Civil and Environmental Engineering Commons^™

Influence Of Concrete Compressive Strength On Transfer And Development Lengths Of Prestressed Concrete, Alberto Teodoro Ramirez-Garcia

Graduate Theses and Dissertations

This research examines the relationship between concrete compressive strength and strand bond. The goal of this research was to develop an equation that relates strand bond to concrete compressive strength at strand release (approximately 1 day of age) and at 28 days of age, and those equations are presented in this investigation. Strand bond is assessed by measuring the transfer length and development length for prestressed beams cast in the laboratory. In the U.S., strand bond is predicted using transfer length and development length equations provided by the American Concrete Institute (ACI-318) Building Code and American Association of State and …

Soil Moduli Obtained From A Back Pressure Constant Rate Of Strain Bender Element Consolidation Apparatus, Yi Zhao

Graduate Theses and Dissertations

A back-pressure saturated, constant-rate-of-strain consolidation device was modified to incorporate bender elements (BP-CRS-BE) and thus allowed for shear wave measurements during consolidation tests. This newly fabricated system has many advantages over other previous or current devices: 1) it can be utilized not only for laboratory prepared soil samples but also for field sampled soils such as Shelby tube samples, and 2) continuous compression curves, and continuous values of vertical hydraulic conductivity and coefficient of consolidation can be acquired with a significant reduction in testing time. Soil modulus values such as shear modulus and constrained modulus are also able to be …

Shear Investigation Of Polypropylene Fiber-Reinforced Concrete Beams, Ehsan Navadeh

Civil Engineering Theses - Archive

This study investigates the effect of macro-synthetic polypropylene fibers on the shear strength and failure behavior of longitudinally reinforced concrete beams with and/ or without transverse reinforcement. Eight large-scale were constructed, cured and tested at Civil Engineering Laboratory Building (CELB). This includes flexural reinforced concrete beams without transverse reinforcement (RC), reinforced concrete beam with minimum transverse reinforcement (RCS), 0.5% volume macro-synthetic polypropylene fiber-reinforced concrete beams without stirrups (SNFRC 0.5%), and 0.75% macro-synthetic polypropylene-fiber reinforced concrete beams without stirrups (SNFRC 0.75%). During production of large-scale beams, 19 Cylinders and 9 small-scale beams were produced from the same mix-design and cured for …

Effect Of Tio2/Uv-Led Operational Parameters On The Degradation Of Pharmaceuticals In Water, Burhanuddin Khuzema Zaveri

Civil Engineering Theses - Archive

The presence of pharmaceutical residues in water resources has alarmed water and health authorities. Among many treatment technologies for pharmaceuticals, ultraviolet (UV)-based oxidation has gained significant attention because it is capable of decomposing a variety of recalcitrant and toxic chemicals. As an alternative UV source to problematic conventional mercury lamps, light-emitting diode (LED) has shown many advantages for water treatment applications, so-called UV-LED. The overall goal of this study is to evaluate the high potential of the UV-LED technology to treat water contaminated with pharmaceuticals including sulfamethoxazole, ibuprofen, and triclosan. In particular, important operational parameters were investigated, including UV wavelength, …

Integration Of Bim And Utility Sensor Data For Facilities Management, Kamal Suprabhas

Open Access Theses

Building information modelling represents a building as a database of coordinated, consistent and computable information in construction (Sabol, 2008). There has been a recent trend to study the usage of BIM for post-construction facility management. Recently, attempts are also being made to link a BIM model with smart sensing technology or building automation systems (BAC). This thesis aims to investigate the feasibility of using sensor data from mote based light sensors tied to a BIM model, to be used for maintenance based facility management. More specifically, a prototype will be developed that integrates lighting sensor data collected using a mote …

Effect Of Manures On Food Waste Degradation In Biocell, Md Nur Basit Zaman

Civil Engineering Theses - Archive

Proper disposal of food waste is a challenge due to adverse effect on the environment through generation of excessive leachate and greenhouse gas (CH4). After food loss through the food supply chain, the food waste ends up mostly in landfills. A study by EPA showed food waste to be the second largest component found in landfill. However, food waste imposes major cost on landfill management, and demands a potential alternative disposal solution that can negate the adverse effects. Though anaerobic digester and composting are possible solutions for food waste disposal, the former is highly expensive while in later solution, a …

Study Of Parameters Impacting Productivity Of Tunnel Boring Machines, Hamed Hashem Pour

Civil Engineering Theses - Archive

Tunnel construction has been on the rise for transportation of humans, freight and fluids. For a successful tunneling project, it is necessary for that tunneling contractors to have sufficient data about scope of work, project features and characteristics of the ground to estimate advance rate of the a tunnel boring machine (TBM). The main objective of this thesis is to study tunneling case studies and literature to analyze TBM productivity based on ground conditions, diameter and length of each project. Project data was tabulated and results are reported in this thesis. The methodology to conduct this research was literature search …

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. …

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 …

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 …