Engineering Commons^™

Laboratory Evaluation Of Tx- Prochem As An Ionic Liquid Stabilizer, Esmat Tavakoli

Civil Engineering Theses - Archive

Chemical treatment of pavement and foundation soil was conducted to improve workability during compaction, to increase the strength and stiffness of a foundation layer, and to reduce potential shrink and swell due to moisture changes and/or frost action. In this study, a commercial liquid ionic stabilizer (Tx ProChem) was evaluated based on its effectiveness to reduce swell potential and improve the strength of Texas expansive clay. This study also evaluated selected, representative liquid chemical stabilizers’ effect on expansive clay soil. The research presented herein assesses how much the chemical treatments changed the relevant engineering properties of the test soil as …

Reflectivity Of Light Emitting Diodes (Led) And Incandescent Lights On Concrete And Asphalt Pavements., Jeremy Elliott Rice

Electronic Theses and Dissertations

The purpose of this study is to investigate the reflectivity of light on concrete and asphalt pavement systems. In 1983, the Illuminating Engineering Society (IES) published the first recommended practice (RP-8) for the design of roadway and parking lot lighting. This design method implemented empirically tested factors which were defined as the “reduced luminance coefficients” or the R-Tables. The R-Tables are essential for proper design of light pole installation dimensions, required power, and the distribution of light. The originally tested pavements are not necessarily representative of modern pavement materials used today. Moreover, recent Light Emitting Diodes (LED) are a relatively …

The Effects Of Notch Geometry On Fracture Testing Of Asphalt Concrete, Rebekah Porter

Civil Engineering Undergraduate Honors Theses

Asphalt concrete is commonly used as the surface layer on pavements because of its convenience, low cost, and smooth ride (Wagoner, 2005). However, there is a significant problem with the cracking and deterioration of asphalt concrete roads. The initiation of cracking in asphalt must be better understood in order to further improve pavement design. Fracture energy is the amount of energy needed to separate two surfaces. The semi circular bend (SCB) test can be used to measure the fracture energy of asphalt concrete. Currently, this method uses a semicircular specimen with a rectangular notch in a three-point bend compression test. …

Dynamic And Static Behavior Of Hollow-Core Frp-Concrete-Steel And Reinforced Concrete Bridge Columns Under Vehicle Collision, Omar I. Abdelkarim, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the difference in behavior between hollow-core fiber reinforced polymer-concrete-steel (HC-FCS) columns and conventional reinforced concrete (RC) columns under vehicle collision in terms of dynamic and static forces. The HC-FCS column consisted of an outer FRP tube, an inner steel tube, and a concrete shell sandwiched between the two tubes. The steel tube was hollow inside and embedded into the concrete footing with a length of 1.5 times the tube diameter while the FRP tube stopped at the top of footing. The RC column had a solid cross-section. The study was conducted through extensive finite element impact analyses …

Hydraulic Performance Evaluation Of Evapotranspiration Cover Systems, Brett James De Vries

Civil Engineering Dissertations - Archive

Although alternative covers such as the evapotranspiration (ET) landfill cover system promise to provide equivalent or greater performance than conventional cover systems, uncertainties remain on the performance of these type of cover systems. The uncertainties associated with performance may derive from the relative newness of these covers (when compared to conventional landfill cover systems); and their dependency on relatively site-specific factors such as: climatic, vegetation, and soil conditions. As a results, the Texas Commission on Environmental Quality (TCEQ) requires a landfill facility to design and then verify the design and performance through site specific field scale testing (TCEQ 2012). Utilizing …

Novel Approach For Selective Decomposition Of Target Water Contaminants Onto Porous Titanium Dioxide, Abolfazl Zakersalehi

Civil Engineering Dissertations - Archive

Manipulation of physical and chemical properties of matter with nanoscale precision will enhance our ability for fabrication of material with intended characteristics for environmental applications. In this study we presented two main frameworks for addressing non-selectivity issue in TiO2 photocatalysts, which is believed to be a major drawback in full-scale application of this technology. First, a purely physical approach for enhancing selectivity of nanostructured TiO2 photocatalysts toward water target contaminants have been achieved via tailor-designing meso-porous structure of TiO2. This simple, yet effective method is mainly based on size-exclusion as a mean toward preferential decomposition. It was hypothesized controlled mesoporous …

Harmful Algal Blooms And Biological Toxins Productions; From Integrated Monitoring Approach To On-Site Solar Photocatalytic Decomposition, Hesam Zaman Khan Malayeri

Civil Engineering Dissertations - Archive

Occurrence of Harmful Algal Blooms (HABs) worldwide has caused concern to environmental and health authorities because of their potential to generate and release biological toxins. In particular, microcystins (MCs) produced from cyanobacteria are of great concern. MCs are among the most powerful natural poisons. The presence of MCs in drinking water sources has raised major concern. The overall goal of this research is to predict formation of biological toxins in water bodies and to develop a new sustainable approach to decompose them, if feasible, on-site and in real-time with minimal efforts, less chemicals, and low energy inputs. In order to …

Moisture Distribution Efficiency And Performance Evaluations Of Bioreactor Landfill Operations, Md Zahangir Alam

Civil Engineering Dissertations - Archive

Bioreactor landfills are operated in a modern engineered way to accelerate waste decomposition, gas production, and waste stabilization. The major aspect of a bioreactor landfill operation is associated with the addition of supplemental liquid or leachate recirculation, and the effective operation primarily depends on efficient moisture distribution throughout the waste mass, which enhances performance. The performance of an effective landfill operation can be assessed by several indicators, i.e., leachate generation, gas production, and landfill settlement. Bioreactor landfill operations have several significant economic and environmental advantages, but the impact of efficient moisture distribution and the assessment of performance through combined indicators …

Investigation Of Fiber-Reinforced Concrete Crack Width Measurement By Finite Element Method, Sina Abhaee

Civil Engineering Theses - Archive

This study presents numerical and experimental investigations of flexural cracking, post-cracking strength, and fracture energy of the dry-cast synthetic fiber reinforced concrete (FRC). Notched and un-notched beams for two fiber volume fractions were tested under flexural loading based on the recommendations of RILEM TC 162-TDF and ASTM C1609. The crack profile in terms of crack propagation and crack width, was assessed, using the two-dimensional digital image correlation (2D DIC) technique. Images of the specimen’s surface were captured during the test, and, surface deformation field was obtained by means of 2D DIC analysis. The nonlinear, 3D finite element method (FEM) modeling …

Application Of Wavelet Transform In Structural Health Monitoring, Yashodhya Swarna Sri Dhanapala Liyana Kankanamge

Masters Theses

Structural Health Monitoring (SHM) is a process of implementing a damage detection strategy in structures to evaluate the condition of existing structures to ensure the safety of users in the future. The changes in the material, geometric and/or structural properties affect structural responses, which can be captured and analyzed for condition assessment. Various vibration-based damage detection algorithms have been developed in the past decades. Among them, the Continuous Wavelet Transform (CWT) gained popularity as an efficient method of signal processing to build a framework to identify model properties and detect damage in structures. In this study, the application of wavelet …

Safety Benefit Analysis Of Alternative Delineation Practices In Michigan, Brenda C. Burdick

Masters Theses

Among the many aspects of roadway design, one important system is roadway delineation. The main purposes of roadway delineation include regulating, warning, and guiding drivers in a safe manner. Delineation systems have the potential to reduce crashes. This research sought to perform safety benefit analysis of roadway delineation practices in Michigan. Through literature review, several delineation practices, selection criteria, and previously developed crash modification factors were researched. Even though several pavement marking materials have been implemented in Michigan, a safety benefit analysis of various materials had not been performed. Sites were selected, and pavement marking material inventory data were combined …

Bim Innovation Capability Programme: An Irish Bim Study, Barry Mcauley, Alan Hore, Roger West

Articles

In 2011 the Royal Institute of Architects Ireland (RIAI) conducted a survey which found that BIM adoption within Ireland was quite low at 16%. Over the last five years these figures have risen significantly, with the 2016 Irish Digital Transition Survey reporting that 76% of respondents possess confidence in their organisation’s BIM skills and knowledge. This represents a significant shift of BIM adoption in Ireland over the last five years.

The BIM Innovation Capability Programme (BICP) Irish BIM study, builds on the findings from the BICP Global BIM Study by providing an in depth review of BIM in Ireland with …

Multimedia Techniques For Construction Education And Training, Wayne A. Bunnell

Open Access Theses

The current profession of civil engineering often focuses education and training on code compliance rather than constructability and construction techniques. Also, it is well accepted that it takes a decade or more for engineers to develop a high-level project construction understanding and many state departments of transportation rely on in-field training for entry-level inspectors, with little or no education provisions for contractors. This research investigated the use of time-lapse photography to develop training and education material that will improve the understanding of project construction and crucial quality control specifications of an entry-level engineer, contractor, or inspector. Overall, the project team …

New Screening Method For Overweight Vehicles, Goran Veljko Milutinovic

Open Access Theses

Throughout the U.S., state agencies are issuing an increasingly large number of permits for overweight vehicles every year. There are various methods used by state agencies to process permit requests; the Indiana Department of Transportation employs a screening process that consists of the Tennessee Formula (allowable weight is determined and checked, for every axle group) in combination with the Gross Vehicle Weight limit. If a permit truck satisfies these two screening criteria, it is permitted; otherwise, it is further processed with refined analyses. The Tennessee Formula is based on Allowable Stress Design. However, most design and evaluation conducted today is …

Quantifying Asphalt Emulsion-Based Chip Seal Curing Times Using Electrical Resistance Measurements, Miguel A. Montoya Rodriguez

Open Access Theses

Chip seals are among the most cost-effective surface treatments available for asphalt pavement preventive maintenance. Chip sealing typically consists of covering a pavement surface with asphalt emulsion into which aggregate chips are embedded. The asphalt emulsion cures through the evaporation of water, which helps to provide mechanical strength for the chip seal. Ultimately, the curing process enables the emulsion to adhere to the pavement while keeping the aggregate chips in place. The curing time for the chip seal depends on many factors, such as the asphalt emulsion and aggregate types, aggregate moisture content, emulsion and aggregate application rates, and environmental …

Effect Of Temperature On Deep Lined Circular Tunnels In Isotropic And Transversely Anisotropic Elastic Ground, Fei Tao

Open Access Theses

A tunnel is a passageway constructed through soil or rock. It is one of the most important underground structures and has been widely used in transportation. Much research has been done on tunnel performance and on the interaction between ground, excavation, liner installation and support. The work has provided a better understanding of the interplay that exists between deformations and stresses transferred from the ground to the support. Significant insight into the problem has been provided by closed-form analytical solutions. A number of analytical formulations have been obtained for underground openings and lined tunnels under different scenarios, namely shallow or …

The Influence Of Alkalinity Of Portland Cement On The Absorption Characteristics Of Superabsorbent Polymers (Sap) For Use In Internally Cured Concrete, Juan D. Tabares Tamayo

Open Access Theses

The concrete industry increasingly emphasizes advances in novel materials that promote construction of more resilient infrastructure. Due to its potential to improve concrete durability, internal curing (IC) of concrete by means of superabsorbent polymers (SAP) has been identified as one of the most promising technologies of the 21st century. The addition of superabsorbent polymers into a cementitious system promotes further hydration of cement by providing internal moisture during the hardening and strength development periods, and thus limits self-desiccation, shrinkage, and cracking.

This thesis presents the work performed on the series of cement pastes with varying alkalinity of their pore solutions …

Fea Methodology For System-Level Redundancy Evaluation: Application To Non-Composite Steel Bridges, Francisco Javier Bonachera Martin

Open Access Dissertations

Currently, all steel bridges with members designated as Fracture Critical Members (FCMs) are required to undergo hands-on inspections every 24 months. A FCM is a primary steel tension member (or portion of) which failure results in collapse or loss of serviceability of a bridge. However, presently, there are no codified procedures used to evaluate system-level redundancy in steel bridges. In this dissertation, finite element analysis (FEA) procedures, techniques and inputs were researched in order to develop bridge models that account for the mechanisms that lead to redundant capacity after the failure of a primary steel member. These mechanisms include partial …

The Effects Of Chloride-Based Deicing Chemicals On Degradation Of Portland Cement Mortars With Alkali Reactive Aggregate, Charles Yicheng Chiu

Open Access Dissertations

The assessment of the influence of deicing chemicals on alkali reactivity of aggregates is still an area of active research, particularly with respect to the combined effects of long-term exposure to deicers, freezing and thawing cycles, and wetting and drying cycles. In order to develop a more comprehensive view of these topics, the present study was conducted in three phases. The focus of the first phase was on studying the effects of the chloride-based deicers on the alkali silica reaction (ASR) using accelerated test methods (i.e. the test was performed at high temperature (80 °C) as per modified ASTM C1260). …

Bridge Maintenance To Enhance Corrosion Resistance And Performance Of Steel Girder Bridges, Luis M. Moran Yanez

Open Access Dissertations

The integrity and efficiency of any national highway system relies on the condition of the various components. Bridges are fundamental elements of a highway system, representing an important investment and a strategic link that facilitates the transport of persons and goods. The cost to rehabilitate or replace a highway bridge represents an important expenditure to the owner, who needs to evaluate the correct time to assume that cost. Among the several factors that affect the condition of steel highway bridges, corrosion is identified as the main problem. In the USA corrosion is the primary cause of structurally deficient steel bridges. …

Fracture Analysis In Biomimetic Bouligand Architectures, Nobphadon Suksanqpanya

Open Access Dissertations

The Bouligand structure, which is found in many biological materials, is a hierarchical architecture that features uniaxial fiber layers assembled periodically into a helicoidal pattern. Many studies have highlighted the high damage-resistant performance of Bouligand structures and its biomimetic materials. One of the outstanding species with the Bouligand structures is the smashing Mantis Shrimp, Odontodactylus Scyllarus, (or stomatopod) due to its capability of generating high speed, high acceleration blows using its raptorial appendage to defeat highly armored preys. The load-bearing part of this appendage, the dactyl club, contains an interior region, which is mainly characterized by the Bouligand structure. This …

Geometric Accuracy Evaluation Of Mobile Terrestrial Lidar Surveys With Supporting Algorithms, Chisaphat Supunyachotsakul

Open Access Dissertations

Mobile Mapping System (MMS) technology is widely used for many applications, hence quantifying its accuracy is a very important and essential task and is a primary focus of this research. In general, to perfrom geometric accuracy evaluation of MMS data, validation points/features are needed. A method is needed to capture a point feature off the roadway in a position where a target on the ground surface would not be visible to the scanner. In this study, eight sphere targets with 14" diameter were placed on the shoulder of the roadway over validation points on the ground. The sphere targets were …

Policy Design Tool For Managing Indoor Residential Water Demand In Water-Scarce Regions, Mujahed M. Thneibat

Open Access Dissertations

In view of population growth; climate change; and economic evolution, water resources in numerous parts of the world have reached their natural capacities. Consequently, the ability of many countries to grow; meet the basic needs of inhabitants; and protect the environment will be endangered like never before unless water resources are smartly handled and managed. ^ In the past few decades, many developed and developing countries have suffered from water scarcity, and more are certain to follow. The water security dilemma is much more challenging in developing countries. Water utilities have had to follow regulatory plans to manage demand on …

Computer Vision-Based Structural Assessment Exploiting Large Volumes Of Images, Chul Min Yeum

Open Access Dissertations

Visual assessment is a process to understand the state of a structure based on evaluations originating from visual information. Recent advances in computer vision to explore new sensors, sensing platforms and high-performance computing have shed light on the potential for vision-based visual assessment in civil engineering structures. The use of low-cost, high-resolution visual sensors in conjunction with mobile and aerial platforms can overcome spatial and temporal limitations typically associated with other forms of sensing in civil structures. Also, GPU-accelerated and parallel computing offer unprecedented speed and performance, accelerating processing the collected visual data. However, despite the enormous endeavor in past …

Triclosan: An Instructive Tale, Patrick J. Mcnamara, Stuart B. Levy

Civil and Environmental Engineering Faculty Research and Publications

The Food and Drug Administration (FDA) recently released a final rule to ban triclosan and 18 other antimicrobial chemicals from soaps. We applaud this rule specifically because of the associated risks that triclosan poses to the spread of antibiotic resistance throughout the environment. This persistent chemical constantly stresses bacteria to adapt, and behavior that promotes antibiotic resistance needs to be stopped immediately when the benefits are null.

Sulfate Resistance Of Nanosilica Contained Portland Cement Mortars, Iani Batilov Batilov

UNLV Theses, Dissertations, Professional Papers, and Capstones

Soils, sea water and ground water high in sulfates are commonly encountered hostile environments that can attack the structure of concrete via chemical and physical mechanisms which can lead to costly repairs or replacement. Sulfate attack is a slow acting deteriorative phenomenon that can result in cracking, spalling, expansion, increased permeability, paste-to-aggregate bond loss, paste softening, strength loss, and ultimately, progressive failure of concrete. In the presented research study, Portland cement (PC) mortars containing 1.5% to 6.0% nanosilica (nS) cement replacement by weight were tested for sulfate resistance through full submersion in sodium sulfate to simulate external sulfate attack. Mortars …

Causes And Impacts Of Geotechnical Problems On Bridge And Road Construction Projects, Krishna Prasad Neupane

UNLV Theses, Dissertations, Professional Papers, and Capstones

Changes during the construction phase generate cost growth, schedule delays, and claims in any project. However, the impact of geotechnical problems on construction costs, schedules, and claims in bridge and road projects had not been investigated in depth. The major objectives of this study were to determine the geotechnical-related causes of cost and schedule growth and claims as well as their impacts on the bridge and pavement projects’ performance. This study also identifies mitigation measures to avoid cost and schedule growth and claims in these projects.

A survey was conducted with 53 engineers from state Department of Transportations (DOTs) and …

Occurrence And Proliferation Of Antibiotics And Antibiotic Resistance In Wastewater Treatment Plants, Majid Neyestani

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solids retention time (SRT) is one of the most important factors in designing and operating activated sludge systems for biological wastewater treatment. Longer SRTs have been shown to alter the structure and function of microbial communities, thereby leading to improved treatment efficacy with respect to bulk and trace organics, nutrient removal, and membrane fouling. However, research has also shown that longer SRTs lead to increased prevalence of antibiotic resistant bacteria, perhaps due to increased exposure to antibiotics present in influent wastewater. The purpose of this study was to characterize changes in microbial community structure in a laboratory-scale activated sludge system …

Analyses Of Streamflow Change Patterns And Correlation Of These Changes With Sea-Surface Temperature Fluctuations, Kazi Ali Tamaddun

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents a comprehensive statistical analysis that determines the direction, rate, and interval of significant streamflow change patterns in the continental U.S. and correlates these changes with sea-surface temperature fluctuations. First, by using two non-parametric tests, namely, the Mann-Kendall trend test and the Pettitt’s test, the presence of long-term trends and abrupt shifts were determined at 10% significance level over continuously adjustable periods that stretched from 1903 to 2012. Modified versions of the tests were applied to account for the presence of persistence (autocorrelation) in data. Theil-Sen slope was determined to evaluate the rate of change across multiple temporal …

Evaluating The Suitability Of Microbial Induced Calcite Precipitation Technique For Stabilizing Expansive Soils, Sikha Neupane

Boise State University Theses and Dissertations

Expansive soils, also known as swell-shrink soils have been a problem for civil infrastructures including roads and foundations from ancient times. The use of chemical additives such as cement and lime to stabilize expansive soils is a common practice among geotechnical engineers especially for lightly loaded structures. However, several occurrences of subgrade failures were observed after stabilizing with chemical additives hence engineers are in search of sustainable stabilization alternatives. Microbial Induced Calcite Precipitation (MICP) is gaining attention as an environmental friendly soil improvement technique. Several researchers have successfully tested its feasibility in mitigating liquefaction induced problems in sandy soils. This …