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.
Jeffrey Karl Ochsner; David A. Rash. (2017). Research Notes: Design for Mobility: Intercity Bus Terminals In The Puget Sound Region. Buildings & Landscapes: Journal Of The Vernacular Architecture Forum, 24(1), 67 – 91.
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Abstract
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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.]
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
Acolin, Arthur; Goodman, Laurie S.; Wachter, Susan M. (2016). A Renter or Homeowner Nation? Cityscape, 18(1), 145 – 158.
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Acolin, Arthur; Calem, Paul; Jagtiani, Julapa; Wachter, Susan. (2018). First-Time Homebuyers: Toward a New Measure. Cityscape, 20(1), 193 – 204.
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Abstract
Existing data sources show divergent estimates of the number of homes purchased by first-time homebuyers as a share of all home purchases. In this article, we use a new dataset to construct a time series of the share of first-time homebuyers. This series, based on the Federal Reserve Bank of New York Equifax Consumer Credit Panel, shows a significant decline in the share of first-time homebuyers, particularly among young households, consistent with the decline in homeownership in this age cohort since the early 2000s.
Hess, Christian; Walter, Rebecca J.; Acolin, Arthur; Chasins, Sarah. (2019). Comparing Small Area Fair Market Rents with Other Rental Measures across Diverse Housing Markets. Cityscape, 21(3), 159 – 186.
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Abstract
Small Area Fair Market Rents (SAFMRs) are calculated at the 40th percentile of the U.S. postal ZIP Code instead of the metropolitan area in an effort to capture localized rents to expand choice for voucher holders to access housing in higher-opportunity neighborhoods. Existing studies on the potential and actual outcomes of SAFMRs demonstrate that findings vary for different types of housing markets. Furthermore, the decisions public housing authorities (PHAs) make in the implementation process affect PHAs' program budget and the rent burden and locational outcomes for voucher households. This study aims to address how these implementation factors are affected by local rental market conditions for three PHAs-Housing Authority of the City of Fort Lauderdale, San Antonio Housing Authority, and Seattle Housing Authority-in diverse housing markets. By comparing different sources of market rent estimates with SAFMRs in each location, we contribute new information about how this rule is likely to produce different residential outcomes in terms of increased access to low-poverty neighborhoods and adjustments to payment standards in low-rent neighborhoods. The findings reveal differences across rent measures in terms of estimated levels and relative differences across ZIP Codes. These findings suggest that housing authorities may face challenges in meeting the objectives of the SAFMR final rule without some form of local adjustments.]
Acolin, Arthur; Vitiello, Domenic. (2018). Who Owns Chinatown: Neighbourhood Preservation and Change in Boston and Philadelphia. Urban Studies, 55(8), 1690 – 1710.
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Abstract
The survival of Chinatowns and other ethnic enclaves in cities is largely determined by who owns property. Ethnic enclaves such as Chinatowns have traditionally played important economic, social and cultural functions as places for recent immigrants to live and work, though Chinatowns have long faced redevelopment pressures. In North America, as Chinese immigrants and their descendants settle in the suburbs, and as historic Chinatowns’ locations close to revitalising downtowns attract increasing investment, the future of these historic enclaves is shaped by various, often intense and divergent, forces. This article describes changes in the patterns of property ownership in Boston and Philadelphia’s downtown Chinatowns over the last decade (2003–2013) and relates them to changes and continuities in these neighbourhoods’ population, commercial activities and building stock. The trends we observe simultaneously reinforce and complicate debates about gentrification and longstanding efforts to preserve these Chinatowns as ethnic Chinese residential, commercial, and cultural centres.]
Keywords
Chinatown, Ethnic Enclave, Neighbourhood Change, Ownership