Civil Engineering Commons^™

Halloysite Clay Nanotubes For Controlled Delivery Of Chemically Active Agents, Elshard Abdullayev

Doctoral Dissertations

In this work we explored the capabilities of halloysite nanotubes as capsules for encapsulation and controlled delivery of the chemically and biologically active substances. Halloysite is a two-layered aluminosilicate which has a predominantly hollow tubular structure in the submicron range and is chemically similar to kaolinite [1, 2].

In the first section of this work, we analyzed the structure of the halloysite nanotubes as well as its capability to encapsulate and deliver biologically and chemically active agents, similarities and differences between release characteristics of different agents and how these differences relate with their chemical structure. Models were used to describe …

Elimination Of Deck Joints Using A Corrosion Resistant Frp Approach, Ashok Reddy Aleti

Doctoral Dissertations

The research presented herein describes the development of durable link slabs for jointless bridge decks based on using FRP grid for reinforcement. Specifically, the ductility of the FRP material was utilized to accommodate bridge deck deformations imposed by girder deflection, temperature variations, and concrete shrinkage. It would also provide a solution to a number of deterioration problems associated with bridge deck joints.

The design concept of the link slabs was then examined to form the basis of design for FRP grid link slabs. Improved design of FRP grid link slab/concrete deck slab interface was confirmed in the numerical analysis. The …

Mitigation Of Chloride And Sulfate Based Corrosion In Reinforced Concrete Via Electrokinetic Nanoparticle Treatment, Kunal Kupwade-Patil

Doctoral Dissertations

Concrete is a porous material which is susceptible to the migration of highly deleterious species such as chlorides and sulfates. Various external sources, including sea salt spray, direct seawater wetting, deicing salts and chlorides can contaminate reinforced concrete. Chlorides diffuse into the capillary pores of concrete and come into contact with the reinforcement. When chloride concentration at the reinforcement exceeds a threshold level it breaks down the passive oxide layer, leading to chloride induced corrosion. The application of electrokinetics using positively charged nanoparticles for corrosion protection in reinforced concrete structures is an emerging technology. This technique involves the principle of …

Development Of A Geopolymer-Based Cementitious Coating For The Rehabilitation Of Buried Concrete Infrastructure, Carlos Montes

Doctoral Dissertations

The current research project was devoted to the incorporation of geopolymers as a new material for Trenchless projects, taking advantage of their properties in a field in which they had not been used before, providing a substantial help to municipalities to meet their rehabilitation needs. Trenchless Technologies are a family of methods, materials and equipment capable of being used for the installation of new or replacement or rehabilitation of existing underground infrastructure with minimal disruption to surface traffic, business, and other activities.

The dissertation research work described herein is divided into six primary objectives: (1) the evaluation of geopolymer as …

Integrated, Multi-Attribute Decision Support System For The Evaluation Of Underground Utility Construction Methods, John C. Matthews

Doctoral Dissertations

The dissertation research work described herein is comprised of three primary objectives: (1) the development of a rehabilitation method selection software (TAG-R) for the National Association of Sewer Service Companies (NASSCO) and its subsequent validation and combination with TAG (a sister decision support system (DSS) software developed by the author in an earlier work); (2) the development of a social cost calculator (SCC) and its validation; and (3) the development of a proposed framework for multi-segment optimization for construction methods selection using the tools developed in the first two objectives as well as additional project related data.

The selection of …

Improvised Explosive Device Crater Repair For Enduring Route Remediation, Daniel Roman Kienitz

Doctoral Dissertations

"Recent road repairs performed on main supply routes (MSRs) and alternative supply routes (ASRs) in Iraq and Afghanistan revealed several deficiencies in current repair techniques. Temporary solutions such as aggregate backfill, asphalt, and traditional concrete repairs were unacceptable due to the ease of emplacement of additional improvised explosive devices (IEDs). In addition to the threat of IED placement, the threat from exposure of the repair teams to enemy attack during placement and curing was substantial. In order to address these problems, this project investigated rapid hardening materials for improvised explosive device crater repair. A laboratory test program along with performance …

Behavior Of Externally Bonded Fiber Reinforced Polymer Systems For Strengthening Concrete Girders In Shear, Michael Shawn Murphy

Doctoral Dissertations

"Deficiencies in shear resistance are a primary concern in concrete members due to the sudden and unpredictable nature of shear failures. Shear deficiencies in concrete structures can arise due to improper design, long-term deterioration, man-made damages, increases in loads, or as a result of over strengthening in flexure. A number of shear strengthening techniques offer a cost effective means for restoring or enhancing the shear capacity of a concrete member. The use of externally bonded fiber reinforced polymers (FRP) is one such technique that has gained recent recognition for its high strength-to-weight ratio and simplicity of application. The development of …

Applications Of Electricity In The Rehabilitation And Health Monitoring Of Concrete Structures, Saiprasad Vaidya

Doctoral Dissertations

The dissertation research work presented herein consists of two separate findings: one investigates a potential new coating technique that could be used to rehabilitate deteriorated concrete sewer pipes, and the other researches inducing electrical conductivity into geopolymer concrete to serve as smart material by being able to sense stress changes. Both applications utilize electricity to enhance the performance and/or functionality of hardened cementitious materials.

Microbiologically induced corrosion (MIC) in concrete wastewater conveyance systems is a leading deterioration mechanism in such structures. This work focuses on breaking the MIC cycle by preventing colonization of the bacteria responsible for converting hydrogen sulfide …

Computational Simulation Of Strain Localization: From Theory To Implementation, Shouxin Wu

Doctoral Dissertations

Strain localization in the form of shear bands or slip surfaces has widely been observed in most engineering materials, such as metals, concrete, rocks, and soils. Concurrent with the appearance of localized deformation is the loss of overall load-carrying capacity of the material body. Because the deformation localization is an important precursor of material failure, computational modeling of the onset and growth of the localization is indispensable for the understanding of the complete mechanical response and post-peak behavior of materials and structures. Simulation results can also be used to judge the failure mechanisms of materials and structures so that the …

Seismic Behavior Of Circular Reinforced Concrete Bridge Columns Under Combined Loading Including Torsion, Suriya Prakash Shanmugam

Doctoral Dissertations

"Reinforced concrete (RC) columns of skewed and curved bridges with unequal spans and column heights can be subjected to combined loading including axial, flexure, shear, and torsion loads during earthquakes. The combination of axial loads, shear force, and flexural and torsional moments can result in complex failure modes of RC bridge columns. This study carried out experimental and analytical studies to investigate the seismic performance of circular RC columns under combined loading including torsion. The main variables considered here were (i) the ratio of torsion-to-bending moment (T/M), (ii) the ratio of bending moment-to-shear (M/V) or shear span (H/D), and (iii) …

Imaging Of Buried Utilities By Ultra Wideband Sensory Systems, Arun Prakash Jaganathan

Doctoral Dissertations

Third-party damage to the buried infrastructure like natural gas pipelines, water distribution pipelines and fiber optic cables are estimated at $10 billion annually across the US. Also, the needed investment in upgrading our water and wastewater infrastructure over the next 20 years is estimated by Environmental Protection Agency (EPA) at $400 billion, however, non-destructive condition assessment technologies capable of providing quantifiable data regarding the structural integrity of our buried assets in a cost-effective manner are lacking. Both of these areas were recently identified several U.S. federal agencies as 'critical national need'. In this research ultra wideband (UWB) time-domain radar technology …

Formation And Removal Of Pesticides And Pesticide Transformation Products During Water Treatment, Evelyn F. Chamberlain

Doctoral Dissertations

"A comprehensive suite of over 60 pesticides (herbicides, insecticides, and fungicides) representing a variety of classes at environmentally relevant concentrations (low µg/L) were screened for reactivity under typical drinking water conditions and dosages. The most common oxidants/transformation agents in water treatment systems were examined for reactivity including free and combined chlorine, chlorine dioxide, permanganate, ozone, hydrogen peroxide, ultraviolet radiation, and high pH (alkaline hydrolysis). Due to the broad nature of the study, pesticide compounds were analyzed as multiple mixes broken into two groups based on analytical methods, those analyzed by GC/ECD and those by LC/MS. Combinations of reactive disinfectant/oxidant and …

Physical Modeling Of Railroad Ballast Using The Parallel Gradation Scaling Technique Within The Cyclical Triaxial Framework, Adam F. Sevi

Doctoral Dissertations

"Due to the difficulties involved with testing large particle granular materials such as rockfill and railroad ballast, several methods of testing scaled down model specimens have been introduced. Of these techniques, the parallel gradation model has been found to be most useful. The parallel gradation model states that a smaller grainsize distribution model granular material, of the same composition as the prototype material, can be used in triaxial testing at a scaled down grainsize, if the model materials grainsize is exactly parallel to the prototype material. Therefore, a model granular material composed of a smaller, but parallel, grainsize distribution can …

Structural And Economical Impacts Of Heavy Truck Loads On Bridges, Xiang Zhou

Doctoral Dissertations

The study included in this dissertation assesses the strength, serviceability, and economic impact of overweight trucks on Louisiana bridges. Truck load configurations FHWA 3S2 and FHWA 3S3 were applied to bridge models that were originally designed for HS20-44 truck configuration to determine the effects of heavy truck loads on bridges. Behaviors of bridge components including bridge girder, deck, and diaphragm were evaluated separately.

AASHTO linear approach and finite element analysis were employed to evaluate bridge girder behaviors under the heavy truck load. Bridge models with different geometric configurations were considered. Both short term and long term effects on simple span …

Uncertainty And Error In Laser Triangulation Measurements For Pipe Profiling, Michael Kenneth Swanbom

Doctoral Dissertations

Underground pipeline infrastructure often receives insufficient attention and maintenance. Those responsible for ensuring the continuing functionality of this infrastructure primarily use subjective information in their decision making, and standards defining the level of damage acceptable before repair or replacement are difficult to implement. Laser pipe profiling is a relatively new technology that has emerged to take a step toward the objective assessment of buried assets. A laser profiler is a device that traverses a section of pipe, taking measurements of radius around the circumference of the inner pipe wall at multiple locations along the length of the pipe. The accuracy …

Position And Orientation Correction For Pipe Profiling Robots, Andrew John Dettmer

Doctoral Dissertations

Sewer pipelines are prevalent, important, valuable, unnoticed, and often in a state of disrepair. Pipeline inspection is essential for effective management of wastewater systems and is now mandated for many municipalities complying with the Governmental Accounting Standards Board Statement 34 and EPA regulations. Pipe inspection robots are routinely used to inspect underground pipelines for cracks, deformations, leaks, blockages and other anomalies to prevent catastrophic failure and to ensure cost effective maintenance and renewal. Most existing pipe inspection robots only collect video footage of pipe condition. Pipe profiling technology has recently been introduced to allow for measurement of the internal coordinate …

The Design And Performance Of Pressure Pipe Liners Under Static And Cyclic Loading, Shanhai Guan

Doctoral Dissertations

Cured-in-place pipe (CIPP), is a widely used trenchless technology. Based on the current liner design method, American Society for Testing and Materials (ASTM) F2207-02, several aspects are studied for the effect on estimating the long-term performance of the liners.

While estimating the liner burst pressure, the effect from host pipe material properties, liner material properties, defect geometry, liner creep properties and loading condition should be considered. The burst pressure calculated based on the existing method is overestimated and this allows an increased risk of structural failure before the expected design life is reached.

Compared with cast-iron, a PVC host pipe …

Innovative Solutions In Bridge Construction, Rehabilitation, And Structural Health Monitoring, Fabio Matta

Doctoral Dissertations

"This dissertation includes three technical papers that investigate the development of innovative technologies for bridge construction, rehabilitation, and structural health monitoring, respectively, at different stages of the technology transfer process...The research impact is twofold: first is the introduction of promising innovative technologies in development and implementation projects with the direct involvement of forward-thinking industry partners; second is the demonstration of the validity of these technologies on the basis of a rigorous scientific approach"--Abstract, page iv.

Experimental And Analytical Evaluation Of Frp-Confined Large Size Reinforced Concrete Columns, Silvia Rocca

Doctoral Dissertations

"Fiber Reinforced Polymer (FRP) jacketing of Reinforced Concrete (RC) columns, as a rapidly growing strengthening technique, requires appropriate design methods. However, the current available design guides are based on models, in their majority semi-empirical, and calibrated with small-scale plain concrete specimens. These models might not be reliable in predicting the strength and ductility enhancement sought through FRP-confinement in RC columns with geometric and material properties as found in practice. This dissertation presents the research conducted in three technical papers. In the first paper, the performance of 22 FRP-wrapped RC columns of medium- and large-scale is studied. The results of the …

Field And Laboratory Investigation Of Ozone-Indoor Surface Reactions: Secondary Emissions Inventory And Implications For Indoor Air Quality, Hong Wang

Doctoral Dissertations

"Interfacial chemistry greatly influences human exposure to reactants and products in indoor environments. Emissions of volatile organic compounds, as a result of ozone-surface interactions, can lower an occupant's exposure to ozone, but increase indoor concentrations of odorous and carcinogenic compounds. Therefore, investigation of ozone-surface interactions are necessary for better understanding and controlling exposure to ozone and the products of indoor surface chemistry. In this dissertation, field experiments were conducted in five homes in three seasons to quantify ozone-initiated secondary emission rates (SERs), yields surface reaction probabilities and study their temporal trends"--Abstract, page iv.

The Leaching Behavior Of Arsenic, Selenium And Other Trace Elements In Coal Fly Ash, Tian Wang

Doctoral Dissertations

"The goals of this study are four fold, they are: (1) to investigate the leaching behavior of arsenic and selenium from fly ash as well as their affecting factors; (2) to analyze the speciation of arsenic and selenium in fly ash leachate; (3) to develop a modeling approach to quantify the availability and stability of trace cationic elements in fly ash; (4) to apply this model to describe the leaching/adsorption behavior of arsenic and selenium on fly ash, as well as the calcium effect on arsenic (V) adsorption process"--Abstract, page iv.

Fatigue Of Drill Pipes Used In Horizontal Directional Drilling, Feibai Ma

Doctoral Dissertations

Fatigue is the most common cause of mini-HDD drill rod failure. It can occur at stress levels far below the normal operating stress in most drill stem components. Fatigue failures occur because the drill rod, after it has been forced into a curved path, undergoes a cyclic bending stress oscillating from tension to compression in concert with the other stress components caused by torque, thrust, or pullback.

When a rod breaks underground, there is considerable extra cost caused by the delay in “fishing” out the broken rod as well as the cost of replacing the rod. On the other hand, …

Comparative Performance Of Rubberized Hot Mix Asphalt Under Alf Loading, Hanlin Qin

Doctoral Dissertations

In response to the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, Louisiana constructed five projects to evaluate several methods of using discarded tire rubber in highway pavements. The field performance was quite variable. To achieve the agreement among state agencies on the engineering benefits of using crumb rubber modifier (CRM) in HMA pavement and to define the circumstances where the LaDOTD can use asphalt rubber materials in the most cost effective way, a full-scale research program has been conducted at the Louisiana Transportation Research Center (LTRC) to evaluate the performance of CRM-HMA asphalt pavement under Accelerated Loading Facilities (ALF). …

A New Long -Term Design Model For Rehabilitation Pipe Liners, Shanyun Wang

Doctoral Dissertations

Thin-walled plastic pipe liners are routinely used to rehabilitate structurally sound host pipes that have lost their hydraulic integrity. Such liners are often installed below the water table and are consequently subjected to external hydrostatic pressure which may lead to creep-induced radial deflections and eventual collapse of the liner within the host pipe. Most of the current liner design model is based on the extension of short-term model to a long-term buckling liner design method. The objective of this thesis is to examine and provide a correction factor C* to allow short-term liner buckling models to be more accurately used …

Ground Movement Associated With Microtunneling, Zhenyang Duan

Doctoral Dissertations

Microtunneling is a trenchless technology for construction of pipelines. Its process is a cyclic pipe jacking operation. Microtunneling has been typically used for gravity sewer systems in urban areas. Despite its good success record overall, several large ground settlement cases caused by microtunneling have been reported. Also, in contrast with large diameter urban tunneling, there are few research projects about the ground settlement caused by microtunneling.

In this dissertation, the ground settlement caused by microtunneling is studied using a theoretical approach, empirical approach, numerical simulation approach, and artificial intelligence approach.

In the theoretical approach, the equivalent ground loss and settlement …

Structural Distress Condition Modeling For Sanitary Sewers, Vani Samyuktha Kathula

Doctoral Dissertations

Sewers represent a very substantial and crucial part of our underground infrastructure and a high level of investment is needed to maintain them. Sewers are generally out of sight and, as long as they continued to function reasonably well, they are also out of mind—that is, until any problems such as structural, hydraulic and functional arise. The criticality of any sewer condition is a combination of the risk of failure and the consequences of it. Therefore, a systematic approach is necessary to fully understand and evaluate the conditions of this underground infrastructure. The present state of the art does not …

Statistical Properties Of Maximum Likelihood Estimates For Accelerated Lifetime Data Under The Weibull Model, Mahmoud A. Yousef

Doctoral Dissertations

Pipe rehabilitation liners are often installed in host pipes that lie below the water table. As such, they are subjected to external hydrostatic pressure. The external pressure leads to early deformation in the liners, which could ultimately lead to its failing or buckling before its expected service lifetime is achieved. Experiments involving long term buckling behavior of liners are typically accelerated lifetime testing procedures. In an accelerated testing procedure a liner is subjected to a constant external hydrostatic pressure and observed until it fails or for a certain time, t whichever occurs first. Liners that do not fail at time …

Computational Investigation Of Stress, Contact Conditions, And Buckling Of Thin-Walled Pipe Liners, Meihuan Zhu

Doctoral Dissertations

Thin walled polymeric liners are often used to rehabilitate deteriorated pipe lines. The host pipes into which these liners are installed are typically assumed to be structurally sound, and the liner is only expected to carry the external pressure exerted by the groundwater. This external pressure will induce creep deformation and radial deflections that may eventually result in collapse of the liner within the host pipe. The aim of this work is use computational modeling to better understand the evolution of conditions leading up to collapse so that improved liner design models can be developed. Emphasis is placed on a …

Finite Element Simulation Of Creep Buckling Of Cipp Liners Under External Pressure, Qiang Zhao

Doctoral Dissertations

The problem of long-term structural behavior of CIPP liners under external hydrostatic pressure has been characterized as a structural instability problem which is induced by time-dependent material deformation or creep. It is also a contact problem since the liner deflection is externally constrained by the host pipe. The intrinsically nonlinear problem is investigated by means of finite element simulation, with emphases on (a) the essential structural behaviors and mechanisms of buckling, and (b) the influences of inelastic material properties (i.e. yield strengths and creep rates) and geometrical parameters on liner's buckling resistance.

A liner first deforms as a free pipe …

An Empirical Investigation On The Impacts Of Ground-Level Ozone Concentrations On National Ambient Air Quality Standards: The Case Of Lake Charles, Louisiana, Benedict Nweke Nwokolo

Doctoral Dissertations

This study presents information upon which the state of Louisiana can base its ozone State Implementation Plans (SIPs) designed to achieve planned emissions reduction that are required by the Clean Air Act (CAAA) of 1990. The research investigation included an assessment survey on a number of Transportation Control Measures (TCMs) and their degree of acceptability by the residents of Lake Charles area of Louisiana, the research target area. The TCMS were first ranked on the basis of people's perception of each TCM and four TCMs were later analyzed for cost-effectiveness using computer mathematical models. The Traffic Flow Improvements TCM was …