Civil Engineering Commons^™

Influence Of Dynamic Factors On Nonwetting Fluid Snap-Off In Pores, Wen Deng, Matthew Balhoff, M. Bayani Cardenas

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Snap-off is an important dynamic multiphase flow phenomenon which occurs in porous media. It plays a dominant role in the residual trapping and mobilization/immobilization of nonwetting fluids such as hydrocarbons or CO₂. Current studies, applications, and threshold criteria of snap-off are mostly based on static or equilibrium conditions. Thus, the dynamics of snap-off which is relevant for many real world applications has rarely been systematically studied. While a static criterion indicates the snap-off potential for nonwetting fluids, the competition between the time required for snap-off and the local pore throat capillary number determines whether snap-off actually occurs. Using a theoretical …

Concrete-Filled-Large Deformable Frp Tubular Columns Under Axial Compressive Loading, Omar I. Abdelkarim, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The behavior of concrete-filled fiber tubes (CFFT) polymers under axial compressive loading was investigated. Unlike the traditional fiber reinforced polymers (FRP) such as carbon, glass, aramid, etc., the FRP tubes in this study were designed using large rupture strains FRP which are made of recycled materials such as plastic bottles; hence, large rupture strain (LRS) FRP composites are environmentally friendly and can be used in the context of green construction. This study performed finite element (FE) analysis using LS-DYNA software to conduct an extensive parametric study on CFFT. The effects of the FRP confinement ratio, the unconfined concrete compressive strength …

Collapse Vulnerability And Fragility Analysis Of Substandard Rc Bridges Rehabilitated With Different Repair Jackets Under Post-Mainshock Cascading Events, Mostafa Fakharifar, Genda Chen, Ahmad Dalvand, Anoosh Shamsabadi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Past earthquakes have signaled the increased collapse vulnerability of mainshock-damaged bridge piers and urgent need of repair interventions prior to subsequent cascading hazard events, such as aftershocks, triggered by the mainshock (MS). The overarching goal of this study is to quantify the collapse vulnerability of mainshock-damaged substandard RC bridge piers rehabilitated with different repair jackets (FRP, conventional thick steel and hybrid jacket) under aftershock (AS) attacks of various intensities. The efficacy of repair jackets on post-MS resilience of repaired bridges is quantified for a prototype two-span single-column bridge bent with lap-splice deficiency at column-footing interface. Extensive number of incremental dynamic …

Work In Progress -- Does A Technology-Rich Transportation Engineering Experiences Increase Interest In Civil Engineering, Marissa K. Orr, Sanjay Tewari, David E. Hall, Norman D. Pumphrey

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper examines whether a technology-rich transportation engineering experience generates interest among college freshman students towards transportation related degrees and careers, specifically, whether it increases interest in civil engineering. Louisiana Tech’s first-year engineering experience provides relevant, project-focused education for over 500 students each year and an opportunity to introduce transportation-related projects. The six semester-hour, three-course sequence, called “Living with the Lab,” boosts experiential learning through student ownership of inexpensive laboratory equipment. In one section of the Living with the Lab course, a transportation engineer visited the class and the students were led through a technology-rich transportation engineering activity. They used …

Factorial Design Approach In Proportioning Prestressed Self-Compacting Concrete, Wu-Jian Long, Kamal Khayat, Guillaume Lemieux, Feng Xing, Wei-Lun Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In order to model the effect of mixture parameters and material properties on the hardened properties of, prestressed self-compacting concrete (SCC), and also to investigate the extensions of the statistical models, a factorial design was employed to identify the relative significance of these primary parameters and their interactions in terms of the mechanical and visco-elastic properties of SCC. In addition to the 16 fractional factorial mixtures evaluated in the modeled region of -1 to +1, eight axial mixtures were prepared at extreme values of -2 and +2 with the other variables maintained at the central points. Four replicate central mixtures …

Evaluation Of Oxidization Of Crumb Rubber-Modified Asphalt During Short-Term Aging, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder is subjected to aging during the construction process and service life of pavement. Aging substantially changes the chemical composition and physical properties of asphalt and leads to premature distresses on pavement. It is speculated that crumb rubber modifier (CRM) reduces the susceptibility of asphalt to aging, but its mechanism is not fully understood. Also, the impact of interaction parameters and exchange of components on the aging behavior of a crumb rubber-modified binder is not fully understood. In this study, the effect of CRM on the short-term aging of asphalt was investigated through an analysis of the distinctions between …

Numerical Simulation Of Prestressed Precast Concrete Bridge Deck Panels Using Damage Plasticity Model, Wei Ren, Lesley Sneed, Yang Yang, Ruili He

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Hybrid Jacketing For Rapid Repair Of Seismically Damaged Reinforced Concrete Columns, Mostafa Fakharifar, Genda Chen, Mahdi Arezoumandi, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study proposes hybrid jacketing for rapid repair of seismically damaged concrete columns for bridge safety. The hybrid jacketing for a reinforced concrete (RC) column is composed of a thin cold-formed steel sheet wrapped around the column and its outside prestressing strands. Although the prestressing strands can prevent buckling of the confining steel sheet, the steel sheet can in turn prevent the prestressing strands from cutting into the concrete. The hybrid jacketing concept was validated with testing of a large-scale RC column with lap splice deficiency typical of pre-1970 bridge constructions in the Central United States. Results from the original …

Determination Of Setting Times By Shear Wave Velocity Evolution In Fresh Mortar Using Bender Element Method, Jianfeng Zhu

Masters Theses

This study aims at using modified bender element (BE) method to monitor the shear wave velocity (V_s) of mortar at early-age and determine initial and final setting times with the V_s method. Modifications of the traditional BE method have been made to overcome the aggressive cementitious environment and eliminate electromagnetic coupling. BE has been successfully employed in mortar samples with and without admixtures to evaluate the evolution of V_s during the early age (first 24 hrs) of hydration. An energy approach method of determining the first arrival time of S-wave has been proposed. Pulse wave velocity …

Unmanned Aircraft Systems Image Collection And Computer Vision Image Processing For Surveying And Mapping That Meets Professional Needs, James Preston Peterson Ii

Doctoral Dissertations

"Unmanned Aerial Systems (UAS) are rapidly blurring the lines between traditional and close range photogrammetry, and between surveying and photogrammetry. UAS are providing an economic platform for performing aerial surveying on small projects. The focus of this research was to describe traditional photogrammetric imagery and Light Detection and Ranging (LiDAR) geospatial products, describe close range photogrammetry (CRP), introduce UAS and computer vision (CV), and investigate whether industry mapping standards for accuracy can be met using UAS collection and CV processing. A 120-acre site was selected and 97 aerial targets were surveyed for evaluation purposes. Four UAS flights of varying heights …

Shear-Friction Of Sand-Lightweight Clay And Slate Aggregate Concretes With Varied Reinforcement Ratios, Samantha Lynn Wermager

Masters Theses

"This thesis focuses on the structural properties of sand-lightweight aggregate concrete in terms of shear transfer strength at cold-joint interfaces. This type of interface is common for precast concrete connections which are typically designed using the shear-friction concept. This testing program was meant to expand the shear-friction database and evaluate the appropriateness of current shear-friction design provisions with respect to sand-lightweight concrete. This study builds on the work done by Shaw (2013) who studied lightweight expanded shale aggregate concrete. The current study included thirty-two push-off specimens constructed from sand-lightweight concrete with a target compressive strength of 5,000 psi. Either expanded …

Behavior Of Crimped Cold-Formed Steel C-Section Beams, Jeffrey Devon Smith

Masters Theses

"This work covers the behavior of crimped cold-formed steel C-section beams under flexural loading. The specific beam shape that was tested was 600S162-54. The crimps were placed in the flange and web of the beam to curve the beam. Three crimp sizes were tested: 0.5 degree, 1.5 degree, and 3.0 degree. In construction practice, the company placed a reinforcing steel band that overlapped the crimped areas to restore strength. These various crimp degrees were tested to evaluate how much strength, if any, was lost. The reinforcing steel band was tested simultaneously with the beam to evaluate if its presence significantly …

3d Numerical Modelling Of Micropiles Interaction With Soil & Rock, Audai Kamal Theinat

Masters Theses

"A 5-span bridge along the Foothills Parkway of the Great Smoky Mountains, TN, was recently completed. Two out of the four piers were instrumented to measure the load transfer in the foundations. The foundations consisted of twenty 10-inch micropiles under the pile cap for each pier. Strain gages were installed and monitored at the different stages of construction. The objective of this research is to examine the interaction between the ground and micropiles using the field data performance and numerical modelling. The 3D computer model consists of the micropile foundation within the steep rock bedding planes and overburden soils. The …

Dynamic Behavior Of Operational Wind Turbines Considering Aerodynamic And Seismic Load Interaction, Mohammad-Amin Asareh

Doctoral Dissertations

"With the advancements in the wind energy production industry, the demand for a cost effective and safe design of wind turbine structures is growing rapidly. The wide deployment of wind turbines in locations with high seismic hazard has lead engineers to take into account a more comprehensive seismic design of such structures. In response to the need for a computational tool that can perform coupled simulations of wind and seismic loads, a seismic module has been developed for the publicly available National Renewable Energy Laboratory (NREL) code, FAST, at the first step of this research. This achievement allows engineers working …

An Integrated Study For Hybrid Composite Beam (Hcb) Structures, Mohamed Abdelkhalik Aboelseoud

Doctoral Dissertations

"The hybrid composite beam (HCB) consists of a self consolidating concrete (SCC) arch that is tied at the end by galvanized strands. The tied arch is encapsulated by a glass fiber reinforced polymer (GFRP) shell. A limited number of researches have studied the essential design methodologies and long-term performance of the HCB. The research presented in this dissertation aimed to more fundamentally understand the structural behavior of this new beam and evaluate its durability. This research study was conducted through four phases. A full-scale bridge load testing was conducted on a single-web HCB bridge during the first phase. The first …

Reliability-Based Optimization Design Of Geosynthetic Reinforced Embankment Slopes, Michelle (Mingyan) Deng

Doctoral Dissertations

"This study examines the optimization design of geosynthetic reinforced embankment slopes (GRES) considering both economic benefits and technical safety requirements. In engineering design, cost is always a big concern. To minimize the cost, engineers tend to seek an optimal combination of design parameters among the considered alternatives while ensuring the optimal solution is safe. Reliability-based optimization (RBO) is such a technique that provides engineers the optimal design with the minimum cost while all technical design requirements are satisfied. The research goal of this study is to implement a mathematical formulation algorithm of the RBO technique in GRES design. To achieve …

Performance Analysis And Modelling Of Hybrid Photovoltaic-Thermal Solar Panels, Nicole C. Annis

Doctoral Dissertations

A photovoltaic-thermal (PVT) panel was constructed, tested, and modelled using both MATLAB and TRNSYS. During the experimental testing, which took place on the Missouri University of Science and Technology campus in Rolla, Missouri; two identical PVT panels were tested alongside two PV panels to gather an electrical baseline for comparison. Approximately 69 days’ worth of data were of data were collected during the summer of 2014. The PV electrical, PVT electrical, PVT thermal and PVT combined (electrical and thermal) efficiencies were 3.5-5.6%, 3.4-5.4%, 20.9-11.6%, and 24.3-17.0%, respectively.

A MATLAB program was developed using existing equations for one-dimensional, quasi-steady model of …

Shape Based Classification And Functional Forecast Of Traffic Flow Profiles, Wasim Kayani

Doctoral Dissertations

This dissertation proposes a methodology for traffic flow pattern analysis, its validation, and forecasting. The shape of the daily traffic flows are directly related to the commuter’s traffic behavior which merit analysis based on their shape characteristics. As a departure from the traditional approaches, this research proposed a methodology based on shape for traffic flow analysis. Specifically, Granulometric Size Distributions (GSDs) were used to achieve classification of daily traffic flow patterns. A mathematical morphology method was used that allows the clustering of shapes. The proposed methodology leads to discovery of interesting daily traffic phenomena such as five normal daily traffic …

Development, Testing, And Analytical Modeling Of Fiber-Reinforced Polymer Bridge Deck Panels, Hesham R. Tuwair

Doctoral Dissertations

A fiber-reinforced, polyurethane foam core was developed, tested, and evaluated as a possible replacement for the costly honeycomb core that is currently used to manufacture fiber-reinforced polymer (FRP) bridge deck panels. Replacing these panels would reduce both initial production costs and construction times while also enhancing structural performance. Experimental, numerical, and analytical investigations were each conducted. Three different polyurethane foam (PU) configurations were used for the inner core during the study’s first phase. These configurations consisted of a high-density PU foam (Type 1), a gridwork of thin, interconnecting, glass fiber/resin webs that formed a bidirectional gridwork in-filled with a low-density …

Mechanical Characteristics Of Organically Modified Fly Ash-Kaolinite Mixtures, Xin Kang

Doctoral Dissertations

"Fly ash is a hazardous waste material to the environment. Beneficial reuse of fly ash, however, brings economic and environmental benefits, i.e., decreases the cost of disposal, reduces greenhouse gas emission, and improves mechanical properties of construction materials. Due to the lack of pozzolanic properties, the reuse rate of Class F fly ash in geotechnical engineering is relatively low (ACAA 2013). In order to promote the effectiveness and sustainability of high volume reuse of class F fly ash in geotechnical engineering, biopolymers (Chitosan, and Xanthan gum) and synthetic polymers (Polyethylene Oxide, PEO) were used instead of the traditional stabilizers to …

Damage Detection Through Acoustic Emission Of Fracture Processes In Concrete Masonry Units, John Alexander Cain

Masters Theses

"Masonry structures are vulnerable to earthquakes; their brittleness and discontinuous formation make them susceptible to collapse. In the event of an emergency, this could be detrimental and perhaps fatal. The area of Structural Health Monitoring (SHM) is focused on understanding the behavior of structures for the sake of safety and predicting their longevity. One applicable technique to monitor this behavior is Acoustic Emission (AE). Acoustic Emissions are transient elastic waves released as microcracks nucleate from stress intensities, coalesce into cracks and then accumulate as damage. AE monitoring is a favorable method because it is capable of detecting cracking from within …

Effect Of Used Motor Oil On The Macro And Micromechanical Properties Of Crumb Rubber Modified Asphalt, Magdy Abdelrahman, Mohyeldin Ragab, Daniel Bergerson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The need to be more environmentally conscious has recently shifted toward the forefront of society. With this new focus on environmentally responsible behavior comes the practice of using recycled materials in construction when possible. Used motor oil (UMO) is an example of waste materials that can be utilized in numerous applications to alleviate its environmental disposal burden. In the current work, the effect of UMO on the internal structure of crumb rubber modified asphalt is investigated. This is carried out by employing rheological analysis including dynamic shear rheometer and microindentation testing. Rheological analysis was employed to determine the change in …

An Investigation Of Shear-Friction Of Lightweight Aggregate Concretes, Kristian Krc

Masters Theses

"This thesis reports the results of research initiated to evaluate the influence of lightweight aggregate type and casting procedure on shear transfer across an interface of concretes cast at different times. The topic of shear transfer has been evaluated and revisited in recent PCI Design Handbooks. In this test program, a series of cold joint as well as monolithic specimens are evaluated. The peak shear strength and post peak behavior are examined. The experimental matrix included 28 push-off specimens that were either cast monolithically or cast at different times creating the condition referred to as a cold joint. The variables …

Advanced Sustainable Concrete Materials For Infrastructure Applications, Kaylea Ann Smith

Masters Theses

"This study was performed to examine the effects of cement replaced by high volumes of Class C fly-ash on durability characteristics of concrete up to 120 days. Specifically, this study investigates possibility of amending American Society for Testing and Materials (ASTM) to allow High Volume Fly-ash (HVFA) concrete to cure until later ages prior to testing instead of 28 days. Five mix designs were compared with varying fly-ash percentages from 0 to 70% (by total cementitious mass). No other additives were present in any of the five mix designs. Water-to-cementitious ratio (w/cm) and total cementitious material remained constant as 0.40 …

Behavior Of Hollow-Core Fiber Reinforced Polymer-Concrete-Steel Bridge Columns Under Extreme Loading, Omar I. Abdelkarim

Doctoral Dissertations

"This study introduces an investigation of the behavior of innovative, resilient, and quickly-constructed hollow-core fiber reinforced polymer-concrete-steel (HC-FCS) bridge columns under extreme loading. The HC-FCS column consists of a concrete wall sandwiched between an outer fiber reinforced polymer (FRP) tube and an inner steel tube. The steel tube was embedded into a reinforced concrete footing with an embedded length of 1.6-1.8 times the diameter of the steel tube. The FRP tube only confined the concrete wall and truncated at the top of the footing level. The hollow steel tube was the only reinforcement for shear and flexure inside the HC-FCS …