Architectural Engineering Commons^™

Use Of Fiber-Reinforced Cements In Masonry Construction And Structural Rehabilitation, Ece Erdogmus

Durham School of Architectural Engineering and Construction: Faculty Publications

The use of fiber reinforcement in traditional concrete mixes has been extensively studied and has been slowly finding its regular use in practice. In contrast, opportunities for the use of fibers in masonry applications and structural rehabilitation projects (masonry and concrete structures) have not been as deeply investigated, where the base matrix may be a weaker cementitious mixture. This paper will summarize the findings of the author’s research over the past 10 years in these particular applications of fiber reinforced cements (FRC). For masonry, considering both mortar and mortar-unit bond characteristics, a 0.5% volume fraction of micro fibers in type …

Performance Analysis And Modelling Of Hybrid Photovoltaic-Thermal Solar Panels, Nicole C. Annis

Doctoral Dissertations

A photovoltaic-thermal (PVT) panel was constructed, tested, and modelled using both MATLAB and TRNSYS. During the experimental testing, which took place on the Missouri University of Science and Technology campus in Rolla, Missouri; two identical PVT panels were tested alongside two PV panels to gather an electrical baseline for comparison. Approximately 69 days’ worth of data were of data were collected during the summer of 2014. The PV electrical, PVT electrical, PVT thermal and PVT combined (electrical and thermal) efficiencies were 3.5-5.6%, 3.4-5.4%, 20.9-11.6%, and 24.3-17.0%, respectively.

A MATLAB program was developed using existing equations for one-dimensional, quasi-steady model of …

A Revisit Of The Equilibrium Assumption For Predicting Near-Wall Turbulence, Farid Karimpour, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, we revisit the consequence of assuming equilibrium between the rates of production (P) and dissipation (∈) of the turbulent kinetic energy (k) in the highly anisotropic and inhomogeneous near-wall region. Analytical and dimensional arguments are made to determine the relevant scales inherent in the turbulent viscosity (νt) formulation of the standard k-∈ model, which is one of the most widely used turbulence closure schemes. This turbulent viscosity formulation is developed by assuming equilibrium and use of the turbulent kinetic energy (k) to infer the relevant velocity scale. We show that such turbulent viscosity formulations are not suitable …

Thickening: A 21st Century Approach For Resilience In Infrastructure, Marco Antonio Ravini

Architecture Thesis Prep

Infrastructure should be designed for higher RESILIENCE, not permanence. Rather than over-engineer to resist the inevitable failure of individual components, the next generation of public infrastructure needs to exceed its technical specifications and seek opportunistic hybridity between systems. In doing so, new possibilities for multi-layered use/outputs emerge which contribute to a more productive and resilient infrastructural lifespan.

Phytoscreening: A Comparison Of In Planta Portable Gc-Ms And In Vitro Analyses, Matt A. Limmer, Gregory D. Martin, Christopher J. Watson, Camilo Martinez, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Phytoscreening Has Been Proven to Rapidly Delineate Subsurface Contaminant Plumes for Semiquantitative Site Assessment, with Minimal Impact to Property or Ecology through the Collection and Analysis of Tree Cores. Here, Three Phytoscreening Methods Were Applied Concurrently to Identify Multiple Chlorinated Volatile Organic Compounds (CVOCs) in a Phytoremediation Treatment System at a Contaminated Industrial Facility. Tree Coring, in Planta Gas Chromatography-Mass Spectrometry (GC-MS), and in Planta Passive Sampling Showed General Agreement, with the in Planta GC-MS Providing the Quickest But Least Quantitative Results. the Portable GC-MS Sampling and Analysis Method Identified Six CVOCs in the Xylem of Hybrid Poplars (Populus Sp.) …

Laminar And Turbulent Regime Changes In Drinking Water Contact Tanks, Taylor C. Barnett, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Transitions in flow regimes that can occur in drinking water contact tanks may significantly affect the disinfection efficiency of the system. To demonstrate these effects, the authors investigated the internal velocity fields and flow regime of a drinking water contact tank located in Jamestown, Colo. The baffling factor (BF) of the system fluctuated annually between 0.5 and 0.6 because of a shift in flow regime caused by changes in the flow rate of the system. The authors studied the effects of the regime change from laminar to turbulent flow (or vice versa) using computational fluid dynamics (CFD) models and physical …

Factors Affecting The Seismic Behavior Of Segmental Precast Bridge Columns, Haitham Dawood, Mohamed Elgawady, Joshua Hewes

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This manuscript discusses the design parameters that potentially affect the lateral seismic response of segmental precast post-tensioned bridge piers. The piers consist of precast circular cross section segments stacked one on top of the other with concentric tendons passing through ducts made in the segments during casting. The bottommost segments of the piers were encased in steel tubes to enhance ductility and minimize damage. An FE model was used to investigate different design parameters and how they influence the lateral force — displacement response of the piers. Design parameters investigated included the initial post-tensioning stress as a percentage of the …

Designing Acoustics For Linguistically Diverse Classrooms: Effects Of Background Noise, Reverberation And Talker Foreign Accent On Speech Comprehension By Native And Non-Native English-Speaking Listeners, Z. Ellen Peng

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

The current classroom acoustics standard (ANSI S12.60-2010) recommends core learning spaces not to exceed background noise level (BNL) of 35 dBA and reverberation time (RT) of 0.6 second, based on speech intelligibility performance mainly by the native English-speaking population. Existing literature has not correlated these recommended values well with student learning outcomes. With a growing population of non-native English speakers in American classrooms, the special needs for perceiving degraded speech among non-native listeners, either due to realistic room acoustics or talker foreign accent, have not been addressed in the current standard. This research seeks to investigate the effects of BNL …

Determining Thresholds Of Annoyance To Tones In Noise, Jennifer Marie Francis

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

Building services equipment often produce noise with prominent tones that can lead to complaints from occupants in the built environment. Previous studies have investigated human perception to tones in noise but it is still unclear at what threshold of prominence these tones lead to human annoyance. The goal of this research is to apply two different methods towards defining thresholds of annoyance to two tonal frequencies: 125 Hz and 500 Hz. In Method I – Direct Assessment with Task, subjects are exposed to 10 minutes of broadband noise with a tonal frequency set at a certain level of prominence while …

Impacts Of Climate Change On Urban Development In The Uae: The Case Of Dubai, Zainab Alrustamani Alrustamani

Theses

This thesis investigates the global calls to prepare for climate change impacts, and the role of cities to respond to it under their sustainable living approaches. It explores how the subject of climate change is integrated in the urban development process, highlighting the role of cities as contributors to the phenomenon and part of the solution. The response to climate change impacts was explored in the UAE and the emirate of Dubai. The main objective of this research is to highlight the future vision in action against climate change in the urban development framework of the emirate of Dubai, and …

Finite Element Modelling And Dilation Of Frp-Confined Concrete Columns, Osama Youssf, Mohamed Elgawady, Julie E. Mills, Xing Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Concrete dilation is one of the main parameters that controls the stress-strain behavior of confined concrete. Several analytical studies have been carried out to predict the stress-strain behavior of concrete encased in fiber-reinforced polymer (FRP), which is crucial for structural design. However, none of these studies have provided a simple formula to determine the dilation parameter that is always required in the finite element (FE) material modelling of concrete. This paper presents a simple empirical model predicting the confined concrete dilation parameter within the theoretical framework of a Karagozian and Case type concrete plasticity model. A set of 105 FRP-confined …

Assessment Of Noise-Induced Annoyance By Tones In Noise From Building Mechanical Systems, Joonhee Lee, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Prominent tones in noise generated by mechanical equipment in buildings can cause complaints from occupants in buildings. The ISO 1996-2 and ANSI S1.13 standards describe methodologies and metrics to quantify tonality perception, but the influence of tones in noise on human annoyance and performance is not fully understood yet. This paper investigates annoyance responses of humans while exposed to background noise with tonal components. Twenty participants completed digit span tasks while exposed to noise signals with differing levels of tones and overall loudness. Subjects were also asked to rate their annoyance after completing tasks under each noise signal. The subjective …

The Impact Of Building Acoustics On Speech Comprehension And Student Achievement, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

The movement for improved classroom acoustics has primarily been grounded on studies that show how building acoustics (i.e. background noise levels and room reverberation) affect speech intelligibility, as determined by speech recognition tests. What about actual student learning, though? If students do not understand each spoken word in the classroom perfectly, can they still manage to achieve high scholastic success? This presentation will review two recent studies conducted at the University of Nebraska – Lincoln, linking classroom acoustic conditions to student learning outcomes and speech comprehension (rather than simply recognition). In the first, acoustic measurements in two public school districts …

Effects Of Room Acoustics On Comprehension Of Foreign-Accented Speech By Native And Non-Native English-Speaking Listeners, Zhao Peng, Kristin E. Hanna, Brenna N. Boyd, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

In a previous study by the authors, reverberation time (RT) and background noise level (BNL) were both found to have negative effects on native and non-native English-speaking listeners in comprehending English speech produced by native American-English-speaking talkers. Comprehension scores were adjusted for listeners’ baseline English proficiency levels. In the present study, instead of native English-speaking talkers, two native Mandarin Chinese talkers (one male, one female) with similar English spoken proficiency were recruited to produce the same speech materials used in the previous study. A similar methodology was adopted to conduct speech comprehension tests on three groups of listeners: 1) native …

Ua66 Ogden College Of Science & Engineering Newsletter, Cheryl Stevens, Dean

Ogden College of Science & Engineering Publications

No abstract provided.

The Bridge Newsletter Winter 2014, Missouri University Of Science And Technology

The Bridge Newsletter

-Smart living
-Bodapati earns lifetime award
-TMS honors Myers
-Mays receives award for research

Designing And Constructing For A Sustainable Future: Community Urban Housing In Timber: Projects By 4th. Year Architecture Students At Dit, Jim Roche

Conference papers

There is some agreement and much debate among interested parties about what constitutes ‘sustainable housing’. The term ‘sustainable’ is used somewhat liberally to mean different things to different listeners. Governments, institutions, interest groups and individual designers often address certain aspects while ignoring the bigger picture. But the bigger picture is such a multivalent issue that includes aspects outside the architect’s immediate remit such as location, transport, security, procurement policy and post-occupancy analysis and management. Or are these outside the architect’s remit?

Teaching sustainable housing within conventional architecture programmes means educators are restricted to identifying certain key issues that students should …

Phytomonitoring Of Chlorinated Ethenes In Trees: A Four-Year Study Of Seasonal Chemodynamics In Planta, Matt A. Limmer, Amanda J. Holmes, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Long-Term Monitoring (LTM) of Groundwater Remedial Projects is Costly and Time-Consuming, Particularly When using Phytoremediation, a Long-Term Remedial Approach. the Use of Trees as Sensors of Groundwater Contamination (I.e., Phytoscreening) Has Been Widely Described, Although the Use of Trees to Provide Long-Term Monitoring of Such Plumes (Phytomonitoring) Has Been More Limited Due to Unexplained Variability of Contaminant Concentrations in Trees. to Assess This Variability, We Developed an in Planta Sampling Method to Obtain High-Frequency Measurements of Chlorinated Ethenes in Oak (Quercus Rubra) and Baldcypress (Taxodium Distichum) Trees Growing above a Contaminated Plume during a 4-Year Trial. the Data Set Revealed …

Effect Of Placement Characteristics On Scc Lateral Pressure Variations, A. F. Omran, Y. M. Elaguab, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Lateral pressure exerted by fresh concrete on vertical formwork systems controls significantly the design of the formwork systems. Several factors including, material properties, placement conditions, and formwork characteristics can affect formwork lateral pressure. This paper presents the results of an extensive experimental work aimed at studying the influence of concrete temperature (10-32 °C), casting depth (up to 13 m), placement rate (2-30 m/h), waiting period between successive lifts, as well as concrete thixotropy on lateral pressure characteristics. The increase of concrete temperature is shown to accelerate the stiffening rate of the concrete leading to reduction in initial lateral pressure. For …

Evaluating Existing And Proposing New Seismic Design Provisions For Rigid Wall - Flexible Diaphragm Buildings, John Lawson, Dominic Kelly, Maria Koliou, Andre Filiatrault

Architectural Engineering

Buildings with heavy concrete on masonry walls supported by flexible wood or steel deck roof diaphragms are ubiquitour across the United States and the rest of North America. The current seismic design approach is based on the equivalent lateral force (ELF) method whose underlying assumptions significantly differ from the actual dynamic response of these buildings. The seismic behavior of rigid wall-flexible rood diaphragm (RWFD) Buildings is dominated by the diaphragm's response instead of the wall' in-plane response. Furthermore, the diaphragm's ductility and overstrength capacity is unique to its own construction. Yet the current design methodology employed by practitioners directly ties …