Ochsner, Jeffrey Karl. (2014). Westlake. The Pacific Northwest Quarterly, 112(2), 68-90.
Research Theme: Design & Building
Built environment scholarship at the scales of the interior space to the building
AIA publishes “Equity in Architectural Education” co-authored by Dean Renée Cheng and Laura Osburn
The American Institute of Architects (AIA) recently published a supplement to the AIA Guides for Equitable Practice titled “Equity in Architectural Education.” Renée Cheng, dean of the College of Built Environments, served as the project lead for the research and writing team, which included Laura Osburn, research scientist in construction management. The supplement argues that organizational culture is critical to achieving goals of equity, diversity, and inclusion, and is intended to inspire discussion within individual institutions, and among thought leaders…
Experimental Investigations and Empirical Modeling of Rubber Wear on Concrete Pavement
Emami, Anahita; Sah, Hos Narayan; Aguayo, Federico; Khaleghian, Seyedmeysam. (2022). Experimental Investigations and Empirical Modeling of Rubber Wear on Concrete Pavement. Journal of Engineering Tribology.
Abstract
Material loss due to wear plays a key role in the service life of rubber components in various tribological applications, such as tires, shoe soles, wiper blades, to name a few. It also adversely affects energy consumption, economy, and CO2 emissions around the globe. Therefore, understanding and modeling the wear behavior of rubbers are important in the design of economic and environment-friendly rubber compounds. In this study, we investigated the effect of normal load and sliding velocity on the wear rate of rubber compounds widely used in the tire treads and evaluated the wear models previously proposed for rubbers to determine the best model to predict the rubber wear rate. The sliding wear rates of different types of Styrene-Butadiene Rubber (SBR) and Isoprene Rubber (IR) compounds on a broom finish concrete slab were measured for different sliding velocities and normal loads. The experimental results were used to evaluate and discuss different wear models proposed in the literature. A new empirical model was proposed to predict the wear rate by considering mechanical properties associated with rubber wear. The experimental results revealed that the wear rate of rubber compounds non-linearly depends on the normal load or friction force, while the effect of sliding velocity on the wear rate is not significant in the 20–100 mm/s range. Moreover, traces of both mechanical (abrasion) and chemical (smearing) wear were observed on all rubber compounds.
Keywords
Tire tread compounds, rubber wear, rubber-concrete interaction, smearing wear and abrasion, wear model
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.
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.
Associations between Neighborhood Built Environment, Residential Property Values, and Adult BMI Change: The Seattle Obesity Study III
Buszkiewicz, James H.; Rose, Chelsea M.; Ko, Linda K.; Mou, Jin; Moudon, Anne Vernez; Hurvitz, Philip M.; Cook, Andrea J.; Drewnowski, Adam. (2022). Associations between Neighborhood Built Environment, Residential Property Values, and Adult BMI Change: The Seattle Obesity Study III. SSM-Population Health, 19.
Abstract
Objective: To examine associations between neighborhood built environment (BE) variables, residential property values, and longitudinal 1-and 2-year changes in body mass index (BMI). Methods: The Seattle Obesity Study III was a prospective cohort study of adults with geocoded residential addresses, conducted in King, Pierce, and Yakima Counties in Washington State. Measured heights and weights were obtained at baseline (n = 879), year 1 (n = 727), and year 2 (n = 679). Tax parcel residential property values served as proxies for individual socioeconomic status. Residential unit and road intersection density were captured using Euclidean-based SmartMaps at 800 m buffers. Counts of supermarket (0 versus. 1+) and fast-food restaurant availability (0, 1-3, 4+) were measured using network based SmartMaps at 1600 m buffers. Density measures and residential property values were categorized into tertiles. Linear mixed-effects models tested whether baseline BE variables and property values were associated with differential changes in BMI at year 1 or year 2, adjusting for age, gender, race/ethnicity, education, home ownership, and county of residence. These associations were then tested for potential disparities by age group, gender, race/ethnicity, and education. Results: Road intersection density, access to food sources, and residential property values were inversely associated with BMI at baseline. At year 1, participants in the 3rd tertile of density metrics and with 4+ fast-food restaurants nearby showed less BMI gain compared to those in the 1st tertile or with 0 restaurants. At year 2, higher residential property values were predictive of lower BMI gain. There was evidence of differential associations by age group, gender, and education but not race/ethnicity. Conclusion: Inverse associations between BE metrics and residential property values at baseline demonstrated mixed associations with 1-and 2-year BMI change. More work is needed to understand how individual-level sociodemographic factors moderate associations between the BE, property values, and BMI change.
Keywords
Body-mass Index; Physical-activity; Food Environment; Socioeconomic-status; Weight-gain; Health; Quality
Metabolist Trajectories
Oshima, Ken Tadashi. (2012). Metabolist Trajectories. Log, 24, 28 – 32.
Automated Extraction of Geometric Primitives with Solid Lines from Unstructured Point Clouds for Creating Digital Buildings Models
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.
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
Richard Haag: New Eyes for Old
Way, Thaisa. (2012). Richard Haag: New Eyes for Old. Sitelines: A Journal Of Place, 7(2), 6 – 8.
Formal Prevention through Design Process and Implementation for Mechanical, Electrical, and Plumbing Worker Safety
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).
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)
Of Mills and Malls: The Future of Urban Industrial Heritage in Neoliberal Mumbai
Chalana, Manish. (2012). Of Mills and Malls: The Future of Urban Industrial Heritage in Neoliberal Mumbai. Future Anterior: Journal Of Historic Preservation, History, Theory, And Criticism, 9(1), 1 – 15.
Abstract
The mandate of historic preservation is to maintain vestiges of diverse cultural heritage, a task that is becoming increasingly difficult in rapidly globalizing India. Much of the country's urban heritage outside of the “monument-and-site” framework is threatened by massive restructuring of cities facilitated by neoliberal urban policies. Mumbai has a rich cultural heritage, associated with diverse sociocultural and economic groups. Much of this is threatened by development practices pursued by various forces with a particular vision of Mumbai as an emerging “global city.” In this work Chalana examines Girangaon, an early industrial district of Mumbai, currently being transformed by forces of domestic and global capital. He argues that Girangaon's urban industrial heritage is a significant piece of the city's development history, which future visions of a global metropolis should embrace. While the expansion of Mumbai's economy has benefited some avenues of preservation practice in Mumbai, in Girangaon its consequences have also been negative, as a working-class neighborhood is restructured into a hypermodern district for the elite. The current forms of preservation practice in the city have been insufficient in addressing the complexity around managing heritage in low-income neighborhoods. Girangaon, and Mumbai overall, reveal the many ways that economic, cultural, and political globalization can impact historic preservation practice.]