Okechi, Ikechukwu K.; Aguayo, Federico; Torres, Anthony. (2022). Coefficient of Thermal Expansion of Concrete Produced with Recycled Concrete Aggregates. Journal of Civil Engineering and Construction, 11(2), 65-74.
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Abstract
This study presents a comparison between the coefficient of thermal expansion (CTE) of concrete produced with natural aggregate and that of concrete produced with recycled concrete aggregate. In order to achieve this, natural aggregate concrete (NAC) specimens were produced, tested, then crushed and sieved in the laboratory to obtain recycled concrete aggregates, which was then used in the production of recycled aggregate concrete (RAC) specimens. The RAC samples were then tested and compared to the NAC samples. The CTE testing was carried out using a AFTC2 CTE measurement system produced by Pine Instrument Company. In addition to CTE testing, the water absorption, specific gravity, and unit weight of the aggregates was determined. A vacuum impregnation procedure was used for the water absorption test. The recycled aggregate properties showed a significantly higher absorption capacity than that of the natural aggregates, while the unit weight and specific gravity of the recycled aggregate were lower than that of the natural aggregates. The average CTE results showed that both the NAC and the RAC samples expanded similarly. The results show that the CTE of RAC depends on the natural aggregate used in the NAC, which was recycled to produce the RAC. Also, there was no significant difference between the average CTE values of the RAC and that of NAC that could discredit the use of recycled aggregate in concrete.
Keywords
Coefficient of thermal expansion; Recycled concrete aggregate; Natural concrete aggregate.
Osburn, Laura; Lee, Hyun Woo; Gambatese, John A. (2022). Formal Prevention through Design Process and Implementation for Mechanical, Electrical, and Plumbing Worker Safety. Journal Of Management In Engineering, 38(5).
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Abstract
There are many studies that focus on Prevention through Design (PtD) for construction workers and developing formalized PtD processes for construction projects. However, few studies have aimed at developing a formalized PtD process for mechanical/electrical/plumbing (MEP) worker safety. A formal process for implementing PtD for MEP worker safety is badly needed because MEP work onsite and during operation and maintenance (O&M) can lead to injury and death. To address this knowledge gap, our research team aimed to create a formalized PtD process for MEP safety and developed case studies that detail how the process can be implemented in the field. The formalized process and case studies would then be used in an implementation guide created specifically for the industry. This project was completed through expert interviews, six case studies, and ongoing discussion and review by an Industry Advisory Council. Using these methods, the team identified factors for implementation success and developed a formalized PtD process specific to the MEP worker context. The process consists of five phases: (1) hazard identification, (2) risk assessment, (3) design review, (4) implementation, and (5) learning. We anticipate that this study will contribute to the field of PtD research through creating one of the first formalized PtD processes for MEP construction and O&M worker safety, and through a cross-case analysis of the six PtD cases that indicated not only the importance of stakeholder engagement and cross-disciplinary dialogue, but that effective PtD implementation can occur even outside of a collaborative project delivery context at any point during design and construction.
Keywords
Construction Safety; Health; Attitude; Prevention Through Design (ptd); Construction Worker Safety; Mechanical; Electrical; Plumbing (mep)
Asl, Bita Astaneh; Dossick, Carrie Sturts. (2022). Immersive VR Versus BIM for AEC Team Collaboration in Remote 3D Coordination Processes. Buildings, 12(10).
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Abstract
Building Information Modeling (BIM) and Virtual Reality (VR) are both tools for collaboration and communication, yet questions still exist as to how and in what ways these tools support technical communication and team decision-making. This paper presents the results of an experimental research study that examined multidisciplinary Architecture, Engineering, and Construction (AEC) team collaboration efficiency in remote asynchronous and synchronous communication methods for 3D coordination processes by comparing BIM and immersive VR both with markup tools. Team collaboration efficiency was measured by Shared Understanding, a psychological method based on Mental Models. The findings revealed that the immersive experience in VR and its markup tool capabilities, which enabled users to draw in a 360-degree environment, supported team communication more than the BIM markup tool features, which allowed only one user to draw on a shared 2D screenshot of the model. However, efficient team collaboration in VR required the members to properly guide each other in the 360-degree environment; otherwise, some members were not able to follow the conversations.
Keywords
Mental Models; Virtual-reality; Performance; Virtual Reality (vr); Building Information Modeling (bim); 3d Coordination; Clash Resolution; Remote Collaboration; Multidisciplinary Aec Team
Lee, Wonil; Lin, Ken-yu; Johnson, Peter W.; Seto, Edmund Y.w. (2022). Selection of Wearable Sensor Measurements for Monitoring and Managing Entry-level Construction Worker Fatigue: A Logistic Regression Approach. Engineering Construction & Architectural Management (09699988), 29(8), 2905-2923.
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Abstract
Purpose: The identification of fatigue status and early intervention to mitigate fatigue can reduce the risk of workplace injuries. Off-the-shelf wearable sensors capable of assessing multiple parameters are available. However, using numerous variables in the fatigue prediction model can elicit data issues. This study aimed at identifying the most relevant variables for measuring occupational fatigue among entry-level construction workers by using common wearable sensor technologies, such as electrocardiogram and actigraphy sensors. Design/methodology/approach: Twenty-two individuals were assigned different task workloads in repeated sessions. Stepwise logistic regression was used to identify the most parsimonious fatigue prediction model. Heart rate variability measurements, standard deviation of NN intervals and power in the low-frequency range (LF) were considered for fatigue prediction. Fast Fourier transform and autoregressive (AR) analysis were employed as frequency domain analysis methods. Findings: The log-transformed LF obtained using AR analysis is preferred for daily fatigue management, whereas the standard deviation of normal-to-normal NN is useful in weekly fatigue management. Research limitations/implications: This study was conducted with entry-level construction workers who are involved in manual material handling activities. The findings of this study are applicable to this group. Originality/value: This is the first study to investigate all major measures obtainable through electrocardiogram and actigraphy among current mainstream wearables for monitoring occupational fatigue in the construction industry. It contributes knowledge on the use of wearable technology for managing occupational fatigue among entry-level construction workers engaged in material handling activities. [ABSTRACT FROM AUTHOR]; Copyright of Engineering Construction & Architectural Management (09699988) is the property of Emerald Publishing Limited and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Keywords
Construction Workers; Wearable Technology; Logistic Regression Analysis; Fatigue (physiology); Frequency-domain Analysis; Heart Beat; Lifting & Carrying (human Mechanics); Construction Safety; Information And Communication Technology (ict) Applications; Management; Technology
Kim, Minju; Lee, Dongmin; Kim, Taehoon; Oh, Sangmin; Cho, Hunhee. (2023). Automated Extraction of Geometric Primitives with Solid Lines from Unstructured Point Clouds for Creating Digital Buildings Models. Automation In Construction, 145.
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Abstract
Point clouds produced by laser scanners are an invaluable source of data for reconstructing multi-dimensional digital models that reflect the as-is conditions of built facilities. However, previous studies aimed to reconstruct models by overlaying the dataset on top of ground-truth reference models to manually adjust the accuracy of the output. Therefore, this paper describes the extraction of geometric primitives with solid lines—the simplest form of objectified data that computer-aided design systems can handle—from unorganized data points and creation of digital models of built facilities in a form of floor plan. The geometric primitives are extracted from 3D points by hybridizing machine learning algorithms, which are mean-shift clustering, non-convex hull, and random sample and consensus (RANSAC). This paper provides a solution for creating a new form of as-built model with high accuracy and robustness from scratch without the involvement of ground-truth solutions or manual adjustments. © 2022 Elsevier B.V.
Keywords
Computer Aided Design; Geometry; Laser Applications; Learning Algorithms; Machine Learning; Scanning; As-build Model Creation; Build Facility; From-point-to-line; Geometric Primitives; Laserscanners; Model Creation; Outline Extractions; Point-clouds; Point-to-line; Solid Lines
Lingzi Wu is an Assistant Professor with the Department of Construction Management (CM) at the University of Washington (UW). Prior to joining UW in September 2022, Dr. Wu served as a postdoctoral fellow in the Department of Civil and Environmental Engineering at University of Alberta, where she received her MSc and PhD in Construction Engineering and Management in 2013 and 2020 respectively. Prior to her PhD, Dr. Wu worked in the industrial construction sector as a project coordinator with PCL Industrial Management from 2013 to 2017.
An interdisciplinary scholar focused on advancing digital transformation in construction, Dr. Wu’s current research interests include (1) integration of advanced data analytics and complex system modeling to enhance construction practices and (2) development of human-in-the-loop decision support systems to improve construction performance (e.g., sustainability and safety). Dr. Wu has published 10 papers in top journals and conference proceedings, including the Journal of Construction Engineering and Management, Journal of Computing in Civil Engineering, and Automation in Construction. Her research and academic excellence has received notable recognition, including a “Best Paper Award” at the 17th International Conference on Modeling and Applied Simulation, and the outstanding reviewer award from the Journal of Construction Engineering and Management.
As an educator and mentor, Dr. Wu aims to create an inclusive, innovative, and interactive learning environment where students develop personal, technical, and transferable skills to grow today, tomorrow, and into the future.
Cheng, Tao; Migliaccio, Giovanni C.; Teizer, Jochen; Gatti, Umberto C. (2013). Data Fusion of Real-Time Location Sensing and Physiological Status Monitoring for Ergonomics Analysis of Construction Workers. Journal Of Computing In Civil Engineering, 27(3), 320 – 335.
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Abstract
Previous research and applications in construction resource optimization have focused on tracking the location of material and equipment. There is a lack of studies on remote monitoring for improving safety and health of the construction workforce. This paper presents a new approach for monitoring ergonomically safe and unsafe behavior of construction workers. The study relies on a methodology that utilizes fusion of data from continuous remote monitoring of construction workers' location and physiological status. To monitor construction workers activities, the authors deployed nonintrusive real-time worker location sensing (RTLS) and physiological status monitoring (PSM) technology. This paper presents the background and need for a data fusion approach, the framework, the test bed environment, and results to some case studies that were used to automatically identify unhealthy work behavior. Results of this study suggest a new approach for automating remote monitoring of construction workers safety performance by fusing data on their location and physical strain. DOI: 10.1061/(ASCE)CP.1943-5487.0000222. (C) 2013 American Society of Civil Engineers.
Keywords
Civil Engineering Computing; Construction Industry; Ergonomics; Occupational Health; Occupational Safety; Personnel; Sensor Fusion; Psm Technology; Rtls Technology; Construction Workforce Health; Construction Workforce Safety; Equipment Location; Material Location; Construction Resource Optimization; Construction Worker; Ergonomics Analysis; Physiological Status Monitoring; Realtime Location Sensing; Data Fusion; Exposure; Tracking; Demands; Sensors; System; Construction Worker Behavior; Remote Location Sensing; Work Sampling; Workforce Safety And Health
Gatti, U.C.; Migliaccio, G.C.; Laird, L. (2014). Design Management in Design-Build Megaprojects: SR 99 Bored Tunnel Case Study. Practice Periodical On Structural Design And Construction, 19(1), 148-58.
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Abstract
The increasing use of the design-build project delivery method has resulted in it now being one of the most popular nontraditional methods for delivering road, bridge, mass transit, and rail projects in the United States. However, although the use of design-build is widespread, there remains a substantial lack of information about how to effectively plan and implement design management procedures for design-build transportation projects. In particular, transportation agencies lack information about how to shape appropriate design management roles for various contractual parties and to manage design activities for design-build megaprojects. To fill this gap, this paper presents a case study of the SR 99 Bored Tunnel project in Seattle, Washington. It provides detailed information on how the owner, the Washington State DOT (WSDOT), incorporated design management procedures into its requirements and how the design-builder, Seattle Tunnel Partners, implemented them within its project management processes.
Keywords
Boring; Design Engineering; Project Management; Tunnels; Design-build Megaproject; Design-build Project Delivery Method; Road Project; Bridge Project; Mass Transit Project; Rail Project; United States; Design-build Transportation Project; Transportation Agency; Sr 99 Bored Tunnel Project; Seattle; Washington State Dot; Wsdot; Design Management; Project Management Process
Shakouri, Mahmoud; Lee, Hyun Woo; Choi, Kunhee. (2015). PACPIM: New Decision-Support Model of Optimized Portfolio Analysis for Community-Based Photovoltaic Investment. Applied Energy, 156, 607 – 617.
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Abstract
Inherent in large-scale photovoltaic (PV) investments is volatility that stems from a unique set of spatial factors, such as shading, building orientation, and roof slope, which can significantly affect both the level of risk and the return on investment. In order to systematically assess and manage the volatility, this study seeks to create a quantitative decision-support model: Portfolio Analysis for Community-based PV Investment Model (PACPIM). Focusing on residential PV systems, PACPIM determines optimized portfolios by applying the Mean Variance Portfolio theory. The model is intended to play an instrumental role in: (1) maximizing the hourly electricity output of PV systems; (2) minimizing the hourly volatility in electricity output; and (3) optimizing the risk-adjusted performance of community-based PV investment. The application and framework of PACPIM were deployed with an actual residential community consisting of 24 houses and their simulated data utilizing PVWatts (R) for estimating hourly electricity production. Results reveal that the optimized portfolios developed by PACPIM (1) increased annual electricity output of PV systems by 4.6%; (2) reduced the volatility in electricity output by 4.3%; and (3) offered the highest risk-adjusted performance among all possible portfolios based on the Sharpe ratios. This study is expected to effectively assist project owners and investors in systematically assessing their community-based PV projects and in developing optimized investment strategies. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords
Photovoltaic Cells; Rate Of Return; Electricity; Dwellings; Electric Utilities; Community-based Investments; Decision-support Model; Mean–variance Portfolio Theory; Residential Photovoltaic Systems; Solar Energy; Decision Support Systems; Investment; Photovoltaic Power Systems; Large-scale Photovoltaic Investments; Spatial Factors; Shading; Building Orientation; Roof Slope; Return On Investment; Quantitative Decision-support Model; Portfolio Analysis For Community-based Pv Investment Model; Pacpim; Residential Pv Systems; Mean-variance Portfolio Theory; Hourly Electricity Output; Hourly Volatility; Risk-adjusted Performance; Hourly Electricity Production Estimation; Community-based Pv Projects; Optimized Investment Strategies; Romanian National Strategy; Renewable Energy; Public-attitudes; Wind Power; Pv Module; Performance; Implementation; Efficiency; Form; Economic Theory; Electricity Generation; Models; Risk; Shade; Solar Collectors
Ottesen, Jeffery L.; Migliaccio, Giovanni C.; Wulfsberg, H. James. (2016). Contractual Battles for Higher Ground: Case Examples. Journal Of Legal Affairs And Dispute Resolution In Engineering And Construction, 8(1).
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Abstract
Dispute resolution requires pursuit of mutual agreement and implies accordant resolve between the disputing parties. In truth, mutual agreement stems from acceptable risks and negotiated terms centered upon equity arguments wherein the parties assess, evaluate, negotiate, and battle for high ground. Where the parties clearly understand their respective positions relative to the applicable laws, facts outweigh emotions, and the parties are more likely to avoid disputes. This paper defines high ground based upon legal theory in quantum meruit, which means, as much as he deserves. Equity arguments can trump written contractual provisions. Owners, architects, engineers, and contractors must become wise to these arguments to protect its shareholders' interests. To promote understanding, five different case scenarios are presented using actual disputes experienced on (1) notice provisions, (2) cumulative impact claims, (3) no damages for delay clauses, (4) acceleration, and (5) owner review durations. These case scenarios demonstrate that acquiring high ground requires clear understanding and synchronization of both the contract and the applicable governing laws. Ultimately, the party possessing higher ground will find itself in a more favorable position when disputes occur. (c) 2015 American Society of Civil Engineers.
Keywords
Legislation; Subcontracting; Disputing Parties; Equity Arguments; Legal Theory; Quantum Meruit; Contractual Provisions; Architects; Notice Provisions; Cumulative Impact Claims; Owner Review Durations; Governing Laws; Engineers; Contractors; Dispute Resolution; Contractual Battles; Project; Equity; Delay; Contractual Notice; Cumulative Impact; Total Cost Claim; No Damages For Delay; Acceleration