using test subgrade plots in the field. Field measurements of resilience modulus and deflection confirmed that the strength of the subgrade …

Rejection Of Low Molecular Weight Neutral Organics By Reverse Osmosis Membranes For Potable Reuse, Lauren N. Breitner

Civil Engineering ETDs

Factors such as increasing population, urbanization, and climate change have made the management of water resources a challenge for many municipalities. Water reuse, especially direct potable reuse (DPR) of treated wastewater, is increasingly seen as a potential source of water for communities facing water shortages. Due to improvements in analytical capabilities as well as concerns regarding toxicology of contaminants of emerging concern (CECs), the need for investigating the removal of CECs has become crucial for further DPR considerations. Reverse osmosis (RO) has been demonstrated to remove many CECs. Many studies, however, have investigated the removal of well-known CECs, often with …

A Numerical Investigation Of The Implications Of Altered Channel-Floodplain Connectivity On Hydrodynamic Flood Wave Processes, Colin F. Byrne

Civil Engineering ETDs

With severely altered rivers throughout the developed world, hydrodynamic processes and floodplain connectivity have changed drastically. The research presented here focuses on quantification of two hydrodynamic processes: flood wave attenuation and channel-floodplain fluxes. Objectives of the three research chapters were to (1) evaluate how the ecosystem service of flood wave attenuation has changed with the implementation of river engineering practices as well as contemporary river restoration efforts, (2) describe the sensitivities of flood wave attenuation to contemporary and altered conditions, and (3) characterize channel-floodplain connectivity through lateral flux metrics. All chapter objectives were met using high-resolution, two-dimensional hydrodynamic modeling techniques …

An Evaluation Of The Efficiency Of Compartmented Alginate Fibres Encapsulating Rejuvenator As Asphalt Pavement Healing System, Amir Tabakovic, Luke Schuyffel, Aleksandar Karac, Erik Schlangen

Articles

This paper explores the potential methods for evaluating a healing system for asphalt pavements. The healing system under investigation involves compartmented calcium-alginate fibres encapsulating an asphalt binder healing agent (rejuvenator). This system presents a novel method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are used to distribute the rejuvenator throughout the pavement mixture, thereby overcoming some of the problems associated with alternate asphalt pavement healing methods, i.e., spherical capsules and hollow fibres. The asphalt healing efficiency methods to be evaluated in this paper include: (i) standard test methods for asphalt pavements, such as the Indirect Tensile Strength …

Webinar: Land Use Mix And Pedestrian Travel Behavior: Advancements In Conceptualization And Measurement, Steven R. Gehrke

TREC Webinar Series

Smart growth policies have often emphasized the importance of land use mix as an intervention beholding of lasting urban planning and public health benefits. Past transportation-land use research has identified potential efficiency gains achieved by mixed-use neighborhoods and the subsequent shortening of trip lengths; whereas, public health research has accredited increased land use mixing as an effective policy for facilitating greater physical activity.

However, despite the celebrated transportation, land use, and health benefits of improved land use mixing and the extent of topical attention, no consensus has been reached regarding the conceptualization and measurement of this key smart growth principle …

Effects Of Nonlinearity In Primary Systems On Acceleration In Secondary Systems: Piers, Wharves, And Marine Oil Terminals, Rakesh K. Goel

Civil and Environmental Engineering

This investigation examines the effects of nonlinearity in the primary system of the coupled primary-secondary systems on accelerations in the secondary systems during seismic loading. The coupled primary-secondary systems considered in this investigation are those typically found in piers, wharves, and marine oil terminals. This investigation first examines the effects of nonlinearity in the primary system on acceleration at the point of attachment of the secondary system to the primary system and found that:  The acceleration at the point of attachment of the secodnary system to the primary system decreases with increasing level of nonlinearity in the primary system. …

Interannual Variability And Seasonal Predictability Of Wind And Solar Resources, Nir Krakauer, Daniel S. Cohen

Publications and Research

Solar and wind resources available for power generation are subject to variability due to meteorological factors. Here, we use a new global climate reanalysis product, Version 2 of the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA-2), to quantify interannual variability of monthly-mean solar and wind resource from 1980 to 2016 at a resolution of about 0.5 degrees. We find an average coefficient of variation (CV) of 11% for monthly-mean solar radiation and 8% for wind speed. Mean CVs were about 25% greater over ocean than over land and, for land areas, were greatest at high latitude. The correlation …

The Impact Of Power Curve Estimation On Commercial Wind Power Forecasts - An Empirical Analysis, Gianni Goretti, Aidan Duffy, Tek Tjing Lie

Conference papers

An increasing number of utilities participating in the energy market require short term (i.e. up to 48 hours) power forecasts for renewable generation in order to optimize technical and financial performances. As a result, a large number of forecast providers now operate in the marketplace, each using different methods and offering a wide range of services. This paper assesses five different day-ahead wind power forecasts generated by various service providers currently operating in the market, and compares their performance against the state-of-the-art of short-term wind power forecasting. The work focuses on how power curve estimations can introduce systematic errors that …

Characterization Of Unknown Bridge Foundations, Saman Rashidyan

Civil Engineering ETDs

The National Bridge Inventory (NBI) recognized 86,133 bridges in the United States have no foundation data on record in 2003. It is evident that an unknown percentage of the 86,133 bridges identified by NBI with missing foundation data could also be highly vulnerable to scouring induced by water flow coupled with erodible soils. Conventional excavation, coring and boring excavations to identify unknown bridge foundation depths and types are deemed to be expensive, destructive, and limited in their application to the unknown foundation problem. Many surface and borehole nondestructive testing (NDT) technologies have been developed for this purpose. Three economical proven …

The Fate Of Fecal Indicator Bacteria In Passive Nitrogen Reduction Systems, Michelle B. Henderson

USF Tampa Graduate Theses and Dissertations

The sustainability of water resources is an international and national concern. With increased human activity, water distribution on a global, regional, and local scale has been negatively impacted. Managing water resources also includes managing wastewater. A promising solution to the issues of water scarcity and distribution in the environment is the reuse of wastewater. Wastewater is produced from various sources (domestic, industrial, and commercial); however, if this water is able to be reused closer to the source of generation it could positively impact water distribution. In the United States, approximately 25% of domestic wastewater is treated in onsite wastewater treatment …

A New Fiber Reinforced Polymer Composite For Infrastructure Applications Using Recycled Carbon Fibers, Mojgan Maadandar

Civil Engineering ETDs

Abstract

Carbon fiber reinforced polymer (CFRP) composites have been attractive materials for many civil and mechanical applications. However, the high cost of carbon fibers has hindered its wide spread in many civil and structural applications. Furthermore, CFRP composites have been mostly disposed of in landfills after their end of service life, creating environmental concerns and potential release of toxic byproducts. A significant interest in recycling composites has appeared in the last decade for obtaining recycled carbon fiber. A process based on wet chemical degradation and thermal treatments of FRP composites showed the ability to produce recycled carbon fibers with 99% …

Performance Study On Evacuated Tubular Collector Coupled Solar Still In West Texas Climate, Roy Issa, Byungik Chang

Civil Engineering Faculty Publications

Experimental study was performed on a single basin active solar distillation system augmented with a solar collector using evacuated solar tubes. Field tests were conducted over several days under the climatic conditions of West Texas to evaluate the effect evacuated solar tubes have on the daily distillate yield rate. To investigate the feasibility of the solar tubes, active and passive solar stills with and without exterior insulation were examined. The maximum daily production rate for the active distillation system using evacuated solar tubes and the passive distillation system was 3.6 and 1.4 kg/m²day, respectively. The results showed the …

Design And Experimental Investigation Of 500kv Current Transformer Seismic Retrofit Utilizing Structure Rocking And Supplemental Damping With Self-Centering, Ilya S. Palnikov

Dissertations and Theses

Electrical substations perform a key role in electrical transmission and distribution; the ability for a substation to remain functional during and after a seismic event contributes significantly to the resilience of the clients supplied. Many legacy components currently installed in the main grid substations were designed with minimal consideration of lateral loads and are not qualified per IEEE693. One of the more critical high-voltage substation components that are vulnerable to earthquake damage is the 500kV freestanding current transformer (CT). The CT is particularly vulnerable due to the slenderness and mass distribution of the component. Current transformers are typically constructed from …

Effect Of Austempering Time On The Microstructure And Carbon Partitioning Of Ultrahigh Strength Steel 56nicrmov7, Quanshun Luo, Matthew Kitchen, Shahriar Abubakri

Henry M. Rowan College of Engineering Departmental Research

Ultrahigh strength steel 56NiCrMoV7 was austempered at 270 °C for different durations in order to investigate the microstructure evolution, carbon partitioning behaviour and hardness property. Detailed microstructure has been characterised using optical microscopy and field emission gun scanning electron microscopy. A newly developed X-ray diffraction method has been employed to dissolve the bainitic/martensitic ferrite phase as two sub-phases of different tetragonal ratios, which provides quantitative analyses of the carbon partitioning between the resultant ferrites and the retained austenite. The results show that, a short-term austempering treatment was in the incubation period of the bainite transformation, which resulted in maximum hardness …

Advanced Treatment Technologies For Mitigation Of Nitrogen And Off-Flavor Compounds In Onsite Wastewater Treatment And Recirculating Aquaculture Systems, Laura C. Rodriguez-Gonzalez

USF Tampa Graduate Theses and Dissertations

Non-point sources (NPS) of pollution are non-discernable, diffuse sources of pollution that are often difficult to localize and in turn mitigate. NPS can include stormwater runoff, agricultural/aquaculture wastes and wastes from small decentralized wastewater treatment systems, such as conventional septic systems. The mitigation of these NPS is imperative to reduce their potential detrimental effects on the water environment. This dissertation addresses novel treatment technologies for the mitigation of nutrients, particularly nitrogen, in Recirculating Aquaculture Systems (RAS) and onsite wastewater treatment systems (OWTS). The removal of trace organics limiting RAS production and water reuse were also investigated.

The first question this …

Bim Innovation Capability Programme Of Ireland, Barry Mcauley, Alan Hore, Roger West

Conference papers

The Irish Government has requested that Enterprise Ireland, an organisation responsible for the development and growth of Irish enterprises in world markets to actively promote the use of BIM in Ireland. This promotion has taken the form of an opportunity for Enterprise Ireland clients to apply for a grant under their BIM Enable and BIM Implementation schemes and also through their funding of the BIM Innovation Capability Programme (BICP) of Ireland. The BICP is a two-year project (2016-2018) which seeks to capture the capability of the Irish Construction Industry and the Higher Education Institutes to respond to the increased requirement …

Autonomous Vehicles: An Empirical Assessment Of Consumers’ Perceptions, Intended Adoption, And Impacts On Household Vehicle Ownership, Nikhil Menon

USF Tampa Graduate Theses and Dissertations

Emerging automotive and transportation technologies have provided revolutionary possibilities in the way we might travel in the future. Major car manufacturers and technology giants have demonstrated significant progress in advancing and testing autonomous vehicles in real-life traffic conditions. Governmental agencies are grappling with how to plan transportation systems for a world with autonomous vehicles. Past research has shown that not all technologies are immediately welcomed by the public. Autonomous Vehicles would have to likely go through a similar phase, and would need to overcome not just technological challenges but also social barriers for successful penetration into the marketplace. Most previous …

Seepage Monitoring And Diagnosis Of Distresses In An Earth Embankment Dam Using Probability Methods, Seyed Mohammad Reza Mousavian

Dissertations

Failure of embankment dams may result in catastrophic consequences. Considering seepage and internal erosion are accounted as one of the major causes of failure in earth embankment dams, it is essential to detect any concentrated seepage and sources of distress at early stages. A number of investigation and monitoring methods exist for the detection of seepage, with varying degrees of technological and implementation complexity. This research, focuses on the Electrical Resistivity Monitoring Method (ERM), and develops a condition assessment process that allows 1) the identification of potential seepage areas and progress through visual observation and flow measurement, and 2) the …

Long-Term Management And Condition Assessment Of Concrete Culvert, Zhenting Zou

Dissertations

Infrastructure is the backbone of national security, economic growth, public safety and other aspects of the society. Nationwide, the condition of America’s infrastructure was graded as “D+” by the American Society of Civil Engineers (ASCE) in 2013.

Owners and responsible agencies have employed various cost-effective maintenance and repair methods as well as analytical tools to repair and extend the service life of the infrastructure. However, without a long-term plan, maintenance work can be delayed by lack of funds. Maintenance delay may cause significant reduction in condition state leading to premature failure of the infrastructure. Consequently, a long-term rehabilitation plan is …

Polymer-Capped Nanoparticle Transport In Granular Media Filtration: Deviation From The Colloidal Filtration Model, Ijung Kim, Tongren Zhu, Sungmin Youn, Desmond F. Lawler

All Engineering Faculty Research

The single-collector removal efficiency based on the colloidal filtration model is widely used to quantify deposition of nanoparticles in porous media filtration. The validity of this theory for nanoparticles, especially at filtration rates used in water treatment, was evaluated. Granular media filtration experiments were performed under widely variant physical conditions. Chemical effects were minimized by selecting spherical branched polyethylenimine capped silver nanoparticles as a positively charged nanoparticle to avoid electrostatic repulsion with the negatively charged silica filter media. The model and experimental results agreed well for 50 and 100 nm particles, but 10 nm particles were removed to a lesser …

Introduction To Signal Timing & Traffic Control, Sarah V. Hernandez, Mariah Crew, Karla Diaz-Corro, Taslima Akter

Civil Engineering Teaching and Learning

The purpose of these lesson plans is to introduce students to traffic signalization basics. Students will be lead through a series of mini-lectures on traffic control and signalization including a discussion on the limitations and benefits of traffic signalization. The lesson plans compliment a computer simulation “game” in which students act as manual operators for a single up to four by four gridded intersection. Students attempt to control the progression of signals to understand the relationship between signal timing and user delay. Through experimentation with the simulation, students generate a presentation discussing the benefits and drawbacks of signal timing and …

A Statistical Investigation Of Lower Columbia River Water Temperature, 1915-2003, Corina Christina Mae Overman

Civil and Environmental Engineering Undergraduate Honors Theses

The Columbia River is home to anadromous salmon populations that migrate upriver every year to spawn. These fish require cool water temperatures (T_w) to survive. In recent years, high summer T_w in the Columbia River has caused increased mortality of salmon. Different possible explanations for increased T_w include climate change, deforestation, and decreased summertime streamflow (Q) due to dams. In this study, robust linear regression models of T_w based on air temperature (T_a) and Q were developed to examine the change in T_w over time. The data was …

The Prevalence Of Six Sigma Trends In The Construction Industry In Pakistan, Muhammad M. Hassan

Masters Theses & Specialist Projects

Economic development in any country or area depends heavily on the performance of the construction industry. This is because the subsequent development of infrastructure increases economic activity, living standards, direct foreign investments, and business opportunities. The construction industry in Pakistan also plays a significant role in its economic activity, and the government’s focus towards increasing infrastructure development provides the construction industry with growth prospects. It is observed that quality management practices in the Pakistan construction industry are highly inadequate to enhance quality. The construction industry there is highly challenged with inadequate delays in projects and project quality. The need for …

Real-Time Traffic State Estimation With Connected Vehicles, Sakib Mahmud Khan, Kaken Dey, Mashrur Chowdhury

Publications

A novel framework is developed in this paper, to increase the real-time roadway traffic condition assessment accuracy, which integrates connected vehicle technology (CVT) with artificial intelligence (AI) paradigm forming a CVT-AI method. Traffic density is a major indicator of traffic conditions. In this paper, the traffic operational condition is assessed based on traffic density. A simulated network of Interstate 26 in South Carolina is developed to investigate the effectiveness of the method. The assumption is that the vehicle onboard units will forward the CV generated data to the edge devices (e.g., roadside units) for further processing. CV generated distance headway …

Blending And Mixed Variational Principles To Overcome Locking Phenomena In Isogeometric Beams, Kyle Dennis Richardson

Theses and Dissertations

Two methods for overcoming locking phenomena in isogeometric beams are presented. The first method blends the rotation of a Timoshenko beam with the rotation of a Bernoulli beam to produce realistic displacements in straight beams. The second method uses mixed variational principles, specifically the Hu-Washizu Principle, to produce realistic displacements as well as realistic strains without post-processing.

Evaluation Of The Fertilization Properties Of Algal Biomass And Assessment Of Koh-Induced Flocculation Of Pw95 Algal Cells, Olakunle Ogunsakin

Graduate Theses & Non-Theses

Microalgae from the Coal Bed Methane (CBM) ponds of the Powder River Basin (PRB) in Southeastern Montana have the potential to be utilized as fertilizer for use on the economically important plants of Montana. Three very important economic field crops of Montana (winter wheat - Triticum aestivum, potato - Solanum tuberosum, and flax - Linum usitatissimum) were used for the fertilization experiments. Isolates of unicellular green algae - PW95 (sequenced as Neospongiococcum sp.) from the CBM ponds, and blue-green microalgae – Cyanobacteria (Anabaena Cylindrica) were cultured in the laboratory and the cells were concentrated using gravity sedimentation. Nutrient analysis of …

Proposal For Monitoring Concrete Painting As A Preventive Maintenance Tool (Abutments And Pier Caps), Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Technical Assistance Report

One of the growing number of preventive bridge maintenance activities conducted by the Kentucky Transportation Cabinet (KYTC) is washing and applying thin film protective coatings to bridge abutments and piers. Previous work conducted by Kentucky Transportation Center (KTC) under KYSPR 10-406 documented increased chloride contamination of these bridge components and the need for protective coatings. KYTC Contract ID 162952 includes, among other tasks, cleaning and coating specific concrete elements of eighteen bridges in Anderson and Woodford counties (District 7). These elements are interior faces of the barrier walls, pier caps, and abutment seats. The contract was let on July 29, …

Proposed Testing Of Concrete Sealers, Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Technical Assistance Report

Chlorides, in sufficient concentrations, will cause corrosion of steel reinforcement in bridge decks. Previous studies have shown that de-icing chemicals and practices used by the Kentucky Transportation Cabinet (KYTC) can result in problematic levels of chloride at steel reinforcing depths in a relatively short amount of time. With the advent of liquid applied pre-treatment deicing chemicals, testing performed in Kentucky indicate chloride levels in bridge decks at a depth of two inches have increased significantly.

Chlorides, in sufficient concentrations, will cause corrosion of steel reinforcement in bridge decks. Previous studies have shown that de-icing chemicals and practices used by the …

Collection And Analysis Of 2013-2014 Travel Time Data, Mei Chen, Xu Zhang

Kentucky Transportation Center Research Report

This report documents the findings of Planning Study 27, Collection and Analysis of 2013-2014 Travel Time Data, which is a continuation of Planning Study 24, Analysis of Historical Travel Time Data. The main scope is to analyze newly acquired link-referenced speed data on Kentucky roads from 2013 and 2014.

Results of the analysis demonstrate the value of probe data in measuring and tracking the performance of roadways across several years. In addition, such data can help KYTC and MPOs identify bottlenecks in the network, prioritize improvement strategies, and assess the effectiveness of projects. As data collection techniques advance, …