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Organic Electronics In Biosensing: A Promising Frontier For Medical And Environmental Applications, Jyoti Bala Kaushal, Pratima Raut, Sanjay Kumar Nov 2023

Organic Electronics In Biosensing: A Promising Frontier For Medical And Environmental Applications, Jyoti Bala Kaushal, Pratima Raut, Sanjay Kumar

Durham School of Architectural Engineering and Construction: Faculty Publications

The promising field of organic electronics has ushered in a new era of biosensing technology, thus offering a promising frontier for applications in both medical diagnostics and environmental monitoring. This review paper provides a comprehensive overview of organic electronics’ remarkable progress and potential in biosensing applications. It explores the multifaceted aspects of organic materials and devices, thereby highlighting their unique advantages, such as flexibility, biocompatibility, and low-cost fabrication. The paper delves into the diverse range of biosensors enabled by organic electronics, including electrochemical, optical, piezoelectric, and thermal sensors, thus showcasing their versatility in detecting biomolecules, pathogens, and environmental pollutants. Furthermore, …


Ten Questions Concerning Smart And Healthy Built Environments For Older Adults, Sanjay Kumar, Samuel H. Underwood, Julie L. Masters, Natalie A. Manley, Iason Konstantzos, Josephine Lau, Ryan Haller, Lily M. Wang Aug 2023

Ten Questions Concerning Smart And Healthy Built Environments For Older Adults, Sanjay Kumar, Samuel H. Underwood, Julie L. Masters, Natalie A. Manley, Iason Konstantzos, Josephine Lau, Ryan Haller, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

In the past decade, the term ‘global aging’ has gained much attention among researchers, policymakers, civil societies, and governments worldwide. The continuous decline in fertility rates and increased life expectancy have resulted in an ongoing demographic transition where the share of adults aged 65 or older is increasing and outnumbering children younger than five years. In the United States and other developed countries, this rapid demographic transition is expected to continue to strain the existing health infrastructure as it becomes increasingly challenging to ensure healthy living environments for older adults. The ten questions and answers in this paper have been …


Incentivizing Electric Vehicle Adoption Through State And Federal Policies: Reviewing Influential Policies, Joshua Sabata, Subhaditya Shom, Ahmad Almaghrebi, Anne Mccollister, Mahmoud Alahmad Jun 2023

Incentivizing Electric Vehicle Adoption Through State And Federal Policies: Reviewing Influential Policies, Joshua Sabata, Subhaditya Shom, Ahmad Almaghrebi, Anne Mccollister, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

All-electric vehicles (EVs), battery-powered EVs (BEVs), and plug-in hybrid EVs (PHEVS) are gaining market share and increasing in popularity with the buying public because the battery range (longer) and cost (lower) have reached sweet spots, the charging infrastructure is more robust, and concern with global cli­mate change is high. In 2013, only 100,000 EVs were sold in the United States, but by 2022, approximately 800,000 have been purchased. A similar growth is seen in EV sup­ply equipment (EVSE), i.e., EV charging stations, with 19,742 documented EV charging station locations in the United States in 2013 to 50,054 documented EV charging …


Out-Of-Plane Flexural Behavior Of Insulatedwall Panels Constructed With Large Insulation Thicknesses, Jacob Luebke, Fray F. Pozo-Lora, Salam Al-Rubaye, Marc Maguire May 2023

Out-Of-Plane Flexural Behavior Of Insulatedwall Panels Constructed With Large Insulation Thicknesses, Jacob Luebke, Fray F. Pozo-Lora, Salam Al-Rubaye, Marc Maguire

Durham School of Architectural Engineering and Construction: Faculty Publications

Insulated concrete sandwich wall panels (ICSWPs) are gaining popularity as energy regulations become stricter worldwide. ICSWPs are now being constructed with thinner wythes and thicker insulation to keep up with the changing market, which is reducing material costs and increasing thermal and structural efficiency. However, there is a need for adequate experimental testing to validate the current design methods for these new panels. This research aims to provide that validation by comparing the predictions of four different methods with experimental data obtained from six large-scale panels. The study found that while current design methods adequately predict the behavior of thin …


Simplified Engineering For Architects And Builders, 13th Edition, Sharon Kuska, Patrick Tripeny, James Ambrose May 2023

Simplified Engineering For Architects And Builders, 13th Edition, Sharon Kuska, Patrick Tripeny, James Ambrose

Durham School of Architectural Engineering and Construction: Faculty Publications

The twelfth edition of the Work was published by the Publisher under the agreement between the Publisher and Patrick Tripeny dated February 24, 2014 (the “Twelfth Edition”).

The Publisher and the Author wish to work together to achieve the professional standards and success that they each desire from the Work, and agree as follows:


Reconfigurable Metatiles With Circular Maze-Like Space-Coiling-Based Acoustic Metastructure For Low-To-Mid Frequency Sound Attenuation, Sanjay Kumar, Heow Pueh Lee Apr 2023

Reconfigurable Metatiles With Circular Maze-Like Space-Coiling-Based Acoustic Metastructure For Low-To-Mid Frequency Sound Attenuation, Sanjay Kumar, Heow Pueh Lee

Durham School of Architectural Engineering and Construction: Faculty Publications

This study presents a compact, lightweight, and reconfigurable acoustic metatile for sound mitigation applications. The metatile prototype is designed based on a circular maze-like acoustic metastructure, which utilizes a space-coiling technique for enhanced acoustic performance in low-to-mid frequencies. The proposed labyrinthine acoustic metadisk structure comprises a central hollow front face sheet and two coiling-up backing cavities. Experimental results show that the metadisk has high absorption peaks of 0.81 and 0.75 at 574 and 1436 Hz, respectively, and exhibits high sound transmission loss (STL) values (≥25 dB) in separate wide frequency bands between 100–580 Hz and 820–1600 Hz. Based on the …


Structural Testing Of Concrete Walls On-Edge With Combined Axial And Out-Of-Plane Loading, Salam Al-Rubaye, Marc Maguire Apr 2023

Structural Testing Of Concrete Walls On-Edge With Combined Axial And Out-Of-Plane Loading, Salam Al-Rubaye, Marc Maguire

Durham School of Architectural Engineering and Construction: Faculty Publications

Full-scale testing of structural components can be time consuming and difficult. The design of full- scale slender concrete walls is highly influenced and controlled by second-order and out-of-plane bending loads. Previous experiments on out-plane bending of slender walls and insulated walls have been performed with bending in the direction of gravity (with or against). Additionally, most of the research considering out-of-plane bending does not include an axial load and suffers from inaccurate results due to not simulating the actual loading and constraining conditions or safety issues. This testing method was developed expressly for the determination of slender wall behavior in …


Relationships Between Residence Characteristics And Nursing Home Compare Database Quality Measures, Brian J. Puckett, Erica E. Ryherd, Natalie Manley, Carey S. Ryan Apr 2023

Relationships Between Residence Characteristics And Nursing Home Compare Database Quality Measures, Brian J. Puckett, Erica E. Ryherd, Natalie Manley, Carey S. Ryan

Durham School of Architectural Engineering and Construction: Faculty Publications

Objective: This study evaluated relationships between physical characteristics of nursing home residences and quality-of-care measures.

Design: This was a cross-sectional ecologic study. The dependent variables were 5 Centers for Medicare & Medicaid Services (CMS) Nursing Home Compare database long-stay quality measures (QMs) during 2019: percentage of residents who displayed depressive symptoms, percentage of residents who were physically restrained, percentage of residents who experienced 1 or more falls resulting in injury, percentage of residents who received antipsychotic medication, and percentage of residents who received anti-anxiety medication. The independent variables were 4 residence characteristics: ownership type, size, occupancy, and region …


Analysis And Design Of Lateral Framing Systems For Multi-Story Steel Buildings, Husam Al Dughaishi, Jawad Al Lawati, Moad Alosta, Shaker Mahmood, Mohamed Faisal Al-Kazee, Nur Izzi Md Yusoff, Abdalrhman Milad Mar 2023

Analysis And Design Of Lateral Framing Systems For Multi-Story Steel Buildings, Husam Al Dughaishi, Jawad Al Lawati, Moad Alosta, Shaker Mahmood, Mohamed Faisal Al-Kazee, Nur Izzi Md Yusoff, Abdalrhman Milad

Durham School of Architectural Engineering and Construction: Faculty Publications

This study focused on identifying the most appropriate structural system for multi-story buildings and analyzing its response to lateral loads. The study analyzed and compared the different structural systems to determine the most suitable option. The study aims to utilize three lateral framing systems (moment, braced, and diagrid) in order to investigate which system needs the least amount of steel to meet the design requirements. Thus, in order to determine the estimated steel savings of this system as compared to the moment and braced frames, the four-story and eight-story buildings that are 96' × 96' in the plane and utilize …


A Framework To Predict Variability Characteristics In Building Load Profiles, Sam Moayedi, Andrew Parker, Kevin James, Xiaoyue Cheng, Michael Hempel, Hamid Sharif, Mahmoud A. Alahmad Jan 2023

A Framework To Predict Variability Characteristics In Building Load Profiles, Sam Moayedi, Andrew Parker, Kevin James, Xiaoyue Cheng, Michael Hempel, Hamid Sharif, Mahmoud A. Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

The expansion of Advanced Metering Infrastructure (AMI) has provided building operators and researchers detailed information on building energy consumption. The majority of AMI systems, however, record data at relatively low resolutions of 15, 30, or 60 minutes, due to cost, storage and bandwidth limitations. Emerging applications in power flow analysis, Quasi-Static Time-Series Simulation (QSTS), smart grid integration and load matching, however, require data at higher resolutions. Short-term energy demand can deviate significantly from long-term averages, with an unknown magnitude and frequency when only low-resolution load profile data is available. This paper presents a novel data-driven approach to predict characteristics of …


Integration Of Real-Time Semantic Building Map Updating With Adaptive Monte Carlo Localization (Amcl) For Robust Indoor Mobile Robot Localization, Matthew Peavy, Pileun Kim, Hafiz Oyediran, Kyungki Kim Jan 2023

Integration Of Real-Time Semantic Building Map Updating With Adaptive Monte Carlo Localization (Amcl) For Robust Indoor Mobile Robot Localization, Matthew Peavy, Pileun Kim, Hafiz Oyediran, Kyungki Kim

Durham School of Architectural Engineering and Construction: Faculty Publications

A robot can accurately localize itself and navigate in an indoor environment based on information about the operating environment, often called a world or a map. While typical maps describe structural layouts of buildings, the accuracy of localization is significantly affected by nonstructural building elements and common items, such as doors, appliances, and furniture. This study enhances the robustness and accuracy of indoor robot localization by dynamically updating the semantic building map with non-structural elements detected by sensors. We propose modified Adaptive Monte Carlo Localization (AMCL), integrating object recognition and map updating into the traditional probabilistic localization. With the proposed …


Applying Unsupervised Machine Learning Clustering Techniques To Early Childcare Soundscapes, Kenton Hummel, Erica E. Ryherd, Iason Konstantzos, Abbie Raikes Dec 2022

Applying Unsupervised Machine Learning Clustering Techniques To Early Childcare Soundscapes, Kenton Hummel, Erica E. Ryherd, Iason Konstantzos, Abbie Raikes

Durham School of Architectural Engineering and Construction: Faculty Publications

Early childhood is a critical time period for language, brain, cognitive, and social/emotional development. Out-of-home childcare is a normative, typical experience for millions of young children. Although Indoor Environmental Quality (IEQ) in K-12 settings has received recent, significant attention, the links between IEQ and children’s learning and development in early childcare settings is a less understood topic. This work focuses specifically on the sound aspect of IEQ in early childcare settings to better understand typical noise levels and occupant experience. Standard approaches to analyzing background noise will be presented alongside more detailed statistical analyses utilizing unsupervised machine learning clustering techniques. …


Foreign Object Debris Detection For Airport Pavement Images Based On Self-Supervised Localization And Vision Transformer, Travis Munyer, Daniel Brinkman, Xin Zhong, Chenyu Huang, Iason Konstantzos Oct 2022

Foreign Object Debris Detection For Airport Pavement Images Based On Self-Supervised Localization And Vision Transformer, Travis Munyer, Daniel Brinkman, Xin Zhong, Chenyu Huang, Iason Konstantzos

Durham School of Architectural Engineering and Construction: Faculty Publications

Supervised object detection methods provide subpar performance when applied to Foreign Object Debris (FOD) detection because FOD could be arbitrary objects according to the Federal Aviation Administration (FAA) specification. Current supervised object detection algorithms require datasets that contain annotated examples of every to-be-detected object. While a large and expensive dataset could be developed to include common FOD examples, it is infeasible to collect all possible FOD examples in the dataset representation because of the openended nature of FOD. Limitations of the dataset could cause FOD detection systems driven by those supervised algorithms to miss certain FOD, which can become dangerous …


Zero Net Energy Test House, Timothy Hemsath, James D. Goedert, Avery Don Schwer, Yong Cho Sep 2022

Zero Net Energy Test House, Timothy Hemsath, James D. Goedert, Avery Don Schwer, Yong Cho

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper describes the first phase of a residential research program to reduce the impact of new construction on the environment through research and education using a Zero Net Energy Test House as a framework. Containing four bedrooms, three and a half baths, the 1,800 square foot house, 1,000 square foot basement, is located in Omaha, Nebraska. It is being used to validate several research projects and provides a platform for applications research of a number of technological advances. Laminated photovoltaic solar panels, a wind turbine, and an occupant monitoring energy control system are some of the sustainable design innovations …


Intelligibility Of Medically Related Sentences In Quiet, Speech-Shaped Noise, And Hospital Noise, Tessa Bent, Melissa Baese-Berk, Erica E. Ryherd, Sidney Perry May 2022

Intelligibility Of Medically Related Sentences In Quiet, Speech-Shaped Noise, And Hospital Noise, Tessa Bent, Melissa Baese-Berk, Erica E. Ryherd, Sidney Perry

Durham School of Architectural Engineering and Construction: Faculty Publications

Noise in healthcare settings, such as hospitals, often exceeds levels recommended by health organizations. Although researchers and medical professionals have raised concerns about the effect of these noise levels on spoken communication, objective measures of behavioral intelligibility in hospital noise are lacking. Further, no studies of intelligibility in hospital noise used medically relevant terminology, which may differentially impact intelligibility compared to standard terminology in speech perception research and is essential for ensuring ecological validity. Here, intelligibility was measured using online testing for 69 young adult listeners in three listening conditions (i.e., quiet, speech-shaped noise, and hospital noise: 23 listeners per …


Neuromorphic Computing Using Electrostatic Mems Devices, Fadi Alsaleem Apr 2022

Neuromorphic Computing Using Electrostatic Mems Devices, Fadi Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

A continuous - time recurrent neural network ( CTRNN ) is described that exploits the nonlinear dynamics of micro electro - mechanical system ( MEMS ) devices to model a neuron in accordance with a neuron rate model that is the basis for dynamic field theory . Each MEMS device in the CTRNN is configured to simulate a neuron population by exploiting the characteristics of bi - stability and hysteresis inherent in certain MEMS device structures . In an embodiment , the MEMS device is a microbeam or cantilevered microbeam device that is excited with an alternating current ( AC …


Ahp Based Multi Criteria Decision Analysis Of Success Factors To Enhance Decision Making In Infrastructure Construction Projects, Solomon Belay, James D. Goedert, Asregedew Woldesenbet, Saeed Rokooei Feb 2022

Ahp Based Multi Criteria Decision Analysis Of Success Factors To Enhance Decision Making In Infrastructure Construction Projects, Solomon Belay, James D. Goedert, Asregedew Woldesenbet, Saeed Rokooei

Durham School of Architectural Engineering and Construction: Faculty Publications

The study presents analytical data-based multi-criteria approach of critical success factors of infrastructure construction projects analyzed in the Ethiopian construction industry. This multi-criteria technique helps to improve the decision capabilities and ultimate performance of construction processes in various low-income countries of the East African region. The aim of this paper is to establish a logical relationship and interdependencies of success-related factors for enhancing decision making for various project teams and identify priorities while taking into account all known construction organizational constraints. A structured hierarchical matrix was developed based on a pre-identified success-related factors, and initially evaluated by experienced professionals as …


Tilt-Up Partially Composite Insulated Wall Panels, Marc Maguire, Salam Al-Rubaye Jan 2022

Tilt-Up Partially Composite Insulated Wall Panels, Marc Maguire, Salam Al-Rubaye

Durham School of Architectural Engineering and Construction: Faculty Publications

This research project was initiated to investigate the behavior of load-bearing concrete insulated wall panels for use in tilt-up construction. The primary objective was to understand the inelastic behavior of these panels so that engineers could perform a proper second-order analysis for combined axial and out-of-plane loading. Toward this aim, the Tilt-up Concrete Institute (TCA) and wythe connector suppliers Innstruct, Thermomass, HK Composites, Dayton Superior, and IconX, funded this study.

This report contains information related to testing of solid and partially composite insulated wall panels that integrated proprietary wythe connection systems. Using the information from these tests, a method to …


Higher Sound Levels In K-12 Classrooms Correlate To Lower Math Achievement Scores, Laura Caroline Brill, Lily M. Wang Nov 2021

Higher Sound Levels In K-12 Classrooms Correlate To Lower Math Achievement Scores, Laura Caroline Brill, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Sound levels from occupied classrooms have been gathered from 220 classrooms across four grade levels (3, 5, 8 and 11) over six school days each and processed with k-means clustering into speech and non-speech clusters. Three metrics describing the classroom acoustics, including the average daily A-weighted equivalent level for non-speech, the average daily difference between the A-weighted equivalent levels for speech and nonspeech (a signal to noise ratio), and the mid-frequency averaged reverberation time, were analyzed against classroom-aggregated standardized reading and math achievement test scores, while controlling for classroom demographics including socioeconomic status. Interactions between the metrics and demographics were …


The Effects Of The Visual Environment On K-12 Student Achievement, Michael Kuhlenengel, Iason Konstantzos, Clarence E. Waters Oct 2021

The Effects Of The Visual Environment On K-12 Student Achievement, Michael Kuhlenengel, Iason Konstantzos, Clarence E. Waters

Durham School of Architectural Engineering and Construction: Faculty Publications

The varying indoor environments among educational buildings can have an impact on students’ ability to learn. This study looks at field data from 220 classrooms in the Midwest, United States, over a two-year period, to analyze the effects of the visual environment on student achievement. The visual environmental metrics considered within this scope include the three new view metrics introduced within the EN 17037 “Daylight of Buildings” standard (Horizontal Sight Angle, Outside Distance of View, and Number of View Layers), as well as standard daylight and electric lighting metrics, focusing on light availability and glare. To capture student achievement, math …


Simulation For A Mems-Based Ctrnn Ultra-Low Power Implementation Of Human Activity Recognition, Muhammad Emad-Ud-Din, Mohammad H. Hasan, Roozbeh Jafari, Siavash Pourkamali, Fadi M. Alsaleem Sep 2021

Simulation For A Mems-Based Ctrnn Ultra-Low Power Implementation Of Human Activity Recognition, Muhammad Emad-Ud-Din, Mohammad H. Hasan, Roozbeh Jafari, Siavash Pourkamali, Fadi M. Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper presents an energy-efficient classification framework that performs human activity recognition (HAR). Typically, HAR classification tasks require a computational platform that includes a processor and memory along with sensors and their interfaces, all of which consume significant power. The presented framework employs microelectromechanical systems (MEMS) based Continuous Time Recurrent Neural Network (CTRNN) to performHAR tasks very efficiently. In a real physical implementation, we show that the MEMS-CTRNN nodes can perform computing while consuming power on a nano-watts scale compared to the micro-watts state-of-the-art hardware. We also confirm that this huge power reduction doesn’t come at the expense of reduced …


Arise (Certcoin)- Inspiring Demand For Sustainable Energy Skills, Barry Mcauley, Paul Mccormack, Andrew Hamilton, Eduardo Rebelo Sep 2021

Arise (Certcoin)- Inspiring Demand For Sustainable Energy Skills, Barry Mcauley, Paul Mccormack, Andrew Hamilton, Eduardo Rebelo

Conference papers

The European AEC Sector now faces impending challenges over the next decade concerning escalating climate targets. To reach these targets, it vital that the green economy deliver a better-skilled workforce and develops new competencies and methods of working. Training in the domain of digital construction technologies and processes, such as Building Information Modelling (BIM), are now seen as essential upskilling vehicles that must be embraced if the sector is to transition towards a greener agenda. To assist in meeting these training needs a selection of partners from the BIM EPA will partake in the Horizon 2020 ARISE project, aiming to …


Framework To Develop Time- And Voltage-Dependent Building Load Profiles Using Polynomial Load Models, Andrew Parker, Mhd Anas Alkrch, Kevin James, Ahmad Almaghrebi, Mahmoud Alahmad Sep 2021

Framework To Develop Time- And Voltage-Dependent Building Load Profiles Using Polynomial Load Models, Andrew Parker, Mhd Anas Alkrch, Kevin James, Ahmad Almaghrebi, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

The power consumption of buildings over the course of each minute, hour, day and season plays a major role in how this load influences the Electric Power System voltage and frequency, and vice versa. This consumption is based on the building's load component types, efficiencies, and how they consume power and react to changes in real time. Due to this complexity, standard full-building load models are typically voltage-invariant. This paper proposes a novel framework to transform these voltage-invariant building load models into fully time- and voltage-dependent load profiles using available data on the voltage sensitivity of individual load components. While …


A Case Study To Quantify Variability In Building Load Profiles, Andrew Parker, Sam Moayedi, Kevin James, Dongming Peng, Mahmoud Alahmad Sep 2021

A Case Study To Quantify Variability In Building Load Profiles, Andrew Parker, Sam Moayedi, Kevin James, Dongming Peng, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

Recent technology development and penetration of advanced metering infrastructure (AMI), advanced building control systems, and the internet-of-things (IoT) in the built environment are providing detailed information on building operation, performance, and user's comfort and behavior. Building owners can obtain a wide range of energy consumption details at various levels of time granularity to augment their decisions as they manage the building operation and interact with the grid. AMI data are providing a new level of detail and visibility that may enhance building services and assets in the smart grid domain and make buildings inch closer to becoming a grid-interactive energy …


Digital Construction And Bim Research In Ireland 2016-2020, Barry Mcauley, Roger P. West, Alan V. Hore Aug 2021

Digital Construction And Bim Research In Ireland 2016-2020, Barry Mcauley, Roger P. West, Alan V. Hore

Conference papers

As the construction industry opens up post pandemic, new and significant challenges will demand considerable expertise, not least in financial viability, solving the housing crisis and facing the very significant climate change pressures to make the industry less wasteful and less carbon intensive. This presents an excellent opportunity to further inculcate aspects of lean construction, particularly BIM into many aspects of construction not traditionally associated with digital construction, provided the necessary expertise is available and known to exist. Following a well-received recent conference paper summarising BIM-related research published by academics in Ireland’s higher education institutions in 2020, this paper will …


Evaluating Prediction Models Of Creep And Drying Shrinkage Of Self-Consolidating Concrete Containing Supplementary Cementitious Materials/Fillers, Micheal Asaad, George Morcous Aug 2021

Evaluating Prediction Models Of Creep And Drying Shrinkage Of Self-Consolidating Concrete Containing Supplementary Cementitious Materials/Fillers, Micheal Asaad, George Morcous

Durham School of Architectural Engineering and Construction: Faculty Publications

Supplementary cementitious materials (SCMs) and fillers play an important role in enhancing the mechanical properties and durability of concrete. SCMs and fillers are commonly used in self-consolidating concrete (SCC) mixtures to also enhance their rheological properties. However, these additives could have significant effects on the viscoelastic properties of concrete. Existing models for predicting creep and drying shrinkage of concrete do not consider the effect of SCM/filler on the predicted values. This study evaluates existing creep and drying shrinkage models, including AASHTO LRFD, ACI209, CEB-FIP MC90-99, B3, and GL2000, for SCC mixtures with different SCMs/fillers. Forty SCC mixtures were proportioned for …


Designing Gfrp-Reinforced Tilt-Up Wall Panels, Fray F. Pozo-Lora, Marc Maguire Aug 2021

Designing Gfrp-Reinforced Tilt-Up Wall Panels, Fray F. Pozo-Lora, Marc Maguire

Durham School of Architectural Engineering and Construction: Faculty Publications

Tilt-up construction was effectively enabled on a wide scale in 1979, when the ACI committee 551 report on Tilt-up construction was published, the Recommended Tilt-Up Wall Design, aka, the Yellow Book and the subsequent ACI-SEASC Task, aka the Green Book, and another Tilt-up design and construction manual developed by the ACI in 1988. The Tilt-up Concrete Association was created in 1986 by a group of industry professionals who had the need of an organization dedicated to the industry. ACI 551 maintains a document outlining the standard practice for contemporary Tilt-up design and construction. The ACI 551 document does not consider …


The Facility Infection Risk Estimator™: A Web Application Tool For Comparing Indoor Risk Mitigation Strategies By Estimating Airborne Transmission Risk, Marcel Harmon, Josephine Lau Aug 2021

The Facility Infection Risk Estimator™: A Web Application Tool For Comparing Indoor Risk Mitigation Strategies By Estimating Airborne Transmission Risk, Marcel Harmon, Josephine Lau

Durham School of Architectural Engineering and Construction: Faculty Publications

The COVID-19 pandemic created needs for (a) estimating the existing airborne risk of infection from SARS-CoV-2 in existing facilities and new designs and (b) estimating and comparing the impacts of engineering and behavioural strategies for contextually reducing that risk. This paper presents the development of a web application to meet these needs, the Facility Infection Risk Estimator™, and its underlying Wells–Riley based model. The model specifically estimates (a) the removal efficiencies of various settling, ventilation, filtration and virus inactivation strategies and (b) the associated probability of infection, given the room physical parameters and number of individuals infected present with either …


Performance Evaluation Of A Prestressed Belitic Calcium Sulfoaluminate Cement (Bcsa) Concrete Bridge Girder, Nick Markosian, Raed Tawadrous, Mohammad Mastali, Robert J. Thomas, Marc Maguire Jul 2021

Performance Evaluation Of A Prestressed Belitic Calcium Sulfoaluminate Cement (Bcsa) Concrete Bridge Girder, Nick Markosian, Raed Tawadrous, Mohammad Mastali, Robert J. Thomas, Marc Maguire

Durham School of Architectural Engineering and Construction: Faculty Publications

Belitic calcium sulfoaluminate (BCSA) cement is a sustainable alternative to Portland cement that offers rapid setting characteristics that could accelerate throughput in precast concrete operations. BCSA cements have lower carbon footprint, embodied energy, and natural resource consumption than Portland cement. However, these benefits are not often utilized in structural members due to lack of specifications and perceived logistical challenges. This paper evaluates the performance of a full-scale precast, prestressed voided deck slab bridge girder made with BCSA cement concrete. The rapid-set properties of BCSA cement allowed the initial concrete compressive strength to reach the required 4300 psi release strength at …


Discrete Rigid Block Analysis To Assess Settlement Induced Damage In Unreinforced Masonry Façades, Ryan Ehresman, Nathan Taylor, Bora Pulatsu, Ece Erdogmus Jul 2021

Discrete Rigid Block Analysis To Assess Settlement Induced Damage In Unreinforced Masonry Façades, Ryan Ehresman, Nathan Taylor, Bora Pulatsu, Ece Erdogmus

Durham School of Architectural Engineering and Construction: Faculty Publications

In this study, a system of discontinuous rigid blocks is employed to simulate the possible damage mechanisms in unreinforced masonry (URM) façades and load-bearing frame systems subjected to settlement using the discrete element method (DEM). First, the employed modeling strategy is validated utilizing the available experimental results presented in the literature. Once there is a good agreement between the computational models and experimental findings, a sensitivity analysis is performed to quantify the influence of the input parameters defined in the DEM-based numerical model. Finally, the proposed modeling strategy is further utilized to assess the damage pattern that may develop in …