Technology & Innovation Archives - Page 5 of 19

Coefficient of Thermal Expansion of Concrete Produced with Recycled Concrete Aggregates

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.

Using Open Data and Open-source Software to Develop Spatial Indicators of Urban Design and Transport Features for Achieving Healthy and Sustainable Cities

Boeing, Geoff; Higgs, Carl; Liu, Shiqin; Giles-corti, Billie; Sallis, James F.; Cerin, Ester; Lowe, Melanie; Adlakha, Deepti; Hinckson, Erica; Moudon, Anne Vernez; Salvo, Deborah; Adams, Marc A.; Barrozo, Ligia, V; Bozovic, Tamara; Delclos-alio, Xavier; Dygryn, Jan; Ferguson, Sara; Gebel, Klaus; Thanh Phuong Ho; Lai, Poh-chin; Martori, Joan C.; Nitvimol, Kornsupha; Queralt, Ana; Roberts, Jennifer D.; Sambo, Garba H.; Schipperijn, Jasper; Vale, David; Van De Weghe, Nico; Vich, Guillem; Arundel, Jonathan. (2022). Using Open Data and Open-source Software to Develop Spatial Indicators of Urban Design and Transport Features for Achieving Healthy and Sustainable Cities. Lancet Global Health, 10(6), E907-E918.

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Abstract

Benchmarking and monitoring of urban design and transport features is crucial to achieving local and international health and sustainability goals. However, most urban indicator frameworks use coarse spatial scales that either only allow between-city comparisons, or require expensive, technical, local spatial analyses for within-city comparisons. This study developed a reusable, open-source urban indicator computational framework using open data to enable consistent local and global comparative analyses. We show this framework by calculating spatial indicators-for 25 diverse cities in 19 countries-of urban design and transport features that support health and sustainability. We link these indicators to cities' policy contexts, and identify populations living above and below critical thresholds for physical activity through walking. Efforts to broaden participation in crowdsourcing data and to calculate globally consistent indicators are essential for planning evidence-informed urban interventions, monitoring policy effects, and learning lessons from peer cities to achieve health, equity, and sustainability goals.

Keywords

Systems; Access; Care

Immersive VR Versus BIM for AEC Team Collaboration in Remote 3D Coordination Processes

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

Selection of Wearable Sensor Measurements for Monitoring and Managing Entry-level Construction Worker Fatigue: A Logistic Regression Approach

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

Lingzi Wu

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.

Narjes Abbasabadi

Narjes Abbasabadi, Ph.D., is an Assistant Professor in the Department of Architecture at the University of Washington. Dr. Abbasabadi also leads the Sustainable Intelligence Lab. Abbasabadi’s research centers on sustainability and computation in the built environment. Much of her work focuses on advancing design research efforts through developing data-driven methods, workflows, and tools that leverage the advances in digital technologies to enable augmented intelligence in performance-based and human-centered design. With an emphasis on multi-scale exploration, her research investigates urban building energy flows, human systems, and environmental and health impacts across scales—from the scale of building to the scale of neighborhood and city.

Abbasabadi’s research has been published in premier journals, including Applied Energy, Building and Environment, Energy and Buildings, Environmental Research, and Sustainable Cities and Society. She received honors and awards, including “ARCC Dissertation Award Honorable Mention” (Architectural Research Centers Consortium (ARCC), 2020), “Best Ph.D. Program Dissertation Award” (IIT CoA, 2019), and 2nd place in the U.S. Department of Energy (DOE)’s Race to Zero Design Competition (DOE, 2018). In 2018, she organized the 3rd IIT International Symposium on Buildings, Cities, and Performance. She served as editor of the third issue of Prometheus Journal, which received the 2020 Haskell Award from AIA New York, Center for Architecture.

Prior to joining the University of Washington, she taught at the University of Texas at Arlington and the Illinois Institute of Technology. She also has practiced with several firms and institutions and led design research projects such as developing design codes and prototypes for low-carbon buildings. Most recently, she practiced as an architect with Adrian Smith + Gordon Gill Architecture (AS+GG), where she has been involved in major projects, including the 2020 World Expo. Abbasabadi holds a Ph.D. in Architecture from the Illinois Institute of Technology and Master’s and Bachelor’s degrees in Architecture from Tehran Azad University.

Transportation-Efficient Land Use Mapping Index (TELUMI), a Tool to Assess Multimodal Transportation Options in Metropolitan Regions

Moudon, Anne Vernez; Sohn, D. W.; Kavage, Sarah E.; Mabry, Jean E. (2011). Transportation-Efficient Land Use Mapping Index (TELUMI), a Tool to Assess Multimodal Transportation Options in Metropolitan Regions. International Journal Of Sustainable Transportation, 5(2), 111 – 133.

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Abstract

The Transportation-Efficient Land Use Mapping Index (TELUMI) is a tool to visualize and to quantify micro-level metropolitan land use and development patterns as they affect travel demand. It can assist transportation and urban planning authorities in identifying zones where land use supports multimodal travel and in determining a region's transportation system efficiency. An application of the TELUMI in the Seattle region showed that residential units and employment concentrated in transportation-efficient areas covering less than 20 percent of the region. An interactive, multi-scaled tool, the TELUMI can also support scenario building to simulate land use changes that improve transportation system performance.

Keywords

Urban; Geographic Information Systems; Land Use; Mapping Index; Metropolitan; Multimodal Travel; Transportation Efficiency

A User-centered Information And Communication Technology (ict) Tool To Improve Safety Inspections.

Lin, Ken-yu; Tsai, Meng-han; Gatti, Umberto C.; Lin, Jacob Je-chian; Lee, Cheng-hao; Kang, Shih-chung. (2014). A User-centered Information And Communication Technology (ict) Tool To Improve Safety Inspections. Automation In Construction, 48, 53 – 63.

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Abstract

Occupational safety is imperative in construction, and safety inspection is among the most common practices that help enforce job safety on site. The safety inspection process, however, suffers from several drawbacks that hinder the efficiency, effectiveness, and analytical learning capacity of the process. Dedicated tools for user-centered information and communications technology could significantly reduce such drawbacks. This paper discusses the use of an original two-step user-centered design approach to develop and evaluate an iPad application that aims to address such drawbacks and improve the day-to-day practices and management of safety inspections. Evaluation results indicate the usefulness and practicality of the application and identify innovative uses not previously envisioned. Furthermore, the developed tool allows consistent data collection that can eventually be used to aid the development of advanced safety and health data analysis techniques. (C) 2014 Elsevier B.V. All rights reserved.

Keywords

Information & Communication Technologies; Industrial Safety; Data Analysis; Technological Innovations; Ipads; Construction Safety; Field Data Collection; Field Inspection; Information And Communication Technology; Research To Practice; Safety Audit; Safety Inspection; Safety Technology; Site Inspection; User-centered Design; User-centered Information And Communication Technology Tool; Safety Inspection Process; Occupational Safety; Job Safety; Analytical Learning Capacity; Communications Technology; Two-step User-centered Design Approach; Ipad Application; Innovative Uses; Consistent Data Collection; Construction; Advanced Safety-health Data Analysis Techniques; Construction Industry; Information Technology; Inspection; Occupational Health; User Centred Design; Construction Site Safety; Management-system; Design; Productivity

Wearable Sensors For Monitoring On-duty And Off-duty Worker Physiological Status And Activities In Construction.

Lee, Wonil; Lin, Ken-yu; Seto, Edmund; Migliaccio, Giovanni C. (2017). Wearable Sensors For Monitoring On-duty And Off-duty Worker Physiological Status And Activities In Construction. Automation In Construction, 83, 341 – 353.

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Abstract

Total Worker Health (R) (TWH) integrates occupational health and safety with the promotion of workers' off-duty wellbeing. Wearable sensors (e.g., activity trackers and physiological monitors) have facilitated personalized objective measurement of workers' health and wellbeing. Furthermore, the TWH concept is relevant to construction workers, especially roofing workers, as they encounter high on-duty health and safety risks and have poor off-duty lifestyles. This study examined the reliability and usability of wearable sensors for monitoring roofing workers' on-duty and off-duty activities. The results demonstrated the usability of these sensors and recommended a data collection period of three consecutive days for obtaining an intraclass correlation coefficient of 0.75 for heart rate, energy expenditure, metabolic equivalents, and sleep efficiency. The participants exhibited significant variations in their physical responses, health statuses, and safety behaviors. Moreover, several issues were identified in the application of wearable sensors to TWH evaluations for construction workers including roofers.

Keywords

Construction Workers; Wearable Technology; Employee Health Promotion; Roofing Industry; Body Sensor Networks; Health; Construction Safety And Health; Usability Study; Wearable Sensors; Worker Monitoring; Worker Physiology; Construction Industry; Ergonomics; Occupational Health; Occupational Safety; Patient Monitoring; Personnel; Roofs; Sleep; Off-duty Worker Physiological Status; Total Worker Health¬Æ; Off-duty Wellbeing; Activity Trackers; Physiological Monitors; Twh Concept; On-duty Health; Safety Risks; Off-duty Lifestyles; Monitoring Roofing Workers; Off-duty Activities; Health Statuses; Heart-rate-variability; Energy-expenditure; Health Protection; Physical-activity; Validity; Reliability; Validation; Promotion; Productivity; Actigraph

Is There a Limit to Bioretention Effectiveness? Evaluation of Stormwater Bioretention Treatment Using a Lumped Urban Ecohydrologic Model and Ecologically Based Design Criteria

Wright, Olivia M.; Istanbulluoglu, Erkan; Horner, Richard R.; Degasperi, Curtis L.; Simmonds, Jim. (2018). Is There a Limit to Bioretention Effectiveness? Evaluation of Stormwater Bioretention Treatment Using a Lumped Urban Ecohydrologic Model and Ecologically Based Design Criteria. Hydrological Processes, 32(15), 2318 – 2334.

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Abstract

In this study, we developed the urban ecohydrology model (UEM) to investigate the role of bioretention on watershed water balance, runoff production, and streamflow variability. UEM partitions the land surface into pervious, impervious, and bioretention cell fractions. Soil moisture and vegetation dynamics are simulated in pervious areas and bioretention cells using a lumped ecohydrological approach. Bioretention cells receive runoff from a fraction of impervious areas. The model is calibrated in an urban headwater catchment near Seattle, WA, USA, using hourly weather data and streamflow observations for 3years. The calibrated model is first used to investigate the relationship between streamflow variability and bioretention cell size that receives runoff from different values of impervious area in the watershed. Streamflow variability is quantified by 2 indices, high pulse count (HPC), which quantifies the number of flow high pulses in a water year above a threshold, and high pulse range (HPR), which defines the time over which the pulses occurred. Low values of these indices are associated with improved stream health. The effectiveness of the modelled bioretention facilities are measured by their influence on reducing HPC and HPR and on flow duration curves in comparison with modelled fully forested conditions. We used UEM to examine the effectiveness of bioretention cells under rainfall regimes that are wetter and drier than the study area in an effort to understand linkages between the degree of urbanization, climate, and design bioretention cell size to improve inferred stream health conditions. In all model simulations, limits to the reduction of HPC and HPR indicators were reached as the size of bioretention cells grew. Bioretention was more effective as the rainfall regime gets drier. Results may guide bioretention design practices and future studies to explore climate change impacts on bioretention design and management.

Keywords

Performance Assessment; Hydrologic Alteration; Automated Techniques; Management-practices; Land-cover; Streams; Water; Impact; Area; Runoff; Bioretention; Ecohydrology; Green Infrastructure; Stormwater; Stream Health; Urban Hydrology; Evaluation; Urbanization; Watersheds; Soil Moisture; Water Balance; Stream Flow; Design; Variability; Ecological Monitoring; Computer Simulation; Storms; Climate Change; Duration; Water Runoff; Flow Duration Curves; Flow Duration; Cell Size; Soils; Duration Curves; Rainfall; Rivers; Cells; Headwaters; Surface Runoff; Dynamics; Rainfall Regime; Catchment Area; Design Criteria; Environmental Impact; Retention Basins; Soil Dynamics; Stream Discharge; Climatic Changes; Meteorological Data; Headwater Catchments