Civil and Environmental Engineering Commons^™

Effect Of Cement Chemistry And Properties On Activation Energy, Andre J. Bien-Aime

USF Tampa Graduate Theses and Dissertations

The objective of this work is to examine the effect of cement chemistry and physical properties on activation energy. Research efforts indicated that time dependent concrete properties such as strength, heat evolution, and thermal cracking are predictable through the concept of activation energy. Equivalent age concept, which uses the activation energy is key to such predictions. Furthermore, research has shown that Portland cement concrete properties are affected by particles size distribution, Blaine fineness, mineralogy and chemical composition. In this study, four Portland cements were used to evaluate different methods of activation energy determination based on strength and heat of hydration …

Risk Assessment Of Driving Safety In Long Scaled Bridge Under Severe Weather Conditions, Shengdi Chen

USF Tampa Graduate Theses and Dissertations

Weather conditions have certain impacts on roadway traffic operations, especially traffic safety. Bridges differ from most surface streets and highways in terms of their physical properties and operational characteristics. This research assess the driving risk under different weather conditions through focus group firstly, then it develops a multi-ordered discrete choice model that is used to analyze and evaluate driving risks under both single and dual weather conditions. The data is derived from an extensive questionnaire survey in Shanghai. And the questionnaire includes those factors related to roadway, drivers, vehicles, and traffic that may have significant impacts on traffic safety under …

A Study On Lane-Change Recognition Using Support Vector Machine, Weiping Deng

USF Tampa Graduate Theses and Dissertations

This research focuses primary on recognition of lane-change behaviors using support vector machines (SVMs). Previous research and statistical results show that the vast majority of motor vehicle accidents are caused by driver behavior and errors. Therefore, the interpretation and evaluation of driver behavior is important for road safety analysis and improvement. The main limit to understanding driver behavior is the data availability. In particular, a full-scale lane-change data set is difficult to collect in a real traffic environment because of the safety and cost issues. Considering the data demands of the recognition model development and the obstacles of field data …

Geometric Optimization Of Retroreflective Raised Pavement Markers, Lukai Guo

USF Tampa Graduate Theses and Dissertations

As the field service life of retroreflective raised pavement marker (RRPM) is much shorter than expected, it is necessary to identify the causes and thus improve the RRPM structural design to mitigate the main failure modes, such as poor retention from pavements, structural damage, and loss of retroreflectivity. One strategy for extending RRPM service life is to enhance RRPM geometric characteristics to decrease critical stresses in markers. The main purpose of this thesis is to analyze the relationship between stresses, failure modes, and RRPM profiles. Based on this research, some measures are suggested in order to avoid corresponding failure modes …

Corrosion Of Post-Tensioning Strands In Ungrouted Ducts - Unstressed Condition, Michael John Hutchison

USF Tampa Graduate Theses and Dissertations

Recent failures and severe corrosion distress of post-tensioned (PT) bridges in Florida have revealed corrosion of the 7-wire strands in tendons. Post-tensioned duct assemblies are fitted with multiple 7-wire steel strands and ducts are subsequently filled with grout. During construction, the length of time from the moment in which the strands have been inserted into the ducts, until the ducts are grouted, is referred to as the `ungrouted' period. During this phase, the steel strands are vulnerable to corrosion and consequently the length of this period is restricted (typically to 7 days) by construction guidelines. This investigation focuses on determining …

Towards Rans Parameterization Of Vertical Mixing By Langmuir Turbulence In Shallow Coastal Shelves, Nityanand Sinha

USF Tampa Graduate Theses and Dissertations

Langmuir turbulence in the upper ocean is generated by the interaction between the wind-driven shear current and the Stokes drift velocity induced by surface gravity waves. In homogenous (neutrally stratified) shallow water, the largest scales of Langmuir turbulence are characterized by full-depth Langmuir circulation (LC). LC consists of parallel counter-rotating vortices aligned roughly in the direction of the wind. In shallow coastal shelves, LC has been observed engulfing the entire water column, interacting with the boundary layer and serving as an important mechanism for sediment re-suspension.

In this research, large-eddy simulations (LES) of Langmuir turbulence with full-depth LC in a …

A Methodology To Consolidate Transit Stops For Enhancing Transit Users Travel Times, Mohammad Nurul Hassan

Theses

This study develops a methodology to consolidate transit stops. It develops a mathematical model and a program which takes stop consolidation decision(s) according to users travel time savings and desired accessibility. The model iterates until the users travels time savings are maximized. The study tests this mathematical model in different hypothetical scenarios. Six factors (distance between stops, passengers’ activity, average cruising speed, and maximum walkable distance, frequency of service and percentage of decreased passengers) with multiple levels were set to build the scenarios. Three responses (percentage of consolidated stops, percentage of travel time savings and percentage of operating …

Investigation Of The Mechanical Behavior Of I-Shaped Steel Beams Strengthened By Mechanically-Fastened Frp Laminates, Hothifa Nayef Rojob

Theses

Retrofitting and strengthening of steel structures have gained significant importance due to the highly increasing number of deteriorated steel structures in many places around the globe. The conventional method of retrofitting or strengthening of steel structures by replacing steel members or attaching additional external steel plates are usually time-consuming, corrodible, and a cumbersome task. Many of the drawbacks of the conventional retrofitting systems can be overcome through the use of Fiber Reinforced Polymers (FRP) due to their high strength-to-weight ratio. Furthermore, FRP materials are corrosion resistant, which makes them more durable especially when environmental deterioration is a concern. In recent …

Cardinal Raúl Silva Henríquez Bridge During The 2010 Chile Earthquake, Zuocai Wang, Genda Chen, W. Phillip Yen, Ian G. Buckle

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents a case study of the Cardinal Raúl Silva Henríquez Bridge, which experienced significant damage during an earthquake that occurred in Chile on February 27, 2010. Supported by reinforced concrete and steel columns of varying heights, the superstructure of the bridge consisted of 22 steel-girder spans, with one intermediate expansion joint located at the middle of the bridge. At each end of the bridge, the bottom flanges of the girders were welded to their bearing steel plates, which were embedded and anchored into the bridge abutment. Two, three-dimensional, finite element models (global versus local) with beam and solid …

Library Holdings (2013) Ce Report, Georgia Southern University, Zach S. Henderson

Program Accreditation Reports (2013-2023)

This document is a part of the 2013 Library Holdings Report for the Zach S. Henderson Library at Georgia Southern University. The report includes data for the library resources and services supporting the research of the Allen E. Paulson College of Engineering and Computing, Department of Civil Engineering and Construction.

Shear And Fracture Behavior Of High Performance Concretes, Mahdi Arezoumandi

Doctoral Dissertations

"Concrete is the most widely used man-made material in the world. Like other materials, it has been improved over time. Nowadays, with continued development of science and technology, a new generation of concretes is produced and is termed high performance concretes. A review of previously published work indicates that very few studies (in some cases none) have addressed the structural behavior of full-scale, high performance concrete elements. This study investigated the shear and fracture behavior of two types of high performance concrete - high-volume fly ash concrete (HVFAC) and self-consolidating concrete (SCC). The HVFAC incorporates up to 70% cement replacement …

Numerical Analyses Of Long Carbon Fiber Reinforced Concrete Panels Exposed To Dynamic Loading, Zahra Sadat Tabatabaei

Doctoral Dissertations

"The purpose of this research was to evaluate impact and blast performance of long carbon fiber reinforced concrete experimentally and numerically. Experimental tests were conducted on plain concrete (PC), reinforced concrete, and four different types of long carbon fiber reinforced concrete (LCFRC). The results from each test were then compared to one another. This comparison indicates that adding long carbon fibers to concrete both increases the post-cracking behavior of concrete and decreases the spalls in either an impact or blast test. Among all of the fibers tested, Fiber Type B3 outperformed the other fibers, absorbing more energy during impact. Numerical …

A Method To Reduce Plastic Shrinkage Cracking Of Concrete Using Re-Vibration Technique, Mustafa Abushaala Aldalinsi

Open Access Theses & Dissertations

One of the problems that reduce durability; thus, performance of concrete is the development of plastic shrinkage cracking (PSC). Traditionally, the development of PSC has been minimized by controlling its exposure to weather conditions or by adding fibers. In this study, concrete re-vibration was used as an alternative technique to control PSC because of the limited availability of fibers in the developing countries. In this study, the wait time after slab casting and before vibration was selected to be 90 minutes while length of re-vibration time was varied from 15 to 45 seconds. Also, the water-cement ratios were selected to …

A Hybrid Modelling Approach For Maintenance And Rehabilitation Treatment Effectiveness Of Asphalt Pavements In Texas, Daniel Saenz

Open Access Theses & Dissertations

Analysis tools in pavement management systems are critical to assist transportation agencies in developing the most adequate maintenance and rehabilitation program. The significant elements are not only the type of treatment selected and its cost, but also the quantification of its short-term and long-term effectiveness and the timing of intervention. Methodologies with complex statistical approaches and performance model theories have been previously implemented in their derivation, but they may not be suitable or accurate. Therefore, it is imperative to factor in engineering experience in their assessment. In this thesis, a hybrid modelling approach was presented to systematically introduce expert knowledge …

A Systematic Approach To Manage Missing Data In Pavement Management Systems, Mazin M. Al-Zou'bi

Open Access Theses & Dissertations

Pavements are an important part of the highway transportation infrastructure, accounting for the largest share of the overall investment. A tremendous amount of time and money is spent each year on the construction of new pavements, as well as on the maintenance and rehabilitation of existing pavements.

Transportation agencies use pavement management systems (PMS) for their maintenance and rehabilitation planning, programming, and budgeting. PMS are used to make decisions regarding when maintenance and rehabilitation should be applied. The systems also select what type of treatment should be applied for each pavement section in the network with clear estimations of the …

Investigation Into The Operation And Safety Of Freeway Auxiliary Lanes: Towards Uniform Design Guidelines, Yubian Wang

Open Access Theses & Dissertations

Freeways operate closest to the purest form of uninterrupted traffic flow. There is no constant interruption to traffic flow (such as stop sign and traffic signal), and access is limited to ramp locations. Therefore, at freeways, bottlenecks, if exist, are usually caused by merging and diverging traffic at ramp locations. Bottleneck removal at freeway ramp areas can reduce average freeway commuter delay. Currently, engineers may add auxiliary lanes at ramp areas to mitigate or remove bottlenecks.

The American Association of State Highway Transportation Officials (AASHTO) publication A Policy on Geometric Design of Highways and Streets, commonly known as the "Green …

An Evaluation Of The Cerro Process As An Efficient Ro Concentrate Management System, Guillermo Guadalupe Delgado

Open Access Theses & Dissertations

The Concentrate Enhanced Recovery Reverse Osmosis (CERRO) Process is a new method to treat RO concentrate and brackish water with high concentrations of silica and calcium sulfate. Prior investigations have shown that the CERRO process can treat this kind of water without fouling or scaling the membranes, but the main factors that allow the system to operate in such conditions were not studied. The research presented here is an evaluation of the CERRO process as an efficient RO concentrate management system. The parameters of operation of the system were evaluated and improved. The precipitation of calcium sulfate was identified as …

Optimization Of Stress Wave-Based Nondestructive Methods In Identifying Deterioration In Concrete Structures, Hoda Azari

Open Access Theses & Dissertations

The transportation infrastructure across the United States is deteriorating and requires periodic inspection to predict the cost of repair and extent of maintenance activities, to remedy structural problems, and to ensure safety and serviceability. The use of nondestructive testing (NDT) methods in detecting and characterizing flaws in the infrastructure has become more common. Among different NDT methods, the stress wave-based methods, including ultrasonic surface waves (USW) and impact echo (IE) methods, are widely used to maintain concrete structures. In this dissertation, a complete literature review of seismic wave theory and wave propagation in plate like structures, and stress wave-based methods …

Attitude Towards Green Warehousing In El Paso, Texas: An Exploratory Analysis, Lynda Jeanette Macias

Open Access Theses & Dissertations

The increasing reliance on fossil fuels by today's emerging economies has a profound implication on the sustainability of many warehousing and distribution logistical systems worldwide. This research attempts to fill the gap in current green warehousing literature by investigating how warehousing and distribution facilities view greener strategies as a way to increase operation efficiency through a stated preference approach. A survey instrument was developed, and the survey was conducted to identify warehousing characteristics, green practices, and current green views of warehouse managers in El Paso, Texas. The survey results found a balanced outlook within the environment and business needs. Companies …

Adsorption Of Arsenic, Chromium, And Uranium From Saline Water On Clinoptilolite And The Treatment Of The Spent Regenerant By Duffusion Dialysis, Mutiu Olaitan Tanimola

Open Access Theses & Dissertations

Among various water purification and recycling technologies, adsorption is a fast, inexpensive and universal method. The development of low-cost adsorbents has led to the rapid growth of research interests in this field. The objective of this present study is the optimization of process parameters in adsorption of arsenic, chromium and uranium ions. The adsorption behavior of natural zeolite (clinoptilolite) has been studied in order to determine its applicability in treating water containing arsenic, chromium and uranium. The multiple adsorption of arsenic As (V), trivalent chromium Cr (III)] and uranium (VI) on natural zeolite (clinoptilolite) in single component and multiple component …

Analysis Of Vehicle Interactions On Interstate Highways: Discrete Choice And Linear System Approaches, Alicia Romo

Open Access Theses & Dissertations

The research in this dissertation developed statistical and linear system models to predict driving behavior according to driver attributes, vehicle characteristics, car-following dynamics and/or driving conditions. The scope of this research was limited to the interaction of two vehicles traveling in the same direction on interstate highways.

The statistical models proposed in this research investigated the contributions of the different vehicle types on the manner and likelihood of collision. Discrete choice models were used to estimate the probability of the types of collision (rear-end, angle and sideswipe) as functions of driver attributes, striking and struck vehicle types, pre-crash driving actions …

Recovering Magnesium Hydroxide And Sodium Chloride From Zero Discharge Desalination Concentrate Streams, Alemayehu Asfaw Yetayew

Open Access Theses & Dissertations

UTEP and Veolia Water Solutions & Technologies have been demonstrating and commercializing the Zero Discharge Desalination (ZDD) technology as part of a three year project sponsored by the U.S. Bureau of Reclamation. ZDD is able to achieve up to 98% recovery by desalinating brackish groundwater. ZDD is typically comprised of a reverse osmosis (RO) or nanofiltration (NF) system and a unique variation of electrodialysis called electrodialysis metathesis (EDM). The ZDD technology increases the yield of fresh water from water supplies that contain enough CaSO4 to cause precipitation problems when the water is treated with RO or NF alone. The EDM …

Thermo-Elasto-Plastic Behavior Of Biaxially Loaded Steel Beam-Columns Inducing Those From World Trade Center Towers, Yanhong Zhao

Civil & Environmental Engineering Theses & Dissertations

An experimental and theoretical investigation into the behavior of biaxially loaded steel beam-columns is conducted including the effects of high temperature. Systems of materially nonlinear differential equations of beam-column equilibrium are first formulated for both ambient and high temperature conditions. An iterative finite integral procedure is formulated and programmed to solve the governing differential equations. To check the validity of the theoretically predicted behavior and strength of the beam-columns, a series of forty-two laboratory tests are conducted at both ambient and high temperature up to 950°F. Upon achieving a good agreement between the predicted beam-column behavior and that observed in …

Exploring Travel And Activity Behavior In Transit-Oriented Developments: Insights Into Transportation Benefits And Travel Demand Modelling, Sanghoon Son

Civil & Environmental Engineering Theses & Dissertations

As a sustainable urban development and transportation planning strategy, researchers and planners are increasingly interested in transit-oriented development (TOD). By integrating transit system and neighborhood design, TOD aims to provide a livable environment that is alternative mode friendly, higher density, and mixed-use to residents and workers in the vicinity of transit stations. Despite the recent growing interest in TOE), however, transportation benefits of TOD are not well quantified and characteristics of TOD are not adequately reflected in travel demand models.

This dissertation contributes to understanding of the travel and activity behavior by comprehensively exploring them in the context of TOD. …

Microsimulation Evaluation Of Eurocode Load Model For American Long-Span Bridges, Bernard Enright, Colm Carey, Colin Caprani

Articles

The ability to accurately predict traffic loading is essential for cost-effective bridge maintenance and repair programs. The traffic load model currently used in the United States for the design of long-span bridges was developed over three decades ago. In the meantime vehicle characteristics and traffic patterns have changed. The Eurocode for traffic loading is more recent, but was calibrated only for bridges up to 200 m long. In this work, Weigh-In-Motion traffic records from 11 different sites across Alabama are used to establish congested traffic loading. Traffic microsimulation is used to generate the congestion, based on the real traffic data. …

Chapter Green Nanotechnology: Development Of Nanomaterials For Environmental And Energy Applications, Rachel Fagan, Changseok Han, Joel Andersen, Suresh Pillai, Polycarpos Falaras, Anthony Byrne, Patrick S.M. Dunlop, Hyeok Choi, Wenjun Jiang, Kevin O’Shea, Dionysios D. Dionysiou

Books/Book Chapters

This book chapter discusses the syntheses of various nanomaterials, for green nanotechnology applications in detail. Special attention is given to the development of emerging areas, such as environmental as well as energy materials. Various approaches for preparing nanostructured photocatalysts, such as titanium dioxide, zinc oxide, iron oxide, and metal sulfides, different conventional methods and novel methods, including sol-gel methods, hydrothermal methods, microwave-assisted methods and sonochemical methods are introduced. The use of nanomaterials as photocatalysts, supporting materials for solar cells, and disinfectants is reported for environmental remediation and energy applications. Advanced applications of nanomaterials for water detoxification, air purification, and the …

Watershed-Scale Hybrid Stochastic-Deterministic Modeling Framework And Diffused Sources Superpositioning, Ruby Juvah Damalie

Civil & Environmental Engineering Theses & Dissertations

Predicting hydrologic system behavior is imperative to planning and management of water resources. The study developed an integrated hybrid stochastic and deterministic framework to improve prediction accuracy for overland flow and diffused sources in a watershed. The methodology includes sampling input parameters at system level and contribution of nonpoint source from hydrologically disconnected areas (heretofore referred to as system-level approach and superpositioning respectively). System-level approach includes the integration of a topography-based sampling grid generalized linear model developed by the study and Monte Carlo methods. The superpositioning method adopts in-stream water quality equation for overland flow pollution estimation.

The system-level approach …

Effect Of Crumb Rubber Modifier Dissolution On Storage Stability Of Crumb Rubber-Modified Asphalt, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Crumb rubber-modified asphalt (CRMA) extensively suffers from high-temperature storage instability. Because of the higher density of the crumb rubber modifier (CRM) particles, they settle down to the bottom of storage tanks and cause variation between physical properties of the top and bottom samples. The storage stability of the CRMA changes under different interaction parameters and consequently different mechanisms of interaction. In this research the mechanism of separation under different levels of CRM dissolution was investigated by using Stokes' law. The extent and mechanism of CRM dissolution in asphalt was controlled through regulating interaction temperature and interaction mixing speed. A standard …

Modeling Of The Resilient Modulus For Recycled Asphalt Pavement Applications In Base Course Layers, Ehab Noureldin, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The resilient modulus (M_R) is an important parameter for the base course layer in the pavement design process. Use of recycled asphalt pavement (RAP) for this layer must take into consideration the effect of various factors that may occur in the field on the M_R. Previous numerical models used for the granular base layer could be used for the RAP. The study reported here examined the suitability of RAP procedures under the effect of different factors (e.g., water content, dry density, freeze-thaw cycles). Various percentages of the RAP (50%, 75%, and 100% by weight) were employed …

Performance Enhancement Of Crumb Rubber-Modified Asphalts Through Control Of The Developed Internal Network Structure, Mohyeldin Ragab, Magdy Abdelrahman, Amir Ghavibzaoo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Control of the internal network structure of crumb rubber-modified asphalt (CRMA) was investigated for its effect on property development in the study presented in this paper. The investigation included evaluation by rheological and interrupted shear tests. Rheological testing involved the monitoring of the changes of the produced complex modulus (G*) and phase angle (δ) for CRMA. In the interrupted shear tests, the shear stress profile for the produced CRMA was investigated. It was found that triggering the critical conditions of the combined interaction of speed, temperature, and time was essential to inducing the formation of the three-dimensional network …