Engineering Commons^™

A Rupture Limit Equation For Pre-Loaded Composite Plates, William P. Schonberg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fiber-reinforced polymer composites offer inherent advantages over traditional metallic materials in a number of different ways; however, these materials are also highly susceptible to impact damage. In this paper, we explore the response of FRP (fiber reinforced polymer) composites under impact conditions that could result in their rupture or catastrophic failure. The work performed was aimed at developing a general, data-driven equation for initially-stressed, flat, composite plates that would differentiate between impact conditions that would result in only a hole or crack and those which would cause catastrophic plate failure or rupture. If this equation were to be subsequently shown …

Enhancing The Crumb Rubber Modified Asphalt's Storage Stability Through The Control Of Its Internal Network Structure, Mohyeldin Ragab, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The current research investigated the effect of the internal network structure developed in the crumb rubber modified asphalt (CRMA) on its storage stability. The authors investigated the influence of asphalt-crumb rubber modifier (CRM) interaction parameters (interaction time, interaction speed, and interaction temperature) on the development of the internal network structure in CRMA. The authors found that the existence of three dimensional (3D) network structures in the CRMA enhanced its storage stability. Fourier Transform Infrared (FTIR) Spectroscopy was utilized to determine the nature of CRM components responsible for the development of 3D network structure in the liquid phase of CRMA. This …

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%, …

Hollow-Core Frp-Concrete-Steel Bridge Columns Under Torsional Loading, Sujith Anumolu, Omar I. Abdelkarim, Mohanad M. Abdulazeez, Ahmed Gheni, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the behavior of hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) columns under cyclic torsional loading combined with constant axial load. The HC-FCS consists of an outer fiber-reinforced polymer (FRP) tube and an inner steel tube, with a concrete shell sandwiched between the two tubes. The FRP tube was stopped at the surface of the footing, and provided confinement to the concrete shell from the outer direction. The steel tube was embedded into the footing to a length of 1.8 times the diameter of the steel tube. The longitudinal and transversal reinforcements of the column were provided by the steel tube …

Corrosion Map For Metal Pipes In Coastal Louisiana, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Transportation agencies often allow metal pipes as an option for cross drains under/along roads and highways. Metal culverts can corrode over time at various rates based on their environmental conditions (e.g., corrosive nature of coastal soils, high water table, and saltwater intrusion).

This project was focused on applying available soil data, such as spatial distribution of soil types and soil characteristics (e.g., pH and conductivity), towards creating a Geographic Information System (GIS) based map to identify corrosion zones in coastal Louisiana. The effect of the soil characteristics (pH and conductivity) was incorporated in to the published corrosion models for calculating …

Dynamic And Static Behavior Of Hollow-Core Frp-Concrete-Steel And Reinforced Concrete Bridge Columns Under Vehicle Collision, Omar I. Abdelkarim, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the difference in behavior between hollow-core fiber reinforced polymer-concrete-steel (HC-FCS) columns and conventional reinforced concrete (RC) columns under vehicle collision in terms of dynamic and static forces. The HC-FCS column consisted of an outer FRP tube, an inner steel tube, and a concrete shell sandwiched between the two tubes. The steel tube was hollow inside and embedded into the concrete footing with a length of 1.5 times the tube diameter while the FRP tube stopped at the top of footing. The RC column had a solid cross-section. The study was conducted through extensive finite element impact analyses …

Design Of Magnesium Phosphate Cement Based Composite For High Performance Bipolar Plate Of Fuel Cells, Wenbin Hao, Hongyan Ma, Zeyu Lu, Guoxing Sun, Zongjin Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this work, we report a comprehensive study on a magnesium phosphate cement (MPC) based composite as the construction material for high performance bipolar plates of fuel cells. MPC with partial replacement of fly ash was employed as the binding matrix. Some carbon-based materials, such as graphite, carbon black, carbon fiber, and multi-walled carbon nanotubes were used to construct the conductive phase. A simple hot-press process was applied to produce the composite. The formula and the structure of the composite was modified and adjusted to optimize the properties of the composite to meet the US DOE 2015 technical targets, including …

Environmental Engineering Laboratory Development To Promote Active And Hands-On Learning, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This extended abstract details one instructor’s experience in incorporating hands-on laboratory portion in a junior level civil engineering class, Environmental Engineering. The objective of the change was to help students become more involved and aware of their own learning through active participation so that they can relate to course contents in a better way. The author sought to achieve this through a laboratory structure that 1) required students to reflect on certain topics and device a do-it-yourself experiment to measure certain parameters and 2) provided a level of autonomy by allowing them to choose to work alone or in small …

Traffic Study Using A Video Camera And An Image Processing Software Lessons Learned, Sanjay Tewari, Nazimuddin Wasiuddin, Marissa K. Orr

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Highway Engineering I – CVEN332, is a junior-level course in civil engineering that covers primarily traffic engineering and transportation planning. Traffic engineering topics include isolated intersection signal timing design, intersection capacity analysis and freeway capacity analysis. In fall 2015, students collected real life and local field data in two design modules and used a traffic camera compatible with the video processing software in one design module. The objective of this study is to assess if the usage of local, real life field data and introduction of a traffic camera have any impact on increasing learning, increasing feeling of preparedness and …

Numerical Simulation Of Shock Response And Dynamic Fracture Of A Concrete Dam Subjected To Impact Load, Lu Lu, Xin Li, Jing Zhou, Genda Chen, Dong Yun

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The shock response and dynamic fracture of concrete gravity dams under impact load are the key problems to evaluate the antiknock safety of the dam. This study aims at understanding the effects of impact shock on the elastic response and dynamic fracture of concrete gravity dams. Firstly, this paper uses acceleration records of a concrete gravity dam under impact to establish the correct way to determine the concrete gravity dam of the fundamental frequency and present cut sheets multi-degree-of-freedom dynamic modeling. Under strong impact loading, the constitutive relation of concrete gravity dam and the highest frequency of the impact are …

Strain Distribution And Crack Detection In Thin Unbonded Concrete Pavement Overlays With Fully Distributed Fiber Optic Sensors, Yi Bao, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims at evaluating the feasibility of strain measurement and crack detection in thin unbonded concrete pavement overlays with pulse prepump Brillouin optical time domain analysis. Single-mode optical fibers with two-layer and three-layer coatings, respectively, were applied as fully distributed sensors, their performances were compared with analytical predictions. They were successfully protected from damage during concrete casting of three full-scale concrete panels when 5 to 10-cm-thick protective mortar covers had been set for 2 h. Experimental results from three-point loading tests of the panels indicated that the strain distributions measured from the two types of sensors were in good …

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 …

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 …

Environmental Study Of The Release Of Btex From Asphalt Modified With Used Motor Oil And Crumb Rubber Modifier, Daniel Bergerson, Magdy Abdelrahman, Mohyeldin Ragab

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. Therefore it is necessary to carefully evaluate the safety of any recycled materials being used in pavement materials. Under this study, a reference of testing is presented and implemented to test leachate of samples of two different asphalt binder types containing used motor oil (UMO) and/or crumb rubber modifier (CRM) for the presence of benzene, toluene, ethylbenzene, and xylenes (BTEX). Alongside batch leaching tests, air testing …

Quantifying Economic Benefits For Rail Infrastructure Projects, Suzanna Long, Ruwen Qin, John Betak, Akhilesh Ojha, John J. Myers

Engineering Management and Systems Engineering Faculty Research & Creative Works

This project identifies metrics for measuring the benefit of rail infrastructure projects for key stakeholders. It is important that stakeholders with an interest in community economic development play an active role in the development of the rail network. Economic development activities in both rural and urban settings are essential if a nation is to realize growth and prosperity. Many communities have developed goals and visions to establish an economic development program, but they often fail to achieve their goals due to uncertainties during the project selection and planning process. Communities often select a project from a vast pool of ideas …

Corrosion Resistance Of A Sand Particle-Modified Enamel Coating Applied To Smooth Steel Bars, Fujian Tang, Genda Chen, Richard K. Brow, Michael L. Koenigstein

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The protective performance of a sand particle-modified enamel coating on reinforcing steel bars was evaluated in 3.5 wt% NaCl solution by electrochemical impedance spectroscopy (EIS). Seven percentages of sand particles by weight were investigated: 0%, 5%, 10%, 20%, 30%, 50% and 70%. The phase composition of the enamel coating and sand particles were determined with the X-ray diffraction (XRD) technique. The surface and cross-sectional morphologies of the sand particle-modified enamel coating were characterized using scanning electron microscopy (SEM). XRD tests revealed three phases of sand particles: SiO₂, CaCO₃ and MgCO₃. SEM images demonstrated that the …

Modot Pavement Preservation Research Program, David Newton Richardson, Neil Lennart Anderson, John Bowders, Andrew Z. Boeckmann, Ronaldo Luna, S. Michael Lusher, Brent Rosenblad, Lesley Sneed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The following report documents a research project on pavement preservation performed by the Missouri University of Science and Technology (Missouri S&T) and the University of Missouri-Columbia (UMC) on behalf of the Missouri Department of Transportation (MoDOT). the report consists of a Summary Report followed by six detailed technical reports. to achieve the goal of reducing maintenance costs and improving minor road ratings, MoDOT has embarked upon a plan of formalizing its maintenance/preservation planning. to assist in developing the plan, MoDOT contracted with the Missouri S&T and UMC to conduct a research project, entitled "MoDOT Pavement Preservation Research Program". the product …

Chemical And Hydrodynamic Mechanisms For Long-Term Geological Carbon Storage, Susan J. Altman, Wen Deng, For Full List Of Authors, See Publisher's Website.

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Geological storage of CO₂ (GCS), also referred to as carbon sequestration, is a critical component for decreasing anthropogenic CO₂ atmospheric emissions. Stored CO₂ will exist as a supercritical phase, most likely in deep, saline, sedimentary reservoirs. Research at the Center for Frontiers of Subsurface Energy Security (CFSES), a Department of Energy, Energy Frontier Research Center, provides insights into the storage process. The integration of pore-scale experiments, molecular dynamics simulations, and study of natural analogue sites has enabled understanding of the efficacy of capillary, solubility, and dissolution trapping of CO₂ for GCS. Molecular dynamics simulations provide insight on relative wetting of …

Study On Surface Permeability Of Concrete Under Immersion, Jun Liu, Feng Xing, Biqin Dong, Hongyan Ma, Dong Pan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, concrete specimens are immersed in ultrapure water, to study the evolutions of surface permeability, pore structure and paste microstructure following the prolonging of immersion period. According to the results, after 30-day immersion, the surface permeability of concrete becomes higher as compared with the value before immersion. However, further immersion makes the surface permeability decrease, so that the value measured after 150-day immersion is only half that measured after 30-day immersion. The early increase in surface permeability should be mainly attributed to the leaching of calcium hydroxide, while the later decrease to the refinement of pore structure due …

Effect Of Crumb Rubber Dissolution On Low-Temperature Performance And Aging Of Asphalt-Rubber Binder, Amir Ghavibazoo, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder plays a critical role in defining the low-temperature performance of asphalt pavement, and, therefore, enhancing its mechanical behavior at low service temperatures through modification always has been of great interest. Crumb rubber modification of asphalt is one of the common practices in the industry. However, the effect of a crumb rubber modifier (CRM) on low-temperature performance of the binder is not well understood. A CRM swells by absorbing the aromat-ics and light molecular components of asphalt at low interaction temperatures (i.e., 160°C) and dissolves at higher interaction temperatures (i.e., 190°C, 220°C). Each of those activities affects the performance …

Effects Of Interaction Conditions On Internal Network Structure Of Crumb Rubber-Modified Asphalts, Mohyeldin Ragab, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Investigation of the effect of interaction conditions on the development of the internal network structure of crumb rubber-modified asphalt (CRMA) was carried out. Enhancements in the CRMA physical properties, such as stiffness, expressed in the complex modulus (G*), and elasticity, expressed in the phase angle (δ), as a result of the development of three-dimensional (3-D) entangled network structure were achieved. These results came from controlling the interaction conditions of CRMA synthesis to regulate the crumb rubber-modified (CRM) components that were responsible for the formation of the 3-1) entangled network structure. Dissolution tests and thermogravimetric analysis (TGA) were performed on the …

Parametric Analysis Of Resilient Modulus Modeling For Recycled Asphalt Pavement In Base Layer, Ehab Noureldin, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The resilient modulus (M_R) has been found to be the most important parameter in the Mechanistic-Empirical Pavement Design Guide (MEPDG) for the base layer. A literature review showed that the use of recycled asphalt pavement (RAP) in the base layer had many economic and structural benefits. The prediction of M_R with the specific MEPDG model for the base layer mixed with RAP was found to be reliable for several field conditions. However, further studies of the MEPDG model are needed for an understanding of the physical meaning of each parameter in the model. The most important factor …

Mechanism Of Crumb Rubber Modifier Dissolution Into Asphalt Matrix And Its Effect On Final Physical Properties Of Crumb Rubber-Modified Binder, Amir Ghavibazoo, Magdy Abdelrahman, Mohyeldin Ragab

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Modification of asphalt by crumb rubber modifier (CRM) is mostly done through exchange of components between asphalt and CRM. At 160⁰ C and 10 Hz, CRM absorbs aromatics of asphalt and swells; however, at 220⁰ C and 50 Hz, CRM dissolves into the asphalt; this process leads to the release of different components of CRM including carbon black, fillers, and polymeric and oily components. Depending on interaction conditions, CRM dissolution is performed differently, and therefore the state and role of the released components can be different. In this research different mechanisms of dissolution of one size of CRM in asphalt …