Civil and Environmental Engineering Commons^™

Structural Retrofit Of Reinforced Concrete Circular Columns Using Cfrp, Ahmed Haider Mohiuddin

Civil Engineering Theses - Archive

Fiber reinforced polymer (FRP) composites have developed numerous applications in the field of Civil Engineering, mostly because of their beneficial properties like high strength-to=weight ratio and high corrosion resistance. This study presents an easy and expedient finite element (FE) able to accurately estimate the axial load carrying capacity of reinforced concrete (RC) circular columns confined with externally bonded carbon fiber reinforced polymer (CFRP) sheets. The element is able to model collapse due to concrete crushing. The FE generated in this study is used the load carrying capacity of CFRP confined RC columns subjected to concentric loading. Constitutive models for materials …

Sustainability Assessment Of Recycled Asphalt Mixtures In Texas, Reza Saeedzadeh

Civil Engineering Dissertations - Archive

The pavement practitioners use more recycled materials in asphalt mixtures in order to compensate for the high price of petroleum products and save the limited resources of virgin materials. Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) have been in wide use in asphalt mixtures for several decades. Public perception on the utilization of recycled materials is that the mixtures become more cost effective and more environmental friendly. This is true when the initial stage of construction of pavements is assessed. However, a mixture that costs less and/or burdens the environment less at the beginning may require more frequent …

Emerging Investigators Series: Virus Mitigation By Coagulation: Recent Discoveries And Future Directions, Joe Heffron, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Waterborne viruses are widespread and persistent in the environment. Coagulation is an effective process for mitigating viruses in drinking water. This review examines recent studies of virus mitigation by coagulation processes in the context of the latest scientific advances. Virus sorption is impacted by electrostatic forces, as well as the hydrophobic effect, steric hindrance, hydrodynamics and interactions with the water matrix. Organic matter in the water may hinder or enhance sorption, depending on virus structure and environmental factors. In addition to physical separation in flocs, coagulation processes have been shown to inactivate viruses. This review evaluates reports of virus inactivation …

Design And Resistance Factor Calibration Of Pipe Piles In California, Yujie Hu

Civil Engineering Theses - Archive

Steel pipe piles, either open ended or close ended, are widely used in the state of California as bridge foundations due to high load bearing capacity, light weight, and outstanding workability. The design methods currently used by Caltrans were developed based on limited field data and are lack of field validations of the recent development of steel pipe piles. In this thesis study, 45 high quality steel pipe pile load tests performed in various soil conditions were collected from Caltrans’ load test data to evaluate available design methods and calibrate the resistance factors of selected design methods. A total of …

Potential Application Of Ultra-High Performance Fiber-Reinforced Concrete With Wet-Mix Shotcrete System In Tunneling, Jean Gamarra

Civil Engineering Theses - Archive

In the tunneling industry, shotcrete has been used for several decades. The use of shotcrete or wet-mix spray-on methods allows the application of this method in complex underground profiles and shapes. The need for time efficient spraying methods and constructability for lining coverage opens the door for technologies like steel and synthetic fiber reinforced shotcrete to achieve a uniform and a good quality product. An important advantage of the application of fiber reinforced concrete in shotcrete systems for tunneling is that almost no steel fixing is required. This leads to several other advantages including safer working conditions during excavation, less …

Effects Of Vertical Ground Motion On Seismic Performance Of Reinforced Concrete Flat-Plate Buildings, Sara Jean George

UNLV Theses, Dissertations, Professional Papers, and Capstones

Reinforced concrete flat plate is a type of structural system widely used for office and residential buildings in many areas including those with high seismic risk. In the regions of high seismicity, moment frames or shear walls are employed to resist lateral loading while the flat-plate system is designed to primarily resist gravity loading. Flat-plate structures must maintain lateral deformation capacity as well as resist gravity loading under seismic loads. The deformation capacity of a slab-column connection is a function of vertical shear transferred from slab to column. The effects of vertical loading become even more exaggerated when the flat-plate …

Solar Energy Storage In Molten Salt Shell Structures, Nathan David Tyrrell Loyd

UNLV Theses, Dissertations, Professional Papers, and Capstones

Molten salts (MS) in the 580°C range could be used to store excess energy from solar power stations and possibly from nuclear or coal. The energy can be stored up to a week in large containers at elevated temperature to generate eight hours of electricity to be used at night or during peak demand hours. This helps to reduce the fluctuation experienced at thermal solar power stations due to weather conditions. Our research supported by Office of Naval Research (ONR), presents a survey of salts to be used in molten salt technology and the design of large steel and hybrid …

Laboratory Evaluation Of Geogrid-Reinforced Flexible Pavements, Mohammadreza Sharbaf

UNLV Theses, Dissertations, Professional Papers, and Capstones

An experimental laboratory program to assess the effectiveness of biaxial and triaxial geogrid-reinforced flexible pavements to reduce roadway section was carried out. Six laboratory tests were conducted using a steel cylindrical mold with dimensions of 1.8 m (6 ft) in diameter and 2.1 m (7 ft) in height. The studied reinforced and unreinforced (without geogrid) sections consisted of a locally-obtained subgrade with a minimum thickness of 1.5 m (5 ft) and an asphaltic surface course of 7.6 cm (3 in). The base thickness of three tests was 30.5 cm (12 in) while for the other three tests used base thickness …

Perchlorate Bioremediation: Controlling Media Loss In Ex-Situ Fluidized Bed Reactors And In-Situ Biological Reduction By Slow-Release Electron Donor, Sichu Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

The main concern of perchlorate exposure through drinking water is its effects on the production of thyroid hormone, which is important for human metabolism and child’s brain development. The US Environmental Protection Agency (EPA) has listed perchlorate in the contaminant list as well as in the Unregulated Contaminant Monitoring rule.

The extent of perchlorate contamination can be categorized by the level of contamination into parts per million (ppm) levels, typically in locations where perchlorate was manufactured, and parts per billion (ppb) levels where perchlorate was used for various purposes. Ion-exchange is generally adopted for treating ppb levels of perchlorate while …

Strengthening Of Lightweight Reinforced Concrete Beams Using Carbon Fiber Reinforced Polymers (Cfrp), Tariq Al Jaafreh

Civil Engineering Dissertations - Archive

This research aimed to investigate the effect of utilizing “Fiber Reinforced Polymer” (FRP) on the light weight concrete beams. The main hypothesis is that such utilization of the FRP will lead to strengthened lightweight beams. The research that has been done on this relationship is somewhat broad in the scope and have mostly focused on the normal-weight concrete. However, only few studies that have considered the light weight concrete. Eight Beams were tested in this research under four point bending test. Two beams were taken as a control beams without any external bonding of Carbon Fiber Reinforced polymer. Another two …

Comparison Of Construction Methods For Building An Underground Freight Transportation In Texas, Niloofar Rezaei

Civil Engineering Theses - Archive

Freight transportation by trucks constitutes approximately 80% of total freight transportation in Texas and it is expected to approximately double by the year 2040. Social and environmental costs are adverse impacts of moving freights by trucks. Underground Freight Transportation (UFT) significantly reduces these negative impacts and is more sustainable method of freight transportation. UFT includes close-fitting vehicles carrying freight through underground pipelines or tunnels between terminals. The main objective of this research is to compare two construction methods: (1) tunneling using tunnel boring machine (TBM) and (2) tunneling using open-cut. To conduct this research, a comprehensive literature search on various …

Enhancing Productivity By Using Building Information Modeling Applications In Pipeline Construction Projects, Harsha Vardhan Reddy Guduru Penusila

Civil Engineering Theses - Archive

Building Information Modeling (BIM) is a technology and associated set of processes to produce, communicate, and analyze building models. BIM is a new concept within the construction industry. The objective of this thesis is to utilize BIM in pipeline construction projects as one of the pioneering steps to reduce rework and delays due to unforeseen conditions. This thesis presents evaluation and recommendations to help pipeline construction industry’s transition from traditional two-dimensional drawings to a BIM management process aiding owners and contractors to develop and implement a basic form of BIM technique to manage their projects. This thesis uses two pipeline …

Enhanced Seismic Performance Of Special Truss Moment Frames And Staggered Truss Framing System For Seismically Active Areas, Sanputt Simasathien

Civil Engineering Dissertations - Archive

Due to their ability to achieve large column-free floor spaces, special truss moment frames (STMFs) and staggered truss frames (STFs) are unique valuable options for structural engineers. However, although STMFs and STFs offer a wide range of structural, architectural, and economical benefits, limited research data is available on the seismic performance of these systems. STMF system is a relatively new type of steel framing system for use in high seismic areas. STMFs dissipate earthquake energy through ductile special segments located near the mid-span of the truss girders, while the other members outside the special segment, including truss members, columns, and …

Investigation Of Strength-Enhancement Mechanism And Size Effect On Ultimate Shear Strength Of Steel Fiber-Reinforced Concrete (Sfrc) Slender Beams, Mohammad Reza Zarrinpour

Civil Engineering Dissertations - Archive

This research study consists of two separate phases. In the first phase, an experimental study was conducted to identify the shear-enhancement and failure mechanisms behind the ultimate shear strength of steel fiber-reinforced concrete (SFRC) slender beams by utilizing the full field deformation measuring capability of digital image correlation (DIC) technology. A total of 12 large-scale simply supported SFRC and RC beams with a range of heights including 12 in. (305 mm), 18 in. (457 mm), 24 in. (610 mm), 36 in. (915 mm), and 48 in. (1220 mm) were tested under monotonic point load. The greater shear strength in SFRC …

Using Ceramic Waste Powder In Producing Self-Compacting Concrete, Sama Tarek Sayed Taha

Civil and Environmental Theses

Self-compacted (i.e. consolidated) concrete (SCC) is a special type of concrete that represents a great advancement towards a better quality of sustainable concrete. This unique type is known for its high flowability and superior levels of surface finish without tendency for segregation. The inherited distinct features can be achieved by the addition of high powder content as filler (i.e. size < 0. 125 mm) in the concrete mixture. The filler enhances the rheological properties of the SCC mixture without the need for using higher cement contents and hence, reduces the cost and heat of hydration. Lately, various regulating measures were imposed by governments and environmental organizations all over the world to seize the negative impact on the ecosystem resulting from huge amounts of solid waste materials being dumped in landfills causing major environmental problems. As a result, the utilization of alternative industrial waste constituents in construction materials has been the research focus for many years to evaluate their competence in SCC industry, and their feasibility as filler materials. In this study, ceramic waste powder (CWP) produced during the polishing process of ceramic tiles will be particularly investigated. Fresh and hardened tests are conducted to evaluate the influence of CWP on the rheological and mechanical properties of SCC mixtures. It was concluded that CWP can be used to successfully produce SCC mixtures with improved fresh and hardened properties. The inclusion of CWP up to 200 kg/m³ in SCC mixtures resulted in denser compacted mixtures with low permeability characteristics and high strength values. In addition to enhanced segregation resistance with good deformability and passing abilities for the mixtures under their own weight. The successful completion of …

Causes Of Change Orders And Its Impact On Road Maintenance Contracts, Kabindra Kumar Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Change orders (CO) commonly generate cost-growth, schedule-growth or both, in construction as well as in maintenance contracts. Literature reviews revealed that the causes and impact of CO on new construction contracts had been comprehensively studied, but the causes and impact of CO in maintenance contracts remained neglected. This study collected CO data on road maintenance contracts to determine the amount of CO and the most frequent and high-risk road maintenance activities that had CO. A Delphi study was conducted with 33 maintenance engineers from the state Department of Transportation (DOT) to identify causes of CO and its impact on cost …

Evaluation Of Unbound Pavement Layers Moduli Using The Miniaturized Pressuremeter Test, Alaa Mohammed Shaban

Theses and Dissertations

A small version of pressuremeter known as Miniaturized Pressuremeter (MPMT) was designed and built to provide high quality pavement parameters. The device, which is a modified version of PENCEL Pressuremeter (PPMT) has a 6 inch inflatable probe capable of quickly and reliably measuring the stress-strain response of thin pavement layers. The MPMT stress-strain data can be used as inputs to evaluate existing pavement structures as a part of a pavement management system, and as critical inputs in empirical pavement design methods. To check in-situ operational performance of the new probe, twenty four MPMT and PPMT tests were performed in parallel …

Bs News May/June

Building Services Engineering

No abstract provided.

Validation Of An Internal Camera Based Volume Determination System For Triaxial Testing, Leah D. Miramontes

Civil Engineering Undergraduate Honors Theses

Accurate strain and volume measurements are critical to phase relationships and strength determination for saturated and unsaturated soils. In recent years, laboratory-based photographic techniques of monitoring soil specimens have become more common. These techniques have been used to reconstruct 3D models and to determine strain and volumetric changes of triaxial specimens. A new technique that utilized digital photographs of the soil specimen, captured from within a triaxial testing cell, was utilized. Photographs were processed using photogrammetry software to reconstruct 3D models of the soil specimens. By placing camera equipment within the cell, the technique eliminated the need to account for …

Analysis Of Bolted Beam-Column Connections With Multiple Bolts Per Row And Column Web Stiffeners, Benjamin C. Sutherland

Civil Engineering Undergraduate Honors Theses

Bolted beam-column connections are a common moment connection used in the design of steel buildings. Existing design guides include design parameters for bolt configurations having one bolt on either side of the beam web for each row of bolts. There is potential for increasing connection strength by adding additional bolts on the outside of these rows. This addition could be useful in retrofit scenarios, or even in the design of new structures. In this research, finite element analysis is used to analyze various beam-column connections and t-stub connections. The modeling methods, research process, and conclusions are explained in the thesis …

Measuring Relative Humidity In Concrete Pavements As A Method To Assess Asr Mitigation Measures, Remington G. Reed

Civil Engineering Undergraduate Honors Theses

Alkali-silica reaction (ASR) in concrete is partly facilitated by available moisture within the concrete. In order to better understand this facilitation and to develop processes for ASR mitigation methods, it is necessary to establish a means of monitoring internal relative humidity (RH) within the concrete. Current procedures for measuring RH are time consuming; requiring several hours of equilibration time and specific external conditions to yield accurate results. In order to better understand RH monitoring, laboratory tests were conducted using commercially available RH probes and different controlled environments. Probes were carefully monitored and calibrated in controlled environments, and laboratory tests on …

Framework Of Performance-Based Contracting For Chip Seal And Striping Maintenance Activities, Kishor Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the United States, there are more than four million miles of road network and new roads are being constructed every year. Most of the road networks were constructed more than two decades ago. Therefore, the age of the majority of the pavement inventory has exceeded original design life. This results in increased work load for the maintenance division of the state Departments of Transportation (DOTs). To maintain the road system, state DOTs use In-House or outsource maintenance works to private contractors using Method Based Contracting (MBC), or Performance Based Contracting (PBC), or any combination of these three. Literature reviews …

A Comprehensive Safety Analysis Of Diverging Diamond Interchanges, Holly Lloyd

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the implementation of new roadway configurations, there is a great need to study the influence of the roadway design on the crash rate. Utah is one of the leading states in the implementation of the Diverging Diamond Interchange.

In order to determine the effects of the new roadway configuration on the safety of the intersection, this study employs an Empirical Bayes before-after study of the crash rates at selected Diverging Diamond Interchanges in Utah. The results of the Empirical Bayes method were also used to calculate crash modification factors. The total number of crashes at each site were analyzed. …

Evapotranspiration Estimation: A Study Of Methods In The Western United States, Clayton S. Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Theoretical water use of well-watered vegetation in the western United States was investigated by comparing a gridded dataset developed from satellite and ground instruments to weather stations representative of irrigated agricultural conditions. Since wetter environments are cooler and therefore subject to lower levels of evaporation than the same scenario with warmer temperatures, models derived from dryland and often populated areas overestimate potential plant needs in semi-arid or arid conditions. Evaluation of the model revealed an acceptable fit for air temperatures and solar radiation but with less confidence in humidity and wind speeds. Ultimately, the last two parameters were minor components …

Traffic Sign Management: Data Integration And Analysis Methods For Mobile Lidar And Digital Photolog Big Data, Majid Khalilikhah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Traffic signs often convey critical information to drivers. However, traffic signs are only effective when clearly visible and legible. This study aims to determine the effects of various damage and deterioration forms on sign retroreflectivity, identify the most important factors affecting traffic sign visual condition, predict traffic sign vandalism that obstructs critical messages to drivers, and identify important environmental factors contributing to the temporary obstruction of the sign messages. To do so, two data sets are used. A sample data of over 1,700 signs was manually collected in the field, and the background retroreflectivity of each sign was measured using …

Microbial Degradation Of Sulfonamide Antibiotics, Rachel Levine

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

Certain microbes can transform antibiotics in the environment. However, little is known about the identity of these microbes and their antibiotic biotransformation processes. The objectives of this study were to (1) isolate bacterial strains capable of transforming antibiotics, (2) determine the biotransformation kinetics of antibiotics, (3) characterize the effects of background carbons on the biotransformation kinetics, and (4) identify biotransformation products under various environmental conditions. Sulfadiazine (SDZ) was used as the model antibiotic in this study due to its frequent occurrence in livestock wastes. Surface soil from a cattle feedlot was collected to enrich potential SDZ degrading bacteria. A mixed …

Recycling Ceramic Waste Powder And Its Usage As An Alternative Ingredient In Concrete, Dima Mamoun Kanaan

Theses

Green environment is a challenging concern to accomplish in today’s world. This could be accomplished through an effective and beneficial recycling system through reusing solid waste materials. The study and exploration of alternative ingredients for concrete-making industry started more than five decades ago. Concrete that contains solid waste is referred to as “Green” concrete. Ceramic tiles are widely used in most structures; its production creates waste powder. Using ceramic waste powder (CWP) as an ingredient to partially replace cement in concrete will have a positive and progressive environmental impact in addition will help reserve natural resources. In this study, CWP …

Relating Anaerobic Digestion Microbial Community And Process Function, Kaushik Venkiteshwaran, Benjamin T.W. Bocher, James Maki, Daniel Zitomer

Biological Sciences Faculty Research and Publications

Anaerobic digestion (AD) involves a consortium of microorganisms that convert substrates into biogas containing methane for renewable energy. The technology has suffered from the perception of being periodically unstable due to limited understanding of the relationship between microbial community structure and function. The emphasis of this review is to describe microbial communities in digesters and quantitative and qualitative relationships between community structure and digester function. Progress has been made in the past few decades to identify key microorganisms influencing AD. Yet, more work is required to realize robust, quantitative relationships between microbial community structure and functions such as methane production …

Investigation On The Effect Of Recycled Asphalt Shingle (Ras) In Portland Cement Mortar, Jinwoo An, Boo Hyun Nam, Heejung Youn

Civil Engineering Faculty Publications

Tear-off roofing shingle, referred to as Reclaimed asphalt shingle (RAS), is the byproduct of construction demolition and it is a major solid waste stream in the U.S. Reuse of this byproduct in road construction sector can contribute to the success of materials sustainability as well as landfill conservation. Ground RAS has similar particle distribution as sand and its major component includes aggregate granules, fibers, and asphalt. To promote the beneficial utilization of RAS, this study evaluates the effect of RAS in cement mortar when used as replacement of sand. In addition, the study investigates how cellulose fibers from RAS behave …

Evaluation Of Resistance To Rutting And Moisture Susceptibility On High Rap Content Asphalt Concretes Using Hamburg Wheel Tracking Device, Sungun Kim

GS4 Student Scholars Symposium

Reclaimed or recycled asphalt pavement (RAP) stands for materials that are removed and reprocessed asphalt pavement materials. It is usually from asphalt road maintenance and reconstruction. Past research has proved that the use of RAP will save natural resources by incorporating the old asphalt and aggregates into the new asphalt paving material production. This practice results in cost reduction in roadway construction and maintenance, and thus benefits both the agencies and the public. However, there is a concern over the strength and durability of the pavements containing high RAP content because the old asphalt binder and aggregates aged by traffic …