Engineering Commons^™

Multi-Objective Optimization Of A Ridesharing System Performance, Mohammad Nasr Azadani

Graduate Theses, Dissertations, and Problem Reports

Ridesharing is a shared vehicle service with the potential to meet the growing travel demand due to population increase, economic growth, and shortage in transportation infrastructure capacity. Compared to the current system of predominantly using personal vehicles, ridesharing services reduce the number of vehicles while providing mobility services to the same number of people with no additional investment in the transportation infrastructure. One of the big challenges in implementing ridesharing services is matching drivers and riders. Conflicts between matching-objectives to comply with the interests of diverse stakeholders influence the efficiency of ridesharing in a transportation system. This study investigates the …

Effect Of Binder Modification And Aggregate Size On Modulus And Fatigue Of Asphalt Concrete, Elizabeth Bashiti

Graduate Theses, Dissertations, and Problem Reports

Asphalt concrete is one of the main ingredients used in the paving of roadways across the globe. These roadways have been deteriorating from overuse, under design, and a lack of understanding of the engineering properties. In the asphalt community, it is agreed upon that polymer modifiers and aggregate size have comparable impacts on the performance of a pavement, such as, low creep at high temperatures, high ductility at low temperatures, high toughness, resistance to moisture and temperature, high cohesive and adhesive strength. With all of these advantages, it has been often assumed that polymer modifiers extend/improve the expected life of …

Field Evaluation Of A Modular Press-Brake-Formed Steel Tub Girder In An Application That Includes Skew And Superelevation, Adam D. Roh

Graduate Theses, Dissertations, and Problem Reports

The Short Span Steel Bridge Alliance (SSSBA) is a group of bridge and culvert industry leaders (including steel manufacturers, fabricators, service centers, coaters, researchers, and representatives of related associations and government organizations) who have joined together to provide educational information on the design and construction of short span steel bridges in installations up to 140’-0” in length. A technical working group from within the SSSBA developed the notion for the modular shallow press-brake-formed steel tub girder as a solution for the short span steel bridge market.

After extensive testing at West Virginia University and multiple successful field demonstrations, members of …

Scaling-Based Robust Predictions Of Periodic Stream Water Quality Variables Across The Contiguous U.S., Mohammad Abu Zafer Siddik

Graduate Theses, Dissertations, and Problem Reports

Stream water quality is at the core of the biological and ecological health of streams and rivers. Subject to the environmental variation and in-stream metabolic activities, key water quality indicators such as dissolved oxygen (DO), water temperature (Tw), and chlorophyll a (Chl a, an indicator of primary productivity) typically follow a concave-shaped diurnal cycle. Variation and changes in climatic drivers (e.g., solar radiation, air temperature, and pressure), land uses, and hydrologic variables lead to a high spatiotemporal variability in stream water quality. The spatiotemporal variation challenges the development of robust models for predictions across large scales (e.g., county, state, country), …

Review Of Modern Nondestructive Testing Techniques For Civil Infrastructure, Shabnam Khanal

Graduate Theses, Dissertations, and Problem Reports

The repair and maintenance of aging infrastructures, in the United States alone, are estimated to have backlogs of trillions of dollars. This has posed widespread concerns about the existing and proposed infrastructures to adequately sustain the quality of life in the near future. Efficient and cost-effective approaches, such as nondestructive testing (NDT), are therefore required to better shape our future. Various NDT techniques have been developed over the past two decades with cutting-edge advances towards investigation and condition assessment of civil infrastructures. While the performance of NDT techniques has reached unparalleled heights, limitations remain. On one side, are the instrument …

Experimental And Field Evaluation Of Frp Pedestrian Bridge Decks, Kalrav Singh Tomer

Graduate Theses, Dissertations, and Problem Reports

Traditional materials such as steel, timber, and concrete have continued to dominate their usage in civil infrastructure. They offer great advantages like strength and stiffness but at the same time they pose major issues in terms of durability and maintenance. Fiber reinforced polymer (FRP) exhibits outstanding properties like lightness, excellent corrosion and wear resistance along with superior thermo-mechanical properties. Glass FRPs (GFRPs) have emerged as one of the best alternatives in the field of civil infrastructure. It has been more than four decades since fiber reinforced polymer (FRP) composites have gained notable applications in civil infrastructure industry. However, FRPs have …

Study On The Thermal Properties Of Concrete Containing Ground Granulated Blast Furnace Slag, Fly Ash And Steel Reinforcement, Bekir Erdem Bas

Graduate Theses, Dissertations, and Problem Reports

In this study, the thermal and mechanical properties of two types of concrete were measured. The first type contained ground granulated blast furnace slag, and the second type contained Class F fly ash. The compressive and splitting tensile strength, static elastic modulus, thermal conductivity, adiabatic temperature rise, shrinkage, and compressive creep of the two concretes were measured. Then, the experimental shrinkage and compressive creep results were compared to ACI 209.2R-08 using the material properties of each mix design. Additionally, two semi-adiabatic designs were made and compared with the adiabatic calorimetry measurements. Also, in this study, the thermal conductivity of concrete …

Monotonic Response Of Rc Exterior Beam-Column Joints Reinforced With Filler-Modules And Frp Composite Wraps/Gussets, Praveen Kumar Reddy Majjigapu

Graduate Theses, Dissertations, and Problem Reports

A review of post-earthquake reconnaissance studies revealed that reinforced concrete (RC) structures, designed and built before the development of Uniform Building Code (UBC) seismic design guidelines in 1976, have suffered complete collapse or severe damages due to the brittle failure of exterior beam-column joints. Over the past 50 years, several studies were conducted to strengthen exterior joints of in-service structures, with limited emphasis on developing simple, economic and durable repair strategies to improve energy absorption through large inelastic joint deformations. Even less emphasis was devoted to developing repair procedures that minimize stress-concentrations at joint corners and enhancing the strength, ductility, …

Evaluating The Polishing Of Skid Aggregates In Asphalt Using The British Pendulum Tester, Allison Nicole Givens

Graduate Theses, Dissertations, and Problem Reports

To ensure the pavements in West Virginia have adequate skid resistance the Division of Highways evaluates and approves skid resistant aggregate sources for all wearing courses on roads with an ADT of 3,000 or greater. Unfortunately, the supply of skid aggregates in West Virginia is depleting quickly. To find a potential alternative to using skid resistant aggregates, laboratory polishing of asphalt samples was performed using a Circular Track Polishing Machine, and friction was tested using a British Pendulum Tester. The experiment was designed to investigate how a specific aggregate type provides skid resistance to a hot asphalt mixture.

The objective …

The Energy Efficiency And Living Comfort Of A Stabilized Rammed Earth Dwelling In Comparison With A Traditional Stud Frame Building, David C. Johnson Iii

Graduate Theses, Dissertations, and Problem Reports

During the last several decades, rammed earth construction has received renewed attention due to its many desirable characteristics. For construction, use, and end of life treatment, rammed earth construction has shown in research to reduce the embodied energy of residential building construction by 66-85% compared to building methods that use fired brick and concrete members. Research thus far also indicates that rammed earth construction may indeed be more energy efficient since the building material has a very high thermal inertia, henceforth, the rammed earth walls absorb thermal energy from the sun and release it into the building to reduce the …

Transit Agencies Performance Assessment And Implications, Parisa Hajibabaee

Graduate Theses, Dissertations, and Problem Reports

Although most transit systems operate in small urban and rural areas in the United States, these systems have rarely received the same attention as their urban counterparts, both in terms of ensuring the efficiency and effectiveness of their operations and understanding the factors that affect their performance. This thesis's main goals are to assess the performance of rural and small urban public transit agencies and help them evaluate adopting a ridehailing program, thereby improving their performance. We applied operations research and decision-making tools to two public transit projects in small urban and rural areas. The first project focuses on three …

Large-Scale Modeling And Assessments Of Climate, Land Cover, And Sea Level Change Impacts On Stormwater Runoff In Coastal Urban-Natural Environments, Erfanul Huq

Graduate Theses, Dissertations, and Problem Reports

This dissertation investigated the potential impacts of changing climate, land cover, and sea level on the future stormwater budget and extreme runoff in coastal urban-natural environments. Two large-scale basins, namely Florida Southeast Coasts Basin (7117 km2) and Saint Johns River Basin (24928 km2), were selected for this study. The basins represented gradients in climate, land cover, and hydrology across the Atlantic coasts of Florida and the southeast U.S. Two mechanistic hydrologic models were developed for the basins using U.S. Environmental Protection Agency (U.S. EPA)’s Storm Water Management Model (SWMM) 5.1. The models were calibrated and validated with observed historical streamflow …

Procedure For Asphalt Mixture Friction Evaluation For Wvdoh, Danielle Marie Hoyer

Graduate Theses, Dissertations, and Problem Reports

Monitoring asphalt skid resistance in the laboratory could aid in improved friction prediction capabilities and provide insight for developing alternative asphalt mixture designs in the future. The West Virginia Department of Highways (WVDOH) sought the design of a laboratory accelerated asphalt polishing machine to further expand on current skid resistance measurement practices. The design is modeled after the North Carolina State University (NCSU) polishing machine detailed in ASTM E660. The purpose of this research was to develop a testing procedure for the polishing equipment. Friction was monitored with the British Pendulum Tester (BPT) according to ASTM E303.

Specimens were prepared …

Potential Benefits From Practices In Construction Waste Material Controls, Abdulaziz Alwadhenani

Graduate Theses, Dissertations, and Problem Reports

Construction waste is generated from the various construction activities of building, maintaining, renovating, and demolishing infrastructure facilities. These materials include, but are not limited to, concrete, rubble, fiberglass, asphalt, bricks, wood, and scrap metals. In the last few decades, there has been a significant increase in the volume of construction and demolition (C&D) waste materials in the United States (U.S.). Between 1990 and 2017, the total increase in debris generation has surpassed 320%. According to U.S. solid waste management statistics, more than 50% of C&D waste has been and continues to be transported to landfills. The disposal of C&D waste …

Selective Precipitation And Recovery Of Rare Earth Elements From Acid Mine Drainage, Robyn Lauren Christoferson

Graduate Theses, Dissertations, and Problem Reports

The ability to secure rare earth elements (REEs) in the United States is of concern due to the rapid growth in demand and the monopolistic supply chain. The demand for REEs has skyrocketed in recent years due to the development of many green technologies. The United States and many other countries are currently reliant on China for REEs, who currently control greater than 90% of the global supply. Due to the severe impact of previous Chinese export quotas, it is important to lessen the reliance on importation and explore methods of recycling REEs from secondary sources. A secondary REE source …

Effects Of Supplementary Cementitious Materials On Early-Age Tensile Creep And Shrinkage Of Concrete, Lucas James Bucklen

Graduate Theses, Dissertations, and Problem Reports

Determination of early-age tensile creep properties is critical for the performance of mass concrete structures at an early age. Due to the stress relaxation that tensile creep induces in concrete structures, accurate quantification of creep deformation is needed to determine the stress profile of the structure. Conventional methods of measuring tensile creep include the direct tension test where the concrete is subject to constant tensile stress. This method requires large quantities of concrete with embedded strain gauges which can only be used once. In this paper, the tensile creep parameters of concrete are found by using the restrained concrete ring …

Impacts Of Bike Sharing On Transit Ridership, Moathe Salah Aljeri

Graduate Theses, Dissertations, and Problem Reports

Biking is an active, environmentally friendly, and sustainable transportation mode that facilitates short utilitarian and recreational trips. As such, cities around the world have been implementing bicycle sharing/renting programs at stations in a wide network so that a traveler can mount one close to their origins and drop it off at a station nearest to their destinations. In addition, bike sharing programs can solve the first-mile and last-mile connectivity problems of transit modes. Such programs also enable short trips that were previously impossible without using transit modes. This research investigated the relationship between New York City (NYC) subway ridership and …

Time-Dependent Reliability Framework For Durability Design Of Frp Composites, Rajneesh Kumar Bharil

Graduate Theses, Dissertations, and Problem Reports

The life-cycle performance, durability, and aging characteristics of Fiber Reinforced Polymer (FRP or Structural Composites) have been of keen interest to the engineers engaged in the FRP design, construction, and manufacturing. Unlike conventional construction materials such as steel and concrete, the design guidelines to account for the aging of FRP are somewhat scattered or not available in an approved or consistent format. Loss of strength over time or aging of any structural material should be of concern to engineers as the in-service lifespan of many engineering structures is expected to exceed 100 years. Use of durability strength-reduction factors or factors …

An In-Depth Investigation Of The Effects Of Work-Related Factors On The Development Of Knee Musculoskeletal Disorders Among Construction Roofers, Amrita Dutta

Graduate Theses, Dissertations, and Problem Reports

Construction roofers have the uppermost likelihood of developing knee musculoskeletal disorders (MSDs). Roofers spend more than 75% of their total working time being restricted to awkward kneeling postures and repetitive motions in a sloped roof setting. However, the combined effect of knee-straining posture, roof slope and their association to knee MSDs among roofers are still unknown. This dissertation aimed to provide empirical evidence of the effects of two roofing work-related factors namely, roof slope and kneeling working posture, on the development of knee MSDs among construction roofers. These two factors were assessed as potential to increase knee MSD risks in …

Evaluation Of Test Specimen Geometry Of Asphalt Mixes Tested With The Asphalt Mixture Performance Tester, Abha Dwivedy

Graduate Theses, Dissertations, and Problem Reports

Asphalt concrete, AC, is a heterogeneous material that is modeled as a homogeneous material. The disparity between material structure and theory presents issue with performance testing with test sample geometries, resulting in variability. The purpose of this research is to develop appropriate sample geometry for AMPT test for accurate characterization of asphalt mix and ease of testing.

Four sample geometries were fabricated for three mix types. All specimens are fabricated at 7%0.5% air voids and tested for AMPT tests. The effect of sample geometry was statistically analyzed using laboratory test results and performance predictions using FlexPAVE. For ranking analysis all …

Innovative Fe(Iii)-Dosed Anaerobic Biological Treatment System: From Fe And S Biogeochemical Reactions To Engineering Process, Musfique Ahmed

Graduate Theses, Dissertations, and Problem Reports

In moving toward more sustainable wastewater management, anaerobic treatment is gaining increasing popularity due to its simplicity, low energy requirement, low sludge production and less emission of greenhouse gases compared to typical aerobic wastewater treatment systems. Electron acceptors such as nitrate, sulfate, and CO₂ have been used in various anaerobic processes for removal of organic matters from wastewater under anoxic or anaerobic environments. In energy producing regions, ferric iron, Fe(III), is a predominant element in iron containing wastes such as acid mine drainage (AMD) and coal ash, which can potentially be used as a source of iron in novel …

On-Site Measurement Of The Water-Cementitious Ratio And Heat Of Hydration Of Delivered Concrete, Seyednavid Mardmomen

Graduate Theses, Dissertations, and Problem Reports

In this study, AASHTO T318-15 was adopted to estimate the water content of fresh concrete mixes and then revised to have better precision. The additional step required sieving out the coarse aggregate after drying the sample in a microwave oven, and it was then used in the calculation of the absorbed water and cementitious material content. Several laboratory batches, as well as on-site water-cementitious (w/cm) ratio tests, were performed on concrete mixes containing ordinary Portland cement, ground granulated blast furnace slag, and Class F fly ash. The results of the experiments indicated that the accuracy of the revised method was …