Civil Engineering Commons^™

Development Of Environmentally-Friendly Stabilization Methods For Transportation Infrastructure Based On Geopolymers, Miladin Radovic, Anand Puppala

Publications

Geopolymers (GPs) have received much attention as an eco-friendly and sustainable alternative to conventional chemical additives, since they can be processed at room temperatures from aqueous solutions by utilizing waste materials (e.g. fly ash) or abundant natural sources (e.g. clay). A collaborative research study is carried out by teams from Texas A&M University (TAMU) and University of Texas at Arlington (UTA) to investigate the effectiveness of GPs for stabilizing base and subgrade materials by considering the strength and shrink-swell characteristics. Two types of clay, obtained from the North Dallas area, were mixed with a potassium-based GP synthesized from metakaolin and …

Sustainable And Equitable Financing For Pedestrian Infrastructure Maintenance, Gregory Rowangould

Publications

In many communities, pedestrian infrastructure is discontinuous, inaccessible to those with physical disabilities, and poorly maintained. Correcting these problems would be a first step in providing infrastructure to achieve the active travel and related transportation goals of many communities. One nearly universal challenge to maintaining sidewalks in a state of good repair and addressing environmental justice concerns is an adequate, sustainable, and equitable source of funding. Municipal governments across the country maintain and repair their streets and roadways; however, most require residents to maintain and repair public sidewalks adjacent to their property. These policies are difficult to enforce and may …

Bridge Deck Overlays Using Ultra-High Performance Concrete, Craig Newtson, Brad Weldon

Publications

This study investigated the use of a locally produced ultra-high performance concrete (UHPC) as an alternative to typical overlay materials. Several bond strength tests including slant-shear, splitting tension, and direct tension tests were performed to assess the bond strength between UHPC and normal strength concrete (NSC) substrate with varying surface textures. Tests were also conducted to assess the early-age and longer-term shrinkage behavior and coefficient of thermal expansion of the UHPC as well as rapid chloride permeability testing. Good bond between UHPC and NSC substrate was observed even with inadequate surface texture. Combined shrinkage and thermal effects were investigated for …

Numerical Modeling Of Submarine Minibasin Flow And Morphodynamics, Elena Bastianon

Theses and Dissertations

Intraslope basins, or minibasins, are important morphological features of the continental slope in both modern and ancient sedimentary systems. Minibasins have an elliptical or spherical shape with a steep inlet or proximal zone followed by an almost horizontal basin floor, and an overflow zone near the downstream basin lip. These basins are filled with sediment transported by successive events of turbidity currents and other types of submarine flows. The work presented here focuses on turbidity current sedimentation in intraslope minibasins, which is often described in terms of the ‘fill-and- spill’ conceptual model. The ‘fill-and-spill’ model has been used previously to …

Characterization Of The Spatial And Temporal Changes In River Geometry And Sand Load With Field Data Analysis And 1d Numerical Modeling, Zeyad Ayoob Sulaiman

Theses and Dissertations

The quantification of the changes in channel geometry and sand load that have occurred on the Missouri River after engineering works and that characterize the Altamaha River in the fluvial-tidal transition zone is the main objective of this research. Dam construction and channelization on the Missouri River resulted in flow regulation, sediment shortage by dam reservoir trapping, channel straightening and narrowing. Quantifying the morphodynamic response of the Lower Missouri River to these engineering projects at short and long-time scales is a difficult problem that we approach with the analysis of the available field data and with the aid of a …

Shear Strength Characteristics And Failure Mechanism Of Slopes In Overconsolidated Soils Of Nebraska, Hossein Bahmyari

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Geotechnical engineers deal with some challenging problems when encountering long-term slope stability in overconsolidated clays and clayey shales. One of these problems is determining a suitable method to estimate the reliable shear strength of overconsolidated clayey soils for long-term slope stability. According to Eversol (2013), one half of the counties in Nebraska have experienced slope failure in overconsolidated soils, especially in north and east Nebraska. In this research, shear strength characteristics of overconsolidated clayey soils of Nebraska is investigated in regard to long-term stability of slopes, and the failure mechanism in such soils is examined.

Undisturbed samples from boring logs …

Managing Diffuse Phosphorus At The Source Versus At The Sink, Katrina A. Macintosh, Brooke K. Mayer, Richard W. Mcdowell, Stephen M. Powers, Lawrence A. Baker, Treavor H. Boyer, Bruce E. Rittmann

Civil and Environmental Engineering Faculty Research and Publications

Judicious phosphorus (P) management is a global grand challenge and critical to achieving and maintaining water quality objectives while maintaining food production. The management of point sources has been successful in lowering P inputs to aquatic environments, but more difficult is reducing P discharges associated with diffuse sources, such as nonpoint runoff from agriculture and urban landscapes, as well as P accumulated in soils and sediments. Strategies for effective diffuse-P management are imperative. Many options are currently available, and the most cost-effective and practical choice depends on the local situation. This critical review describes how the metrics of P quantity …

Physical Modeling Of Flow Nets In Groundwater And Determination Of Hydraulic Conductivity, Hannah Nicholas, Moses Karakouzian

AANAPISI Poster Presentations

The goal of this study is to physically model the paths that water particles take through soil, and estimate hydraulic conductivity for several soil configurations. Water paths, or flow lines, are shown by injecting dye into sand contained in a rectangular acrylic glass tank with a vertical barrier in the center; water is poured on one side of the tank and a pump is used to maintain constant head loss. If flow lines are formed, a flow net is to be drawn using photos of the tank and hydraulic conductivity is to be calculated.

This project consists of four phases: …

Coir Fiber Reinforced Concrete, Jose De La Serna, Moses Karakouzian

AANAPISI Poster Presentations

This poster exhibits the testing and research done on general Portland Cement Concrete with the addition of coir (coconut) fibers as reinforcement. Using the fundamental constituents of cement (water, cement, fine and coarse aggregate) and processed coir fiber, concrete specimens were batched to test for compressive and flexural strengths (per appropriate ASTM standards). Cylindrical and rectangular beam specimens were subjected to loadings until failure occurred. The capacity and modes of failures of the specimens were observed. It was determined that:

• The addition of processed coir fibers decreases the overall strength of general Portland Cement Concrete. • The tested concrete’s …

Coupled Thermally-Enhanced Bioremediation And Renewable Energy Storage System: Conceptual Framework And Modeling Investigation, Ali Moradi, Kathleen M. Smits, Jonathan O. Sharp

Civil Engineering Faculty Publications - Archive

This paper presents a novel method to couple an environmental bioremediation system with a subsurface renewable energy storage system. This method involves treating unsaturated contaminated soil using in-situ thermally enhanced bioremediation; the thermal system is powered by renewable energy. After remediation goals are achieved, the thermal system can then be used to store renewable energy in the form of heat in the subsurface for later use. This method can be used for enhanced treatment of environmental pollutants for which temperature is considered a limiting factor. For instance, this system can be used at a wide variety of petroleum-related sites that …

Reducing Exposures Traffic-Related Air Pollution And Urban Building Design, Elliott T. Gall, Linda George

Mechanical and Materials Engineering Faculty Publications and Presentations

No abstract provided.

Evaluation Of Model Concepts To Describe Water Transport In Shallow Subsurface Soil And Across The Soil–Air Interface, Zhen Li, Jan Vanderborght, Kathleen M. Smits

Civil Engineering Faculty Publications - Archive

Soil water evaporation plays a critical role in mass and energy exchanges across the land– atmosphere interface. Although much is known about this process, there is no agreement on the best modeling approaches to determine soil water evaporation due to the complexity of the numerical modeling scenarios and lack of experimental data available to validate such models. Existing studies show numerical and experimental discrepancies in the evaporation behavior and soil water distribution in soils at various scales, driving us to revisit the key process representation in subsurface soil. Therefore, the goal of this work is to test different mathematical formulations …

Properties And Mechanisms Of Self-Sensing Carbon Nanofibers/Epoxy Composites For Structural Health Monitoring, Yanlei Wang, Yongshuai Wang, Baolin Wan, Baoguo Han, Gaochuang Cai, Zhizheng Li

Civil and Environmental Engineering Faculty Research and Publications

In this paper, carbon nanofibers (CNFs) with high aspect ratio were dispersed into epoxy matrix via mechanical stirring and ultrasonic treatment to fabricate self-sensing CNFs/epoxy composites. The mechanical, electrical and piezoresistive properties of the nanocomposites filled with different contents of CNFs were investigated. Based on the tunneling conduction and percolation conduction theories, the mechanisms of piezoresistive property of the nanocomposites were also explored. The experimental results show that adding CNFs can effectively enhance the compressive strengths and elastic moduli of the composites. The percolation threshold of the CNFs/epoxy composites is 0.186 vol% according to the modified General Effective Media Equation. …

Mechanical And Sorptivity Characteristics Of Edge-Oxidized Graphene Oxide (Eogo)-Cement Composites: Dry- And Wet-Mix Design Methods, Yousef Alharbi, Jinwoo An, Byoung Hooi Cho, Mohammad Khawaji, Wonseok Chung, Boo Hyun Nam

Civil Engineering Faculty Publications

This paper aims to investigate the effects of edge-oxidized graphene oxide nanoflakes (EOGO) on the mechanical properties and sorptivity of cement composites. The EOGO used in this study was produced by a mechanochemical process that assists the production of EOGO in large quantities at significantly reduced costs, enabling its practical use for infrastructure construction. The scope of this work includes the use of EOGO as an additive in cement composites, including cement paste and mortar. This study explores two mixing methods: The dry-mix method and the wet-mix method. The dry-mix method uses EOGO as dry powder in cement composites whereas …

Where There Is No Engineer - Designing For Community Resilience, Liam Mccarton, Sean O'Hogain

Books/Book Chapters

Where There Is No Engineer – Designing for Community Resilience” is a design initiative coordinated by the Development Technology in the Community (DTC) Research Group, Technological University Dublin (DIT) and Engineers Without Borders (EWB) Ireland.

The programme is delivered in partnership with various development partners and Engineers Ireland. It provides participants with the opportunity to learn about design, teamwork and communication through real, inspiring, sustainable and crosscultural development projects. By participating in the programme, students and professionals will have the opportunity to design creative solutions to real life development projects. This initiative formed part of the DIT team submission which …

Optical-Fiber-Based Smart Concrete Thermal Integrity Profiling: An Example Of Concrete Shaft, Ruoyu Zhong, Ruichang Guo, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Concrete is currently the most widely used construction material in the world. The integrity of concrete during the pouring process could greatly affect its engineering performance. Taking advantage of heat production during the concrete curing process, we propose an optical-fiber-based thermal integrity profiling (TIP) method which can provide a comprehensive and accurate evaluation of the integrity of concrete immediately after its pouring. In this paper, we use concrete shaft as an example to conduct TIP by using the optical fiber as a temperature sensor which can obtain high spatial resolution temperature data. Our method is compared with current thermal infrared …

Rheological Properties Of Warm Mix Asphalt Binders And Warm Mix Asphalt Binders Containing Polyphosphoric Acid, Jun Liu, Kezhen Yan, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the laboratory investigation of properties of warm mix asphalt (WMA) binders and WMA binders containing polyphosphoric acid (PPA).Two types of warm mix additives were used to produce the WMA binders. Superpave tests were carried out on original and short-term aged binders through the rotational viscometer, the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). The results indicated that the WMA binders with different warm mix additives showed different viscosity values, however, the addition of PPA remarkably increased the viscosity values of these two kinds of WMA binders used, in the present study, to a similar …

Advancing Bridge Technology, Task 10: Statistical Analysis And Modeling Of Us Concrete Highway Bridge Deck Performance -- Internal Final Report, Omar Ghonima, Thomas Schumacher, Avinash Unnikrishnan, Adam Fleischhacker

Civil and Environmental Engineering Faculty Publications and Presentations

Concrete highway bridge deck repairs represent the highest expense associated with bridge maintenance cost. In order to optimize such activities and use the available monies effectively, a solid understanding of the parameters that affect the performance of concrete bridge decks is critical. The National Bridge Inventory (NBI), perhaps the single-most comprehensive source of bridge information, gathers data on more than 600,000 bridges in all fifty states, the District of Columbia, and the Commonwealth of Puerto Rico. Focusing on concrete highway bridge deck performance, this research developed a nationwide database based on NBI data and other critical parameters that were computed …

Development Of Domain Analysis For Determining Potential Pavement Damage, Angeli Gamez, Jaime Hernandez, Hasan Ozer, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

A new approach for quantifying flexible pavement damage potential is proposed. The new method, domain analysis, utilizes multiaxial results from advanced finite element models to calculate the response of flexible pavements to tire loading. The output is a single scalar value, which is unique to a given pavement structure and loading configuration. The ability of the domain analysis to quantify bulk damage potential and overcome flaws of conventional approaches based on point responses is demonstrated by testing three case studies: (1) comparison of typical loading conditions of dual-tire assembly (DTA), new-generation wide-base tire (NG-WBT), and steer tire; (2) effect of …

Concrete Pavement Blowup Considering Generalized Boundary Conditions, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

An analytical expression for static stability of a rectangular slab with two simply supported and two elastically restrained edges is presented. The linear elastic isotropic slab can represent a rigid pavement resting on an elastic foundation and loaded by a uniform in-plane axial load per unit length along the edges. The partially restrained edges are connected to the ground by translational and rotational elastic springs; an appropriate magnitude of the springs can capture classical boundary conditions such as free, simply supported, and clamped edges. Results from classical boundary conditions and a finite-element model were used to validate the proposed stability …

Bs News September/October

Building Services Engineering

No abstract provided.

Prediction Of Flood Hydrograph In Small River Catchments Using System Modelling Approach, Ahmed Nasr, Zeinab Bedri, Loreta Ramanauske

Conference papers

Floods remain to be one of the natural catastrophic disasters with serious adverse social and economic implications on individuals and communities all around the world. In Ireland, frequency of flood events have increased dramatically during the last forty years and is expected to continue to rise primarily due to changes in rainfall and temperature patterns as a result of the global climate change. Small river catchments are usually vulnerable to different types of flooding particularly those associated with “monster” rainfall events, which are characterised by short durations and high intensities. Therefore accurate prediction of flood hydrographs resulting from these rainfall …

Development Of Long-Term Aging Factor For Asphalt Mixtures’ Cracking Resistance, Yucheng Shi

LSU Master's Theses

To characterize the cracking resistance of asphalt mixtures, semi-circular bend (SCB) test has been developed and subsequently accepted as a routine test in mixture design in Louisiana. However, SCB test requires specimens to be aged for five days in laboratory, which makes it not implementable in quality control (QC)/quality assurance (QA).

The primary project objective was to develop an aging factor to transfer the unaged SCB Jc to the aged SCB Jc. Specific objectives were to: (1) investigate the effect of laboratory aging on asphalt mixtures’ cracking resistance and asphalt binders’ rheological and chemical properties, (2) develop an aging …

Evaluation Of Undrained Shear Strength And Soil Classification From Cone Penetration Test, Md Imran Hossain

LSU Master's Theses

The in-situ cone and piezocone penetration tests (CPT, PCPT) has been widely used by the geotechnical engineering community for subsurface soil characterization and classification, and for the evaluation of many engineering soil properties, such as undrained shear strength (s_u), unit weight (γ), constrained modulus (M), coefficient of consolidation (c_v), and stress history (OCR). The objective of this research study was to estimate the undrained shear strength of clayey soil using CPT/PCPT data in addition to some soil boring log data. At the same time, soil classification charts/methods based …

Introducing A New Cement Hydration And Microstructure Model, Niall Holmes, Anselm Griffin, Bernard Enright, Denis Keliher

Conference papers

This paper presents a new cement hydration model to predict the microstructure evolution of hydrating tricalcium silicate (C3S). The model is written in MATLAB and employs the continuum approach and integrated particle kinetic relationships to show the change in C3S and the growth of Calcium Silicate Hydrate (C-S-H) and Calcium Hydroxide (CH) in the pore space over time.

Cement hydration is a highly complex process. While hydration models should never completely remove experimental analysis, they are an aid to better understand cement hydration and microstructure development by providing a method to analyse a large number of pastes with different cementitious …

Modeling And Simulation Of Damage In The Brazilian Indirect Tension Test Using The Finite-Discrete Element Method, Jeremiah C. Leyba

Civil Engineering ETDs

The Brazilian indirect tension test is used to investigate possible correlations between progressive damage and associated permeability changes. The test offers ease of replicability with a damage behavior known to lead to fracture openings as a tool for interpreting the indirect tensile strength of concrete and rocks. This behavior can lend insight into the nature of tensile damage and fracture progression in association with changes in permeability. The nature of these brittle materials is known to exhibit rapid failures in the Brazilian indirect tension test and require a method to retard the progression of damage for the possibility of acquiring …

Safety Ramifications Of A Change In Pedestrian Crosswalk Law: A Case Study Of Oregon, Usa, Yue Ke, Konstantina Gkritza

Lyles School of Civil Engineering Faculty Publications

Pedestrians are some of the most vulnerable road users as they are not protected by safety devices, and must also share the road with vehicles traveling at dangerous speeds, particularly during road crossings. In 2011, the state of Oregon changed their traffic laws to be more accommodating to pedestrians by giving right of way to pedestrians using a crosswalk, regardless if whether the crosswalk is marked or unmarked. This paper estimates a panel logit model to evaluate the efficacy of the law in preventing pedestrian fatalities. Pedestrian fatalities are shown to decrease over time, with smaller likelihood of a fatality …

Characterization Of Grain-Size Distribution, Thermal Conductivity, And Gas Diffusivity In Variably Saturated Binary Sand Mixtures, T.K.K. Chamindu Deepagoda, Kathleen Smits, J.R.R.N. Jayarathne, Benjamin M. Wallen, Timothy J. Clough

Civil Engineering Faculty Publications - Archive

Characterization of differently textured porous materials, as well as different volumetric porous media mixtures, in relation to mass and heat transport is vital for many engineering and research applications. Functional relations describing physical (e.g., grain-size distribution, total porosity), thermal, and gas diffusion properties of porous media and mixtures are necessary to optimize the design of porous systems that involve heat and gas transport processes. However, only a limited number of studies provide characterization of soil physical, thermal, and gas diffusion properties and the functional relationships of these properties under varying soil water contents, especially for soil mixtures, complicating optimization efforts. …

Development Of Self-Healing Mechanisms For Asphalt Pavements, Max Abelardo Aguirre Deras

LSU Doctoral Dissertations

Self-healing mechanisms, such as microcapsules or hollow-fibers, filled with an asphalt rejuvenator present an emerging technology that would enhance an asphalt mixture’s resistance to cracking damage caused by vehicular and environmental loading. The objectives of this study were to: (a) Evaluate the effects of asphalt rejuvenators on hot-mix asphalt mixtures in order to test its effects on the fundamental engineering properties of the mixtures at high and intermediate temperatures; (b) Develop a synthesis procedure for production of microcapsules and hollow-fibers containing an asphalt rejuvenator; (c) Evaluate the self-healing efficiency of double-walled microcapsules and hollow-fibers filled with an asphalt rejuvenator, through …

Evaluation Of Site Variability And Its Application In Design, Abu Hakim Muhammad Hasan Faisal

LSU Master's Theses

Geotechnical characterization has an important role in engineering geology as well as in implementation of any project. There are several variables and uncertainties involved in characterizing a project site. Four different sources of uncertainties represent the characterization of geotechnical variability, which include spatial variability, measurement error, statistical error and model bias. Spatial variability is expressed in terms of the mean, variance, and scale of fluctuation. Several statistical techniques such as the Gauge R & R, which includes X-Bar/R and ANOVA, and the Second Moment can be applied to compute site variability in terms of the coefficient of variations. Measurement error …