Architectural Engineering Commons^™

Comparison Of Prestress Losses For Pedestrian Bridges Constructed With High-Strength Concrete And High-Strength Self-Consolidating Concrete, John J. Myers, Kurt E. Bloch

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Abstract Two precast prestressed high-strength concrete and high-strength self-consolidating concrete pedestrian bridges were designed and erected in Rolla, Missouri, for an in situ investigative study to monitor time-dependent losses. Using the temperature and strain data monitored by the vibrating wire strain gauges within the beam cross sections, time-dependent losses were determined and compared between the bridges and various empirical expressions presented by AASHTO and the Precast/Prestressed Concrete Institute. © 2013 American Society of Civil Engineers.

Distribution And Accumulation Of Trichloroethylene And Trichloroacetic Acid In Hybrid Poplars, Lucas Odom, Joel Gerard Burken, Lee Newman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Hybrid Poplar Trees Are Known to Take Up Trichloroethylene (TCE) into above Ground Tissues, Where It Degrades into the Metabolites Trichloroacetic Acid (TCAA), Dichloroacetic Acid, and Trichloroethanol and Where Parent Chlorinated Solvents Volatilize to the Atmosphere. based on This Knowledge, Numerous Phytoremediation Applications Have Been Implemented for TCE and Other Chlorinated Solvents. Sampling of Plant Tissues Has Proven Effective for Phytoforensic and Phytoscreening Applications in Assessing Sites and Evaluating the Efficacy of Phytoremediation. However, Little is Known About the Appropriate Exposure Times and Sampling Locations Required to Obtain an Accurate Assessment of TCE and Metabolites. in This Study, Hybrid Poplars …

Numerical Simulation Of Vortex-Induced Vibration Of Two Circular Cylinders Of Different Diameters At Low Reynolds Number, Ming Zhao, Guirong Yan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Two-Degree-Of-Freedom Vortex-Induced Vibration (VIV) of Two Rigidly Coupled Circular Cylinders of Different Diameters at a Low Reynolds Number of 250 is Investigated Numerically. While the Diameter Ratio and the Mass Ratio Are Kept Constant, the Study is Focused on the Effect of the Position Angle of the Small Cylinder on the Lock-In Regime of the VIV. Simulations Are Carried Out for Position Angles Α of the Small Cylinder Ranging from 0° to 180° with an Interval of 22.5° and the Reduced Velocities Ranging from 1 to 15 with an Increment of 1. in Order to Find the Effect of the …

Directional Phytoscreening: Contaminant Gradients In Trees For Plume Delineation, Matt A. Limmer, Mikhil K. Shetty, Samantha Markus, Ryan Kroeker, Beth L. Parker, Camilo Martinez, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Tree Sampling Methods Have Been Used in Phytoscreening Applications to Delineate Contaminated Soil and Groundwater, Augmenting Traditional Investigative Methods that Are Time-Consuming, Resource-Intensive, Invasive, and Costly. in the Past Decade, Contaminant Concentrations in Tree Tissues Have Been Shown to Reflect the Extent and Intensity of Subsurface Contamination. This Paper Investigates a New Phytoscreening Tool: Directional Tree Coring, a Concept Originating from Field Data that Indicated Azimuthal Concentrations in Tree Trunks Reflected the Concentration Gradients in the Groundwater Around the Tree.To Experimentally Test This Hypothesis, Large Diameter Trees Were Subjected to Subsurface Contaminant Concentration Gradients in a Greenhouse Study. These Trees …

Dynamic Properties Of Fine-Grained Soils Engineered With A Controlled Organic Phase, B. Bate, H. Choo, S. E. Burns

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Soils with high organic content are frequently encountered beneath earthquake sensitive infrastructure, such as bridges or levees. Historically, the dynamic properties of these organically rich soils have been difficult to predict due to the heterogeneity of the natural organic matter that is found in natural soils, even though their response to dynamic loading remains critical to assessing the ongoing stability of the infrastructure. In this study, an experimental investigation was performed on a montmorillonite soil that was modified with a controlled organic phase. Quaternary ammonium cations were exchanged onto the soil particle surfaces through cation exchange with the clay's naturally …

How Kaizen Group Leader Selection Affects Group Participation, M. Joleen Byerline

Masters Theses & Specialist Projects

Organizational communication research indicates group member participation increases as the legitimate power differences among group members decreases. Lean principles and practices indicate Kaizen Event members will contribute regardless of legitimate power levels, due to member training, education, and the Lean team-oriented culture. Further study is needed to determine if Lean culture and training maximize group member contribution, or if legitimate power levels in Lean environments manipulate participation. The focus of this case study is a central Kentucky Lean manufacturing organization that practiced Lean principles for at least three years and completed a Kaizen Event within twelve months previous to the …

Relevance Of The Thorpe Length Scale In Stably Stratified Turbulence, Benjamin D. Mater, Simon M. Schaad, Subhas Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Direct numerical simulations of stably stratified turbulence are used to compare the Thorpe overturn length scale, LT, with other length scales of the flow that can be constructed from large-scale quantities fundamental to shear-free, stratified turbulence. Quantities considered are the turbulent kinetic energy, k, its dissipation rate, ε, and the buoyancy frequency, N. Fundamental length scales are then the Ozmidov length scale, LO, the isotropic large scale, Lkε, and a kinetic energy length scale, LkN. Behavior of all three fundamental scales, relative to LT, is shown to be a function of the buoyancy strength parameter NTL, where TL = k/ε …

Modified Time Of Setting Test For Fly Ash Paste And Fly Ash-Soil Mixtures, Xin Kang, Gi Chun Kang, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A survey of current literature has revealed that the testing protocol for determining the time of setting of fly ash-soil mixtures is not available. Although the current ASTM standard recommends using the Vicat needle method with a water-to-fly ash weight ratio of 0.35, it was originally proposed for testing the time of setting of cement. The current study showed that the Vicat needle method yielded poor test results for some common fly ashes. Moreover, the water-to-fly ash weight ratio of 0.35 may not be appropriate for some fly ashes because the chemical components are varied in different fly ashes. Therefore, …

Centrifuge Modeling And Mitigation Of Manhole Uplift Due To Liquefaction, Gi Chun Kang, Tetsuo Tobita, Susumu Iai, Louis Ge

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Because low-compacted trench backfill around a manhole is normally liquefiable, the manhole could suffer uplift damage associated with soil liquefaction during a strong earthquake. In this study, 22 dynamic centrifuge models were tested to investigate the response of a buried manhole subjected to a dynamic load. The models were tested under 20g, and a substitute pore fluid was used to avoid the scaling law conflict between the dynamic and diffusion processes. It was found that excess pore water pressure is one of the contributing factors to the magnitude of the manhole uplift. Using this result, new mitigation methods against the …

Portable Pressure Device To Evaluate Lateral Formwork Pressure Exerted By Fresh Concrete, Ahmed F. Omran, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Use of a reliable and accurate measuring system to determine lateral pressure exerted on formwork by self-consolidating concrete can lead to economic and safe formwork systems. In this paper, a portable and field-compatible pressure device is developed to enable factors affecting lateral pressure of fresh concrete on formwork system to be explored prior to conducting onsite full-scale tests. The pressure device requires a sample of 16 L of fresh concrete to determine lateral pressure envelope that can be exerted by a concrete column of up to 13 m in height. The pressure device enables the simulation of such concrete head …

Wind-Induced Torsion Vibration Of The Super High-Rise Building Of Shenzhen Energy Center, Feng Ruo-Qiang, Ye Jihong, Guirong Yan, Li Qing-Xiang, Yao Bin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Synchronous Multipoint Scanning System Technique in Wind Tunnel Tests and Random Vibration Theory Method Were Used to Analyze the Wind-Induced Torsion Vibration of Some Irregularly Shaped Super High-Rise Buildings in Downtowns. the Torsion Vibration Modes and the Spectra of Torsion Wind Load Were Studied, and the Proportions of Mean Wind Torsion, Inertia Torsion and the Mass Eccentricity Torsion Caused by Horizontal Inertia Forces Are Discussed. the Following Conclusions Can Be Drawn. First, the Third and Fourth Modes Have Torsion Vibration Shapes, and their Frequencies Are in the High-Energy Area of the Spectra of the Torsion Wind Load; the Third …

Teaching Archtecture, Engineering And Construction Disciplines: Using Various Pedagogical Styles To Unify The Learning Process, Jill Nelson, John W. Lawson

Architectural Engineering

The Architectural Engineering Department at the California Polytechnic State University, San Luis Obispo (Cal Poly) teaches introductory sophomore level statics and mechanics of materials courses to students in three departments in the College of Architecture and Environmental Design. These courses are unique in that students in the Architectural Engineering Department share coursework with students in the Architecture and Construction Management Departments. While learning and problem solving in these multidisciplinary courses have many advantages, they also offer many challenges. The learning preference of the students in these three distinctly different disciplines requires a fresh approach to the course structure. The courses …

A Structural Engineering Master's Program -- The Trials And Tribulations, Cole C. Mcdaniel, Allen Estes

Architectural Engineering

This paper is specifically intended for the advertised session in the CE Division on “current issues affecting graduate CE programs such as double dipping, accreditation of masters programs, combined MS/BS degree, research versus practice oriented masters degrees, etc.” California Polytechnic State University in San Luis Obispo (Cal Poly) is a predominately undergraduate university. Cal Poly has recently expanded master’s level graduate programs to support advanced education and faculty-student professional development opportunities. The Architectural Engineering Department in the College of Architecture and Environmental Design (CAED) started a structural engineering master’s degree program six years ago and has graduated five separate classes. …

Interdisciplinary Design - Forming And Evaluating Teams, Allen Estes, Brent Nuttall, Jill Nelson P.E., Margot Mcdonald, Gregory F. Starzyk Jd

Architectural Engineering

The College of Architecture and Environmental Design at California Polytechnic State University has offered an upper division, interdisciplinary experience for every student in the form of a project based, team oriented five unit studio laboratory. The course is now in its fifth year and requires small teams of architecture, engineering and construction students to complete the schematic level design of an actual building for a real client. The quality of the projects and student deliverables has been outstanding and students are clearly meeting the objective to prepare an integrated building design. The other course objective is to function as a …

Rating Low Levels Of Ambient Noise In Performing Arts Facilities, Lily M. Wang, Brent A. Kraay

Durham School of Architectural Engineering and Construction: Faculty Publications

Previous studies have indicated that common indoor noise rating metrics, such as Noise Criteria NC and Room Criteria RC, do not best correlate to human perceptions of annoyance and distraction in typical office environments. Based on investigations conducted at the University of Nebraska using noise levels between 30 – 60 dBA, the author has proposed that an effective indoor noise rating method should begin with a rating of level (either dBA or sones), then an assessment of spectral quality, tones, and fluctuations. How well would such a system work at very low levels of ambient noise, though, as found in …

Quantifying The Just Noticeable Difference Of Reverberation Time With Band-Limited Noise Centered Around 1000 Hz Using A Transformed Up-Down Adaptive Method, Matthew G. Blevins, Adam T. Buck, Zhao Peng, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

This study seeks to quantify the just noticeable difference (JND) of reverberation time (RT) using band-limited noise. ISO 3382-1 lists the JND of reverberation metrics at 5% based on work by Seraphim (1958). However, others have found the JND of RT to be higher from 6% to 39%. Many of these studies utilized band-limited stimuli, e.g. speech, music motifs and bandlimited noise. A previous study by the authors conducted on 30 subjects using white noise demonstrated a JND of RT at 22%. To further verify these results and investigate potential upward frequency masking, the present study was conducted following the …

Performance Of No Vibration / No Admixture Masonry Grout Containing High Replacement Of Portland Cement With Fly Ash And Ground Granulated Blast Furnace Slag, James P. Mwangi, Craig V. Baltimore Dr, Eric W. Bateman

Architectural Engineering

When hollow concrete masonry is used for construction in high seismic regions, structural designs typically require fully grouted walls. For a fully grouted 203x203x406 mm (8x8x16) concrete masonry unit (CMU), 52 percent of total volume is grout. Grouting process is labor-intensive, time consuming and has a high energy demand due to requirements of consolidation in each and subsequent grout lifts. Self-consolidating grout with admixtures has been successfully used without segregation in walls of up to 3.86 m (12.67 ft.) in height. Investigation of self-consolidating grout mixes without admixtures has potential for sustainability improvement. This paper reports on the compression strength …

Effects Of Background Noise Alternating Between Two Levels At Varying Time Intervals On Human Perception And Performance, Andrew Hathaway, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

This research experiment aims to better quantify human perception and performance under increased background noise levels of varying intervals. Twenty-seven participants were tested over five 30 minute sessions where they were subjected to RC-29(H) and RC-47(RV) conditions created by broadband noise fluctuating on different time intervals. These intervals varied from two minutes to ten minutes, simulating the conditions of a noisy HVAC system turning on and off. The performance results of an arithmetic test dealing with short-term memory and a subjective questionnaire will be presented and compared to a similar test using broadband noise bursts and correlated to noise metrics …

Effects Of Reverberation And Noise On Speech Comprehension By Native And Non-Native English-Speaking Listeners, Zhao Peng, Lily M. Wang, Siu Kit Lau, Adam M. Steinbach

Durham School of Architectural Engineering and Construction: Faculty Publications

Previous studies have demonstrated the negative impact of adverse signal-to-noise-ratios on non-native English-speaking listeners' performance on speech recognition using recall tasks, as well as implied that comprehension skills were more impaired than recognition skills under reverberation and noise. The authors have themselves previously conducted a pilot study on three native and three non-native Englishspeaking listeners to examine the effects of reverberation and noise using speech comprehension tasks. Those results suggested that speech comprehension performance is worse under longer reverberation times (RT), and that a longer RT is more detrimental to speech comprehension by non-native listeners than native listeners. This paper …

Seismic Performance Comparison Of A Fixed-Base Versus A Base-Isolated Office Building, Nicholas Reidar Marrs

Master's Theses

The topic of this thesis is base isolation. The purpose of this thesis is to offer a relative understanding of the seismic performance enhancements that a typical 12-story steel office building can achieve through the implementation of base isolation technology. To reach this understanding, the structures of a fixed-base office building and a base-isolated office building of similar size and layout are designed, their seismic performance is compared, and a cost-benefit analysis is completed. The base isolation system that is utilized is composed of Triple Friction Pendulum (TFP) bearings.

The work of this thesis is divided into four phases. First, …

Cal Poly Brocade Challenge 2013, Chandler Morehardt, Alexa Coburn, Juan Silva, Kerry Sun, Greg Wang, Raul Chagoya, Jd Torres

Architectural Engineering

No abstract provided.

Comparative Pedestrian Visibility Under Solid State Led Sources, Dana Younis

Theses

One of the important factors in striving towards sustainable urban living is the safety of pedestrians. This safety is influence by many factors, one of which is the ability of drivers to see pedestrians. During the night, pedestrian visibility becomes more difficult, especially on two-way streets, where headlamps of cars from the opposite direction cause glare to drivers. Newer types of headlamps are using LEDs and Xenon which are glarier than older halogen types.

This study is arranged in two parts. The first part of which examines the effect of oncoming car headlamps on pedestrian night time visibility. Detection distance …

Evaluating The Performance Of Urban Public Plazas In Al Ain Downtown In Relation To Physical Characteristics And Social Principles, Merai Ismail Al-Zoubi

Theses

The thesis studies the existing problems of AI Ain Downtown plazas mainly from the physical and social points of view. AI Ain downtown plazas are designed to provide a high level of social life. The main problem of these plazas is that they are used by only a particular social group. This study intends to develop a framework for evaluating and enhancing the urban public spaces in AI Ain city.

The framework is classified into two main dimensions; physical and social. Each dimension has a set of principles that affect the performance of the plaza. A descriptive analysis method is …

Architectural Engineering Earthquake Shake Table, Garrett Gudgel, John Whitmer, Brandan Williams

Mechanical Engineering

The Architectural Engineering Department at California Polytechnic State University, San Luis Obispo, owns and operates a single-axis earthquake shake table that previously was only capable of basic wave motion. After implementing a computer based interface to the existing system, Mechanical Engineering student seniors were able to create control algorithms that can take existing or user created acceleration data from earthquakes as well as any user defined position data to be accurately run on the earthquake shake table.

Long-Term Low Do Enriches And Shifts Nitrifier Community In Activated Sludge, Guoqiang Liu, Jianmin Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In the activated sludge process, reducing the operational dissolved oxygen (DO) concentration can improve oxygen transfer efficiency, thereby reducing energy use. The low DO, however, may result in incomplete nitrification. This research investigated the long-term effect of low DO on the nitrification performance of activated sludge. Results indicated that, for reactors with 10- and 40-day solids retention times (SRTs), complete nitrification was accomplished after a long-term operation with a DO of 0.37 and 0.16 mg/L, respectively. Under long-term low DO conditions, nitrite oxidizing bacteria (NOB) became a better oxygen competitor than ammonia oxidizing bacteria (AOB) and, as a result, no …

Collective Chord Behavior In Large Flexible Diaphragms, J. W. Lawson, C. N. Yarber

Architectural Engineering

The seismic behavior of large low-rise buildings with rigid walls and flexible diaphragms will be dominated more by the diaphragm’s seismic response than by the very stiff vertical walls. For practitioners, estimating the stiffness of large flexible diaphragms is important for computing building setbacks from property lines and adjacent structures as well as evaluating structural integrity under seismic loads. In addition, researchers attempting to accurately model a building’s dynamic behavior need to assemble an accurate diaphragm stiffness prediction. The traditional diaphragm chord model consists of a single continuous line of axial resistance at the diaphragm boundaries; however, as this paper …

Pump Controller Design For Variable Primary Flow Configuration Systems, Yifan Shi

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Pump systems are utilized widely in Heating, Ventilation and Air-Conditioning (HVAC) systems. There are mainly three configuration types: (1) the constant primary-only flow configuration, (2) the constant primary/variable secondary flow configuration, and (3) the variable primary-only flow configuration. This thesis focuses on finding the optimal control strategy for it and programming a controller for easy in-field usage.

In this thesis, the pump brake horse power (BHP) of the three pump configurations is simulated and compared using varying control methods. The best pump efficiency staging and DP reset control methods are implemented into the pump controller. A one month field experiment …

Investigating The Effect Specific Credits Of The Leed Rating System Have On The Energy Performance Of An Existing Building, Richelle Fosu

Department of Computer Graphics Technology Degree Theses

Throughout this thesis the potential financial and energy usage impact an upgrade to green building standards would have on an antiquated building has been analyzed. The extent of the implementation of specific LEED rating system credits that relate directly or indirectly to the energy consumption of a building have been demonstrated, through the means of several simulations using Revit, eQuest, Ecotect and Vasari simulation tools. This thesis also attempted to provide a clear understanding and overview of the plausibility of the suggested upgrades to be made, with regards to financial investment required for such upgrades, by using simple payback calculations …

Vulnerability Of Progressive Collapse In Reinforced Concrete Flat-Plate Buildings, Jinrong Liu

College of Engineering: Graduate Celebration Programs

• Progressive collapse is the spread of initial local failure, causing partial or
  even total collapse of a building.
• Flat plate structure is widely used for office and residential buildings.
• There is a large inventory of older flat plate building without continuous slab bottom reinforcement through columns.
• Limited knowledge exists regarding the risk of disproportionate collapse in
  older flat-plates under sudden column removal during abnormal events.
• Reliable mechanical model is needed for structural evaluation.

Precast Concrete Insulated Wall Panel Corbels Without Thermal Bridging, Mohamed Elkady

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

The common practice in corbel design is to block out the insulation in order to provide a solid concrete area at the corbel location. This connection practice results in thermal bridging, which significantly reduces the energy performance of the panel. For example, the PCI Design Handbook indicates that the reduction in thermal resistance caused by a solid part with an area equal to 9% of the total panel surface area is as high as 42%. This paper presents a discussion of a new concept for corbel design of insulated wall panels with the thermal break totally preserved. Two different designs …