Civil Engineering Commons^™

Performance Of Light-Frame Wooden Structure (Lfws) Subjected To Combined Wind And Flood Hazards, Ajay Baniya

Civil Engineering Theses - Archive

Light Frame Wooden Structures (LFWS), which are more prone to wind damage by virtue of their light weight, sustain severe damage when they are subjected to simultaneous flood and wind. A difficulty in Multi-hazard design for wind and flood is that the load and resistance factor make use of different design philosophies developed by different sub-disciplines. After Multi-hazard events, in most cases, it is complicated to determine the sole damage done by flood or wind alone. The load path of Wooden structure is already ambiguous, the addition of flood characteristics makes the analysis and design process more complicated. It has …

A Standard Tensile Testing Procedure For Fiber-Reinforced Concrete (Frc) And Ultra-High-Performance Fiber-Reinforced Concrete (Uhp-Frc) Based On Double Punch Test (Dpt), Shuveksha Tuladhar

Civil Engineering Theses - Archive

Current test methods such as ASTM 1609, ASTM 1550 and direct tensile test are used for evaluating the mechanical properties of Fiber Reinforced Concrete (FRC) and to determine the quality of mixture in design and construction practice. These test methods show high variability in the results, requires large specimen and complicated test setup. An ideal material test method for FRC should give consistent results in determining mechanical properties such as peak strength and residual strengths. Moreover, current test methods are expensive and time-consuming as more specimens are needed to acquire reliable test results. Double Punch Test (DPT) is a simple, …

Using Historic Pavement Performance Data To Identify And Select Sites For Asphalt Mixture Design Studies, Allyson Richey

Civil Engineering Undergraduate Honors Theses

Since 1997 Arkansas asphalt mixtures have been designed using a procedure commonly known as ‘Superpave’. In a traditional Superpave mix design, the design considers only traditional volumetric parameters; however, recent advances in mix design technology emphasize mixture’s ability to perform in its environment. There are numerous factors which affect the performance characteristics of an asphalt mix. Certainly, the asphalt binder’s performance is a critical variable in this system. Asphalt binders are sensitive to temperature, so much so that their primary parameter on which they are recommended is a function of both temperature and the geographic latitude in which the pavement …

Investigating Fate Of Silver Nanoparticles In Wastewater Biofilms, Connie Marie Walden

Graduate Theses and Dissertations

As industrial advances make everyday life easier for human kind, the processes by which we need to maintain sanitary conditions for both water and wastewater treatment will become increasingly complex. Innovations in food packaging and textile design incorporate engineered nanoparticles (ENPs) to increase antimicrobial properties of clothing, maintain product color, and keep food in packaging from spoilage. For most products, ENPs released will enter the sanitary sewer system, and ultimately wastewater treatment plants. Biofilms grow universally on surfaces where a protective layer of extracellular polymeric substances (EPS) shields attached cells from stressors. In wastewater treatment, complex biofilms are utilized as …

Effects Of Climatic Loading In Flexible Pavement Subgrades In Texas, Asif Ahmed

Civil Engineering Dissertations - Archive

Expansive soils, which have been reported as a worldwide problem, cover 25% of the United States. Due to the swelling and shrinkage behavior induced by moisture variations, expansive soil contributes to volumetric deformation, which in turn affects the stability and performance of structures. The Texas Department of Transportation (TxDOT) allocates 25% of its budget to pavement maintenance and repairs, much of which is triggered by expansive soil. In order to decrease the burden of this expense on maintenance authorities, it is necessary to have an accurate understanding of expansive subgrade behavior. Applying this knowledge to the pavement design and construction …

Non-Destructive Evaluation Of Soil Moisture In Evapotranspiration Cover System, Md Ishtiaque Hossain

Civil Engineering Dissertations - Archive

A conventional landfill cover system is designed as a barrier layer system, with low hydraulic conductivity, to minimize the percolation of water from the cover to the waste. Evapotranspiration (ET) covers are currently becoming a popular alternative that are acceptable to landfill authorities, due to their cost effectiveness and nature-friendly performance. The principle function of the ET cover is to store the infiltrated water, using the water balance technique, until it is transpired by plants into the atmosphere, thus minimizing percolation. The performance of the final cover system is assessed by monitoring the soil moisture in the ET cover and …

Dynamic Mechanical Properties And Microstructure Of Graphene Oxide Nanosheets Reinforced Cement Composites, Wujian Long, Jingjie Wei, Hongyan Ma, Feng Xing

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents an experimental investigation on the effect of uniformly dispersed graphene oxide (GO) nanosheets on dynamic mechanical properties of cement based composites prepared with recycled fine aggregate (RFA). Three different amounts of GO, 0.05%, 0.10%, and 0.20% in mass of cement, were used in the experiments. The visual inspections of GO nanosheets were also carried out after ultrasonication by transmission electron microscope (TEM) atomic force microscope (AFM), and Raman to characterize the dispersion effect of graphite oxide. Dynamic mechanical analyzer test showed that the maximum increased amount of loss factor and storage modulus, energy absorption was 125%, 53%, …

Development Of Pre-Stressed Retrofit Strategies For Mitigating Fatigue Cracking In Steel Waterway Lock Gate Components, Christine Michelle Lozano

Graduate Theses and Dissertations

Lock gates are an important part of the transportation infrastructure within the United States (US), having many economic, safety, and environmental benefits over rail and highway transportation systems. Unfortunately, many existing lock gates throughout the US have reached or exceeded their initial design life and require frequent repairs to remain in service. Unscheduled repairs often increase as gates age, having a local economic impact on freight transport which can create economic ripples throughout the nation. Fatigue and corrosion are key causes of unscheduled service interruptions, degrading lock gate components over time. Additionally, because lock gates are submerged during operation, crack …

Testing And Modeling Of The Thixotropic Behavior Of Cementitious Materials., Bashir Hasanzadeh

Electronic Theses and Dissertations

During construction, concrete goes under various operations. It is normally transported to the job site, be placed and consolidated in the formwork, etc. The easiness and quality of these operations are very much related to the intrinsic rheological properties of concrete. Therefore, a good understanding of rheological behavior of concrete under various conditions are needed. Thixotropy is an important part of rheology. The thixotropic behaviors of concrete can be good representatives of its flow behaviors on the job site. For example, the breakdown aspect of thixotropy can help to explain how its flow behavior can impact concrete pumping and its …

Investigation Of Setting Time And Compressive Strength Of Ready-Mixed Concrete Blended With Returned Fresh Concrete, Negasi Niguse Gebremichael

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Center for Sustainable Transportation Infrastructure (CSTI), in its 2012 study, estimated that out of all the concrete leaving the plant, between 2% and 7% of concrete returns to the plant unused as a returned fresh concrete (RFC). Disposal of both the truck wash water and RFC is a growing concern for the industry. Most industry personnel contacted during the investigation, agree that reusing is superior to recycling of this substantial RFC economically and environmentally. This study will determine if the reuse of RFC in subsequent batches compromises the quality of newly blended concrete.

The effect of RFC on fresh …

Evaluating The Chemical And Biological Stability Of Finished Waters Blended For Direct Potable Reuse In A Simulated Distribution System, Assumption Grimaldi

UNLV Theses, Dissertations, Professional Papers, and Capstones

This work evaluated the impacts of blending several different high grade recycled waters with conventional source waters for direct potable reuse (DPR) applications. Bench-scale laboratory tests were conducted for recycled water-source water blends from four participating facilities that have either considered adopting DPR or have already implemented DPR as a feasible approach to overcome water scarcity. The chemical and biological stability of the finished waters was investigated after pipe rig incubation to simulate the quality of blended waters that had aged in a potable water distribution system. The effects of blend ratio, reclaimed water treatment, and source water quality were …

Effects Of Contract Procurement Factors On Performance Of Transportation Projects, Ruiko Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cost and schedule savings are the main measures of a project’s success. Several factors affect the cost and schedule performances in a construction project, such as design changes, material, labor and equipment shortages, unpredictable weather conditions, and errors & omissions in contract documents.Some studies have shown that either the construction cost or the schedule performance of a project was dependent on the procurement factors, namely: bid cost, number of bidders, the bid cost deviation between the first and second bidder, the liquidated damage rate per day, the type of a contract, and the project location. However, a comprehensive study on …

Surface Hydrologic Modeling And Analyzing Watershed Hydrologic Response To Landcover Change, Roshan Poudel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Urban flooding is the most frequently occurring disaster in rapidly urbanizing cities. Rapid urbanization in general, is characterized by an increase in the total impervious surface area, which means less soil cover for the stormwater to infiltrate and a greater volume of runoff from the area in case of a storm event. This increased volume of surface runoff, if not drained, results in urban flooding. Urban flooding can cause serious economic and environmental damages by disrupting transportation and spreading pollution. It is therefore, essential to understand the cause, behavior and effects of urban flooding so as to minimize the risks …

Cost Comparison Of Cement Concrete And Polymer Concrete Manholes In Sewer Systems, Sayan Sakhakarmi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cement concrete manholes are generally used in sewer networks in the United States. However, these concrete manholes are highly vulnerable to chemical corrosion and require frequent maintenance and replacement. Polymer concrete manholes as a substitute to the cement concrete manholes in water and wastewater pipelines have proved to have longer service life and more resistance to various chemical corrosions than normal concrete manholes. Despite the benefits that polymer concrete manholes offer, the higher initial installation cost has been a barrier to its wide application in public works. This study has been conducted to compare the cost of cement concrete manholes …

An Investigation Of Employment And Wage Distribution In The Construction Industry By Race/Ethnicity And Gender, Binit Kumar Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the largest job providers in the U.S, is the construction industry, an industry that suffers from critical problems pertaining to a labor shortage. Yet the industry also struggles with insufficient interest and inconsistent participation from underrepresented demographic groups. To address the issue of workforce income inequality and bias, the industry must better understand the current situation regarding inequality; it needs to pinpoint some basic problems. To do so, analysts must scrutinize the following aspects: 1) the current differences within the construction workforce by race/ethnicity and gender with regards to the total employment and 2) the current disparity within …

Evaluating The Effectiveness Of A Hybrid Geosynthetic Reinforcement System To Mitigate Differential Heave On Flexible Pavement Due To Expansive Subgrades, Mir Md. Tamim

Boise State University Theses and Dissertations

Transportation industries encounter substantial challenges with respect to ride quality and serviceability when they deal with expansive soils underneath roadway structures. These soils exhibit swell-shrink behavior with moisture variations, which cause surficial heaving on the pavement structure and cost billions of dollars for the maintenance of pavements. For the past four decades, a particular stretch of US-95 (Oregon line to Elephant Butte) exhibited recurrent swelling distresses due to the underlying expansive soils. Despite remedial measures that exhibited satisfactory results for most of the sections, recurrent damage still continued in few sections. Further research indicated that the problematic soils were located …

Development Of A Production Estimation Model For Tunnel Boring Machines (Tbms), Saeed Janbaz

Civil Engineering Dissertations - Archive

Advance rate (AR) estimation is a crucial factor at the conceptual phase of a tunneling project for preliminary estimation of tunnel boring machines' (TBMs') usage. The primary objective of this research is to develop order of magnitude performance charts for advance rate of TBMs that can be used using the limited information about the tunneling progress at the conceptual phase. The secondary objective of this dissertation is to evaluate factors that impact TBM progress in large diameter applications. Tunnel diameter and uniaxial compressive strength of ground are found to be some of the primary parameters for prediction of advance rate. …

Fatigue Impacts On Hdpe Pipe Material Properties, Marjan Shahrokh Esfahani

Civil Engineering Dissertations - Archive

During a pipe’s life cycle, failures occur due to numerous factors such as age, loading conditions, environmental conditions, installation quality, manufacturing procedures, operation and maintenance strategies and so on. Frequent pressure surges or fluctuations in a piping system may cause a fatigue failure as fatigue is one of the most important issues in water pipes due to water hammer impacts. Application of buried High Density PolyEthylene (HDPE) water pipelines has significantly increased in recent years, and PE4710 is a new member of HDPE family. So, there is not yet enough information about PE4710 long-term performance. Due to lack of enough …

Aermod Modeling Of Air Pollutant Emissions From Backup Generator Use In Lagos, Nigeria, Temitope Abayomi

Civil Engineering Theses - Archive

Generator emissions contribute to increase in air pollution. In developing countries with inadequate electricity supply, many people rely on back-up generators for long-term electricity supply. Nigeria is the second biggest importer of generators in Africa. As of 2009, it was estimated that 60 million people in Nigeria owned and operated small to medium size generators to provide electricity for their daily use. The sheer number of generators in use suggests that generator emissions are a significant source of air pollution in the country, particularly in urban cities. In this work, the concentrations of pollutants emitted from 50 generators in a …

Seismic Performance Of Double-Channel And Double-Hss Sections, Special Truss Moment Frame With Buckling Restrained Braces, And Long Span Special Truss Moment Frame, Chatchai Jiansinlapadamrong

Civil Engineering Dissertations - Archive

Until recently, all special truss moment frame (STMF) experimental research was done on only double angle STMFs. In order to satisfy the code seismic drift limitation, especially for mid-rise and tall multistory buildings, a large column section is needed, when double angle sections are used. However, heavy chord members can be used in this instance. Due to configuration of STMFs, the chord members in the special segment of an STMF experience higher rotational demand than the story drift. As a result, there is a need to verify large rotational capacity of other heavy steel shapes. Recent analytical investigation and experimental …