De Almeida, Catherine. (2019). Performative By-Products: The Emergence of Waste Reuse Strategies at the Blue Lagoon. Journal of Landscape Architecture, 13(3), 64-77.
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Abstract
Materials and landscapes associated with waste are perceived as objectionable. By reactivating and embracing waste conditions as desirable opportunities for diverse programmes rooted in economy, ecology, and culture, designers can form hybrid assemblages on waste sites through the exchange of waste materials—a landscape lifecycles approach. This frame-work is applicable to not only design research, but also as a critical lens for evaluating the landscape performance of existing projects that engage with waste reuse. The Blue Lagoon in southwest Iceland materialized as a spa industry out of geothermal waste effluent from the adjacent Svartsengi Geothermal Power Station, reusing undesirable materials and transforming a waste landscape through diversified material recovery strategies. Featuring an industrial by-product turned economic generator, this case study reveals the opportunities for reusing geothermal ‘waste’ in these emergent landscape conditions, which hybridize economies with recreation, research, and ecology, and shift the conventional relationship with waste from passive to performative.
Keywords
Waste reuse; Blue Lagoon; material lifecycles; Iceland; landscape reclamation
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.
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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
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.
Acolin, Arthur; Wachter, Susan. (2017). Opportunity and Housing Access. Cityscape, 19(1), 135 – 150.
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Abstract
This article examines the relationship between employment opportunity and housing affordability. Access to locations with high-productivity jobs is increasingly limited by regional housing affordability barriers. Recent articles demonstrate a new regional divergence in access to high-productivity regions accompanied by declines in worker mobility associated with affordability barriers. We update these findings and discuss their long-term implications for economic opportunity and intergenerational welfare. We show that areas, from which lower-income households are increasingly priced out, are also more likely to have higher levels of intergenerational mobility. Access to opportunity also continues to be challenged within metropolitan areas as the gentrification of downtown neighborhoods is accompanied by an increase in concentrated poverty in outlying city neighborhoods and inner ring suburbs. These trends on regional and local scales derive from the increased importance of place in the knowledge-based economy and interact to reinforce growing spatial inequality. We conclude with a discussion of the importance of identifying place-based solutions to counter growing spatial inequality of opportunity.]
Li, Guanghao; Cheng, Qingqing; Zhan, Changhong; Yocom, Ken P. (2022). Evaluation Strategies on the Thermal Environmental Effectiveness of Street Canyon Clusters: A Case Study of Harbin, China. Sustainability, 14(20).
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Abstract
Urban overheating significantly affects people's physical and mental health. The addition of street trees is an essential, economical, and effective means by which to mitigate urban heat and optimize the overall thermal environment. Focusing on typical street canyon clusters in Harbin, China, landscape morphology was quantified by streetscape interface measurements (sky view factor, tree view factor, and building view factor). Through ENVI-met simulations, the correlation mechanism between streetscape interface measurements and thermal environment was evaluated, and optimization methods for assessing the thermal environment of urban streets were proposed. The results revealed: (1) The thermal environment optimization efficiency of general street canyon types was greatest when street tree spacing was 12 m. At present, the smaller spacing has not been simulated and may yield better thermal environment results. The average decrease in temperature (Ta), relative humidity (RH) and mean radiant temperature (MRT) was 0.78%, 2.23%, and 30.20%, respectively. (2) Specific street canyon types should adopt precise control strategies of streetscape interface according to their types to achieve the optimal balance between thermal environment optimization and cost. (3) Streetscape interface measurements and thermal environment indexes show quadratic correlation characteristics, and are critical points for further investigation. The conclusions are more specific than previous research findings, which are of great significance for decreasing the urban heat island effect at the block scale, improving residents' physical and mental health, and improving the urban environment quality.
Keywords
Heat Mitigation Strategies; Urban Green Areas; Sky View Factor; Cold Region; Comfort; Tree; Landscape; Park; Simulation; Density; Street Canyon Clusters; Streetscape Interface Measurement; Envi-met Simulation; Thermal Optimization
Giles-corti, Billie; Moudon, Anne Vernez; Lowe, Melanie; Cerin, Ester; Boeing, Geoff; Frumkin, Howard; Salvo, Deborah; Foster, Sarah; Kleeman, Alexandra; Bekessy, Sarah; De Sa, Thiago Herick; Nieuwenhuijsen, Mark; Higgs, Carl; Hinckson, Erica; Adlakha, Deepti; Arundel, Jonathan; Liu, Shiqin; Oyeyemi, Adewale L.; Nitvimol, Kornsupha; Sallis, James F. (2022). What Next? Expanding Our View of City Planning and Global Health, and Implementing and Monitoring Evidence-informed Policy. Lancet Global Health, 10(6), E919-E926.
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Abstract
This Series on urban design, transport, and health aimed to facilitate development of a global system of health-related policy and spatial indicators to assess achievements and deficiencies in urban and transport policies and features. This final paper in the Series summarises key findings, considers what to do next, and outlines urgent key actions. Our study of 25 cities in 19 countries found that, despite many well intentioned policies, few cities had measurable standards and policy targets to achieve healthy and sustainable cities. Available standards and targets were often insufficient to promote health and wellbeing, and health-supportive urban design and transport features were often inadequate or inequitably distributed. City planning decisions affect human and planetary health and amplify city vulnerabilities, as the COVID-19 pandemic has highlighted. Hence, we offer an expanded framework of pathways through which city planning affects health, incorporating 11 integrated urban system policies and 11 integrated urban and transport interventions addressing current and emerging issues. Our call to action recommends widespread uptake and further development of our methods and open-source tools to create upstream policy and spatial indicators to benchmark and track progress; unmask spatial inequities; inform interventions and investments; and accelerate transitions to net zero, healthy, and sustainable cities.
Acolin, Arthur; Bricker, Jesse; Calem, Paul; Wachter, Susan. (2016). Borrowing Constraints and Homeownership. The American Economic Review, 106(5), 625 – 629.
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Keywords
Borrowing Constraints, Homeownership, Credit Supply
Zhai, Wei; Yue, Haoyu; Deng, Yihan. (2022). Examining the Association between Urban Green Space and Viral Transmission of Covid-19 during the Early Outbreak. Applied Geography, 147.
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Abstract
Even though exposure to urban green spaces (UGS) has physical and mental health benefits during COVID-19, whether visiting UGS will exacerbate viral transmission and what types of counties would be more impacted remain to be answered. In this research, we adopted mobile phone data to measure the county-level UGS visi-tation across the United States. We developed a Bayesian model to estimate the effective production number of the pandemic. To consider the spatial dependency, we applied the geographically weighted panel regression to estimate the association between UGS visitation and viral transmission. We found that visitations to UGS may be positively correlated with the viral spread in Florida, Idaho, New Mexico, Texas, New York, Ohio, and Penn-sylvania. Especially noteworthy is that the spread of COVID-19 in the majority of counties is not associated with green space visitation. Further, we found that when people visit UGS, there may be a positive association be-tween median age and viral transmission in New Mexico, Colorado, and Missouri; a positive association between concentration of blacks and viral transmission in North Dakota, Minnesota, Wisconsin, Michigan, and Florida; and a positive association between poverty rate and viral transmission in Iowa, Missouri, Colorado, New Mexico, and the Northeast United States.
Keywords
Public Spaces; Viral Transmission; Covid-19; Extraterrestrial Beings; Covid-19 Pandemic; Smartphones; Cell Phones; Memes; Big Data; Urban Green Space; Geographical Information-system; Parks; Accessibility; Regression; Community; Stress; Health; Level
Acolin, Arthur; Goodman, Laurie S.; Wachter, Susan M. (2016). A Renter or Homeowner Nation? Cityscape, 18(1), 145 – 158.
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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)