Engineering Commons^™

Micromechanical Prediction Model Of Viscoelastic Properties For Asphalt Mastic Based On Morphologically Representative Pattern Approach, Zhichen Wang, Naisheng Guo, Xu Yang, Shuang Wang

Michigan Tech Publications, Part 1

This paper is devoted to the introduction of physicochemical, filler size, and distribution effect in micromechanical predictions of the overall viscoelastic properties of asphalt mastic. In order to account for the three effects, the morphologically representative pattern (MRP) approach was employed. The MRP model was improved due to the arduous practical use of equivalent modulus formula solution. Then, a homogeneous morphologically representative model (H-MRP) with the explicit solution was established based on the homogenization theory. Asphalt mastic is regarded as a composite material consisting of filler particles coated structural asphalt and free asphalt considering the physicochemical effect. An additional interphase …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 …

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 (ETD)

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 …

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 (ETD)

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 …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 …

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 (ETD)

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 …

A Performance-Based Analysis Of Balanced Mix Designs, Elias Aaron Castillo

Open Access Theses & Dissertations

The Superpave design procedure was established to provide a more representative design methodology and to minimize typical pavement distresses such as fatigue cracking and permanent deformation. This Superpave design methodology was developed on the premise that the voids in mineral aggregate can evaluate the quality and constructability of asphalt mixture during the design and production phases. With the increased use of recycled materials, recycling agents, modified binders and warm mix asphalt additives, several highway agencies including the Texas Department of Transportation (TxDOT), have investigated whether the Superpave volumetric-based design method is enough to ensure appropriate performance of the final product. …

Relating Surface Resistivity To Corrosion Of Rebar Embedded In Portland Cement Concrete, Luisa Alejandra Morales

Open Access Theses & Dissertations

Reinforced concrete is widely used as a construction material known for its durability and proficiency of withstanding large forces in severe environments. Despite that the majority of these structures result in long-term performance, there is still a large number of failures of reinforced concrete structures as a result in corrosion of the reinforcement and concrete degradation. It is critical to assess the state of the corroded structure to decide on whether maintaining or replacing the structure is needed. The objective of this study is to characterize a relationship between the steel reinforcement corrosion and the concrete's resistivity. It is widely …

Quantifying Spatiotemporal Patterns Of Past And Future Urban Trends In El Paso, Tx And Their Impact On Electricity Consumption Using Nlcd Data And The Ca-Markov Model, Joanne Michelle Moyer

Open Access Theses & Dissertations

As cities continue to grow, their urban form continues to evolve over. Understanding this evolution allows for planners, engineers, and decision makers to plan for a sustainable community. Change analysis was conducted for El Paso, Texas county to determine the areas of growth within the past 15-years (2001-2016). The results indicate that growth has primarily occurred within the city of El Paso, in particular Districts 5 (east side), 1 (west side), and 4 (northeast), with District 5 experiencing substantial growth. Developed sub-categories medium and High intensity experienced the fastest growth, which represents single-family housing and compact/commercial areas. However, landscape metrics …

Performance Measure Methodology Of Project Management Practices In Local Government Agencies, Johanes Johanes Makahaube

Open Access Theses & Dissertations

Local government agencies have adopted project management practices to deliver public work projects. The agencies need to measure project management performance to ensure the consistency, control, and monitoring of the project delivery process. However, local government agencies have not adopted a systematic method to measure the organization's project-management performance. At present, there is a gap regarding methods to measure project management performance in delivering construction projects. This study aims to assist local government agencies in improving their project management processes by implementing a comprehensive methodology to assess project management's performance. This dissertation is organized into three major chapter-papers: the first …

Performane Characterization Of Stabilized Materials In Pavement Foundations, Mohammad Rashidi

Open Access Theses & Dissertations

Cementitious Stabilization has been widely used to improve the strength and durability of granular materials for the construction and rehabilitation of pavement structures. Improved mechanical properties and durability of the stabilized materials combined with relatively low cost makes it an attractive method for design engineers. Although this technique appears simple and straight forward, engineering properties of individual soils and aggregates may alter widely due to heterogeneity in soil composition, difference in micro structure among soils, heterogeneity of geologic deposits and differences in chemical interactions of water with soil particles. These differences necessitate the comprehensive study in order to provide the …

Rpas: An Enhanced Finite Element Code For The Mechanistic Analysis Of Rigid Pavements, Nancy Aguirre

Open Access Theses & Dissertations

Significant amount of research has been conducted to improve the design of rigid pavements through the development of mechanistic analysis tools capable of accurately modeling the performance of such pavements. The use of the finite element (FE) method as a comprehensive tool for modeling the responses of rigid pavements has been limited in the past because of the complexity of calculations in modeling nonlinear behaviors, which are difficult to describe mathematically and computationally. Researchers from The University of Texas at El Paso developed NYSLAB, an FE modeling tool, for the analysis of rigid pavements subjected to traffic and environmental loading …

Assessment Of Hydraulic And Structural Behavior Of Inundated Pavements, Mojtaba Asadi

Open Access Theses & Dissertations

Severe flooding events have increasingly inundated the transportation infrastructure, including road networks, across the world and the Unites States. Such extreme events induce significant ingress of water into the pavement layers, which in turn leads to structural defects due to the reduction of the shear strength and resilient moduli of the soil layers, asphalt stripping in flexible pavements, pumping effect in rigid pavements, migration of fines into drainable layers, and swelling of expansive soils. Consequently, premature pavement failure may take place that can impose unforeseen maintenance/rehabilitation costs to highway agencies. Although some experimental research studies have been conducted to assess …

Extracting Mechanical Properties Of Compacted Geomaterials Using Intelligent Compaction Technology, Aria Fathi

Open Access Theses & Dissertations

The primary tool currently used for quality management of earthwork and unbound aggregates is the nuclear density gauge (NDG) to ensure appropriate density and moisture content. Measurement of moisture content and dry density, even though quite practical and straightforward, does not directly tie the construction quality with the mechanistic-empirical design processes where stress and modulus are employed. With the recent popularity of the mechanistic pavement design procedures, research efforts have been undertaken to understand and develop procedures for implementing modulus-based quality control (QC) procedures of compacted geomaterials. These procedures involve the use of in-situ nondestructive testing (NDT) devices that estimate …

Development Of A Framework For The Calibration Of Rpas, A 3d Finite Element Analysis Tool For Rigid Pavements, Abbasali Taghavighalesari

Open Access Theses & Dissertations

The accurate analysis of rigid pavements requires a reliable modeling procedure based on integrating mechanistic analysis methods (i.e. closed-form solutions or numerical methods) and empirical observations (i.e. field measurements and laboratory test results). The use of the finite element method to model the response of rigid pavements has increased in recent decades due to its capability to incorporate the complexity of material behavior, traffic information, and environmental condition. Researchers from the University of Texas at El Paso developed the software Rigid Pavement Analysis System (RPAS) to comprehensively analyze the response of concrete pavements under different geometric configurations, foundation models, temperature …

Impact Of Interface Condition On Performance Of Thin Asphalt Overlays, Cheng Zhu

Open Access Theses & Dissertations

Asphalt overlay has been widely used in the United States as a cost-effective maintenance approach to keep the pavement in a satisfactory condition. In recent years, many studies have been conducted to investigate the overlay asphalt mix design, overlay pavement design, and quality control/quality assurance for the asphalt overlay pavement. In Texas, thin overlays (lift thickness less than 2 in.) and ultra-thin overlays (lift thickness of 0.5 in. to 0.75 in.) seem to be more beneficial than conventional asphalt overlays. For this type of overlay, the bonding condition between the overlay and existing AC layer is crucial for the pavement …

The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1

Tanzania Journal of Engineering and Technology (TJET)

Worldwide, every day human beings generate millions of tons of Faecal Sludge (FS), which is rich in water, nutrients, energy, and organic compounds. Yet FS is not being managed in a way that permits us to derive value from its reuse, while at the same time, millions of farmers struggle with depleted soils and lack of water. In most of the developing countries, energy for cooking is mainly derived from cutting of trees, either as wood or charcoal. Resource recovery and reuse from FS can create livelihoods, enhance food security, support green economies, reduce waste and contribute to cost recovery …

Practical Approach For Removal Of Natural Organic Matter And Defluoridation Of Maji Ya Chai River Water: Use Of Acid Pre-Treated Bone Char And Coagulants, Godfrey Mbabaye

Tanzania Journal of Engineering and Technology (TJET)

The removal of natural organic matter (NOM) and fluoride from Maji ya Chai River water (MCRW) using bone char (BC) and coagulants was investigated. Fine BC particles ranging from 0.045 to 0.2 mm were used in a 1 litre half-filled container, stirred at 300 rpm for 60 min followed by addition of a commercial coagulant and allowed to settle for 24 hours to remove NOM. MCRW practicable and affordable defluoridation method for removal of NOM through defluoridation with BC pre-treated with 0.3 N HCl followed by coagulation with Poly-aluminium chloride (PACl) is proposed. Reduction of fluoride from 21 mg/L to …

Reviewing The Potential And Constraints Of Modified Technology Options For Faecal Sludge Management In Dar Es Salaam, Tanzania, Amour Seleman

Tanzania Journal of Engineering and Technology (TJET)

Cities in the developing world face the challenge of safe management of faecal sludge because of rapid population growth that overwhelms the sanitation infrastructure and services. In developing countries, only 50% of faecal sludge (FS) generated is safely managed the remaining portion is haphazardly disposed of in the environment risking public health and environment. In response to the urgent need for safely managed sanitation services, technological options for containment, desludging and transportation of FS are being modified. This paper reviewed current desludging practices and the potential of modified technological options for addressing FSM at containment, desludging, and transportation in Dar …

Land Use/Cover Change And Their Impacts On Streamflow In Kikuletwa Catchment Of Pangani River Basin, Tanzania, Upendo Msovu

Tanzania Journal of Engineering and Technology (TJET)

Streamflow perturbation is highly prevalent in Kikuletwa catchment. However, little is known concerning land use/cover change (LULCC) with regard to streamflow perturbation in the catchment. This study aims to detect the historical and predict future LULCC and assess their impacts on streamflow amounts using the Soil and Water Assessment Tool (SWAT) model. Supervised classification of Landsat imagery data for 1985, 2000 and 2015 years was done in ERDAS 14 Imagine software. Future prediction of LULCC was done using Module for Land Use Change Evaluation (MOLUSCE) tool, a QGIS plug-in. An accuracy ranging from 79% to 82% was obtained for all …

Effect Of Recycled Concrete Aggregates On The Long-Term, Elastic, Total Deflection And Strength Of Precast Prestressed Hollow Core Concrete Slabs, Lizeth Marisol Gomez Santana

Civil Engineering Theses

Concrete constitutes the largest portion of construction and demolition waste generated each year in the United States. The Environmental Protection Agency (EPA) estimates that the total production of construction and demolition of concrete waste during 2015 was 381.8 million tons. In order to reduce the economic and environmental effects of waste concrete, researchers have begun to incorporate it into concrete mixtures. However, the inherent variability in mechanical properties between RCA sources makes it difficult to quantify the maximum permissible replacement of natural aggregate and the end-result properties of concrete. This project investigates the use of recycled concrete aggregates (RCA) obtained …

Strengthening Of Corroded Steel Structures Using Cfrp – An Experimental Review, Ghada El-Mahdy Ph.D., P.Eng, Abdallah H. Yassin, Abdel El Rahman Khaled

Civil Engineering

Fibre reinforced polymers (FRP) have been widely used to strengthen reinforced concrete structures, however, nowadays their use to strengthen steel structures is under investigation. In particular, the need to strengthen corroded steel structures found in aggressive environments, such as marine environments, which have undergone a reduction in cross-sectional area and hence a reduction in their load-carrying capacity is in need of studying. The main problems that arise when using carbon fibre reinforced polymer (CFRP) sheets to strengthen steel structures is the weakness in the interfacial bond between the CFRP and the steel surface, the thinness of CFRP sheet, and the …

In-Plane Vibration Of Hammerhead Resonators For Chemical Sensing Applications, Luke A. Beardslee, Christopher Carron, Kemal S. Demirci, Jonathan Lehman, Steven Schwartz, Isabelle Dufour, Stephen M. Heinrich, Fabien Josse Phd, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Thermally excited and piezoresistively detected in-plane cantilever resonators have been previously demonstrated for gas- and liquid-phase chemical and biosensing applications. In this work, the hammerhead resonator geometry, consisting of a cantilever beam supporting a wider semicircular “head”, vibrating in an in-plane vibration mode, is shown to be particularly effective for gas-phase sensing with estimated limits of detection in the sub-ppm range for volatile organic compounds. This paper discusses the hammerhead resonator design and the particular advantages of the hammerhead geometry, while also presenting mechanical characterization, optical characterization, and chemical sensing results. These data highlight the distinct advantages of the hammerhead …

Examining The Effectiveness Of A 4d Schedule And A Virtual Reality Model On A Modular Project: Unlv Solar Decathlon Case, Rajarshi Ghimire

UNLV Theses, Dissertations, Professional Papers, and Capstones

The use of a 4D schedule as technological advancement has brought significant improvement to the planning and execution of construction projects, through visualizing stepwise construction progress, following a sequence of pre-planned activities, and finalizing a baseline schedule with necessary changes. Moreover, the application of virtual reality (VR) to create interactive 3D models of a planned structure has made it possible to make a detailed planning of any construction project. Because of these benefits, the use of 4D schedules and VR in the construction industry has increased drastically, leading to improved planning and execution. However, past studies have given little attention …

Alkali-Silica Reactivity Of Mortars Containing Natural Pozzolan, Arash Kian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alkali-silica reactivity is one of the most recognized deleterious phenomena in Portland cement concrete resulting in cracks, spalling, and other deleterious mechanisms.

The aim of this study was (i) to assess the extent of reactivity of the aggregates, quarried from seven different sources, suspected of being conducive to ASR, and (ii) to compare the effectiveness of industrial (Class F fly ash) and natural pozzolans in mitigation of alkali-silica reactivity of the studied aggregates. To this end, seven aggregate sources, four natural pozzolan sources, and one source of Class F fly ash were used. ASTM Type V Portland cement was replaced …

Development Of Natural Perlite Based Concrete For Sustainable Construction, Seyedmahmoud Motaharikarein

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study aimed to partially replace Portland Cement (PC) with environmentally friendly binders capable of improving the longevity of concrete. The new binders consisted of different proportions of natural pozzolan (perlite) with various fineness and particle size distributions. A step-by-step research program was designed to: (1) discover the optimum fineness of perlite powder and its optimum replacement level with cement; (2) investigate the rheological properties of the perlite-containing mixtures, and examine whether this binder can be used in selfconsolidating concrete; and (3) assess the weaknesses of the new binder, and improve its deficiencies by using nanomaterials such as nano-silica. The …

Sizing A New Bike Sharing System For The University Of Nevada, Las Vegas, Nesley Orochena

UNLV Theses, Dissertations, Professional Papers, and Capstones

The strategic planning objectives for a novel Bike Sharing Systems (BSS) are to locate the BSS stations, size the stations, and determine the bicycle fleet size, among others. Current guidelines to design BSS programs are tailored to city centers with large coverage areas and high bicycle to population ratios, and thus not directly transferable to a university setting. An ordered probit model was created using data from a university online stated preference survey to determine the key factors that affect the uptake rates for the UNLV BSS program and to estimate the potential demand. The demand analysis was incorporated into …