Civil Engineering Commons^™

Smart Rocks For Bridge Scour Monitoring -- Design And Localization Using Electromagnetic Techniques And Embedded Orientation Sensors, Andro Radchenko

Doctoral Dissertations

"River bridge scour is an erosion process in which flowing water removes sediment materials (such as sand, rocks) from a bridge foundation, river beds and banks. As a result, the level of the river bed near a bridge pier is lowering such that the bridge foundation stability can be compromised, and the bridge can collapse. The scour is a dynamic process, which can accelerate rapidly during a flood event. Thus, regular monitoring of the scour progress is necessary to be performed at most river bridges. Present techniques are usually expensive, require large man/hour efforts, and often lack the real-time monitoring …

Design And Performance Of Cost-Effective Ultra-High Performance Concrete For Prefabricated Elements, Weina Meng

Doctoral Dissertations

"This study presented in this thesis aims to: (1) develop a mixture design methodology for cost-effective ultra-high-performance concrete (UHPC) incorporating high volume of supplementary cementitious materials and conventional concrete and masonry sands; (2) developed UHPC with adapted rheology incorporating lightweight sand, hybrid fibers, and nanomaterials with improved properties; (3) design prefabricated UHPC panels with fiber-reinforced polymers (FRP) for enhanced flexural properties of stay-in-place panels made with optimized UHPC; and (4) explore potential applications of such UHPC elements. The proposed design methodology produced UHPC mixtures with 28-days compressive strengths higher than 125 and 168 MPa under standard water curing and 1-d …

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 …

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 …

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 …

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 …

Rehabilitation And Strengthening Of Reinforced Concrete Members Using A Fiber Reinforced Cementitious Matrix Composite, Zena Riyadh Aljazaeri

Doctoral Dissertations

“Externally bonded fiber reinforced cementitious matrix (FRCM) for structural members was tested and evaluated as a new class of composite material for repairing and strengthening infrastructures. In comparison with fiber reinforced polymer (FRP) composites, FRCM composite has a superior high temperature resistance and great compatibility with concrete substrates. Experimental investigation is ongoing in the United States to evaluate the structural and durability performance of FRCM composite to be implemented in field applications. This experimental program consisted of testing 12 strengthened reinforced concrete (RC) beams to study the fatigue and flexure performance under environmental exposure and sustained stress, 10 strengthened RC …

Behavior Of Ultra-High Performance Concrete Bridge Deck Panels Compared To Conventional Stay-In-Place Deck Panels, Valter Gora Venancio

Masters Theses

"The remarkable features of ultra-high performance concrete (UHPC) have been reported. Its application in bridge construction has been an active research area in recent years, attributed to its higher compressive strength, higher ductility and reduced permeability when compared with conventional concrete and even high-strength concrete. Those characteristics are known to increase bridge durability and, consequently, decrease life-cycle maintenance costs.

With that in mind, this study investigated the performance of UHPC stay-in-place (SIP) bridge deck panels subjected to high loads in both flexure and shear. The test matrix consisted of twelve (12) half-scale panels that were 4 feet long and 2 …

Evaluation Of Ultra-High Performance Concrete (Uhpc) In Joints Of Bridge Girders, Saipavan Rallabhandhi

Masters Theses

"Joints are often considered as the weak link in a structure and often deterioration of the structure initiates from the joints. Joints transfer the stresses from super-structure to sub-structure and in this process are subjected to large transfer stresses. Not much attention is given to the design of joints as they are positioned in low moment regions and typically a 4 to 6 ksi (28 to 41 MPa) concrete is used to fill the joints. One of the solution to this problem is Ultra-high performance concrete (UHPC). In the recent past significant research has been done to use UHPC in …

Behavior Of Hollow-Core Composite Columns Under Torsion Loading, Sujith Anumolu

Masters Theses

"The effect of torsional loads could be significant along with axial and flexural loads on bridge columns during earthquake excitations. The present study presents the torsional behavior of hollow-core steel-concrete-steel columns (HC-SCS) and hollow-core fiber reinforced polymer-concrete-steel columns (HC-FCS). The HC-SCS comprises of sandwiched concrete shell between two steel tubes whereas in HC-FCS column, the outer steel tube of HC-SCS column was replaced by the FRP tube. Both columns have stay-in place permanent form-work to the concrete shell in the form of outer and inner tubes. The steel tubes serve as longitudinal and shear reinforcement to the column. Finite element …

Shear Behavior Of Reinforced Fly Ash-Based Geopolymer Concrete, Noor S. Yacob

Masters Theses

"The geopolymerisation of aluminosilicate materials such as fly ash has been a radical change in construction material's chemistry and composition, compared to the portland cement-based concrete calcium silicate-hydrate chemistry. The adoption of fly ash in concrete industry is a good use of by-product ashes to reduce emissions of the greenhouse gas implicitly. However, in this research, the replacement of portland cement by fly ash is 100%, which makes it a zero-cement concrete with no proprietary chemical additives.

Geopolymer concrete (GC) is a revolutionary synthetic material that combines sustainability and high engineering properties, and it is relatively cost-effective compared to portland …

Influence Of Mix Design Parameters On Dynamic Segregation Of Self-Consolidating Concrete And Consequences On Performance Of Precast Beams, Aida Margarita Ley Hernandez

Masters Theses

"Self-Consolidating Concrete (SCC) is more vulnerable to stability problems as a consequence of its high flowing ability compared to conventional vibrated concrete. Dynamic segregation refers to the tendency of the concrete constituents to separate from the suspended matrix, usually in horizontal direction while being cast into the formwork or due to an impact. Similarly to static segregation, dynamic segregation can affect the homogeneity of SCC. Therefore, it is highly essential to ensure a proper dynamic stability in order to enhance the uniformity of in-situ properties of pre-stressed beams.

In this research project, the effects of SCC mix design parameters are …

Composite Confinement Systems For Rc Column Repair And Construction Under Seismic Loads: Concept, Characterization And Performance, Mostafa Fakharifar

Doctoral Dissertations

"This study aims at developing, characterizing and validating an integrated composite confinement system of conventional jackets for: (1) repair and retrofit of existing bridge columns; and (2) construction of new bridge columns, subjected to earthquake excitations.

A new composite steel confinement jacket was proposed by combining a thin steel sheet and prestressing strands as a hybrid jacket, incorporating active and passive confining pressure on damaged RC columns. Both experimental and analytical studies were conducted to understand the performance and effectiveness of the proposed repair method. The experimental study involved two 1/2-scale lap-spliced deficient RC bridge columns originally tested to failure …

Microwave Material Characterization Of Alkali-Silica Reaction (Asr) Gel In Cementitious Materials, Ashkan Hashemi

Doctoral Dissertations

"Since alkali-silica reaction (ASR) was recognized as a durability challenge in cement-based materials over 70 years ago, numerous methods have been utilized to prevent, detect, and mitigate this issue. However, quantifying the amount of produced ASR byproducts (i.e., ASR gel) in-service is still of great interest in the infrastructure industry. The overarching objective of this dissertation is to bring a new understanding to the fundamentals of ASR formation from a microwave dielectric property characterization point-of-view, and more importantly, to investigate the potential for devising a microwave nondestructive testing approach for ASR gel detection and evaluation. To this end, a comprehensive …

Geotechnical State-Of-The-Art In Guatemala -- Ground Stabilization, Fernando Rafael Callejas Benitez

Doctoral Dissertations

"History provides an understanding of the present and in a way, a guide for the future. The state-of-the-art is often referred to as a snapshot of the most significant works and contributions made in a field of study; In this case the focus is on Guatemalan geotechnical engineering. This study presents a comprehensive description of the different events that impulse geotechnical engineering in Guatemala.

As part of the description of the state-of-the-practice an investigation of the different human (engineers/contractors) and physical resources (laboratories/field equipment) and their capabilities are presented. An overview of the civil engineering programs is presented. Then, the …

Static And Dynamic Characterization Of Tied Arch Bridges, John Edward Finke

Doctoral Dissertations

"Tied arch bridges have been designed and constructed since the late 19th century. With their open vista owing to minimalist features tied arch bridges continue to appeal the public. Tied arch bridges are both aesthetic and economical alternates to long span bridges holding a place in the hierarchy of major bridges. They fit in a niche between viable and economical plate girder spans and short cable stayed bridge spans. There are several variations of the tied arch with the most common form being those having vertical hangers, stiff tie girders and slender arch ribs. This tied arch variation is examined …

Innovative Techniques For Seismic-Resistant Bridge Columns Under Ground Motion Excitations, Ayman A. Moustafa

Doctoral Dissertations

“This dissertation provides innovative alternative solutions for replacing conventional reinforced concrete columns. The proposed columns displayed enhanced seismic resistance and properties compared to their counterpart conventional columns. Two main techniques were followed and proposed to develop seismic-resistant columns. The first technique utilized rubberized concrete to internally enhance energy dissipation and damping. Materials testing of rubberized concrete with scrap tire replacement of fine aggregates were performed to evaluate its dynamic properties. Shaking table testing of a rubberized concrete column was performed and the behavior was compared to that of the conventional one. The rubberized column showed an increase of 16% in …

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 …

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 …

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 …

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 …

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 …