Architectural Engineering Commons^™

Ultrasonic Pulse Velocity Tests On Compacted Soil, David M. Weidinger, Louis Ge, Richard Wesley Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In This Paper, Results of a Series of Ultrasonic Pulse Velocity Tests on Compacted Soil Were Presented and Discussed. Ultrasonic Pulse Velocity Tests Provide Compression and Shear Wave Velocity Information that Can Be Used in Calculating Dynamic Elastic Moduli Such as Young's Modulus and Shear Modulus. from the Test Results, Calculated Poisson's Ratio Shows a Linear Relation with the Water Content in Compacted Soil, Which Leads to a Linear Trend in Both P and S Wave Velocity Against Water Content. Furthermore, Presenting Plots in Bulk Density Versus Wave Velocity Gives a Clearer Trend Than Dry Density Versus Wave Velocity. © …

Material Sustainability, Jessica Meadows, Natasha Morris

Architectural Engineering

This paper addresses the sustainability of the materials used to construct buildings today. Timber, concrete and steel are analyzed for carbon output, cost, and recyclable-ability.

Design And Performance Of Load Bearing Shear Walls Made From Composite Rice Straw Blocks, Kevin Robert Camann

Master's Theses

Although rice straw and other grains have been used in building since pre-history, in the past two decades, there has been a move to utilize this rapidly renewable, locally available, agricultural byproduct as part of the sustainable construction movement. Up to this point, this has been done by simply stacking up the full straw bales. Stak Block, invented by Oryzatech, Inc., is a modular, interlocking block made of a composite of rice straw and binding agent that serves as an evolution in straw construction. This study investigates the feasibility of using these Stak Blocks as a structural system. The report …

Structural Damage Localization With Tolerance To Large Time Synchronization Errors In Wsns, Guirong Yan, Shirley J. Dyke, Wei Song, Gregory Hackmann, Chenyang Lu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

With Recent Technological Advances in Smart Sensor Platforms, Structural Condition Monitoring Implementations based on Wireless Sensor Networks (WSNs) Have Received Considerable Attention. Modal Identification is an Integral Step in Many Structural Condition Monitoring Systems. However, Accurate Time Synchronization is Not Always Possible, Leading to Incorrect Identification of the Mode Shapes. Although Strict Time Synchronization of the Wireless Sensors Has Been Viewed as Crucial for the Identification of Mode Shapes, a New Perspective is Taken Herein. the Distortion in the Identified Mode Shapes is Characterized and Accommodated. Then the Resulting Mode Shapes Are Used with a Flexibility-Based Damage Detection Approach to …

Use Of In-Planta Solid Phase Sampling Devices To Delineate Voc Plumes, Joel Gerard Burken, Kendra Waltermire, Emily Sheehan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Plants Directly Interact with Surrounding Water, Air, and Soil, Collecting and Storing Chemicals and Elements from the Surrounding Environment. Two New and Innovative Sampling Methods in Which This Valuable Data Can Be Accessed to Replace as Well as Supplement Contaminated-Site Investigations Have Been Developed. When Determining the Extent of the Plume on a Contaminated Site, Groundwater Sampling May Be Limited Due to Time, Site Access, and Expense. by using New Techniques that Place Sampling Devices Inside the Trees on Site, We Can Sample Trees Naturally Occurring on a Contaminated Site or Those Planted in Phytoremediation or Redevelopment Efforts, Evaluate the …

Simulations Of Aquaculture Dissolved Waste Transport And Mixing In Near-Coastal Waters, S. K. Venayagamoorthy, O. B. Fringer, J. R. Koseff, R. L. Naylor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The present study focuses on understanding the transport and fate of dissolved waste from aquaculture pens in near-coastal environments using the hydrodynamic code SUNTANS, which employs unstructured grids to compute flows at very high resolution. We perform simulations of the dissolved waste field and study the effects of different flow conditions (tides and currents) on the evolution of the waste plume. The fish pen causes partial blockage of the flow, leading to the deceleration of the approaching flow and the formation of a downstream wake. Results of the concentration field for an oscillatory flow condition superimposed on a mean current …

Optimization Of Two-Way Post-Tensioned Concrete Floor Systems, Gaelyn B. Krauser

Master's Theses

This thesis investigates a parametric study of a flat plate floor system designed using post-tensioning. The load balanced by the post-tensioning, the slab depth, and the strength of concrete were varied to create the parametric study of a hotel/condominium grid layout. In order to perform the parametric study, research was conducted on the development of post-tensioning, methods of analysis for two-way slab design, and post-tensioning methods of analysis. Design was conducted by hand through a series of Excel spreadsheets and compared to results found using the computer analysis program, ADAPT-PT. The designs found in the parametric study were then used …

Model For Reinforced Concrete Members Under Torsion, Bending, And Shear. Ii: Model Application And Validation, Gary Greene, Abdeldjelil Belarbi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A model was recently proposed for predicting the load-deformation response of a reinforced concrete member under torsion combined with bending and shear to spalling or ultimate. This paper shows the application of the model to create interaction surfaces to predict the failure of a member subjected to different ratios of applied torsion, bending, and shear. the model was validated by comparing the predicted and experimental behavior of 28 members from three experimental studies available in the literature. the members were loaded under torsion combined with different ratios of bending, and shear. the torque-twist behavior, reinforcement stress, and concrete surface strain …

Model For Reinforced Concrete Members Under Torsion, Bending, And Shear. I: Theory, Gary Greene, Abdeldjelil Belarbi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A model has been developed that can predict the load-deformation response of a reinforced concrete (RC) member subjected to torsion combined with bending and shear to spalling or ultimate capacity. the model can also be used to create interaction surfaces to predict the failure of a member subjected to different ratios of applied torsion, bending, and shear. the model idealizes the sides of a reinforced concrete member as shear "wall panels." the applied loads are distributed to the wall panels as uniform normal stresses and uniform shear stresses. the shear stress due to an applied torsional moment and shear force …

Lignin And Lipid Impact On Sorption And Diffusion Of Trichloroethylene In Tree Branches For Determining Contaminant Fate During Plant Sampling And Phytoremediation, Gayathri Gopalakrishnan, Joel Gerard Burken, Charles J. Werth

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Plants Draw All They Need from their Surrounding Environment and in Doing So Also Draw Anthropogenic Contaminants from their Surroundings. Several Natural Processes (E.g., Active Transport, Diffusion, Sorption, and Degradation) Occur within Trees and Affect Chemical Concentrations in Tree Samples. This Study Elucidates Tree Contaminant Chemical Interactions on Equilibrium Sorption and Diffusion into Branch Tissue (I.e., Wood Core and Bark), Specifically the Impacts of Lipid and Lignin Content. Five Tree Species Were Selected to Span a Range of Lignin and Lipid Contents. Linear Isotherms Were Obtained for All Sampled Species over a Limited Concentration Range (2 Μg/ ML < C Gas < 12 Μg/mL), and Equilibrium Distribution Coefficients (Kd) Were Linearly Correlated to Lipid (R2 > 0.83) But …

Conference Review - 4th International Phytotechnologies Conference, Denver, Co, September 24-26, 2007, Jason C. White, Joel G. (Gerard) Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Land Conservation And Land Use In New England: Trends, Challenges & Opportunities, Amanda Loomis, Tom Devine, Andrea Small, Brittany Howard, Brett Richardson, Stephanie Dulac

Land Conservation

Sprawling development patterns accelerated across the New England landscape in the last three decades and consumed the region‘s forests, farms, and open spaces at an unprecedented rate. New England‘ers in all six states formed land trusts, supported statewide conservation organizations, and collaborated with state and federal partners to protect some of their most-prized recreation lands, wildlife habitats, and working lands. The current economic recession has slowed development pressures across the region and offers an opportunity to build on recent successes. The time is right to plan a coordinated New England conservation strategy that protects and links the region‘s natural assets. …

Why Is Fresh Self-Compacting Concrete Shear Thickening?, Dimitri Feys, Ronny Verhoeven, Geert De Schutter

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Rheological Properties of Fresh Concrete Are Mostly Described by Means of the Bingham Model. for Self-Compacting Concrete, the Bingham Model is Applicable in a Lot of Cases, But Some Authors Report that the Rheological Behavior is Non-Linear. the Apparent Viscosity Increases with Increasing Shear Rate and the SCC Shows Shear Thickening Behavior. Shear Thickening Becomes Important in Operations Occurring at High Shear Rates, Like Mixing and Pumping. in These Cases, Shear Thickening Should Not Be Forgotten in Order to Avoid Breaking of the Mixer, Pump or Pipes. This Paper Will Describe Two Possible Theories for Shear Thickening Behavior of …

Interview With Kirk Davis, Glumac International, 2009 (Audio), Kirk Davis

All Sustainability History Project Oral Histories

Interview of Kirk Davis by Jay Fielding at Glumac International, Portland, Oregon on May 22nd, 2009.

The interview index is available for download.

Integration Approach Of The Couette Inverse Problem Of Powder Type Self-Compacting Concrete In A Wide-Gap Concentric Cylinder Rheometer. Part Ii. Influence Of Mineral Additions And Chemical Admixtures On The Shear Thickening Flow Behaviour, G. Heirman, R. Hendrickx, L. Vandewalle, D. Van Gemert, D. (Dimitri) Feys, G. De Schutter, B. Desmet, J. Vantomme

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Influence of Mineral Additions and Chemical Admixtures on the Shear Thickening Flow Behavior of Powder Type Self-Compacting Concrete (SCC) is Studied by Means of a Wide-Gap Concentric Cylinder Rheometer. the Couette Inverse Problem is Treated by Means of the Integration Method in Order to Derive the Flow Curve Τ(Γ̇) from the Torque Measurements. According to the Experimental Results, the Shear Thickening Effect is Found to Be Strongly Influenced by the Addition of the Chemical Admixture (A Polycarboxylate Ether based Superplasticizer), Whereas Mineral Additions Were Found to Modify the Intensity of Shear Thickening. the Limestone, Quartzite and Fly Ash Addition …

Taproot™ Technology: Tree Coring For Fast, Noninvasive Plume Delineations, Joel Gerard Burken, Sallie Bailey, Matt Shurtliff, Jeff Mcdermott

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In Efforts to Evaluate the Use of Plants as a Forensic Tool for Delineating Contaminated Soil and Groundwater, a Laboratory Experiment and a Field Sampling Effort Were Undertaken. Site Assessments Are Often Costly and Inaccurate, Requiring Multiple Mobilizations to Hone in on Source Areas and Getting Accurate Estimates of Contaminant Extent and Distribution. as These Extensive Site Delineations Take Place, Valuable Time and Resources Are Lost. the Findings of This Study Show that Plants Can Be Used as a Tool to Evaluate a Variety of Subsurface Contaminants, Either in the Vadose Zone or in the Saturated Zone. in the First …

Risk Indexes For Draft Ccl3 Chemicals, J. Alan Roberson, Matthew Lueders, Craig Adams, Jeffrey S. Rosen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To supplement the processes used for developing the draft third Contaminant Candidate List (CCL3) and better inform decisions made by the US Environmental Protection Agency on future CCLs, the authors offer an evaluation tool for efficiently synthesizing, visualizing, and organizing data for effective comparisons among contaminants. Graphical presentations of health effects-occurrence indexes were developed for more than 300 chemical contaminants, including those on the draft CCL3. a risk indexes framework was then used to elucidate the extent of available data, the data quality, and the underlying uncertainties for occurrence and toxicity. Choosing the appropriate contaminant for regulation is a complex …

Predicting The Perforation Response Of Honeycomb Sandwich Panels Using Ballistic Limit Equations, William P. Schonberg, Frank Schäfer, Robin Putzar

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Man-made debris from previous spacecraft missions poses a serious threat to spacecraft that are launched to operate in Earth orbit because it can strike such spacecraft at extremely high velocities and consequently damage mission-critical systems. Most satellites are constructed with honeycomb sandwich panels as their primary structural elements. to be able to perform a risk analysis, it is important to know, in the event of such a meteoroid or orbital debris particle impact, whether or not the impacting particle or parts thereof will exit the rear of the sandwich panel. a recently developed set of ballistic limit equations for two …

Damage Characterization Of Beam-Column Joints Reinforced With Gfrp Under Reversed Cyclic Loading, Aly M. Said

Civil and Environmental Engineering and Construction Faculty Research

The use of fiber reinforced polymer (FRP) reinforcement in concrete structures has been on the rise due to its advantages over conventional steel reinforcement such as corrosion. Reinforcing steel corrosion has been the primary cause of deterioration of reinforced concrete (RC) structures, resulting in tremendous annual repair costs. One application of FRP reinforcement to be further explored is its use in RC frames. Nonetheless, due to FRP's inherently elastic behavior, FRP-reinforced (FRP-RC) members exhibit low ductility and energy dissipation as well as different damage mechanisms. Furthermore, current design standards for FRP-RC structures do not address seismic design in which the …

Liquefaction Behavior Of Mississippi River Silts, Ali M. Izadi, Ronaldo Luna, Richard Wesley Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Civil Infrastructure Built on Alluviums and Recent Deposits, Such as Dams, Contain Significant Amount of Silts. the Static and Dynamic Behavior of These Fine-Grained Soils Has Been Investigated Less Than the Clay-Like or Sand-Like Soils. Low Plasticity Silts (PI = 6) Obtained East of St. Louis in Illinois Are Known as Loess that Has Been Re-Deposited by Water in the Floodplains of the Mississippi River. These Silts Were Reconstituted in the Laboratory by Slurry at Water Content above the Liquid Limit and Then Consolidated to an Initial Effective Stress. the Initial Laboratory Characterization under Monotonic Loading Included a Series of …

Piles Under Earthquake Loads, Shamsher Prakash, Vijay K. Puri

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Piles are preferred type of foundation for supporting structures in seismic areas. their performance is affected by soil, pile and earthquake related parameters. in non-liquefying soils, the shear modulus may degrade, and material damping may increase with increasing strain/displacement. in liquefying soils, the lateral ground displacement may lead to increased lateral loads and moments on the pile leading to pile failure in bending. the loss of lateral support can also lead to buckling type failure. These issues for pile design in seismic areas are examined. © 2008 ASCE.

Fresh Self Compacting Concrete, A Shear Thickening Material, Dimitri Feys, Ronny Verhoeven, Geert De Schutter

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In Literature, the Rheological Properties of Concrete Have Been Investigated Thoroughly, resulting in a Simple Description, in Steady State, by Means of the Bingham Model. Self-Compacting Concrete Shows a Lower Yield Stress, Which in Some Cases is Very Close to Zero, or Can Even Appear to Be Negative When Extrapolating the Bingham Model. in the Latter Case, the Bingham Model is Not Valid and Other Solutions Must Be Found. in This Paper, the Non-Linearity - or Shear Thickening - in the Rheological Behavior of Fresh SCC is Described with the Modified Bingham Model, after the Elimination of Possible Measurement Artefacts. …

Predicting The Seismic Behavior Of The Dywidag Ductile Connector (Ddc) Precast Concrete System, Elizabeth Mary Kenyon

Master's Theses

Structural engineering is heavily dependent on the use of computers. When creating a building model using structural analysis software, it is required that the designer have an understanding of the system behavior and the modeling program capabilities.

Some engineers in the Southern California region are taking steps towards incorporating the Dywidag ductile connector (DDC) and super hybrid systems into building practice due to the advantages found in these systems’ construction methods and seismic performance.

As the DDC and super hybrid systems reach industry, the design engineer will need to model these systems using structural analysis programs. This report describes two …

Brunswick Me: De-Militarizing The Bnas, Anne Holland, Brett Richardson, Richard Barringer

Planning

Closure of the Brunswick Naval Air Station in 2011 will have profound economic impacts on the entire mid-coast Maine region of Maine, with an estimated loss of 6,500 jobs and $330 million annual income. Throughout the Base Realignment and Closure process, Brunswick, the region, and the State of Maine followed federal rules and developed the federally-funded Brunswick Local Redevelopment Authority (BLRA) to plan for reuse of the 3300 acre base. In its planning process, the BLRA adhered to a number of well thought-out Guiding Principles, including the use of extensive public participation and the consideration of “smart growth” principles and …

Effects Of Ionic Strength, Temperature, And Ph On Degradation Of Selected Antibiotics, Keith A. Loftin, Craig D. Adams, Michael T. Meyer, Rao Surampalli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Aqueous degradation rates, which include hydrolysis and epimerization, for chlorretracycline (CTC), oxytetracycline (OTC), tetracycline (TET), lincomycin (LNC), sulfachlorpyridazine (SCP), sulfadimethoxine (SDM), sulfathiazole (STZ), trimethoprim (TRM), and tylosin a (TYL) were studied as a function of ionic strength (0.0015, 0.050, or 0.084 mg/L as Na2HPO4), temperature (7, 22, and 35°C), and pH (2, 5, 7, 9, and 11). Multiple linear regression revealed that ionic strength did not significantly affect (α = 0.05) degradation rates for all compounds, but temperature and pH affected rates for CTC, OTC, and TET significand (α = 0.05). Degradation also was observed for TYL at pH 2 …

Review Of Design Guidelines For Frp Confinement Of Reinforced Concrete Columns Of Noncircular Cross Sections, Silvia Rocca, Nestore Galati, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Current international design guidelines provide predictive design equations for the strengthening of reinforced concrete (RC) columns of both circular and prismatic cross sections by means of fiber-reinforced polymer (FRP) confinement and subjected to pure axial loading. Extensive studies (experimental and analytical) have been conducted on columns with circular cross sections, and limited studies have been conducted on members with noncircular cross sections. in fact, the majority of available research work has been on small-scale, plain concrete specimens. in this review paper, four design guidelines are introduced, and a comparative study is presented. This study is based on the increment of …

Kinetics And Reaction Products Of Ozone And Surface-Bound Squalene, J. R. Wells, Glenn Morrison, Beverly K. Coleman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Because of the high occupant density in aircraft, the surface chemistry of ozone and squalene, an important component of skin oil, was evaluated. a reaction probability of 45±14) x 10 -5 was determined for the reaction of squalene (2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22- tetracosahexaene) with ozone (50 parts per billion (ppb)) on a glass plate surface using the Field and Laboratory Emission Cell (FLEC) Automation and Control System (FACS). to more clearly define part of squalene's indoor environment degradation mechanism, gas-phase and surface-bound products of the squalene+O3 reaction were also investigated. Emitted products were captured in solution, derivatized with O-(2,3,4,5,6pentafluorobenzyl) hydroxylamine (PFBHA), and analyzed …

Extension Of The Poiseuille Formula For Shear-Thickening Materials And Application To Self-Compacting Concrete, Dimitri Feys, Ronny Verhoeven, Geert De Schutter

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In Practice, While Placing Concrete in a Formwork by Pumping, the Pressure Generated by the Pump is Not Controlled. in Order to Enhance the Safety on the Worksite, and in View of the Current Economic and Ecologic Arguments, It Would Be Useful to Dispose of an Equation Able to Predict Pressure Losses based on the Rheological Properties of the Concrete and the Pipe Configuration. This Paper Describes the Derivation of an Extended Version of the Poiseuille Formula, for Shear-Thickening Materials with a Yields Stress, Described by the Modified Bingham Equation. This Formula is Applied to Flow-Tests with Self-Compacting Concrete. the …

Evaluation Of A Virtual Refrigerant Charge Sensor, Woohyun Kim, James E. Braun, Haorong Li

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper presents a thorough evaluation of a method for determining refrigerant charge that employs low-cost, non-invasive measurements (i.e., surface mounted temperature measurements). The method could be used as part of a protocol for verified service providers (VSPs) in AC diagnostic tune-up or refrigerant charge, air flow (RCA) verification programs. Ultimately, the method could be embedded within a portable virtual refrigerant charge gauge for a technician’s use or permanently installed on the AC unit. The accuracy of the virtual refrigerant charge sensor method is evaluated in this paper using laboratory data for a number of different systems and over a …

Sustainable Lunar Habitat Protection Against Damage By Meteoroid Impacts, William P. Schonberg, Robin Putzar, Frank Schaefer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Sustainability is a key consideration in the design and establishment of human habitats on the Moon (and on Mars as well). One hazard faced by such habitats is the damage that can be caused by the impact of a meteoroid on a critical habitat structure or structural component. in this paper we discuss various approaches to meteoroid shielding for lunar habitats, focusing on approaches that use resources mined or extracted from the moon. Advantages and disadvantages of these various techniques are also presented and discussed. the Moon's mineralogy is highlighted, and suggestions are presented for materials that can be used …