Civil 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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Simulated Dynamics Of Soil Water And Pore Vapor In A Semi-Arid Sandy Ecosystem, Shohreh Pedram

Civil & Environmental Engineering Theses & Dissertations

Understanding dynamics of soil water content (SWC) and pore air relative humidity (RHpa), as influenced by wetting-drying cycles, is crucial for sustaining fragile ecosystems of desert lands across the world and needed for improving the prediction accuracy of global climate change. However, to date, such an understanding is still incomplete. The objective of this dissertation was to examine such dynamics at a typical desert site within the Horqin Sandy Land, located in Mongolian Plateau of north China. The examination was done by using a HYDRUS-1D computer simulation model and the continuous sensor-based soil water data for two calendar years. HYDRUS-1D …

Reply To Comment By Fred L. Ogden Et Al. On "Beyond The Scs-Cn Method: A Theoretical Framework For Spatially Lumped Rainfall-Runoff Response", Mark Bartlett, Anthony J. Parolari, Jeffrey Mcdonnell, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

Though Ogden et al. list several shortcomings of the original SCS-CN method, fit for purpose is a key consideration in hydrological modelling, as shown by the adoption of SCS-CN method in many design standards. The theoretical framework of Bartlett et al. [2016a] reveals a family of semidistributed models, of which the SCS-CN method is just one member. Other members include event-based versions of the Variable Infiltration Capacity (VIC) model and TOPMODEL. This general model allows us to move beyond the limitations of the original SCS-CN method under different rainfall-runoff mechanisms and distributions for soil and rainfall variability. Future research should …

Development Of Adjustment Factors For Mepdg Pavement Responses Utilizing Finite-Element Analysis, Osman Erman Gungor, Imad L. Al-Qadi, Angeli Gamez, Jaime Hernandez

Civil and Environmental Engineering Faculty Research and Publications

The Mechanistic-empirical pavement design guide (MEPDG) provides theoretically superior methodology, as compared with its predecessor, for the design and analysis of pavement structures. The mechanistic part refers to simulating pavement–tire interaction to calculate critical responses within pavement. The empirical part means prediction of pavement distress propagation over time using transfer functions that link a critical pavement response to a particular pavement distress. The mechanistic part of MEPDG simulates tire–pavement interaction in three steps: subdivision of pavement layers; complex modulus calculation at the middepth of each sublayer, considering velocity and temperature; and running the multilayered elastic theory (MLET) software, …

Viscoelastic Effects In Carbon Fiber Reinforced Polymer Strain Energy Deployable Composite Tape Springs, Elisa C. Borowski

Civil Engineering ETDs

Strain energy deployable composite structures are of great importance to the aerospace community due to their light weight, high stiffness, impressive flexibility, compact stowage configuration, and ability to self-deploy. These attributes make composite deployable hinges ideal for aerospace applications that can benefit from decreased payload and decreased structural complexity through a reduction in deployment parts. However, successful application of these deployable structures requires an in-depth understanding of their mechanical behavior throughout stowage and deployment processes. Upon release from a high strain stowage configuration, high deployment accelerations caused by a great amount of stored strain energy could potentially damage the structure …

An Improved Method Of Arsenic (Iii) Removal By Reverse Osmosis Membrane, Yizhi Hou

Master's Theses (2009 -)

Arsenic is a Group 1 carcinogen as there is abundant research to support that ingestion of arsenic in drinking water and food can lead to liver, lung, kidney, or bladder cancer in humans. The recommend World Health Organization (WHO) arsenic standard in drinking water is 10 µg/L, while the Environmental Protection Agency's (EPA) Maximum Contaminant Level (MCL) of arsenic in drinking water is 10 µg/L. Globally, at least 40 million people face more than 10 µg/L arsenic contamination in their drinking water. As(III) (trivalent state, such as arsenite), and As(V) (pentavalent state, such as arsenates) are the dominant arsenic forms …

Bs News July/August

Building Services Engineering

No abstract provided.

A Simulator-Based Analysis Of Engineering Treatments For Right-Hook Bicycle Crashes At Signalized Intersections, Jennifer Warner, David S. Hurwitz, Christopher M. Monsere, Kayla Fleskes

Civil and Environmental Engineering Faculty Publications and Presentations

A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures – regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design – at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections …