Skip to content

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.

View Publication

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.

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).

View Publication

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)

First-Time Homebuyers: Toward a New Measure

Acolin, Arthur; Calem, Paul; Jagtiani, Julapa; Wachter, Susan. (2018). First-Time Homebuyers: Toward a New Measure. Cityscape, 20(1), 193 – 204.

View Publication

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.

Hedonic, Residual, and Matching Methods for Residential Land Valuation

Bourassa, Steven C.; Hoesli, Martin. (2022). Hedonic, Residual, and Matching Methods for Residential Land Valuation. Journal Of Housing Economics, 58.

View Publication

Abstract

• Our first method involves a hedonic model estimated for sales of vacant lots. • Another method depreciates improvements, obtaining land value as a residual. • Our third approach matches the sales of vacant and subsequently developed lots. • This allows us to estimate a hedonic model of land leverage (the ratio of land to total property value) for improved properties. • We conclude that the third approach is the most promising of the three methods. Accurate estimates of land values on a property-by-property basis are an important requirement for the effective implementation of land-based property taxes. We compare hedonic, residual, and matching techniques for mass appraisal of residential land values, using data from Maricopa County, Arizona. The first method involves a hedonic valuation model estimated for transactions of vacant lots. The second approach subtracts the depreciated cost of improvements from the value of improved properties to obtain land value as a residual. The third approach matches the sales of vacant lots with subsequent sales of the same properties once they have been developed. For each pair, we use a land price index to inflate the land price to the time of the improved property transaction and then calculate land leverage (the ratio of land to total property value). A hedonic model is estimated and used to predict land leverage for all improved properties. We conclude that the matching approach is the most promising of the methods considered. [ABSTRACT FROM AUTHOR]; Copyright of Journal of Housing Economics is the property of Academic Press Inc. 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

Hedonic Method; Land Leverage; Land Valuation; Matching Approach; Residual Approach

Comparing Small Area Fair Market Rents with Other Rental Measures across Diverse Housing Markets

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.

View Publication

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.]

Housing Cost Burden and Life Satisfaction

Acolin, Arthur; Reina, Vincent. (2022). Housing Cost Burden and Life Satisfaction. Journal Of Housing & The Built Environment, 37(4), 1789-1815.

View Publication

Abstract

The share of income that households spent on their housing has been increasing over time in a wide range of countries, particularly among lower income households. In theory, the share of income spent on housing can reflect variations in household preferences for housing consumption but for low-income household, high burdens are likely more reflective of constraints and force these households to face tradeoffs between housing and non-housing consumption that negatively affect their overall life satisfaction. This paper uses data from the 2018 European Union Statistics on Income and Living Conditions (EU-SILC) for 14 countries. We find that, controlling for household sociodemographic characteristics, households spending more than 30 percent of their income and those spending more than 50 percent of their income on housing report significantly lower levels of life satisfaction. The estimated relationship is largest for this latter heavily cost burdened group. The negative relationship between housing cost burden and reported life satisfaction is found across countries but varies in magnitude, suggesting that stronger welfare systems may mediate the negative impacts of housing cost burdens, although further research is needed to confirm both this relationship and the precise mechanisms driving it.

Keywords

Life Satisfaction; Income; Housing; Poor Communities; Subjective Well-being (psychology); Living Conditions; European Countries; Housing Cost; Subjective Wellbeing; Economic Hardship; Homeownership; Affordability; Determinants; Cost Analysis; Housing Costs; Households; Consumption; Low Income Groups; Expenditures; Welfare; Sociodemographics

Who Owns Chinatown: Neighbourhood Preservation and Change in Boston and Philadelphia

Acolin, Arthur; Vitiello, Domenic. (2018). Who Owns Chinatown: Neighbourhood Preservation and Change in Boston and Philadelphia. Urban Studies, 55(8), 1690 – 1710.

View Publication

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

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).

View Publication

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

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.

View Publication

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.]